From dforbes at dakotacom.net Tue Jul 1 03:28:56 2008 From: dforbes at dakotacom.net (David Forbes) Date: Tue, 1 Jul 2008 00:28:56 -0700 Subject: [time-nuts] HP 105 manual finally scanned Message-ID: I wanted to do this two years ago, but computer events conspired to slow me down. http://www.nixiebunny.com/HP105AB.pdf It's about 9 MB, 400DPI scans in B&W for the text/drawings and 8 bit grey for the photos. I scanned all the schematics as two B&W pages and glued them together into one 11x17 page per sheet using Photoshop. I added the board photos with the same page numbers as regular sized pages before the schematics, sort of like it appears in the manual's fold-out pages. Please let me know if anything needs fixing. Also, anyone who knows the Agilent obsolete-manual librarians, perhaps you could pass it along to them. It's been a rather glaring omission from their collection for a long time now. And I'll be happy to take it down from my website if such things as manuals for obsolete electronic items shouldn't be exposed to the world. Enjoy. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ From GandalfG8 at aol.com Tue Jul 1 03:51:17 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Tue, 1 Jul 2008 03:51:17 EDT Subject: [time-nuts] HP 105 manual finally scanned Message-ID: In a message dated 01/07/2008 08:31:28 GMT Daylight Time, dforbes at dakotacom.net writes: wanted to do this two years ago, but computer events conspired to slow me down. http://www.nixiebunny.com/HP105AB.pdf ---------------------------------------------- Hi David Many thanks for the file, it's come out well. You could have saved yourself some work though, I don't know how long it's been available but I downloaded a similar copy from Didier's site, albeit lacking the first two pages, in December 2007. regards Nigel GM8PZR From J.Bastemeijer at TUDelft.nl Tue Jul 1 10:27:30 2008 From: J.Bastemeijer at TUDelft.nl (Jeroen Bastemeijer) Date: Tue, 01 Jul 2008 16:27:30 +0200 Subject: [time-nuts] Agilent 58531A Software Message-ID: <486A3ED2.4070707@TUDelft.nl> Dear All, While cleaning up the mess in my office, I bumped into a Agilent/Symmetricom 58534A timing antenna which I acquired some time ago. At that time, I was busy with other things, so I put it aside. Now I want to have a further look, and I'm trying to locate the software package "GPS Timing Receiver Analysis and Control Software" from Agilent, PN 58531a. I have been searching the Symmetricom/Agilent website, but I didn't find a download of the software. Is thereanyone who has a copy of the software, or knows where to get/download it? Thank you, best regards, Jeroen -- Ing. Jeroen Bastemeijer Delft University of Technology Department of Electrical Engineering Electronic Instrumentation Laboratory Mekelweg 4, Room 13.090 2628 CD Delft The Netherlands Phone: +31.15.27.86542 Fax: +31.15.27.85755 E-mail: J.Bastemeijer at TUDelft.nl GPS: Lat N52.00002 Lon E4.37157 Alt 46.2m From dforbes at dakotacom.net Tue Jul 1 12:17:41 2008 From: dforbes at dakotacom.net (David Forbes) Date: Tue, 1 Jul 2008 09:17:41 -0700 Subject: [time-nuts] HP 105 manual finally scanned In-Reply-To: References: Message-ID: At 3:51 AM -0400 7/1/08, GandalfG8 at aol.com wrote: >In a message dated 01/07/2008 08:31:28 GMT Daylight Time, >dforbes at dakotacom.net writes: > >wanted to do this two years ago, but computer events conspired to >slow me down. > >http://www.nixiebunny.com/HP105AB.pdf > >---------------------------------------------- > >Hi David > >Many thanks for the file, it's come out well. > >You could have saved yourself some work though, I don't know how long it's >been available but I downloaded a similar copy from Didier's site, albeit >lacking the first two pages, in December 2007. > >regards > >Nigel >GM8PZR Hmm... If I'd realized he had scanned the thing, I probably wouldn't have bothered. They seem to be equivalent in quality. But it's still not on the Agilent website, so let's get it put up there where it will do lots of people some good! -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ From gbusg at comcast.net Tue Jul 1 13:06:11 2008 From: gbusg at comcast.net (Greg Burnett) Date: Tue, 1 Jul 2008 11:06:11 -0600 Subject: [time-nuts] HP 105 manual finally scanned References: Message-ID: <006701c8db9c$c36f94f0$6501a8c0@gb02> David, Thanks much for the manual scan. Excellent job, and great resolution! I forwarded your announcement to a friend at Agilent and he says he's sent your scan to be put out on the web. (Note, this typically take some time to go through their process; so don't expect it to show up immediately on their web site.) A couple folks at Agilent asked me to thank you for your contribution. Again, Thanks! Greg ----- Original Message ----- From: "David Forbes" To: "Time Nuts" Sent: Tuesday, July 01, 2008 1:28 AM Subject: [time-nuts] HP 105 manual finally scanned I wanted to do this two years ago, but computer events conspired to slow me down. http://www.nixiebunny.com/HP105AB.pdf It's about 9 MB, 400DPI scans in B&W for the text/drawings and 8 bit grey for the photos. I scanned all the schematics as two B&W pages and glued them together into one 11x17 page per sheet using Photoshop. I added the board photos with the same page numbers as regular sized pages before the schematics, sort of like it appears in the manual's fold-out pages. Please let me know if anything needs fixing. Also, anyone who knows the Agilent obsolete-manual librarians, perhaps you could pass it along to them. It's been a rather glaring omission from their collection for a long time now. And I'll be happy to take it down from my website if such things as manuals for obsolete electronic items shouldn't be exposed to the world. Enjoy. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From stanley_reynolds at yahoo.com Tue Jul 1 16:05:01 2008 From: stanley_reynolds at yahoo.com (Stanley Reynolds) Date: Tue, 1 Jul 2008 13:05:01 -0700 (PDT) Subject: [time-nuts] Use of Austron 2100F "Phase Corrected Output" Message-ID: <115018.32341.qm@web30306.mail.mud.yahoo.com> I would like to know as well. My experiment in the thread "Calibrating the Lucent RFG-M-XO Efratom 10MHz OCXO Oscillator w/ EFC" using the phase corrected output has failed twice, not sure of the reason could be a problem with my lack of knowledge abt the Lucent error correcting oscillator or the 2100F.? It takes > 10 hours for it to fail think this could be related to the?rate the Austron updates. The chart output is also available to steer the disciplined oscillator but with my unit this output jumps around quite a bit. Either output could be processed / filtered to slow the skew. Stanley? ----- Original Message ---- From: Jim Robbins To: time-nuts at febo.com Sent: Sunday, June 29, 2008 9:16:25 PM Subject: [time-nuts] Use of Austron 2100F "Phase Corrected Output" Hi all, I believe I read that it was a mistake to use the "Phase Corrected Output" 10 MHz signal from the 2100F as the time base source for other equipment?? Something about the corrections being in steps.? Has anyone else had any experience with this?? If so, what is the problem with the output?? Thanks. Jim Robbins, N1JR _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From gbusg at comcast.net Wed Jul 2 00:13:45 2008 From: gbusg at comcast.net (Greg Burnett) Date: Tue, 1 Jul 2008 22:13:45 -0600 Subject: [time-nuts] HP 105 manual finally scanned References: Message-ID: <006701c8dbfa$059532b0$6501a8c0@gb02> David, ...another question... What make/model scanner did you use? (Your manual scan quality/resolution is so good, I'd like to know what scanner was used. ...Maybe I'll buy the same model in the future?) Thanks again, Greg From ssybert at kb1fxy.us Wed Jul 2 01:51:47 2008 From: ssybert at kb1fxy.us (Scott A Sybert) Date: Tue, 1 Jul 2008 22:51:47 -0700 Subject: [time-nuts] FS: Brandywine GPS-4 - Last call - 2 left References: Message-ID: Hi Guys, Last call on these Brandywine GPS4 recievers. I have 2 left. First come first serve. Scott KB1FXY ________________________________ From: Scott A Sybert Sent: Fri 6/27/2008 8:56 PM To: time-nuts at febo.com Subject: FS: Brandywine GPS-4 - Qty: 7 available Hi Everyone, I have a number of Brandywine GPS-4 units available. They are all NOS pulls from a cancelled project. They provide a number of outputs including 1PPS and 10MHZ. If anyone is interested I can email you pictures and a copy of the owners manual. Price is $400 and that includes USPS Priority shipping to anywhere in the US. All units are guaranteed working 100%. I also have outdoor Panasonic marine antenna kits w/ 90ft coax. They have a waterproof TNC connecter on the antenna side and a BNC on the GPS side. These kits are also brand new and the price is $40. I can bundle them with the shipping on the GPS. Thanks, Scott KB1FXY From dforbes at dakotacom.net Wed Jul 2 01:57:57 2008 From: dforbes at dakotacom.net (David Forbes) Date: Tue, 1 Jul 2008 22:57:57 -0700 Subject: [time-nuts] HP 105 manual finally scanned In-Reply-To: <006701c8dbfa$059532b0$6501a8c0@gb02> References: <006701c8dbfa$059532b0$6501a8c0@gb02> Message-ID: At 10:13 PM -0600 7/1/08, Greg Burnett wrote: >David, >...another question... > >What make/model scanner did you use? (Your manual scan quality/resolution is >so good, I'd like to know what scanner was used. ...Maybe I'll buy the same >model in the future?) > >Thanks again, >Greg Greg, I used my trusty old HP ScanJet IIcx. It was made in 1994 and still works like a charm, although the foam under the cover pad just failed so I removed the cover and used a handy 1981 HP catalog as a paperweight. These scanners turn up on ebay now and then for less than the shipping charge. It's built like a tank, and is definitely worth hanging on to! I run the scanner with VueScan by Hamrick Software. It does an excellent job of controlling the older SCSI scanners. I have an old Adaptec SCSI to PCI interface card in a computer with a new motherboard with 5-year-old technology. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ From gbusg at comcast.net Wed Jul 2 03:07:11 2008 From: gbusg at comcast.net (Greg Burnett) Date: Wed, 2 Jul 2008 01:07:11 -0600 Subject: [time-nuts] HP 105 manual finally scanned References: <006701c8dbfa$059532b0$6501a8c0@gb02> Message-ID: <03d101c8dc12$3ff08af0$6501a8c0@gb02> David, that you're using the old HP ScanJet IIcx is a revelation! FYI, I googled it and found an old HP Journal article about it at: http://findarticles.com/p/articles/mi_m0HPJ/is_n4_v44/ai_14191761/print?tag=artBody;col1 Thanks again, Greg ------------- David wrote: ...I used my trusty old HP ScanJet IIcx. It was made in 1994 and still works like a charm. ...clip... From daun at yeagley.net Wed Jul 2 08:30:34 2008 From: daun at yeagley.net (Daun Yeagley) Date: Wed, 2 Jul 2008 08:30:34 -0400 Subject: [time-nuts] HP 105 manual finally scanned In-Reply-To: References: <006701c8dbfa$059532b0$6501a8c0@gb02> Message-ID: <000a01c8dc3f$6e578920$0c00a8c0@daundell> Hi Greg I have a surplus IIcx that I really don't have room for. If you are interested in it, drop me a note off list. Daun N8ASB www.yeagley.net -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of David Forbes Sent: Wednesday, July 02, 2008 1:58 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 105 manual finally scanned At 10:13 PM -0600 7/1/08, Greg Burnett wrote: >David, >...another question... > >What make/model scanner did you use? (Your manual scan quality/resolution is >so good, I'd like to know what scanner was used. ...Maybe I'll buy the same >model in the future?) > >Thanks again, >Greg Greg, I used my trusty old HP ScanJet IIcx. It was made in 1994 and still works like a charm, although the foam under the cover pad just failed so I removed the cover and used a handy 1981 HP catalog as a paperweight. These scanners turn up on ebay now and then for less than the shipping charge. It's built like a tank, and is definitely worth hanging on to! I run the scanner with VueScan by Hamrick Software. It does an excellent job of controlling the older SCSI scanners. I have an old Adaptec SCSI to PCI interface card in a computer with a new motherboard with 5-year-old technology. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From pvince at theiet.org Wed Jul 2 10:51:30 2008 From: pvince at theiet.org (Peter Vince) Date: Wed, 2 Jul 2008 15:51:30 +0100 Subject: [time-nuts] TBolt UK import In-Reply-To: <485E5E06.9080006@usa.net> References: <485E5E06.9080006@usa.net> Message-ID: It depends on the value. I understand that items with a declared value of less than 100 pounds will be passed through by UK customs. However above that, VAT (at our standard rate of 17.5%) is added, as well as import duties (if applicable) at about 5% (depending on the item). Carriers will then usually charge a fee for sorting out all the customs paperwork. I have had charges as low as 5 pounds from FedEx, and 8 to 12 pounds from Royal Mail ParcelForce (who take in packages sent by USPS). Some carriers (FedEx, TNT) will deliver as soon as possible, and subsequently send you an invoice for the import charges; but ParcelForce always sends you the bill, and awaits payment before delivery. International couriers always want a contact telephone number for the recipient: I find this shows up on the PayPal payment screen, but that information isn't forwarded to the seller, so be sure to include it in the comments box. Regards, Peter Vince (G8ZZR, London, England) >Phil Staton wrote: >> For Info: >> Importing 2 TBolts into the UK costs $29.11 duties and fees. >> Phil G4FXY >> > >I think that depends on the carrier. I received recently items from >the US. In one case the shipping was done using the >TNT - Traco courier, and they dutifully passed the goods through the >custom, and all the duties and fees were applied. >In the second case the item was shipped via the First-Class Mail? >International Package of USPS (BTW the cheapest one), >and the package arrived in just one week, and with NO duties nor fees. > >So my suggestion would be that TAPR uses USPS to send the TB units worldwide. > >73 Alberto I2PHD From GandalfG8 at aol.com Wed Jul 2 11:18:18 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Wed, 2 Jul 2008 11:18:18 EDT Subject: [time-nuts] TBolt UK import Message-ID: In a message dated 02/07/2008 15:53:10 GMT Daylight Time, pvince at theiet.org writes: I understand that items with a declared value of less than 100 pounds will be passed through by UK customs. However above that, VAT (at our standard rate of 17.5%) is added, as well as import duties (if applicable) at about 5% (depending on the item). Carriers will then usually charge a fee for sorting out all the customs paperwork. I have had charges as low as 5 pounds from FedEx, and 8 to 12 pounds from Royal Mail ParcelForce ------------------------------ Hi Peter Unfortunately the VAT threshold is much lower than ?100. Quote from HMRC web site..... --------------------------------- If you purchase goods through the Internet you should be aware that customs duty and VAT will be payable, as follows: Customs Duty - if the amount of duty is ?7 and over Import VAT - if the value of the goods is ?18 and over --------------------------------- On top of that the standard ParcelForce admin charge is ?8, increased from ?5 a year or so ago. Assuming that the parcel value is correctly quoted it seems to be a question of luck as to whether or not you get charged. I still get packages through with no charge on them, sometimes of quite high value, but I was told by ParcelForce a few years ago that, even then, the number of Customs agents employed at the main ParcelForce sorting centre had increased hugely after the international success of Ebay and other internet sales. For relatively low cost purchases from the US say, that might only just cross the ?18 threshold, it's not unusual to receive a small VAT charge but still with the ?8 admin fee...ouch!! From phk at phk.freebsd.dk Thu Jul 3 15:53:41 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Thu, 03 Jul 2008 19:53:41 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver Message-ID: <14904.1215114821@critter.freebsd.dk> ST microelectronics have made a new ARM chip: ST32M* and it almost fits the bill for a single-chip Loran-C frequency receiver: it has a 1 million samples per second A/D converter. Olimex has an eval-board costing EUR 46: http://olimex.com/dev/stm32-p103.html (Check sparkfun for US pricing) Unfortunately, the clock-circuit in the chip prevents use of the USB port at 1Msps A/D sampling rate, or if your input clock is 10MHz, but it has a serial port as well. I have played with various low-cpu/low-ram reception scenarios as part of my SDR experiements, and I think we can fit it comfortably into the available flash/ram of the chip. I wrote 280 lines of simulation code in C yesterday, and using my spectrum recording from the 2006-01-01 leapsecond, I was able to detect the existence of signals as far away as GRI 8830, 7980 and 7270 in just 2 minutes integration time and get good clean signals from 7499, 6731, 9007, 8000 and 7001. Anybody interested in doing a little group-project to complement all the disciplined GPS oscillators we've see recently ? Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From magnus at rubidium.dyndns.org Thu Jul 3 17:03:45 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Thu, 03 Jul 2008 23:03:45 +0200 (CEST) Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <14904.1215114821@critter.freebsd.dk> References: <14904.1215114821@critter.freebsd.dk> Message-ID: <20080703.230345.407454645627532368.cfmd@bredband.net> From: "Poul-Henning Kamp" Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver Date: Thu, 03 Jul 2008 19:53:41 +0000 Message-ID: <14904.1215114821 at critter.freebsd.dk> > > ST microelectronics have made a new ARM chip: ST32M* and it almost > fits the bill for a single-chip Loran-C frequency receiver: it has > a 1 million samples per second A/D converter. > > Olimex has an eval-board costing EUR 46: > http://olimex.com/dev/stm32-p103.html > (Check sparkfun for US pricing) > > Unfortunately, the clock-circuit in the chip prevents use of the > USB port at 1Msps A/D sampling rate, or if your input clock is > 10MHz, but it has a serial port as well. > > I have played with various low-cpu/low-ram reception scenarios as > part of my SDR experiements, and I think we can fit it comfortably > into the available flash/ram of the chip. > > I wrote 280 lines of simulation code in C yesterday, and using my > spectrum recording from the 2006-01-01 leapsecond, I was able to > detect the existence of signals as far away as GRI 8830, 7980 and > 7270 in just 2 minutes integration time and get good clean signals > from 7499, 6731, 9007, 8000 and 7001. > > Anybody interested in doing a little group-project to complement > all the disciplined GPS oscillators we've see recently ? Interesting. Hmm. The GNSS Sampler uses a very nice USB chip which would allow a very minimal wireup from a A/D chip and then you have a pipe of samples straight into the computer. I think they picked that idea up from the Software Receiver project (somebody please correct me on the details and links, I'm in low bitrate country, the summerhouse). It would be nice to have LORAN-C, MSF and DCF-77 in the same solution if possible. I am sure some of the US signals can be included. Cheers, Magnus From phk at phk.freebsd.dk Thu Jul 3 17:38:41 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Thu, 03 Jul 2008 21:38:41 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Your message of "Thu, 03 Jul 2008 23:03:45 +0200." <20080703.230345.407454645627532368.cfmd@bredband.net> Message-ID: <17856.1215121121@critter.freebsd.dk> In message <20080703.230345.407454645627532368.cfmd at bredband.net>, Magnus Danie lson writes: >It would be nice to have LORAN-C, MSF and DCF-77 in the same solution if >possible. I am sure some of the US signals can be included. It's trivial to do phase-tracking on any moderately strong CW signal at the same time, so that could easily be done using the same chip. The analog side would need to allow for those signals also then. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From danrae at verizon.net Thu Jul 3 18:25:16 2008 From: danrae at verizon.net (Dan Rae) Date: Thu, 03 Jul 2008 15:25:16 -0700 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <17856.1215121121@critter.freebsd.dk> References: <17856.1215121121@critter.freebsd.dk> Message-ID: <486D51CC.7020700@verizon.net> Poul-Henning Kamp wrote: > It's trivial to do phase-tracking on any moderately strong CW signal > at the same time, so that could easily be done using the same chip. > > The analog side would need to allow for those signals also then. > > At least where I am the 60 kHz signal from WWVB is quite weak. The need is for as narrow an RF band width as possible for 60 kHz and a wider band for Loran 100 kHz, around 15 kHz, and much stronger signals are the norm here, so this needs to be allowed for if you want your project to be dual purpose. Fascinating idea though! Dan From carl at icmp.com Thu Jul 3 18:38:04 2008 From: carl at icmp.com (Carl Walker) Date: Thu, 03 Jul 2008 18:38:04 -0400 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <17856.1215121121@critter.freebsd.dk> References: <17856.1215121121@critter.freebsd.dk> Message-ID: <1215124684.6081.12.camel@bigdog.icmp.com> Therein lies the rub; you'll have a family of signals of widely varying signal strength over a fairly large bandwidth. A real challenge for the analog part of the receiver design. How many bits of A/D do you have at 1MS/S with this device? I've worked on several successful commercial LORAN-C receiver designs over the years - all of them with linear front ends and hard limiting back ends to interface with the tracking logic. These provided very high performance in terms of zero crossing displacement vs signal strength - but were designed to avoid allowing anything we could possibly exclude outside of the 20 percent bandwidth needed for LORAN to make it through the receiver to the limiters - to avoid the "FM capture" effect one often sees with a limiting receiver. Good quality front end filtering with low group delay distortion were the order of the day for performance - along with notch filters for the strong LF RTTY signals that were always annoyingly close by in frequency. Receivers without hard limiting and direct analog sampling by A/D were just becoming practical from a design standpoint when I left the LORAN-C world for greener pastures. I'm happy to join in on the design if there's interest. -Carl On Thu, 2008-07-03 at 21:38 +0000, Poul-Henning Kamp wrote: > In message <20080703.230345.407454645627532368.cfmd at bredband.net>, Magnus Danie > lson writes: > > >It would be nice to have LORAN-C, MSF and DCF-77 in the same solution if > >possible. I am sure some of the US signals can be included. > > It's trivial to do phase-tracking on any moderately strong CW signal > at the same time, so that could easily be done using the same chip. > > The analog side would need to allow for those signals also then. > From hmurray at megapathdsl.net Thu Jul 3 18:51:44 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Thu, 03 Jul 2008 15:51:44 -0700 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Message from Dan Rae of "Thu, 03 Jul 2008 15:25:16 PDT." <486D51CC.7020700@verizon.net> Message-ID: <20080703225145.2AEC4BCCB@ip-64-139-1-69.sjc.megapath.net> > At least where I am the 60 kHz signal from WWVB is quite weak. The > need is for as narrow an RF band width as possible for 60 kHz ... What is the bandwidth of WWVB and similar services? -- These are my opinions, not necessarily my employer's. I hate spam. From magnus at rubidium.dyndns.org Thu Jul 3 19:02:33 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Fri, 04 Jul 2008 01:02:33 +0200 (CEST) Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <17856.1215121121@critter.freebsd.dk> References: <20080703.230345.407454645627532368.cfmd@bredband.net> <17856.1215121121@critter.freebsd.dk> Message-ID: <20080704.010233.197896015547869060.cfmd@bredband.net> From: "Poul-Henning Kamp" Subject: Re: [time-nuts] Near-perfect chip for Loran-C frequency receiver Date: Thu, 03 Jul 2008 21:38:41 +0000 Message-ID: <17856.1215121121 at critter.freebsd.dk> > In message <20080703.230345.407454645627532368.cfmd at bredband.net>, Magnus Danie > lson writes: > > >It would be nice to have LORAN-C, MSF and DCF-77 in the same solution if > >possible. I am sure some of the US signals can be included. > > It's trivial to do phase-tracking on any moderately strong CW signal > at the same time, so that could easily be done using the same chip. Which was my point. Just a thad more work, but more usefull. > The analog side would need to allow for those signals also then. Naturally. The antenna-amplifier design will need to be more wideband oriented. Should not be too hard thought. Cheers, Magnus From carl at icmp.com Thu Jul 3 19:16:39 2008 From: carl at icmp.com (Carl Walker) Date: Thu, 03 Jul 2008 19:16:39 -0400 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <20080704.010233.197896015547869060.cfmd@bredband.net> References: <20080703.230345.407454645627532368.cfmd@bredband.net> <17856.1215121121@critter.freebsd.dk> <20080704.010233.197896015547869060.cfmd@bredband.net> Message-ID: <1215126999.6104.9.camel@bigdog.icmp.com> On Fri, 2008-07-04 at 01:02 +0200, Magnus Danielson wrote: > > The analog side would need to allow for those signals also then. > > Naturally. The antenna-amplifier design will need to be more wideband > oriented. Should not be too hard thought. > > Cheers, > Magnus I respectfully disagree; while making the wide-band receiver is an easy task, you now have a family of unrelated signals - often of widely varying signal strength. Once any of those signals becomes large enough to drive the receiver non-linear, you rapidly run into issues. AGC to maintain linearity isn't practical in this case - since reducing overall receiver gain to compensate for one large signal - like WWVB if you're close by that one transmitter - will potentially drive down the gain for desired LORAN and other signals to the point where you can't acquire and track many of the weaker but never the less desired signals. There's more than meets the eye initially when you attempt a receiver design of this type - at least as far as the analog section goes. Once it becomes 1's and 0's it's all straight forward - at least as far as this old ex-analog guy is concerned ;-) -Carl From bruce.griffiths at xtra.co.nz Thu Jul 3 19:25:10 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 04 Jul 2008 11:25:10 +1200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <20080703225145.2AEC4BCCB@ip-64-139-1-69.sjc.megapath.net> References: <20080703225145.2AEC4BCCB@ip-64-139-1-69.sjc.megapath.net> Message-ID: <486D5FD6.3@xtra.co.nz> Hal Murray wrote: >> At least where I am the 60 kHz signal from WWVB is quite weak. The >> need is for as narrow an RF band width as possible for 60 kHz ... >> > > What is the bandwidth of WWVB and similar services? > > > WWVB uses AM to encode pulses of 200, 500 and 800 millisec duration. Thus the bandwidth only has to be sufficient to allow the various pulse widths to be distinguished. Somewhere in the vicinity of 10Hz or so should suffice. Bruce From bruce.griffiths at xtra.co.nz Thu Jul 3 19:47:47 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 04 Jul 2008 11:47:47 +1200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <1215126999.6104.9.camel@bigdog.icmp.com> References: <20080703.230345.407454645627532368.cfmd@bredband.net> <17856.1215121121@critter.freebsd.dk> <20080704.010233.197896015547869060.cfmd@bredband.net> <1215126999.6104.9.camel@bigdog.icmp.com> Message-ID: <486D6523.7080801@xtra.co.nz> Carl Walker wrote: > On Fri, 2008-07-04 at 01:02 +0200, Magnus Danielson wrote: > >>> The analog side would need to allow for those signals also then. >>> >> Naturally. The antenna-amplifier design will need to be more wideband >> oriented. Should not be too hard thought. >> >> Cheers, >> Magnus >> > > I respectfully disagree; while making the wide-band receiver is an easy > task, you now have a family of unrelated signals - often of widely > varying signal strength. Once any of those signals becomes large enough > to drive the receiver non-linear, you rapidly run into issues. > > AGC to maintain linearity isn't practical in this case - since reducing > overall receiver gain to compensate for one large signal - like WWVB if > you're close by that one transmitter - will potentially drive down the > gain for desired LORAN and other signals to the point where you can't > acquire and track many of the weaker but never the less desired signals. > > There's more than meets the eye initially when you attempt a receiver > design of this type - at least as far as the analog section goes. Once > it becomes 1's and 0's it's all straight forward - at least as far as > this old ex-analog guy is concerned ;-) > > -Carl > This is only true if one is attempting to simultaneously track all the signals with a single receiver. This isnt practical unless one uses separate analog receivers (each using AGC) dedicated to each signal to boost all signals to a similar level before sampling them with the ADC. In practice, it may be simpler to dedicate one digital receiver to each signal with the analog input filtering selected to suit a particular signal and location. There's little point in dedicating resources to receive signals that in particular locations are too weak to be useful. The 12 bit ADC's dynamic range will limit the disparity in signal levels that can be handled simultaneously long before the analog circuitry causes problems (at least in the case where the analog circuitry isnt driven into compression). Bruce From carl at icmp.com Thu Jul 3 20:23:25 2008 From: carl at icmp.com (Carl Walker) Date: Thu, 03 Jul 2008 20:23:25 -0400 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <486D6523.7080801@xtra.co.nz> References: <20080703.230345.407454645627532368.cfmd@bredband.net> <17856.1215121121@critter.freebsd.dk> <20080704.010233.197896015547869060.cfmd@bredband.net> <1215126999.6104.9.camel@bigdog.icmp.com> <486D6523.7080801@xtra.co.nz> Message-ID: <1215131005.6104.26.camel@bigdog.icmp.com> I concur with your observations, Bruce; you've made the points I was alluding to in a far more succinct manner. One broadband beast that solves all of the problems simultaneously and works in any location is a tough nut to crack while maintaining really good weak signal performance. Everything is a compromise. When faced with a similar problem back in the late 70's - tracking LORAN-C and WWVB simultaneously with as high a performance possible in a single receiver - we did just as you suggest; two separate analog receiver channels behind a moderate gain active antenna coupler, with nothing more in terms of filtering than low pass roll off to avoid AM broadcast overload of the first amplifier stage. Each analog channel had its own bandpass filtering centered on the channel operating frequency and specific bandwidth for the signals of concern. Worked like a charm in the marine environment where it was intended to operate - so we never had to worry about 1st stage overload from being too close to the transmitter in Fort Collins at 60 KHz. One gain setting was sufficient. -Carl On Fri, 2008-07-04 at 11:47 +1200, Bruce Griffiths wrote: > Carl Walker wrote: > > On Fri, 2008-07-04 at 01:02 +0200, Magnus Danielson wrote: > > > >>> The analog side would need to allow for those signals also then. > >>> > >> Naturally. The antenna-amplifier design will need to be more wideband > >> oriented. Should not be too hard thought. > >> > >> Cheers, > >> Magnus > >> > > > > I respectfully disagree; while making the wide-band receiver is an easy > > task, you now have a family of unrelated signals - often of widely > > varying signal strength. Once any of those signals becomes large enough > > to drive the receiver non-linear, you rapidly run into issues. > > > > AGC to maintain linearity isn't practical in this case - since reducing > > overall receiver gain to compensate for one large signal - like WWVB if > > you're close by that one transmitter - will potentially drive down the > > gain for desired LORAN and other signals to the point where you can't > > acquire and track many of the weaker but never the less desired signals. > > > > There's more than meets the eye initially when you attempt a receiver > > design of this type - at least as far as the analog section goes. Once > > it becomes 1's and 0's it's all straight forward - at least as far as > > this old ex-analog guy is concerned ;-) > > > > -Carl > > > This is only true if one is attempting to simultaneously track all the > signals with a single receiver. > This isnt practical unless one uses separate analog receivers (each > using AGC) dedicated to each signal to boost all signals to a similar > level before sampling them with the ADC. > > In practice, it may be simpler to dedicate one digital receiver to each > signal with the analog input filtering selected to suit a particular > signal and location. > There's little point in dedicating resources to receive signals that in > particular locations are too weak to be useful. > > The 12 bit ADC's dynamic range will limit the disparity in signal levels > that can be handled simultaneously long before the analog circuitry > causes problems (at least in the case where the analog circuitry isnt > driven into compression). > > > Bruce From ch at murgatroid.com Thu Jul 3 20:41:28 2008 From: ch at murgatroid.com (christopher hoover) Date: Thu, 3 Jul 2008 17:41:28 -0700 Subject: [time-nuts] Near-perfect chip for Loran-C frequency In-Reply-To: References: Message-ID: <000301c8dd6e$b29ace50$17d06af0$@com> Poul-Henning wrote: > Anybody interested in doing a little group-project to complement > all the disciplined GPS oscillators we've see recently ? Count me in. My bench is still in boxes after a move, but this would be a good excuse to get things unpacked. -ch From bruce.griffiths at xtra.co.nz Thu Jul 3 21:24:37 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 04 Jul 2008 13:24:37 +1200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency In-Reply-To: <000301c8dd6e$b29ace50$17d06af0$@com> References: <000301c8dd6e$b29ace50$17d06af0$@com> Message-ID: <486D7BD5.8060101@xtra.co.nz> JJY(40kHz, 60kHz) HBG(75kHz) DCF77(77.5kHz), MSF(60kHz), WWVB(60kHz) all use AM to encode the time using different pulse widths to denote markers , 0 and 1 respectively. WWVB, JJY reduce the power by 10dB to encode 1, 0 etc so that a residual carrier is always present. WWVB also phase modulates the carrier at 1/3600Hz (period = 1hour) with a duty cycle of 5/60. MSF and HBG use ON/OFF keying. DCF77 encodes 1, 0 etc by reducing power to 25%, in addition DCF77 phase modulates the carrier with a PRBS. Since the minimum pulse width used is 0.1sec the receiver's effective bandwidth (when receiving WWVB, MSF or DCF77) need not be more than a few Hz. Bruce From SAIDJACK at aol.com Fri Jul 4 01:37:24 2008 From: SAIDJACK at aol.com (SAIDJACK at aol.com) Date: Fri, 4 Jul 2008 01:37:24 EDT Subject: [time-nuts] new Fury GPSDO firmware available Message-ID: Dear Ladies and Gents, for those of you who have Fury GPSDO's we have placed version 1.18 of the Fury firmware on our website: _http://www.jackson-labs.com/support.html_ (http://www.jackson-labs.com/support.html) This version is the first release since the January release, and includes a number of stability upgrades, minor bug fixes, and other improvements. We hope you enjoy this version, bye, Said **************Gas prices getting you down? Search AOL Autos for fuel-efficient used cars. (http://autos.aol.com/used?ncid=aolaut00050000000007) From phk at phk.freebsd.dk Fri Jul 4 03:16:35 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Fri, 04 Jul 2008 07:16:35 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Your message of "Fri, 04 Jul 2008 01:02:33 +0200." <20080704.010233.197896015547869060.cfmd@bredband.net> Message-ID: <19615.1215155795@critter.freebsd.dk> In message <20080704.010233.197896015547869060.cfmd at bredband.net>, Magnus Danie lson writes: >From: "Poul-Henning Kamp" >Subject: Re: [time-nuts] Near-perfect chip for Loran-C frequency receiver >Date: Thu, 03 Jul 2008 21:38:41 +0000 >Message-ID: <17856.1215121121 at critter.freebsd.dk> > >> In message <20080703.230345.407454645627532368.cfmd at bredband.net>, Magnus Danie >> lson writes: >> >> >It would be nice to have LORAN-C, MSF and DCF-77 in the same solution if >> >possible. I am sure some of the US signals can be included. >> >> It's trivial to do phase-tracking on any moderately strong CW signal >> at the same time, so that could easily be done using the same chip. > >Which was my point. Just a thad more work, but more usefull. > >> The analog side would need to allow for those signals also then. > >Naturally. The antenna-amplifier design will need to be more wideband >oriented. Should not be too hard thought. My present antenna just have a simple low-pass filter that cuts things off above 200-300 kHz. Together with the 1MSPS that's fine. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From phk at phk.freebsd.dk Fri Jul 4 03:32:44 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Fri, 04 Jul 2008 07:32:44 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Your message of "Thu, 03 Jul 2008 19:16:39 -0400." <1215126999.6104.9.camel@bigdog.icmp.com> Message-ID: <19686.1215156764@critter.freebsd.dk> In message <1215126999.6104.9.camel at bigdog.icmp.com>, Carl Walker writes: >On Fri, 2008-07-04 at 01:02 +0200, Magnus Danielson wrote: >There's more than meets the eye initially when you attempt a receiver >design of this type - at least as far as the analog section goes. I hate to say so, but actual experience proces you wrong on all counts. Remember we are not talking about fast signals like RTTY or voice, if we were, you would be right. We are talking about measuring one or more frequency/phase signals and with an OCXO or Rubidium timebase we have minutes, hours or even days of integration time at our disposal. Currently, my AGC is a manual trimmer and I have not touched it for years. I used to have a 246kHz LW station in visual range which set the level for me, and that gave me no trouble at all. Besides, a loop antenna can null out one strong signal very efficiently. A 12bit A/D gives about 72 dB dynamic range to work with, and and as I said, I can detect Loran-C signals as far away as 8830 and 7270. LORAN-C is both spread-spectrum and spread-time, those two signals have amplitudes below one bit, but once they're despread, they stand about 1 bit taller than the remaining noise. The entire point about software defined radio is to do away with the complicated analog side, and do it in the CPU, and VLF time/frequency signals are about the easiest signals you can work with for this. See my earlier work here: http://phk.freebsd.dk/loran-c Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From bruce.griffiths at xtra.co.nz Fri Jul 4 04:21:15 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 04 Jul 2008 20:21:15 +1200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <19686.1215156764@critter.freebsd.dk> References: <19686.1215156764@critter.freebsd.dk> Message-ID: <486DDD7B.1060001@xtra.co.nz> Poul-Henning Kamp wrote: > In message <1215126999.6104.9.camel at bigdog.icmp.com>, Carl Walker writes: > >> On Fri, 2008-07-04 at 01:02 +0200, Magnus Danielson wrote: >> > > >> There's more than meets the eye initially when you attempt a receiver >> design of this type - at least as far as the analog section goes. >> > > I hate to say so, but actual experience proces you wrong on all counts. > > Remember we are not talking about fast signals like RTTY or voice, > if we were, you would be right. > > We are talking about measuring one or more frequency/phase signals > and with an OCXO or Rubidium timebase we have minutes, hours or > even days of integration time at our disposal. > > Currently, my AGC is a manual trimmer and I have not touched it > for years. I used to have a 246kHz LW station in visual range > which set the level for me, and that gave me no trouble at all. > > Besides, a loop antenna can null out one strong signal very > efficiently. > > A 12bit A/D gives about 72 dB dynamic range to work with, and and > as I said, I can detect Loran-C signals as far away as 8830 and > 7270. > > LORAN-C is both spread-spectrum and spread-time, those two signals > have amplitudes below one bit, but once they're despread, they > stand about 1 bit taller than the remaining noise. > > The entire point about software defined radio is to do away with > the complicated analog side, and do it in the CPU, and VLF > time/frequency signals are about the easiest signals you can > work with for this. > > See my earlier work here: > > http://phk.freebsd.dk/loran-c > > Poul-Henning > > You've misunderstood the problem. Extrapolating your limited experience ( Loran) to the more difficult problem of simultaneously detecting/tracking Loran signals and potentially much weaker AM modulated time signals using the same wideband receiver with minimal analog filtering is asking for trouble. Try detecting decoding a 1uV/m signal in the presence of a strong 1V/m signal within the passband and see just how difficult it is without suitable analog filters etc. Not every potential user is conveniently located relatively close to DCF77, MSF, WWVB etc. Just because an ADC with a dynamic range of 72dB is adequate when processing Loran signals doesn't mean that it is adequate when the weak signal one is attempting to track/decode may be 120dB or below a stronger signal within the wide receiver passband. 72dB dynamic range is entirely inadequate if one has a wideband receiver located close to a transmitter whilst simultaneously attempting to detect/decode a very weak signal. The solution (other than using an unobtainable high sampling rate ADC with 120dB or more dynamic range) is off course to not use a wideband receiver. If one wishes to decode the AM time code broadcast by JJY WWVB, MSF, MST etc then the maximum signal averaging time is relatively short. It is perhaps simpler and easier to split the problem into 2 parts: 1) detecting + decoding Loran signals 2) detecting + decoding potentially weak AM time code broadcasts and simultaneously locking to the carrier. ADCs are relatively noisy devices with limited linearity and dynamic range. Some analog filtering and gain is required before the ADC when processing weak signals. Bruce From phk at phk.freebsd.dk Fri Jul 4 05:17:28 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Fri, 04 Jul 2008 09:17:28 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Your message of "Fri, 04 Jul 2008 20:21:15 +1200." <486DDD7B.1060001@xtra.co.nz> Message-ID: <20155.1215163048@critter.freebsd.dk> In message <486DDD7B.1060001 at xtra.co.nz>, Bruce Griffiths writes: >Poul-Henning Kamp wrote: >You've misunderstood the problem. No, you have, and you are barking up a different tree than I'm climbing. Look at the subject, it says "... frequency receiver". >If one wishes to decode the AM time code broadcast by JJY WWVB, MSF, MST >etc then the maximum signal averaging time is relatively short. I don't so it isn't. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From bruce.griffiths at xtra.co.nz Fri Jul 4 05:49:28 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 04 Jul 2008 21:49:28 +1200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <20155.1215163048@critter.freebsd.dk> References: <20155.1215163048@critter.freebsd.dk> Message-ID: <486DF228.6000202@xtra.co.nz> Poul-Henning Kamp wrote: > In message <486DDD7B.1060001 at xtra.co.nz>, Bruce Griffiths writes: > >> Poul-Henning Kamp wrote: >> > > >> You've misunderstood the problem. >> > > No, you have, and you are barking up a different tree than I'm climbing. > > Look at the subject, it says "... frequency receiver". > > The meaning diverged/became ambiguous after Magnus made his post. My comments apply to the extended capability receiver that Magnus envisaged and not to a Loran only receiver. >> If one wishes to decode the AM time code broadcast by JJY WWVB, MSF, MST >> etc then the maximum signal averaging time is relatively short. >> > > I don't so it isn't. > > But locking to a 1uV signal in the presence of a 1V signal within a relatively broad receiver bandpass as Magnus envisaged is unlikely to be possible without substantial analog assistance. > Poul-Henning > > Actual signal levels for MSF, WWVB etc as well as signal levels would be useful in sorting out the limitations of various approaches to combined Loran, MSF/WWVB/etc receivers. Bruce From phk at phk.freebsd.dk Fri Jul 4 06:20:45 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Fri, 04 Jul 2008 10:20:45 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Your message of "Fri, 04 Jul 2008 21:49:28 +1200." <486DF228.6000202@xtra.co.nz> Message-ID: <20486.1215166845@critter.freebsd.dk> In message <486DF228.6000202 at xtra.co.nz>, Bruce Griffiths writes: >Poul-Henning Kamp wrote: >> Look at the subject, it says "... frequency receiver". >> >The meaning diverged/became ambiguous after Magnus made his post. >My comments apply to the extended capability receiver that Magnus >envisaged and not to a Loran only receiver. Not for me. I guess you assumed Magnus wanted to receive the DCF77 timecode, but that's not how I read it, I assumed he wanted to use DCF77 as a frequency reference, in which case you can integrate for days if you want to. >But locking to a 1uV signal in the presence of a 1V signal [...] What is your point here ? I'm not trying to build the receiver to end all receivers, I'm trying to build a simple (one chip), cheap (Actual signal levels for MSF, WWVB etc as well as signal levels would be >useful in sorting out the limitations of various approaches to combined >Loran, MSF/WWVB/etc receivers. It is actually impressive what you can do if you throw enough CPU power at it. You can trivially get 16 bit 1MSPS ADC's today, giving you close to 100dB dynamic range. But that would be quite a high-end project: somebody would have to knit together a moderately complicated PCB with enough DSP power on it to make it worthw,hile and programming would be a non-trivial task. My proposal for this project requires a ferrite-bar, a couple of OP-AMPs and a prototype board you can buy for EUR50, and you can write the software in plain C which can be compiled with GCC. If you live a place where you have 1V/m signals and try to derive frequency fom a 1uV/m signal, or if you live in a faraday-cage at the bottom of a iron-mine, this project may not be for you. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From eliocor at gmail.com Fri Jul 4 07:42:01 2008 From: eliocor at gmail.com (Elio Corbolante) Date: Fri, 4 Jul 2008 13:42:01 +0200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver Message-ID: <6077b10a0807040442y44903dd6vcd36f43f9fe0f888@mail.gmail.com> You can try to ask to IV3NWV (Nico Palermo), the One who developed Perseus: maybe he can say something about the feasibility of such "broadband" receiver ... Elio. From J.Bastemeijer at TUDelft.nl Fri Jul 4 08:11:01 2008 From: J.Bastemeijer at TUDelft.nl (Jeroen Bastemeijer) Date: Fri, 04 Jul 2008 14:11:01 +0200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver Message-ID: <486E1355.3050708@TUDelft.nl> Dear Time-Nuts, I have been reading the discussion about what is possible and impossible with the ARM evaluation board. The proposed idea(s) to build a versatile receiver which could be used for receiving various time/frequency reference transmitter around the world sounds great! It is my believe that the time-nuts group is strong, professional and inventive enough to "produce" such a system. I think it will allow a lot of people to do experiments with (V)LF reception of time/frequency signals in a professional way. The HPSDR project (www.HPSDR.org; which is known by a number of people here) has proven that it is possible for an internet community to produce real hardware! I'm willing to provide my help and knowledge if and where possible. Allthough, I have to admit, I'm at this moment rather busy with the HPSDR project (the power supply part called Demeter). Maybe we could even make a collaboartion with the HPSDR project. There are advantages for both communities: * The HPSDR is still looking for a suitable frequency reference for their system, allthough a start has been made for a GPS-reference system (see Gibraltar) * The Time-nuts list could benefit from the knowledge the HPSDR community already has about production of boards and SDR Furthermore, both communities are collaborating with TAPR! The way HPSDR works is as follows: A project leader is "choosen" (usually the person who volunteers) he makes a proposal for the project. All the others are invited to share their comments. This will lead to a program of requirements. Now the real fun starts, the design of the system, while the design is growing all people can contribute their knowledge, experience and even some hands-on work. This wil yield a system which should be near to everyones wishes! I hope we can start a similar (but probably smaller) project like HPSDR. I think it is a great opportunity. The idea is very interesting, it is difficult for us to compete with the big manufacturers of GPS-based references. But in the field of (V)LF frequency and time-standards there is a lot off room for us, to play and experiment! Question is, are we willing to do that? I would say, let's do it together! I'm very curious about your reaction/opinion! 73 Jeroen PE1RGE -- Ing. Jeroen Bastemeijer Delft University of Technology Department of Electrical Engineering Electronic Instrumentation Laboratory Mekelweg 4, Room 13.090 2628 CD Delft The Netherlands Phone: +31.15.27.86542 Fax: +31.15.27.85755 E-mail: J.Bastemeijer at TUDelft.nl GPS: Lat N52.00002 Lon E4.37157 Alt 46.2m From james.p.lux at jpl.nasa.gov Fri Jul 4 09:49:54 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Fri, 04 Jul 2008 06:49:54 -0700 Subject: [time-nuts] Rb references for audiophiles? Message-ID: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> For your amusement... Sitting in a waiting room yesterday, I read an article in a very-high-end audio magazine describing a $15K Rubidium frequency standard for providing low jitter clocks to your audio system. It has outputs at 44.1, 48, etc. kHz, as well as a 100kHz, which the person writing said might become a new standard (huh?) Aside from the usual blather about how the improved clock jitter made this album or that more open sounding and improved the auditory experience, there were the usual gold plated connectors, etc. Hey... here's a golden opportunity for a time nut. I suspect they generate the various clocks using (gasp) digital dividers and such. Now's your chance to design an incredibly complex all analog synthesis chain with step recovery diodes, mix and add, etc. Everyone knows that for the finest in audio, an all analog (preferably all Class A) design is essential. Make sure that you have at least one vacuum tube in the design, preferably two, that can be "hand selected" and mounted so there's a little window to see the glow, and have some nice analog meters to monitor some useless parameter (suppressor grid voltage or something) I don't know where they get Rubidium, but maybe you could market a concept of terroir (as for wine).. why, the Mark 3000 Rubidium reference source uses Rb extracted only from the finest hand selected ores from Canada, where they have been mined by miners with multiple generations of experience, using trucks fueled with, etc... Or following on the more recent discussions on the list about Cs and NH3 references, maybe you can one-up the Rb maker with a Cs. Or maybe GPS disciplined clock sources (you know... if the 44.1kHz sample stream coming off the CD isn't precisely aligned on the second, sonic quality is definitely impaired.. the only real question is whether you should have a means of adjusting the clock rates to accommodate small changes in the earth's rotation or relativistic effects. A whole magazine, 100 pages long, filled with this sort of thing (and yes, they had the special speaker cables with the arrows to indicate preferred direction of power flow, too....) Jim From david.stelpstra at tomtom.com Fri Jul 4 10:05:33 2008 From: david.stelpstra at tomtom.com (David Stelpstra) Date: Fri, 4 Jul 2008 16:05:33 +0200 Subject: [time-nuts] New leap second Message-ID: Hi, The announcement of a leapsecond end of this year just came in. See: ftp://hpiers.obspm.fr/iers/bul/bulc/bulletinc.dat Regards David This e-mail message contains information which is confidential and may be privileged. It is intended for use by the addressee only. If you are not the intended addressee, we request that you notify the sender immediately and delete or destroy this e-mail message and any attachment(s), without copying, saving, forwarding, disclosing or using its contents in any other way. TomTom N.V., TomTom International BV or any other company belonging to the TomTom group of companies will not be liable for damage relating to the communication by e-mail of data, documents or any other information. From cfharris at erols.com Fri Jul 4 10:14:01 2008 From: cfharris at erols.com (Chuck Harris) Date: Fri, 04 Jul 2008 10:14:01 -0400 Subject: [time-nuts] New leap second In-Reply-To: References: Message-ID: <486E3029.3050901@erols.com> Two leap seconds in as many years! It must be that global warming. -Chuck Harris David Stelpstra wrote: > Hi, > > > > The announcement of a leapsecond end of this year just came in. > > See: ftp://hpiers.obspm.fr/iers/bul/bulc/bulletinc.dat > > > > Regards > > David From GandalfG8 at aol.com Fri Jul 4 11:01:04 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Fri, 4 Jul 2008 11:01:04 EDT Subject: [time-nuts] Rb references for audiophiles? Message-ID: In a message dated 04/07/2008 14:51:19 GMT Daylight Time, james.p.lux at jpl.nasa.gov writes: Sitting in a waiting room yesterday, I read an article in a very-high-end audio magazine describing a $15K Rubidium frequency standard for providing low jitter clocks to your audio system. It has outputs at 44.1, 48, etc. kHz, as well as a 100kHz, which the person writing said might become a new standard (huh?) ------------------------ Any chance you can remember the name and/or issue number of the magazine? No, I don't want to buy or build one, but I'd love to read a copy of that article:-) regards Nigel GM8PZR From RLutwak at Comcast.net Fri Jul 4 11:41:59 2008 From: RLutwak at Comcast.net (Robert Lutwak) Date: Fri, 04 Jul 2008 11:41:59 -0400 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> References: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> Message-ID: http://www.antelopeaudio.com/en/products_iso_10m.html At 09:49 AM 7/4/2008, you wrote: >For your amusement... > >Sitting in a waiting room yesterday, I read an article in a >very-high-end audio magazine describing a $15K Rubidium frequency >standard for providing low jitter clocks to your audio system. It has >outputs at 44.1, 48, etc. kHz, as well as a 100kHz, which the person >writing said might become a new standard (huh?) >... -RL ----------------------- Robert Lutwak Symmetricom - Technology Realization Center RLutwak at Symmetricom.com (Business) Lutwak at Alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) From ne8s at earthlink.net Fri Jul 4 12:09:02 2008 From: ne8s at earthlink.net (NE8S) Date: Fri, 4 Jul 2008 11:09:02 -0500 Subject: [time-nuts] Tektronix TDS Communication Modules Message-ID: <000801c8ddf0$46d801b0$0e01a8c0@HITACHI> Greetings, all, I need any of the compatible Communication Modules for the TDS 2024 DSO. Specifically, the TDS2CMA, TDS2CMAX, TDS2MEM or any of these variants. Please check with all of your colleagues, associates, and constituents for me if you would be so kind. Thank you in advance for any help in this matter. Regards, Doc Federal Consultants Corporation CsUTC Observatory Bio-Nucleonics Laboratory College Hill Wichita csutc.observatory at earthlink.net From james.p.lux at jpl.nasa.gov Fri Jul 4 12:33:00 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Fri, 04 Jul 2008 09:33:00 -0700 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: References: Message-ID: <20080704093300.uee9j4m9wgc80c04@webmail.jpl.nasa.gov> Quoting GandalfG8 at aol.com, on Fri 04 Jul 2008 08:01:04 AM PDT: > > In a message dated 04/07/2008 14:51:19 GMT Daylight Time, > james.p.lux at jpl.nasa.gov writes: > > Sitting in a waiting room yesterday, I read an article in a > very-high-end audio magazine describing a $15K Rubidium frequency > standard for providing low jitter clocks to your audio system. It has > outputs at 44.1, 48, etc. kHz, as well as a 100kHz, which the person > writing said might become a new standard (huh?) > > > > ------------------------ > Any chance you can remember the name and/or issue number of the magazine? I think it was "absolute audio"... I think it's this unit they were reviewing ESOTERIC - G-0Rb MASTER CLOCK GENERATOR (RUBIDIUM) which oddly, is actually made by a division of Teac http://www.teac.com/esoteric/ http://www.teac.com/esoteric/Master-Clock_Up-Converter.html There's also this: http://forum.cakewalk.com/tm.asp?m=1304280 Oh.. maybe it it was in "The Absolute Sound" Mar 2008 Anyway, the data sheet does mention ... both have an input port cabale of receiving a 10 MHz reference signal from an external component. This port can be connected with devices such as an ultra-precise cesium atomic oscillator as a "system upgrade" for special applications. (and, yes, the are proprietary gold plated BNC ports) As for my previous speculation about GPS disciplined sources... why yes, they are also made... excellent... I guess those guys at Teac/Esoteric haven't got on that bandwagon yet. Fascinating, too, that they don't actually have any real data on the jitter performance of their box on the spec sheet.. even though that's what they're selling.. they just quote the absolute frequency accuracy. That's enough for now... I have to get my special green marker to treat the edges of all my CDs to reduce extra internal reflections, and then I have to patch the air bladders on the vibration isolating optical table I have the CD player set up on (granted my first CD player could really have used this...) > > No, I don't want to buy or build one, but I'd love to read a copy of that > article:-) > > regards > > Nigel > GM8PZR > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From dforbes at dakotacom.net Fri Jul 4 12:49:17 2008 From: dforbes at dakotacom.net (David Forbes) Date: Fri, 4 Jul 2008 09:49:17 -0700 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> References: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> Message-ID: At 6:49 AM -0700 7/4/08, Jim Lux wrote: >For your amusement... > >Sitting in a waiting room yesterday, I read an article in a >very-high-end audio magazine describing a $15K Rubidium frequency >standard for providing low jitter clocks to your audio system. It has >outputs at 44.1, 48, etc. kHz, as well as a 100kHz, which the person >writing said might become a new standard (huh?) > > > >A whole magazine, 100 pages long, filled with this sort of thing (and >yes, they had the special speaker cables with the arrows to indicate >preferred direction of power flow, too....) > >Jim Jim, It does sound like a fine way to separate fools from their money, but imagine having to listen to your customers spout that nonsense all day long! I remember reading a 1991 audiophile magazine article about clock jitter in a CD player. They had separated the transport from the DAC and mounted the master timing oscillator in the transport. Then they spent a lot of money on a fiber link to send the clock to the DAC from the transport with low jitter, since the DAC requires low jitter and the oscillator was at the end of a cable, which are known, along with their transmitting/receiving circuitry, for introducing jitter. Not once did they contemplate putting the oscillator next to the DAC where you might say it rightfully belongs. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ From vogelchr at vogel.cx Fri Jul 4 12:59:51 2008 From: vogelchr at vogel.cx (Christian Vogel) Date: Fri, 4 Jul 2008 18:59:51 +0200 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <20080704093300.uee9j4m9wgc80c04@webmail.jpl.nasa.gov> References: <20080704093300.uee9j4m9wgc80c04@webmail.jpl.nasa.gov> Message-ID: <20080704165951.GA12095@lvps80-237-164-40.hedonism.cx> > ESOTERIC - G-0Rb MASTER CLOCK GENERATOR (RUBIDIUM) ??esoteric?? While I realize the absurdity of hooking up such a thing to your CD player at home, there can be merits of having a centrally generated and extremely accurate clock in a professional audio/video production facility. When you are passing around digital audio and video signals between production desks in different rooms or even countries, missing drift can eliminate the need for special resampling equipment (frame stores for video). > which oddly, is actually made by a division of Teac > http://www.teac.com/esoteric/ > http://www.teac.com/esoteric/Master-Clock_Up-Converter.html > There's also this: > http://forum.cakewalk.com/tm.asp?m=1304280 ?that's proably also where it originates at TEAC, my guess is that they modified a professional device to fit into the audiophile market. > Fascinating, too, that they don't actually have any real data on the > jitter performance of their box on the spec sheet.. even though that's > what they're selling.. they just quote the absolute frequency accuracy. I'd say you don't get the concept of ?Audiophile Equipment? here! :-) It doesn't matter what the measurement says as long as you can hear it, the sound is more vivid and? you get the idea. Chris (who get's his 48kHz wordclock by dividing 18.4 MHz from a can oscillator by 348 with a AVR microcontroller?) From magnus at rubidium.dyndns.org Fri Jul 4 13:18:10 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Fri, 04 Jul 2008 19:18:10 +0200 (CEST) Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <20080704165951.GA12095@lvps80-237-164-40.hedonism.cx> References: <20080704093300.uee9j4m9wgc80c04@webmail.jpl.nasa.gov> <20080704165951.GA12095@lvps80-237-164-40.hedonism.cx> Message-ID: <20080704.191810.376383632005254513.cfmd@bredband.net> From: Christian Vogel Subject: Re: [time-nuts] Rb references for audiophiles? Date: Fri, 4 Jul 2008 18:59:51 +0200 Message-ID: <20080704165951.GA12095 at lvps80-237-164-40.hedonism.cx> > > ESOTERIC - G-0Rb MASTER CLOCK GENERATOR (RUBIDIUM) > ??esoteric?? > > While I realize the absurdity of hooking up such a thing to your > CD player at home, there can be merits of having a centrally generated > and extremely accurate clock in a professional audio/video production > facility. When you are passing around digital audio and video signals > between production desks in different rooms or even countries, > missing drift can eliminate the need for special resampling equipment > (frame stores for video). There is great benefits in having a "house clock". Especially when those are GPS coordinated. For TV-production with multiple sources it is painstaiking to use Time Base Correctors all the time. Those are used to overcome the problem of wrong frequency, which include dropping or duplicating images and pitchingshifting sound to handle the error. That the quality suffers comes without saying. This is not the audiofile level quality, this is professional production level quality. Some links may have multiple TBCs in series, since the intermediate network may wander alot. > > Fascinating, too, that they don't actually have any real data on the > > jitter performance of their box on the spec sheet.. even though that's > > what they're selling.. they just quote the absolute frequency accuracy. > > I'd say you don't get the concept of ?Audiophile Equipment? here! :-) True, but it IS a common missconception. Somebody should cook up a good online article and presentation explaining it and separating the issues. Hmm. Wiki. Hmm. Maybe later tonight. > It doesn't matter what the measurement says as long as you can hear it, > the sound is more vivid and? you get the idea. > > Chris > > (who get's his 48kHz wordclock by dividing 18.4 MHz from a can oscillator > by 348 with a AVR microcontroller?) NOOOOOO!!!!! You NEED to use an annealed anisomorph passive divider in a anti-parallel setup to get anywhere near usefullness. Cheers, Magnus From holrum at hotmail.com Fri Jul 4 13:39:44 2008 From: holrum at hotmail.com (Mark Sims) Date: Fri, 4 Jul 2008 17:39:44 +0000 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: References: Message-ID: Try putting the output of a CD or FM radio signal into a FFT based waterfall display. An amazing number of songs, etc have very prominent 15734KHz and/or 15.625KHz harmonics that are obviously from CRT monitors in the recording booth. Recording engineers ain't what they used to be... You can easily tell what continent the piece was mastered on. Some pieces have both PAL and NTSC flyback signals... they were mixed from recordings done on both continents. Anybody know where I can get a (less than $40,000) patch cable that can remove CRT flyback noise from my rubidium clocked Walkman? ---------------------------------------- _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From bill at iaxs.net Fri Jul 4 14:02:47 2008 From: bill at iaxs.net (Bill Hawkins) Date: Fri, 4 Jul 2008 13:02:47 -0500 Subject: [time-nuts] New leap second In-Reply-To: <486E3029.3050901@erols.com> References: <486E3029.3050901@erols.com> Message-ID: <002401c8de00$2a82ca80$021ba8c0@cyrus> Chuck Harris wrote, "Two leap seconds in as many years! It must be that global warming." Well, yes. The Earth expands from the heat, rotation slows, and we get another leap second - as we watch symptom after symptom occur while being unable to come to consensus on what to do. Bill Hawkins From bill at iaxs.net Fri Jul 4 14:11:13 2008 From: bill at iaxs.net (Bill Hawkins) Date: Fri, 4 Jul 2008 13:11:13 -0500 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> References: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> Message-ID: <003101c8de01$58692b00$021ba8c0@cyrus> Jim Lux said, in part, "Hey... here's a golden opportunity for a time nut. I suspect they generate the various clocks using (gasp) digital dividers and such. Now's your chance to design an incredibly complex all analog synthesis chain with step recovery diodes, mix and add, etc. Everyone knows that for the finest in audio, an all analog (preferably all Class A) design is essential." Actually, you can make vacuum tube frequency dividers from phantastron circuits. Find the tubes with the Bugle Boy tubes in Tek scopes. Bill Hawkins From newell at cei.net Fri Jul 4 14:30:04 2008 From: newell at cei.net (Scott Newell) Date: Fri, 04 Jul 2008 13:30:04 -0500 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <20080704165951.GA12095@lvps80-237-164-40.hedonism.cx> References: <20080704093300.uee9j4m9wgc80c04@webmail.jpl.nasa.gov> <20080704165951.GA12095@lvps80-237-164-40.hedonism.cx> Message-ID: <200807041830.m64IUAeu025099@host22.the-web-host.com> At 11:59 AM 7/4/2008, Christian Vogel wrote: > > ESOTERIC - G-0Rb MASTER CLOCK GENERATOR (RUBIDIUM) > ???esoteric??? >? > >While I realize the absurdity of hooking up such a thing to your >CD player at home, there can be merits of having a centrally generated >and extremely accurate clock in a professional audio/video production >facility. When you are passing around digital audio and video signals >between production desks in different rooms or even countries, >missing drift can eliminate the need for special resampling equipment >(frame stores for video). In that case, I really wish all the locals would buy up some freq standards. Not that their staff would know what to do with it if they had it. I'm sick of the digital TV that I see over analog cable. Horrible audio/video sync problems, pixelation, motion artifacts, incorrect aspect ratios, and the latest--weird facial artifacts where the facial features appear to float around the face when the head moves. Pathetic. -- newell N5TNL From ronaldheld at gmail.com Fri Jul 4 14:31:00 2008 From: ronaldheld at gmail.com (Ronald Held) Date: Fri, 4 Jul 2008 14:31:00 -0400 Subject: [time-nuts] New leap second Message-ID: <9a86fb0e0807041131k5d95dd6eje917b06ec0dde253@mail.gmail.com> I just got that bulletin. I will have to adjust all of the programs using the update data from the Astronautic Almanac when the next one is issued. From k1ggi at arrl.net Fri Jul 4 14:35:04 2008 From: k1ggi at arrl.net (Ed, k1ggi) Date: Fri, 4 Jul 2008 14:35:04 -0400 Subject: [time-nuts] Near-perfect chip for Loran-C frequency In-Reply-To: <486D7BD5.8060101@xtra.co.nz> References: <000301c8dd6e$b29ace50$17d06af0$@com> <486D7BD5.8060101@xtra.co.nz> Message-ID: <154801c8de04$adedfdf0$0a01a8c0@ATHLONXP1700> If there is something smaller than a nit to pick in the grand scheme of things, this may be it. Anyway - these days WWVB is running the depth at 17dB. Interesting info at http://tf.nist.gov/timefreq/general/pdf/2139.pdf Ed -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Bruce Griffiths Sent: Thursday, July 03, 2008 9:25 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Near-perfect chip for Loran-C frequency JJY(40kHz, 60kHz) HBG(75kHz) DCF77(77.5kHz), MSF(60kHz), WWVB(60kHz) all use AM to encode the time using different pulse widths to denote markers , 0 and 1 respectively. WWVB, JJY reduce the power by 10dB to encode 1, 0 etc so that a residual carrier is always present. WWVB also phase modulates the carrier at 1/3600Hz (period = 1hour) with a duty cycle of 5/60. MSF and HBG use ON/OFF keying. DCF77 encodes 1, 0 etc by reducing power to 25%, in addition DCF77 phase modulates the carrier with a PRBS. Since the minimum pulse width used is 0.1sec the receiver's effective bandwidth (when receiving WWVB, MSF or DCF77) need not be more than a few Hz. Bruce _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From gbusg at comcast.net Fri Jul 4 14:54:35 2008 From: gbusg at comcast.net (Greg Burnett) Date: Fri, 4 Jul 2008 12:54:35 -0600 Subject: [time-nuts] Rb references for audiophiles? References: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> Message-ID: <004e01c8de07$675ec2e0$6501a8c0@gb02> ---Jim wrote: ...they had the special speaker cables with the arrows to indicate preferred direction of power flow, too....) ---clip--- Jim, "directional" audio interconnect cables typically have two conductors for the signal path, plus a shield. The shield is connected at only the "destination" end of the cable. This is similar to some low-level instrumentation connections (where the signal flows through two inner conductors, and we don't want the shield contributing to circulating AC ground currents). The situation for "directional" speaker cables is a bit stranger, but, again, typically involves a shield connected at only one end of the cable. --Greg From cfharris at erols.com Fri Jul 4 15:05:01 2008 From: cfharris at erols.com (Chuck Harris) Date: Fri, 04 Jul 2008 15:05:01 -0400 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <003101c8de01$58692b00$021ba8c0@cyrus> References: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> <003101c8de01$58692b00$021ba8c0@cyrus> Message-ID: <486E745D.3050007@erols.com> Bill Hawkins wrote: > Jim Lux said, in part, > > "Hey... here's a golden opportunity for a time nut. I suspect they > generate the various clocks using (gasp) digital dividers and such. > Now's your chance to design an incredibly complex all analog synthesis > chain with step recovery diodes, mix and add, etc. Everyone knows > that for the finest in audio, an all analog (preferably all Class A) > design is essential." Only if it uses 300B's in the divider! > Actually, you can make vacuum tube frequency dividers from phantastron > circuits. Find the tubes with the Bugle Boy tubes in Tek scopes. You leave the Tek scopes alone! There are enough audiofools poaching the tubes and transformers as it is. -Chuck Harris From cfharris at erols.com Fri Jul 4 15:07:47 2008 From: cfharris at erols.com (Chuck Harris) Date: Fri, 04 Jul 2008 15:07:47 -0400 Subject: [time-nuts] New leap second In-Reply-To: <002401c8de00$2a82ca80$021ba8c0@cyrus> References: <486E3029.3050901@erols.com> <002401c8de00$2a82ca80$021ba8c0@cyrus> Message-ID: <486E7503.5010605@erols.com> Bill Hawkins wrote: > Chuck Harris wrote, > > "Two leap seconds in as many years! > > It must be that global warming." > > > Well, yes. The Earth expands from the heat, rotation slows, > and we get another leap second - as we watch symptom after > symptom occur while being unable to come to consensus on > what to do. I say that we take up the issue with the Sun. Clearly it is also causing global warming on Mars. -Chuck Harris > > Bill Hawkins > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From imp at bsdimp.com Fri Jul 4 15:36:40 2008 From: imp at bsdimp.com (M. Warner Losh) Date: Fri, 04 Jul 2008 13:36:40 -0600 (MDT) Subject: [time-nuts] New leap second In-Reply-To: <9a86fb0e0807041131k5d95dd6eje917b06ec0dde253@mail.gmail.com> References: <9a86fb0e0807041131k5d95dd6eje917b06ec0dde253@mail.gmail.com> Message-ID: <20080704.133640.1756925481.imp@bsdimp.com> In message: <9a86fb0e0807041131k5d95dd6eje917b06ec0dde253 at mail.gmail.com> "Ronald Held" writes: : I just got that bulletin. I will have to adjust all of the programs : using the update data from the Astronautic Almanac when the next one : is issued. Yes, this is one of the problems with leap seconds. Opinions differ here as to their relevance and suitability to solving the clock skew problem. :-) Warner From holrum at hotmail.com Fri Jul 4 15:36:34 2008 From: holrum at hotmail.com (Mark Sims) Date: Fri, 4 Jul 2008 19:36:34 +0000 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: References: Message-ID: No, no, no... you must use dekatrons for your dividers. Solves many audiophile requirements at one time... vacuum tube, nifty spinning glowing thingies you can watch though cutout windows, endless entertainment for dope addled brains, err uhhh I forget the rest. > Jim Lux said, in part, > > "Hey... here's a golden opportunity for a time nut. I suspect they > generate the various clocks using (gasp) digital dividers and such. > Now's your chance to design an incredibly complex all analog synthesis > chain with step recovery diodes, mix and add, etc. Everyone knows > that for the finest in audio, an all analog (preferably all Class A) > design is essential." >>Only if it uses 300B's in the divider! 308B's cost 10 times as much ($2K+ ea) so those MUST be 10 times more audiolicious. _________________________________________________________________ It?s a talkathon ? but it?s not just talk. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_JustTalk From didier at cox.net Fri Jul 4 16:15:55 2008 From: didier at cox.net (Didier Juges) Date: Fri, 4 Jul 2008 15:15:55 -0500 Subject: [time-nuts] New leap second In-Reply-To: <486E3029.3050901@erols.com> References: <486E3029.3050901@erols.com> Message-ID: <001201c8de12$c49229b0$0a01a8c0@didierhp> No, I think it's just a vast conspiracy :-) Didier KO4BB > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Chuck Harris > Sent: Friday, July 04, 2008 9:14 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] New leap second > > Two leap seconds in as many years! > > It must be that global warming. > > -Chuck Harris > From didier at cox.net Fri Jul 4 16:17:46 2008 From: didier at cox.net (Didier Juges) Date: Fri, 4 Jul 2008 15:17:46 -0500 Subject: [time-nuts] Tektronix TDS Communication Modules In-Reply-To: <000801c8ddf0$46d801b0$0e01a8c0@HITACHI> References: <000801c8ddf0$46d801b0$0e01a8c0@HITACHI> Message-ID: <001301c8de13$066caef0$0a01a8c0@didierhp> These are still available from Tektronix, even though last time I checked, you can buy a working Tek 2430 storage scope on eBay for less. I have one in my TDS-210, but I would not give it up for anything (oh well, almost anything...) Didier KO4BB > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of NE8S > Sent: Friday, July 04, 2008 11:09 AM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] Tektronix TDS Communication Modules > > Greetings, all, > > I need any of the compatible Communication Modules for the > TDS 2024 DSO. > > Specifically, the TDS2CMA, TDS2CMAX, TDS2MEM or any of these variants. > > Please check with all of your colleagues, associates, and > constituents for me if you would be so kind. > > Thank you in advance for any help in this matter. > > Regards, > > Doc > Federal Consultants Corporation > CsUTC Observatory > Bio-Nucleonics Laboratory > College Hill > Wichita > > csutc.observatory at earthlink.net > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, > go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From alan.melia at btinternet.com Fri Jul 4 16:28:23 2008 From: alan.melia at btinternet.com (Alan Melia) Date: Fri, 4 Jul 2008 21:28:23 +0100 Subject: [time-nuts] New leap second References: <486E3029.3050901@erols.com><002401c8de00$2a82ca80$021ba8c0@cyrus> <486E7503.5010605@erols.com> Message-ID: <002c01c8de14$84b621a0$0900a8c0@AM> On the 4th July it (the Sun) was actually at its furtherst point from earth so we were getting less radiation .....did your burghers take longer to cook ?? :-)) Alan G3NYK ----- Original Message ----- From: "Chuck Harris" To: "Discussion of precise time and frequency measurement" Sent: Friday, July 04, 2008 8:07 PM Subject: Re: [time-nuts] New leap second > Bill Hawkins wrote: > > Chuck Harris wrote, > > > > "Two leap seconds in as many years! > > > > It must be that global warming." > > > > > > Well, yes. The Earth expands from the heat, rotation slows, > > and we get another leap second - as we watch symptom after > > symptom occur while being unable to come to consensus on > > what to do. > > I say that we take up the issue with the Sun. Clearly it is > also causing global warming on Mars. > > -Chuck Harris > > > > > Bill Hawkins > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts at febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From tom.k3io at gmail.com Fri Jul 4 17:09:07 2008 From: tom.k3io at gmail.com (Tom Clark, K3IO) Date: Fri, 04 Jul 2008 17:09:07 -0400 Subject: [time-nuts] New leap second In-Reply-To: References: Message-ID: <486E9173.6070908@verizon.net> Chuck Harris commented Two leap seconds in as many years! It must be that global warming. -Chuck Harris UT1 is the time measured with respect to the stars, while UTC and TAI are based on the rate of laboratory atomic clocks; I like to say that UT1 is the time you would read on your sundial. Since the earth's rotation is an imprecise clock, UTC is a hybrid that keeps your sundial's error to < 0.7 seconds (for the navigators, this means <280 meters of east-west position error at the equator). In case anyone is interested, here is the actual UT1-UTC data produced by the group I headed for many years (until I retired in 2001): [cid:part1.06070202.03080904 at verizon.net] Here is what UT1-TAI (i.e. sundial - atomic clock) looks like without the steps. The ~30 second offset represent the accumulated error from a rather arbitrary historical date (1958, when the offset was set to 10.0 seconds). The GPS clocks run on GPS time, which is nominally the same as TAI with a 19 second fixed offset (it was zeroed to UTC as of Jan 6, 1980, which is reckoned as the start of the GPS era). [cid:part2.02060709.08000401 at verizon.net] Regards, Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: 2008-07-04_16-45-44-274.png Type: image/png Size: 10534 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080704/87a08209/attachment.png -------------- next part -------------- A non-text attachment was scrubbed... Name: 2008-07-04_16-52-09-860.png Type: image/png Size: 8788 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080704/87a08209/attachment-0001.png From jherrero at hvsistemas.es Fri Jul 4 18:47:06 2008 From: jherrero at hvsistemas.es (Javier Herrero) Date: Sat, 05 Jul 2008 00:47:06 +0200 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: References: Message-ID: <486EA86A.6000509@hvsistemas.es> What about a chain of E1T tubes? A lot nicer! ;) And... why mess with noisy Rb references? A true audiophile has a H-maser, of course ;) Mark Sims escribi?: > No, no, no... you must use dekatrons for your dividers. Solves many audiophile requirements at one time... vacuum tube, nifty spinning glowing thingies you can watch though cutout windows, endless entertainment for dope addled brains, err uhhh I forget the rest. -- ------------------------------------------------------------------------ Javier Herrero EMAIL: jherrero at hvsistemas.com HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17A FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com From holrum at hotmail.com Fri Jul 4 19:02:49 2008 From: holrum at hotmail.com (Mark Sims) Date: Fri, 4 Jul 2008 23:02:49 +0000 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: References: Message-ID: Bahhh, a TRUE audiophile has three H-masers. You just can't trust your favorite recording of Thick as a Brick to a single reference clock. You need a realtime thee-cornered hat voter/selector to chose the best one. But masers do meet the number one audiophile requirement of a having a glowing vacuum tubey thingy. >What about a chain of E1T tubes? A lot nicer! ;) >And... why mess with noisy Rb references? A true audiophile has a >H-maser, of course ;) _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From ka2cdk at cox.net Fri Jul 4 19:22:18 2008 From: ka2cdk at cox.net (Thomas A. Frank) Date: Fri, 4 Jul 2008 19:22:18 -0400 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <1215126999.6104.9.camel@bigdog.icmp.com> References: <20080703.230345.407454645627532368.cfmd@bredband.net> <17856.1215121121@critter.freebsd.dk> <20080704.010233.197896015547869060.cfmd@bredband.net> <1215126999.6104.9.camel@bigdog.icmp.com> Message-ID: <14647AC2-BDFB-422A-9FCE-BE9D936DF3D9@cox.net> On Jul 3, 2008, at 7:16 PM, Carl Walker wrote: > On Fri, 2008-07-04 at 01:02 +0200, Magnus Danielson wrote: >>> The analog side would need to allow for those signals also then. >> >> Naturally. The antenna-amplifier design will need to be more wideband >> oriented. Should not be too hard thought. >> >> Cheers, >> Magnus > > I respectfully disagree; while making the wide-band receiver is an > easy > task, you now have a family of unrelated signals - often of widely > varying signal strength. Once any of those signals becomes large > enough > to drive the receiver non-linear, you rapidly run into issues. > > AGC to maintain linearity isn't practical in this case - since > reducing > overall receiver gain to compensate for one large signal - like > WWVB if > you're close by that one transmitter - will potentially drive down the > gain for desired LORAN and other signals to the point where you can't > acquire and track many of the weaker but never the less desired > signals. > > There's more than meets the eye initially when you attempt a receiver > design of this type - at least as far as the analog section goes. Once > it becomes 1's and 0's it's all straight forward - at least as far as > this old ex-analog guy is concerned ;-) In as much as we know exactly the frequencies of interest, perhaps the analog front end could consist of multiple signal paths with very narrow band filters to separate out the signals of interest (a 60 kHz channel, a 100 kHz channel, plus whatever other channels are desired), then each channel gets an individual AGC amp, and the matched signals are summed back together for A-D? It might in fact be cheaper to have multiple A-D modules behind such filters... Tom Frank From phk at phk.freebsd.dk Fri Jul 4 19:35:36 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Fri, 04 Jul 2008 23:35:36 +0000 Subject: [time-nuts] New leap second In-Reply-To: Your message of "Fri, 04 Jul 2008 13:02:47 EST." <002401c8de00$2a82ca80$021ba8c0@cyrus> Message-ID: <61481.1215214536@critter.freebsd.dk> In message <002401c8de00$2a82ca80$021ba8c0 at cyrus>, "Bill Hawkins" writes: >Well, yes. The Earth expands from the heat, rotation slows, [...] You're right, but from my back of the envelope calculation, it's negligble. Most of the expected expansion is the water in the oceans, which expand roughly 10^-4 per Kelvin in the relvante temperature range. When you factor in that the average dept of the oceans is close to 4000m, but not all of it is expected to warm up in our lifetime, so you get that 1K increased temperature is roughly 0.1 meter sea level increase. That means that the radius of the earth increases by about 15 parts per billion. But since the density of water is much lower than the rest of the planet, and that the water amounts to less than a twothousandth of the radius, the increase in angular momentum is only in the 10^-12 range. 10^-12 of a year is 31.5 microseconds, which would be added to the UTC-UT1 difference. Measurable, but not a problem compared what else one Kelvin would cause of trouble. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From phk at phk.freebsd.dk Fri Jul 4 19:54:03 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Fri, 04 Jul 2008 23:54:03 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Your message of "Fri, 04 Jul 2008 19:22:18 -0400." <14647AC2-BDFB-422A-9FCE-BE9D936DF3D9@cox.net> Message-ID: <61572.1215215643@critter.freebsd.dk> In message <14647AC2-BDFB-422A-9FCE-BE9D936DF3D9 at cox.net>, "Thomas A. Frank" wr ites: >In as much as we know exactly the frequencies of interest, perhaps >the analog front end could consist of multiple signal paths with very >narrow band filters to separate out the signals of interest (a 60 kHz >channel, a 100 kHz channel, plus whatever other channels are >desired), then each channel gets an individual AGC amp, and the >matched signals are summed back together for A-D? If you really want to do something like that, notch filters are a much better way to go. But as I keep trying to tell you guys: you don't need all that. Look at: http://phk.freebsd.dk/misc/L6/ There are four GRI's: 7499, 6731, 9007 and 8000, each in their own row. The leftmost plot shows the entire FRI (2 times GRI) and is used to locate the individual signals (look for one green (master) and multiple blue (slave) peaks. The small plots show three stations in each chain, to the extent that I have been able to locate them by eyeball. The X, Y designations may not match the official LORAN-C station names. The title on each of these plots show the relative signal strength, and as you can see the 7499M is 44 times stronger than the 9007Y. The data you see there is roughly 8 minutes worth of data at 10 bits per sample, 1Msps, processed as fixedpoint in the time-critical path. The antenna is this one: http://phk.freebsd.dk/loran-c/Antenna/ and it just has a simple Low-pass filter around 200 kHz. Unfortunately, the ST32M103 will have neither the RAM nor CPU power to track that many signals, but how many it can do remains to be seen. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From james.p.lux at jpl.nasa.gov Fri Jul 4 20:30:11 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Fri, 04 Jul 2008 17:30:11 -0700 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: References: Message-ID: <20080704173011.vpq2kv0mg4sw80cc@webmail.jpl.nasa.gov> Quoting Mark Sims , on Fri 04 Jul 2008 04:02:49 PM PDT: > > Bahhh, a TRUE audiophile has three H-masers. You just can't trust > your favorite recording of Thick as a Brick to a single reference > clock. You need a realtime thee-cornered hat voter/selector to > chose the best one. But masers do meet the number one audiophile > requirement of a having a glowing vacuum tubey thingy. Voter? But that's digital. You mean a totally analog combiner that optimizes the overall variance. See, there IS a use for that old analog computer plugboard you scavenged in 1970. (Of course, you WILL be using Philbrick OpAmps with the vacuum tubes like the ones Bob Pease is always talking about) Jim From james.p.lux at jpl.nasa.gov Fri Jul 4 20:34:36 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Fri, 04 Jul 2008 17:34:36 -0700 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <004e01c8de07$675ec2e0$6501a8c0@gb02> References: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> <004e01c8de07$675ec2e0$6501a8c0@gb02> Message-ID: <20080704173436.lspg6wz2ggo4okog@webmail.jpl.nasa.gov> Quoting Greg Burnett , on Fri 04 Jul 2008 11:54:35 AM PDT: > ---Jim wrote: > ...they had the special speaker cables with the arrows to indicate > preferred direction of power flow, too....) > ---clip--- > > Jim, "directional" audio interconnect cables typically have two conductors > for the signal path, plus a shield. The shield is connected at only the > "destination" end of the cable. This is similar to some low-level > instrumentation connections (where the signal flows through two inner > conductors, and we don't want the shield contributing to circulating AC > ground currents). That one I'm familiar with.. (SpaceWire cables, for instance, have 4 shielded twisted pairs, 2 in each direction, with the shields grounded at the sending end for each pair of pairs)... These were just plain old two (gold/palladium plated) pins for each "cable" (granted, the cable is some complex braided combination of silver ribbons, which is a fairly exotic form of Litz wire, I assume... but no shield) > > The situation for "directional" speaker cables is a bit stranger, but, > again, typically involves a shield connected at only one end of the cable. > > --Greg > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From dforbes at dakotacom.net Fri Jul 4 20:43:32 2008 From: dforbes at dakotacom.net (David Forbes) Date: Fri, 4 Jul 2008 17:43:32 -0700 Subject: [time-nuts] HP 113BR manual scanned Message-ID: Another one from the old 36 foot NRAO telescope files - the HP 113BR analog clock unit. http://www.nixiebunny.com/hp113br.pdf Enjoy. Does anyone think Agilent is interested in a manual for something this old, or is this more of an HP Archives sort of boatanchor? I also have a 103AR manual to scan if anyone's interested in this ancient stuff. Let me know. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ From bruce.griffiths at xtra.co.nz Fri Jul 4 20:47:53 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 05 Jul 2008 12:47:53 +1200 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <20080704173436.lspg6wz2ggo4okog@webmail.jpl.nasa.gov> References: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> <004e01c8de07$675ec2e0$6501a8c0@gb02> <20080704173436.lspg6wz2ggo4okog@webmail.jpl.nasa.gov> Message-ID: <486EC4B9.3030603@xtra.co.nz> Jim Lux wrote: > > That one I'm familiar with.. (SpaceWire cables, for instance, have 4 > shielded twisted pairs, 2 in each direction, with the shields grounded > at the sending end for each pair of pairs)... > > > These were just plain old two (gold/palladium plated) pins for each > "cable" (granted, the cable is some complex braided combination of > silver ribbons, which is a fairly exotic form of Litz wire, I > assume... but no shield) > > > Unless each individual strand is insulated from all the others (as it is in true Litzendraht) braiding the wire is ineffective in reducing skin effect. Bruce From james.p.lux at jpl.nasa.gov Fri Jul 4 20:56:34 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Fri, 04 Jul 2008 17:56:34 -0700 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <486EC4B9.3030603@xtra.co.nz> References: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov> <004e01c8de07$675ec2e0$6501a8c0@gb02> <20080704173436.lspg6wz2ggo4okog@webmail.jpl.nasa.gov> <486EC4B9.3030603@xtra.co.nz> Message-ID: <20080704175634.p4idmywhcso8wwws@webmail.jpl.nasa.gov> Quoting Bruce Griffiths , on Fri 04 Jul 2008 05:47:53 PM PDT: > Jim Lux wrote: >> >> That one I'm familiar with.. (SpaceWire cables, for instance, have 4 >> shielded twisted pairs, 2 in each direction, with the shields grounded >> at the sending end for each pair of pairs)... >> >> >> These were just plain old two (gold/palladium plated) pins for each >> "cable" (granted, the cable is some complex braided combination of >> silver ribbons, which is a fairly exotic form of Litz wire, I >> assume... but no shield) >> >> >> > Unless each individual strand is insulated from all the others (as it is > in true Litzendraht) braiding the wire is ineffective in reducing skin > effect. > > Bruce It was unclear from the literature I saw, but I have to assume that they know this (Litz wire and all it's properties have been "fashionable" in one sense or another for the audiophile biz for decades... I had friends who made their own). On the other hand... I did run across an interesting product for high end audio (not recently)... air core tape wound inductors (i.e. a pancake shaped coil with the winding of thin tape, instead of wire) in both silver and copper. Very interesting stuff. A friend was looking at using them for magnets for a rail gun type system (since they have have a hole in the middle for mounting)... Jim From bruce.griffiths at xtra.co.nz Fri Jul 4 21:01:36 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 05 Jul 2008 13:01:36 +1200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <61572.1215215643@critter.freebsd.dk> References: <61572.1215215643@critter.freebsd.dk> Message-ID: <486EC7F0.10006@xtra.co.nz> Poul-Henning Kamp wrote: > In message <14647AC2-BDFB-422A-9FCE-BE9D936DF3D9 at cox.net>, "Thomas A. Frank" wr > ites: > > >> In as much as we know exactly the frequencies of interest, perhaps >> the analog front end could consist of multiple signal paths with very >> narrow band filters to separate out the signals of interest (a 60 kHz >> channel, a 100 kHz channel, plus whatever other channels are >> desired), then each channel gets an individual AGC amp, and the >> matched signals are summed back together for A-D? >> > > If you really want to do something like that, notch filters are > a much better way to go. > > But as I keep trying to tell you guys: you don't need all that. > > Look at: > http://phk.freebsd.dk/misc/L6/ > > Nonsense, although it may work in favourable cases where the signal levels arent too disparate, in the more general case this isnt true. > There are four GRI's: 7499, 6731, 9007 and 8000, each in their own row. > > Thats obviously fine for some Loran applications but you haven't demonstrated that its also true when attempting to simultaneously track another signal of interest that is relatively weak. > The leftmost plot shows the entire FRI (2 times GRI) and is used > to locate the individual signals (look for one green (master) and > multiple blue (slave) peaks. > > The small plots show three stations in each chain, to the extent that > I have been able to locate them by eyeball. The X, Y designations may > not match the official LORAN-C station names. > > The title on each of these plots show the relative signal strength, > and as you can see the 7499M is 44 times stronger than the 9007Y. > > Thats only a 33 dB difference in signal level what happens when the signal strengths differ by 60, 80 dB? > The data you see there is roughly 8 minutes worth of data at > 10 bits per sample, 1Msps, processed as fixedpoint in the > time-critical path. > > The antenna is this one: http://phk.freebsd.dk/loran-c/Antenna/ > and it just has a simple Low-pass filter around 200 kHz. > > Unfortunately, the ST32M103 will have neither the RAM nor > CPU power to track that many signals, but how many it can > do remains to be seen. > > In which case a dedicated ST32M103 for Loran and another for MSF/WWVB/JJYDCF77 etc is appropriate together with optimised analog front ends, bandpass filters, notch filters and orientation of the individual antennae to null strong interfering signals should cope with most problematic sites. These refinements can be omitted at more favourable locations. Bruce From mfeher at eozinc.com Fri Jul 4 21:08:02 2008 From: mfeher at eozinc.com (Mike Feher) Date: Fri, 4 Jul 2008 21:08:02 -0400 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <20080704175634.p4idmywhcso8wwws@webmail.jpl.nasa.gov> References: <20080704064954.btjiho482s44o4ow@webmail.jpl.nasa.gov><004e01c8de07$675ec2e0$6501a8c0@gb02><20080704173436.lspg6wz2ggo4okog@webmail.jpl.nasa.gov><486EC4B9.3030603@xtra.co.nz> <20080704175634.p4idmywhcso8wwws@webmail.jpl.nasa.gov> Message-ID: <001e01c8de3b$94f2b570$0201a8c0@gsmacdq14es> Talking about magnets and skin depth, I recall an incident back in the early to mid 60's. I was living on Long Island at the time and had many friends who worked at Brookhaven National Laboratory. Needless to say I had numerous tours of the facility. At one time I was given a tour of the cryogenic lab, and was shown a magnet that they were using. To my surprise the magnet was wound with un-insulated wire. Naturally I had to ask about that, and was told that at cryogenic temperatures the contact resistance is so much higher than the actual wire resistance that they do not bother. This way they claimed they could get more turns on a given solenoid. Another interesting thing was an LC at cryogenic temperatures. This thing was oscillating on its own, after it was excited. I guess the Q must have approached infinity with such a low R. It was interesting. - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Jim Lux Sent: Friday, July 04, 2008 8:57 PM To: Discussion of precise time and frequency measurement; Bruce Griffiths Subject: Re: [time-nuts] Rb references for audiophiles? Quoting Bruce Griffiths , on Fri 04 Jul 2008 05:47:53 PM PDT: > Jim Lux wrote: >> >> That one I'm familiar with.. (SpaceWire cables, for instance, have 4 >> shielded twisted pairs, 2 in each direction, with the shields grounded >> at the sending end for each pair of pairs)... >> >> >> These were just plain old two (gold/palladium plated) pins for each >> "cable" (granted, the cable is some complex braided combination of >> silver ribbons, which is a fairly exotic form of Litz wire, I >> assume... but no shield) >> >> >> > Unless each individual strand is insulated from all the others (as it is > in true Litzendraht) braiding the wire is ineffective in reducing skin > effect. > > Bruce It was unclear from the literature I saw, but I have to assume that they know this (Litz wire and all it's properties have been "fashionable" in one sense or another for the audiophile biz for decades... I had friends who made their own). On the other hand... I did run across an interesting product for high end audio (not recently)... air core tape wound inductors (i.e. a pancake shaped coil with the winding of thin tape, instead of wire) in both silver and copper. Very interesting stuff. A friend was looking at using them for magnets for a rail gun type system (since they have have a hole in the middle for mounting)... Jim _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From bob.paddock at gmail.com Fri Jul 4 21:13:02 2008 From: bob.paddock at gmail.com (Bob Paddock) Date: Fri, 4 Jul 2008 21:13:02 -0400 Subject: [time-nuts] New leap second In-Reply-To: <486E7503.5010605@erols.com> References: <002401c8de00$2a82ca80$021ba8c0@cyrus> <486E7503.5010605@erols.com> Message-ID: <200807042113.02434.bob.paddock@gmail.com> On Friday 04 July 2008 03:07:47 pm Chuck Harris wrote: > > Well, yes. The Earth expands from the heat, rotation slows, > > and we get another leap second - as we watch symptom after > > symptom occur while being unable to come to consensus on > > what to do. > > I say that we take up the issue with the Sun. Clearly it is > also causing global warming on Mars. http://www.prisonplanet.com/articles/november2006/161106suvjupiter.htm "SUV's On Jupiter? Are humans responsible for climate change on the outer reaches of the solar system, or is it the sun?" -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ From hmurray at megapathdsl.net Fri Jul 4 23:46:47 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Fri, 04 Jul 2008 20:46:47 -0700 Subject: [time-nuts] New leap second Message-ID: <20080705034648.3B147BCCB@ip-64-139-1-69.sjc.megapath.net> tom.k3io at gmail.com said: > In case anyone is interested, here is the actual UT1-UTC data > produced by the group I headed for many years (until I > retired in 2001): Nice graphs. Thanks. What is cusaing the bumps? Why are they now big enough to see easily but much smaller a while ago. The first "big" one I see is mid 1998. There are some wiggles before then, but I wouldn't notice them unless I was looking carefully. -- These are my opinions, not necessarily my employer's. I hate spam. From gbusg at comcast.net Sat Jul 5 00:50:26 2008 From: gbusg at comcast.net (Greg Burnett) Date: Fri, 4 Jul 2008 22:50:26 -0600 Subject: [time-nuts] HP 113BR manual scanned References: Message-ID: <006701c8de5a$a4d9a8d0$6501a8c0@gb02> David, I forwarded your announcement to the same Agilent friend (who works at the Agilent U.S. Technical Call Center and who handled your 105A/B manual contribution). ...And I asked if Agilent is interested in manuals for the very old, rare items like the 113BR. I'll also ask if Agilent has an "official" "front-door" contact person for these manual scan contributions -- or if we should just keep forwarding them through him. I'll let you know what he says after he gets back from the holidays. Thanks again, Greg ----------------- David wrote: Another one from the old 36 foot NRAO telescope files - the HP 113BR analog clock unit. http://www.nixiebunny.com/hp113br.pdf Enjoy. Does anyone think Agilent is interested in a manual for something this old, or is this more of an HP Archives sort of boatanchor? I also have a 103AR manual to scan if anyone's interested in this ancient stuff. Let me know. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ From phk at phk.freebsd.dk Sat Jul 5 02:43:26 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Sat, 05 Jul 2008 06:43:26 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Your message of "Sat, 05 Jul 2008 13:01:36 +1200." <486EC7F0.10006@xtra.co.nz> Message-ID: <63011.1215240206@critter.freebsd.dk> In message <486EC7F0.10006 at xtra.co.nz>, Bruce Griffiths writes: >Poul-Henning Kamp wrote: >> Look at: >> http://phk.freebsd.dk/misc/L6/ >> >Nonsense, although it may work in favourable cases where the signal >levels arent too disparate, in the more general case this isnt true. Bruce, you are input-resistant, please read what I write: 1. I am not trying to solve the general case. 2. I am quite happy for it to work only in "favourable cases", because most people in the western hemisphere live close enough to a Loran-C for it to be a "favourable case". >Thats obviously fine for some Loran applications but you haven't >demonstrated that its also true when attempting to simultaneously track >another signal of interest that is relatively weak. Yes I have, but you seem to refuse to read it: http://phk.freebsd.dk/loran-c/CW/ >Thats only a 33 dB difference in signal level what happens when the >signal strengths differ by 60, 80 dB? Then we don't care to track them, because we will not be able to derive a sensible frequency signal from them. This is *not* an attempt to build a shiny complex, gold-plated contraption that can drag out a signal from half-way around the world in Hi-Fi quality, described as: >In which case a dedicated ST32M103 for Loran and another for >MSF/WWVB/JJYDCF77 etc is appropriate together with optimised analog >front ends, bandpass filters, notch filters and orientation of the >individual antennae to null strong interfering signals should cope with >most problematic sites. That's exactly all the stuff I'm trying to avoid. What I'll build is an References: <63011.1215240206@critter.freebsd.dk> Message-ID: <486F2166.4080907@xtra.co.nz> Poul-Henning Kamp wrote: > In message <486EC7F0.10006 at xtra.co.nz>, Bruce Griffiths writes: > >> Poul-Henning Kamp wrote: >> > > >>> Look at: >>> http://phk.freebsd.dk/misc/L6/ >>> >>> >> Nonsense, although it may work in favourable cases where the signal >> levels arent too disparate, in the more general case this isnt true. >> > > Bruce, you are input-resistant, please read what I write: > > 1. I am not trying to solve the general case. > > 2. I am quite happy for it to work only in "favourable cases", because > most people in the western hemisphere live close enough to a Loran-C > for it to be a "favourable case". > > >> Thats obviously fine for some Loran applications but you haven't >> demonstrated that its also true when attempting to simultaneously track >> another signal of interest that is relatively weak. >> > > Yes I have, but you seem to refuse to read it: > > http://phk.freebsd.dk/loran-c/CW/ > > That is restricted to the Loran-C case only. >> Thats only a 33 dB difference in signal level what happens when the >> signal strengths differ by 60, 80 dB? >> > > Then we don't care to track them, because we will not be able to > derive a sensible frequency signal from them. > > So how come NIST at WWVH in Hawaii still manges to do this then? > This is *not* an attempt to build a shiny complex, gold-plated contraption > that can drag out a signal from half-way around the world in Hi-Fi > quality, described as: > > In the case of LF transmissions you would have us believe that anyone beyond 500km (theoretical limit within which the DCF77 ground wave dominates according to the PTB- excludes Denmark) from the DCF77 transmitter hasnt any hope of usefully accurate (1E-9 or better) frequency comparisons against the received signal. This is not true as it has been achieved many times at various locations around the world. The phase tracking receivers of the 1960's had a sensitivity of 1uVrms or better. For example see the performance data for the HP117A in the October 1964 issue of the HP Journal. >> In which case a dedicated ST32M103 for Loran and another for >> MSF/WWVB/JJYDCF77 etc is appropriate together with optimised analog >> front ends, bandpass filters, notch filters and orientation of the >> individual antennae to null strong interfering signals should cope with >> most problematic sites. >> > > That's exactly all the stuff I'm trying to avoid. > > Most of this is optional, only use it if it is actually needed for successful carrier phase tracking at one's site. It is also relatively inexpensive in most cases, and easy to add if needed - the digital processing back end need not change although long averaging times may be required. If the system is split appropriately into 2 modules the analog front end and the DSP backend, customisation to suit a particular site is easy to do, > What I'll build is an discipline an OCXO or Rb against the strongest Loran-C signal > available. > > ... And make an excellent platform for experimenting with SDR > on other VLF time/frequency signals. > > Bruce From phk at phk.freebsd.dk Sat Jul 5 03:48:28 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Sat, 05 Jul 2008 07:48:28 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Your message of "Sat, 05 Jul 2008 19:23:18 +1200." <486F2166.4080907@xtra.co.nz> Message-ID: <1574.1215244108@critter.freebsd.dk> In message <486F2166.4080907 at xtra.co.nz>, Bruce Griffiths writes: >Poul-Henning Kamp wrote: >> http://phk.freebsd.dk/loran-c/CW/ >> >That is restricted to the Loran-C case only. You have not actually looked at that page have you ? Hint: "CW" is, as usually, used as an abbreviation for "Continous Wave". >>> Thats only a 33 dB difference in signal level what happens when the >>> signal strengths differ by 60, 80 dB? >> >> Then we don't care to track them, because we will not be able to >> derive a sensible frequency signal from them. >> >So how come NIST at WWVH in Hawaii still manges to do this then? I am happy tell you that NIST has taken great care to NOT inform me, that they want to replace their very expensive high-end gear with my In the case of LF transmissions you would have us believe that anyone >beyond 500km (theoretical limit within which the DCF77 ground wave >dominates according to the PTB- excludes Denmark) from the DCF77 >transmitter hasnt any hope of usefully accurate (1E-9 or better) >frequency comparisons against the received signal. I can get 1e-12 from DCF77, as long as I integrate for about a day. I can get 1e-14 from DCF77, as long as I integrate for about a year. Please don't argue any more until you understand that. >If the system is split appropriately into 2 modules the analog front end >and the DSP backend, customisation to suit a particular site is easy to do, If you had read what I wrote originally, you would have realized instantly that it is perfectly possible to use as complex an analog frontend as you want. The goal of my project is to use as simple a frontend as possible, and there is nothing you can say to persuade me to make it more complex than it needs to be. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From bruce.griffiths at xtra.co.nz Sat Jul 5 04:54:25 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 05 Jul 2008 20:54:25 +1200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <1574.1215244108@critter.freebsd.dk> References: <1574.1215244108@critter.freebsd.dk> Message-ID: <486F36C1.7080602@xtra.co.nz> Poul-Henning Kamp wrote: > In message <486F2166.4080907 at xtra.co.nz>, Bruce Griffiths writes: > >> Poul-Henning Kamp wrote: >> > > >>> http://phk.freebsd.dk/loran-c/CW/ >>> >>> >> That is restricted to the Loran-C case only. >> > > You have not actually looked at that page have you ? > Not for a few years anyway. > Hint: "CW" is, as usually, used as an abbreviation for "Continous Wave". > > > Plots without scales are not particularly useful. Given the relatively large field strength (>100uV/m ??) for DCF77 in Denmark perhaps a receiver with an optimised (for DCF77 or other LF station) front end can do better. >>>> Thats only a 33 dB difference in signal level what happens when the >>>> signal strengths differ by 60, 80 dB? >>>> >>> Then we don't care to track them, because we will not be able to >>> derive a sensible frequency signal from them. >>> >>> >> So how come NIST at WWVH in Hawaii still manges to do this then? >> > > I am happy tell you that NIST has taken great care to NOT inform > me, that they want to replace their very expensive high-end gear > with my > Their commercial?? VLF receiver uses a chart recorder and may need replacement eventually. > Likewise, I can inform you that I have neither the budget or level > of ambition of NIST in this area, wherefore a will track a couple of loud loran-C signals is plenty to make me > happy. > > As there is the option of adding a high performance front end and disabling the Loran-C code (where its not sensible/practical to use it), then there will be much wider interest in this. >> In the case of LF transmissions you would have us believe that anyone >> beyond 500km (theoretical limit within which the DCF77 ground wave >> dominates according to the PTB- excludes Denmark) from the DCF77 >> transmitter hasnt any hope of usefully accurate (1E-9 or better) >> frequency comparisons against the received signal. >> > > I can get 1e-12 from DCF77, as long as I integrate for about a day. > > Which perhaps indicates that the effect of the skywave interacting with the groundwave isn't too critical as long as you integrate for long enough. > I can get 1e-14 from DCF77, as long as I integrate for about a year. > > Given the frequency of European power blackouts and transmitter maintenance the latter integration period is perhaps a little impractical. > Please don't argue any more until you understand that. > > >> If the system is split appropriately into 2 modules the analog front end >> and the DSP backend, customisation to suit a particular site is easy to do, >> > > If you had read what I wrote originally, you would have realized instantly > that it is perfectly possible to use as complex an analog frontend as > you want. > > The goal of my project is to use as simple a frontend as possible, > and there is nothing you can say to persuade me to make it more > complex than it needs to be. > > Poul-Henning > > > Your original loop antenna should have a lower phase tempco (particularly if a lower TCE coil former than a plastic lid is used) than any ferrite antenna, particularly so if the antenna is resonated. Quartzlock have abandoned the use of ferrite antennas and substituted a balanced shielded loop antenna for this reason for their VLF phase tracking receivers. Bruce From phk at phk.freebsd.dk Sat Jul 5 05:24:14 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Sat, 05 Jul 2008 09:24:14 +0000 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: Your message of "Sat, 05 Jul 2008 20:54:25 +1200." <486F36C1.7080602@xtra.co.nz> Message-ID: <1939.1215249854@critter.freebsd.dk> In message <486F36C1.7080602 at xtra.co.nz>, Bruce Griffiths writes: >Given the relatively large field strength (>100uV/m ??) for DCF77 in >Denmark perhaps a receiver with an optimised (for DCF77 or other LF >station) front end can do better. I'm sure it can, but that is not the point of this project, as I have tried to explain N times now. >> I am happy tell you that NIST has taken great care to NOT inform >> me, that they want to replace their very expensive high-end gear >> with my > >Their commercial?? VLF receiver uses a chart recorder and may need >replacement eventually. I'll be happy to help them, should they call, my hourly rates are very reasonable. However, I'm sure they can find more competent assistence stateside. >As there is the option of adding a high performance front end and >disabling the Loran-C code (where its not sensible/practical to use it), >then there will be much wider interest in this. I'm not trying to get rich selling anything, so that doesn't give me any reason to make thing more complicated than they have to. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From GandalfG8 at aol.com Sat Jul 5 06:34:08 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Sat, 5 Jul 2008 06:34:08 EDT Subject: [time-nuts] HP 113BR manual scanned Message-ID: In a message dated 05/07/2008 05:51:17 GMT Daylight Time, gbusg at comcast.net writes: I'll also ask if Agilent has an "official" "front-door" contact person for these manual scan contributions -- or if we should just keep forwarding them through him. I'll let you know what he says after he gets back from the holidays. ---------------- Hi Greg Dave Cunningham was the original contact when Agilent started looking for older manuals in mid 2005, I don't know if he still is but I'm sure he could point you in the right direction. His email address, at the time anyway, was _dcunningham at agilent.com_ (mailto:dcunningham at agilent.com) regards Nigel GM8PZR From df6jb at ulrich-bangert.de Sat Jul 5 06:53:19 2008 From: df6jb at ulrich-bangert.de (Ulrich Bangert) Date: Sat, 5 Jul 2008 12:53:19 +0200 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: Message-ID: <0E09608675F04A77B56C8F5EA433F018@athlon> Mark, I hope you are using "Thick as a Brick" just in the way it is mormally used to characterize a person's qualities of mind and that you are NOT refering to Jethro Tull's famous record of the same name or are you? This fine piece of progressive Rock of the 70's is still on my top 100 list of alltime favourite records and is surely also enjoyed by other non-audiophiles all over the world. Otherwise the discussion reflects very well what's going on in my technician's heart concerning audiophile gadgets. Best regards Ulrich Bangert > -----Ursprungliche Nachricht----- > Von: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] Im Auftrag von Mark Sims > Gesendet: Samstag, 5. Juli 2008 01:03 > An: time-nuts at febo.com > Betreff: [time-nuts] Rb references for audiophiles? > > > > Bahhh, a TRUE audiophile has three H-masers. You just can't > trust your favorite recording of Thick as a Brick to a single > reference clock. You need a realtime thee-cornered hat > voter/selector to chose the best one. But masers do meet the > number one audiophile requirement of a having a glowing > vacuum tubey thingy. > > >What about a chain of E1T tubes? A lot nicer! ;) > > >And... why mess with noisy Rb references? A true audiophile has a > >H-maser, of course ;) > > > _________________________________________________________________ > Use video conversation to talk face-to-face with Windows Live > Messenger. > http://www.windowslive.com/messenger/connect_your_way.html?oci d=TXT_TAGLM_WL_Refresh_messenger_video_072008 _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From doug.parker at btinternet.com Sat Jul 5 07:15:22 2008 From: doug.parker at btinternet.com (Doug G4DZU) Date: Sat, 5 Jul 2008 12:15:22 +0100 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: <0E09608675F04A77B56C8F5EA433F018@athlon> Message-ID: Hi, I did better than hearing an Rb referenced audiophile recording of 'thick as a brick'. Jethro Tull were touring earlier this year on their 40th anniversary tour. For my aging ears, they were sonically fantastic, not too loud with excellent clarity. thanks Doug -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On Behalf Of Ulrich Bangert Sent: 05 July 2008 11:53 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Rb references for audiophiles? Mark, I hope you are using "Thick as a Brick" just in the way it is mormally used to characterize a person's qualities of mind and that you are NOT refering to Jethro Tull's famous record of the same name or are you? This fine piece of progressive Rock of the 70's is still on my top 100 list of alltime favourite records and is surely also enjoyed by other non-audiophiles all over the world. Otherwise the discussion reflects very well what's going on in my technician's heart concerning audiophile gadgets. Best regards Ulrich Bangert > -----Ursprungliche Nachricht----- > Von: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] Im Auftrag von Mark Sims > Gesendet: Samstag, 5. Juli 2008 01:03 > An: time-nuts at febo.com > Betreff: [time-nuts] Rb references for audiophiles? > > > > Bahhh, a TRUE audiophile has three H-masers. You just can't > trust your favorite recording of Thick as a Brick to a single > reference clock. You need a realtime thee-cornered hat > voter/selector to chose the best one. But masers do meet the > number one audiophile requirement of a having a glowing > vacuum tubey thingy. > > >What about a chain of E1T tubes? A lot nicer! ;) > > >And... why mess with noisy Rb references? A true audiophile has a > >H-maser, of course ;) > > > _________________________________________________________________ > Use video conversation to talk face-to-face with Windows Live > Messenger. > http://www.windowslive.com/messenger/connect_your_way.html?oci d=TXT_TAGLM_WL_Refresh_messenger_video_072008 _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From holrum at hotmail.com Sat Jul 5 07:34:43 2008 From: holrum at hotmail.com (Mark Sims) Date: Sat, 5 Jul 2008 11:34:43 +0000 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: References: Message-ID: Actually, both... if you happen to press PLAY on my car stereo, out would come Thick As A Brick. Flip it over (yes, I live in the Lands of the Obsolete, it is a cassette) and and you get Sounds From the Woods... Root around under the seats and you would find some Aqualung and who knows what else. I would tell you about my last Jethro Tull concert, but errr, uhhh I can't seem to remember. _________________________________________________________________ It?s a talkathon ? but it?s not just talk. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_JustTalk From holrum at hotmail.com Sat Jul 5 08:02:04 2008 From: holrum at hotmail.com (Mark Sims) Date: Sat, 5 Jul 2008 12:02:04 +0000 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: References: Message-ID: Oh, dear... now you have me thinking... I have that nifty little Symmetricom X72 rubidium oscillator... I have a rather old and frumpy cassette player... I have the technology... I can rebuild it... rubidium locked CD players are just so last year... rubidium locked turn tables are just so last week... I'm gonna be the first kid on the block with a rubidium locked cassette player (patent pending). And remember, rubidium oscillators have that number one audiosnobio requirement of the glowing vacuum tubey thingie. Unfortunately no little window to watch it flicker and glow. But trust me... it's in there. I am taking initial orders now. Deposit (non-refundable) of $100,000 or one active H-maser. Final price to be determined (if you have to ask, your sorry tin ears can't afford it). For maximum organic audio enjoyment it will require my DCC (double cotton covered) audio patch cables with the 25 karat pure unobtainium-235 RCA plugs. A steal at $50,000 per meter. ---------------------------------------- _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From wje at quackers.net Sat Jul 5 08:31:08 2008 From: wje at quackers.net (wje) Date: Sat, 05 Jul 2008 08:31:08 -0400 Subject: [time-nuts] Rb references for audiophiles? In-Reply-To: References: Message-ID: <486F698C.3080700@quackers.net> Here's a site that has some interesting analyses of some of the various topics covered in this wonderful thread: http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/Analog.html In particular, the advanced topics about halfway down the page have a detailed analysis of the real impact of skin effect. It's actually more that I thought it would be. Of course, it's still insignificant. Bill Ezell ---------- They said 'Windows or better' so I used Linux. Mark Sims wrote: > Oh, dear... now you have me thinking... I have that nifty little Symmetricom X72 rubidium oscillator... I have a rather old and frumpy cassette player... I have the technology... I can rebuild it... rubidium locked CD players are just so last year... rubidium locked turn tables are just so last week... I'm gonna be the first kid on the block with a rubidium locked cassette player (patent pending). And remember, rubidium oscillators have that number one audiosnobio requirement of the glowing vacuum tubey thingie. Unfortunately no little window to watch it flicker and glow. But trust me... it's in there. > > I am taking initial orders now. Deposit (non-refundable) of $100,000 or one active H-maser. Final price to be determined (if you have to ask, your sorry tin ears can't afford it). For maximum organic audio enjoyment it will require my DCC (double cotton covered) audio patch cables with the 25 karat pure unobtainium-235 RCA plugs. A steal at $50,000 per meter. > ---------------------------------------- > > _________________________________________________________________ > Use video conversation to talk face-to-face with Windows Live Messenger. > http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > From time-nuts at kasperkp.dk Sat Jul 5 10:28:54 2008 From: time-nuts at kasperkp.dk (Kasper Pedersen) Date: Sat, 05 Jul 2008 16:28:54 +0200 Subject: [time-nuts] Near-perfect chip for Loran-C frequency receiver In-Reply-To: <486F36C1.7080602@xtra.co.nz> References: <1574.1215244108@critter.freebsd.dk> <486F36C1.7080602@xtra.co.nz> Message-ID: <486F8526.70807@kasperkp.dk> Bruce Griffiths wrote: > Your original loop antenna should have a lower phase tempco > (particularly if a lower TCE coil former than a plastic lid is used) > than any ferrite antenna, particularly so if the antenna is resonated. > Quartzlock have abandoned the use of ferrite antennas and substituted a > balanced shielded loop antenna for this reason for their VLF phase > tracking receivers. > When I built a DCF77-DO (selective I/Q front end, the rest a software radio in an AVR), I ran into this problem of phase tempco. A loop was better, but it was unhandy, and I still had phase drift in the amplifiers, filters and mixer propagation delay. My fix was to have a tiny transmitter loop near the antenna (just the feeder cable termination resistor). Once in a while the microcontroller generates a 77.519kHz carrier, gets a phase measurement using the same frontend and I/Q mixer, and uses this for compensation. DCF77 does wiggle quite a bit at dawn, plus there is the occasional 1us phase adjustments at the transmitter end. http://n1.taur.dk/dcf/ (~100km NNW of PHK) I recall having seen better than this with Loran? /Kasper Pedersen From holrum at hotmail.com Sat Jul 5 16:34:28 2008 From: holrum at hotmail.com (Mark Sims) Date: Sat, 5 Jul 2008 20:34:28 +0000 Subject: [time-nuts] Thunderbolt observations In-Reply-To: References: Message-ID: I have modified my Thunderbolt data dumper program to be a (not ready for prime time) control program/ real time data grapher. A few initial observations: The PPS ns error number curve basically mirrors the DAC voltage curve... one goes up, the other goes down. The PPS error and DAC voltage curves show instantaneous discontinuities whenever the satellite constellation changes (which for me can be from a few to dozens of times per hour). The OSC ppb error number graph looks like spikey noise. The envelope basically tracks the DAC voltage curve. The temperature curve looks sine wavey (probably tracking air conditioning cycles). There are occasional (mayby a couple per hour) 50 millidegree or so instantaneous positive spikes in the data that then decay over 30 seconds back to the original smooth curve. These occur on all three units that I have (Rev 2.2 and 3.0 firmware, different types of power supplies on each one). A dozen or so self surveys produced latitude and longitude values spread over 0.00001 degrees (1 meter). The altitude values were spread over 7 meters. _________________________________________________________________ Making the world a better place one message at a time. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_BetterPlace From kc0vsj at yahoo.com Sat Jul 5 22:44:50 2008 From: kc0vsj at yahoo.com (Tom Clifton) Date: Sat, 5 Jul 2008 19:44:50 -0700 (PDT) Subject: [time-nuts] Thunderbolt Power Question Message-ID: <733196.28187.qm@web37001.mail.mud.yahoo.com> As I sit here reviewing the power requirements for the Thunderbolt, I note that the -12v is only 10ma. Does this indicate that it is only used for the RS232 output and if so for a battery backup I can "cheat" and only service the +12v (750ma)and +5v (400ma)? From ddabney01 at yahoo.com Sat Jul 5 22:48:03 2008 From: ddabney01 at yahoo.com (Richard Dabney) Date: Sat, 5 Jul 2008 19:48:03 -0700 (PDT) Subject: [time-nuts] TAPR now open for Thunderbolt orders Message-ID: <182285.39028.qm@web62509.mail.re1.yahoo.com> Hi John. The user name and password given do not work. I hope someone didn't screw it up. I would sure like to order one.....tnx.............de Dick W5UFZ From max at maxsmusicplace.com Sun Jul 6 00:16:17 2008 From: max at maxsmusicplace.com (Max Robinson) Date: Sat, 5 Jul 2008 23:16:17 -0500 Subject: [time-nuts] Rb references for audiophiles? References: Message-ID: <00f001c8df1f$09b81ba0$6401a8c0@BACKROOM> I seldom post but I am really enjoying this thread. I haven't laughed so much in months. Regards. Max. K 4 O D S. Email: max at maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscribe at yahoogroups.com ----- Original Message ----- From: "Mark Sims" To: Sent: Saturday, July 05, 2008 7:02 AM Subject: [time-nuts] Rb references for audiophiles? > > Oh, dear... now you have me thinking... I have that nifty little > Symmetricom X72 rubidium oscillator... I have a rather old and frumpy > cassette player... I have the technology... I can rebuild it... > rubidium locked CD players are just so last year... rubidium locked turn > tables are just so last week... I'm gonna be the first kid on the block > with a rubidium locked cassette player (patent pending). And remember, > rubidium oscillators have that number one audiosnobio requirement of the > glowing vacuum tubey thingie. Unfortunately no little window to watch it > flicker and glow. But trust me... it's in there. > > I am taking initial orders now. Deposit (non-refundable) of $100,000 or > one active H-maser. Final price to be determined (if you have to ask, > your sorry tin ears can't afford it). For maximum organic audio enjoyment > it will require my DCC (double cotton covered) audio patch cables with the > 25 karat pure unobtainium-235 RCA plugs. A steal at $50,000 per meter. > ---------------------------------------- > > _________________________________________________________________ > Use video conversation to talk face-to-face with Windows Live Messenger. > http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From d.seiter at comcast.net Sun Jul 6 03:06:37 2008 From: d.seiter at comcast.net (d.seiter at comcast.net) Date: Sun, 06 Jul 2008 07:06:37 +0000 Subject: [time-nuts] HP 113BR manual scanned Message-ID: <070620080706.21284.48706EFD000E9BD40000532422070009539D0A9B070A9CD20B@comcast.net> I have a 103AR I got about a year ago which doesn't oscillate. I got the manual scans from someone "out there", so it has been done, but is not widely available. Mine is a series of separate files, so a unified file might be useful to others in the future. -Dave -------------- Original message ---------------------- From: David Forbes > Another one from the old 36 foot NRAO telescope files - the HP 113BR > analog clock unit. > http://www.nixiebunny.com/hp113br.pdf > > Enjoy. > > Does anyone think Agilent is interested in a manual for something > this old, or is this more of an HP Archives sort of boatanchor? > > I also have a 103AR manual to scan if anyone's interested in this > ancient stuff. Let me know. > > -- > > --David Forbes, Tucson, AZ > http://www.cathodecorner.com/ > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From Arnold.Tibus at gmx.de Sun Jul 6 11:57:48 2008 From: Arnold.Tibus at gmx.de (Arnold Tibus) Date: Sun, 06 Jul 2008 17:57:48 +0200 Subject: [time-nuts] Thunderbolt and USB to RS232 converters Message-ID: Hello all Thunderbolt enthusiasts, I follow with great interest all the comments and remarks. I have as well a Thunderbolt and I am running it successfully since a few days under WinXP SP2 directly on Com1 and with several USB/RS232 converter I/Fs. Of course all the necessary drivers for my USB/Ser adapters (Prolific v. 2.0.0.18 and CH341PT.DLL & CH341SER.SYS from winchiphead.com/cn) are installed. Most of the day it runs with 6 to 8 satellites, the antenna not yet on the roof. Fortunately Trimble designed the I/F protocols quite straight in line and one can use some features of programs for other models which are not in Tboltmon.. I tried severals and found, beside - Tboltmon.exe (v2.60, Thunderboltmonitor program) as well very interesting and helpful : - DSPMon.exe (v1-53) DSP GPS Timing Monitor - TR_MON.exe Timing Receiver Monitor (the only one with instructiv help file) - trimblemon.exe (v1-06-0) Trimble GPS Monitor with instruction file as pdf explaining "Installing the FTDI USB/Serial Driver Software." "The new Trimble GPS Monitor (TGM) application is a tool that can replace many of the previous monitor and chat programs used for Trimble Embedded and Resolution T products." A nice gimmick is eg. the real time Google on line Sat map etc. Attention: I don't know if it is possible to upset the Thunderbolt with incorrect instructions uploaded, but I do not think so, pse do not make me responsible! Digging around I found a good helper for the ser. interface connection and setting problems: You do not know how to find the right com port setting? There is a way with 'Trimble GPS Monitor' v. 1.06.0 : it does run a test with all possible parameters on the selected port of the list. Connect the GPS RX to the desired Com Port eg. via an USB/RS232 converter, Start 'Trimble GPS Monitor 1.06.0 _07/2008 .exe' (no installation necessary), 'Initialize',: 'Detect Receiver', Select a COM Port out of the list, tick 'Protocols': 'TSIP' & 'Check even parities', follow instruction at 'Status' to start, start 1st com port and repeat it with next port no.until the program does report the successful detection of the GPS-Receiver showing port parameters of receiver. Accept to connect to it and start monitoring. In fact, the default parameters for Thunderbolt seem to be 9600-8-Odd-1. These parameters may then be modified under 'Configure', 'Receiver Configuration', 'Port Configuration' to eg. Parity 'None' (usual) and saved with 'Set and Save Configuration' into non volatile memory. Now you can exit this program and start 'Thunderbolt Monitor' (v. 2.60/1999), you are then asked to set the the now known port no (eg. 13), the program communication should start nominal. As I understand, once properly configured the Thunderbolt does run without the need of the PC, if the position is not changed. The Oscillator continue to run with the (last?) afc value stored in memory. The details for best configuration I don't know yet, I hope there will be more hints given by the experts here in the group. I keep watching ! I am running the TB with a prolific USB to Serial adapter (result: com9) and a cheap ftdi based USB2 adapter (com13) very smooth. Naturally it does work as well directly connected to the db9pin port com1 on the PC, always using a direct 1:1 wired 9p-9s connection and not a wire crossing (null modem) cable! I connected both USB/RS232 adapters simultaneously to my Laptop getting 3 free serial ports available for the GPS Receivers, com1, com9 and com14 (attention, the port numbers may change when plugging in and out, sometimes you may have to search for new devices). Thunderbolt Monitor does show all the assigned ports at the right side column for com ports 1 to 16. Clicking in the empty fields the assigned ports turn yellow (and remain on, the designated and selected GPS-port turns green. That way it is possible to run several GPS devices with different control software. I hope that I could help somebody with these small hints for the first steps. I find it a good idea to design some (small?) h/w to command the Thunderbolt without the need of a PC. good luck and fun experimenting, Thank you Tom and all the others involved here in the group buy of Thunderbolt together with the adequate power supply! regards, Arnold T. On Tue, 24 Jun 2008 16:56:45 +0200, Jeroen Bastemeijer wrote: >Dear All, >More and more people are starting to play with the Thunderbolts. I >already received mine :-) Now playing around with them. >First I powered it up and connected it to the normal serial port of the >PC. The Thunderbolt behaved fine, self survey took some time, because >the antenna is inside a concrete building with very limited view to the sky. >However, next I did a test with the same Thunderbolt but now it was >connected to a USB to Serial converter (brand is Sweex). After >switchinhg it off and on, I expected the same behaviour as when it was >connected to the "real" serial port. But... it started to behave very >strange... instead of starting a normal survey, it started disciplining >after a couple of minutes (almanac was not even valid). The DAC-voltage >clipped to the power rail, and the SV and AMU-fields remained "?". >Resetting (hot, cold, factory default) didn't make any difference. >When power cycling the unit and connecting it back to the normal serial >port the normal behaviour returned. I assume it has something to do with >the USB to serial converter. Is there anyone else with similar >experience? Or who has used a USB to serial converter with succes? >Thank you, best regards, >Jeroen >-- >Ing. Jeroen Bastemeijer >Delft University of Technology >Department of Electrical Engineering >Electronic Instrumentation Laboratory >Mekelweg 4, Room 13.090 >2628 CD Delft >The Netherlands >Phone: +31.15.27.86542 >Fax: +31.15.27.85755 >E-mail: J.Bastemeijer at TUDelft.nl >GPS: Lat N52.00002 Lon E4.37157 Alt 46.2m From daun at yeagley.net Sun Jul 6 12:54:39 2008 From: daun at yeagley.net (Daun Yeagley) Date: Sun, 6 Jul 2008 12:54:39 -0400 Subject: [time-nuts] TAPR now open for Thunderbolt orders In-Reply-To: <182285.39028.qm@web62509.mail.re1.yahoo.com> References: <182285.39028.qm@web62509.mail.re1.yahoo.com> Message-ID: <004401c8df88$fb5afe50$0c00a8c0@daundell> Hi Richard John is on vacation for a few more days, but my understanding is that they sold out pretty much that first day. (there was a HUGE response!) I suspect that's why the account info doesn't work now. Daun N8ASB -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Richard Dabney Sent: Saturday, July 05, 2008 10:48 PM To: time-nuts at febo.com Subject: [time-nuts] TAPR now open for Thunderbolt orders Hi John. The user name and password given do not work. I hope someone didn't screw it up. I would sure like to order one.....tnx.............de Dick W5UFZ _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From mctylr at gmail.com Sun Jul 6 13:50:54 2008 From: mctylr at gmail.com (michael taylor) Date: Sun, 6 Jul 2008 13:50:54 -0400 Subject: [time-nuts] Thunderbolt Power Question In-Reply-To: <733196.28187.qm@web37001.mail.mud.yahoo.com> References: <733196.28187.qm@web37001.mail.mud.yahoo.com> Message-ID: <25630a120807061050y259e6323h5f86afab17b913ff@mail.gmail.com> On Sat, Jul 5, 2008 at 10:44 PM, Tom Clifton wrote: > As I sit here reviewing the power requirements for the Thunderbolt, I note that the -12v is only 10ma. Does this indicate that it is only used for the RS232 output and if so for a battery backup I can "cheat" and only service the +12v (750ma)and +5v (400ma)? > I'm not sure, but it may be (also?) used for an op-amp as -Vs. From hmurray at megapathdsl.net Sun Jul 6 13:54:16 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Sun, 06 Jul 2008 10:54:16 -0700 Subject: [time-nuts] Thunderbolt and USB to RS232 converters In-Reply-To: Message from "Arnold Tibus" of "Sun, 06 Jul 2008 17:57:48 +0200." Message-ID: <20080706175418.16A68BCCB@ip-64-139-1-69.sjc.megapath.net> > I find it a good idea to design some (small?) h/w to command the > Thunderbolt without the need of a PC. Why? Is anything needed? What happens if you just apply power with no PC? I'd expect it would power up and self-survey and after a while, make a good clock. I'm pretty sure mine was working correctly before I got the software working. -- These are my opinions, not necessarily my employer's. I hate spam. From perseidjh at hotmail.com Sun Jul 6 14:16:56 2008 From: perseidjh at hotmail.com (Jim Hall) Date: Sun, 6 Jul 2008 12:16:56 -0600 Subject: [time-nuts] Thunderbolt Power Question In-Reply-To: <733196.28187.qm@web37001.mail.mud.yahoo.com> <25630a120807061050y259e6323h5f86afab17b913ff@mail.gmail.com> References: <733196.28187.qm@web37001.mail.mud.yahoo.com> <25630a120807061050y259e6323h5f86afab17b913ff@mail.gmail.com> Message-ID: The ThunderBoltBook2003 pdf manual Section 3.2 Table 3-1 page 3-4 states that the -12V is the "Prime Voltage for the OXCO". This seems to refute the common belief that the -12V is (only) for the RS232 interface. Jim Hall -------------------------------------------------- From: "michael taylor" Sent: Sunday, July 06, 2008 11:50 AM To: "Discussion of precise time and frequency measurement" Subject: Re: [time-nuts] Thunderbolt Power Question > On Sat, Jul 5, 2008 at 10:44 PM, Tom Clifton wrote: >> As I sit here reviewing the power requirements for the Thunderbolt, I >> note that the -12v is only 10ma. Does this indicate that it is only used >> for the RS232 output and if so for a battery backup I can "cheat" and >> only service the +12v (750ma)and +5v (400ma)? >> > > I'm not sure, but it may be (also?) used for an op-amp as -Vs. > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From cfharris at erols.com Sun Jul 6 14:46:46 2008 From: cfharris at erols.com (Chuck Harris) Date: Sun, 06 Jul 2008 14:46:46 -0400 Subject: [time-nuts] Thunderbolt and USB to RS232 converters In-Reply-To: <20080706175418.16A68BCCB@ip-64-139-1-69.sjc.megapath.net> References: <20080706175418.16A68BCCB@ip-64-139-1-69.sjc.megapath.net> Message-ID: <48711316.7020708@erols.com> Hal Murray wrote: >> I find it a good idea to design some (small?) h/w to command the >> Thunderbolt without the need of a PC. > > Why? Is anything needed? > > What happens if you just apply power with no PC? I'd expect it would power > up and self-survey and after a while, make a good clock. I'm pretty sure > mine was working correctly before I got the software working. It is designed to run just fine without operator intervention. The only problem, is it has no way of informing the user that it is actually working, other than through the RS-232 port. -Chuck Harris From bob.paddock at gmail.com Sun Jul 6 15:16:22 2008 From: bob.paddock at gmail.com (Bob Paddock) Date: Sun, 6 Jul 2008 15:16:22 -0400 Subject: [time-nuts] Thunderbolt and USB to RS232 converters In-Reply-To: References: Message-ID: On Sun, Jul 6, 2008 at 11:57 AM, Arnold Tibus wrote: > Hello all Thunderbolt enthusiasts, > Thunderbolt Monitor does show all the assigned ports at the right side > column for com ports 1 to 16. A tip for anyone that might be designing software. Don't put a fixed limit on the USB virtual COM ports like 1 to 16. Make a pull down that show what ports are really populated via the SetupDI API. The next new USB COM port I plug into my development machine is going to be assigned COM44! Anyone know where in the registry to reset the ever incrementing new COM number? -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ From holrum at hotmail.com Sun Jul 6 16:48:27 2008 From: holrum at hotmail.com (Mark Sims) Date: Sun, 6 Jul 2008 20:48:27 +0000 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: References: Message-ID: The Thunderbolt default config is to not save the survey position. Unless you use some software to save the position, every time you power it up it will do a new survey. This takes from 1 hour to several days to complete. After that you really don't need a controller except for peace of mind that it is working. Mayby once or twice a week I have noticed mine going into holdover mode because of really crappy satellite geometry and signal levels. Without a controller giving a realtime display you would never know your oscillator is undisciplined. A very minimal controller might be an AVR Butterfly. It only has a 6 character display and joyswitch. Rather not up to the task, but dirt cheap (around 20 bucks). It could display a minimal go/nogo type of indication. Best is a dedicated cheap old laptop. You can get them for 50 bucks or so with a 1024x768 full color screen, keyboard, and real serial port. I have a nice controller program in the works that displays full unit and satellite status, graphs the DAC voltage, temperature, OSC error, PPS error, and Allan variances. Allows you to control and configure the unit. Disadvantage is size. The Thunderbolt and power supply do fit nicely under a laptop and add an inch or so the the height. Next best is a dedicated controller based upon the MegaDonkey microcontroller or similar device. It has a 160x80 monochrome LCD with a touch screen and two real serial ports (see mega-donkey.com). Advantage is it allows the Thunderbolt/power supply/controller to be built into a single enclosure to make a stand-alone freq reference with enough display and user input resources to be quite useable. Disadvantage compared to a cheap laptop is cost and the small display. You would have to page though several display screens to get a full take on the unit status. Also the graphs would not be nearly as nice and there is not enough on-chip RAM to do ADEVs, etc. Once I get the laptop program done I'll probably do a controller on the MegaDonkey. > I find it a good idea to design some (small?) h/w to command the > Thunderbolt without the need of a PC. >>Why? Is anything needed? >>What happens if you just apply power with no PC? I'd expect it would power >>up and self-survey and after a while, make a good clock. I'm pretty sure >>mine was working correctly before I got the software working. _________________________________________________________________ Need to know now? Get instant answers with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_messenger_072008 From vogelchr at vogel.cx Sun Jul 6 17:07:58 2008 From: vogelchr at vogel.cx (Christian Vogel) Date: Sun, 06 Jul 2008 23:07:58 +0200 Subject: [time-nuts] Thunderbolt and USB to RS232 converters In-Reply-To: References: Message-ID: <4871342E.5060500@vogel.cx> Hi Bob, > A tip for anyone that might be designing software. Don't put a fixed limit > on the USB virtual COM ports like 1 to 16. Make a pull down that show > what ports are really populated via the SetupDI API. The next new USB > COM port I plug into my development machine is going to be assigned > COM44! > > Anyone know where in the registry to reset the ever incrementing > new COM number? > Control-Panel -> System -> Tab: Hardware -> Device Manager In the device manager, choose "View: Show hidden devices." The grayed out devices have once been, but are no longer, connected to your machine. Remove the ones that you no longer care about. You can also remap the comport-numbers in the properties of the serial port devices, use the button "Advanced..." there. These are the things that make me happy to be using Linux for most of my electronics stuff ;-)... Chris From billj at ieee.org Sun Jul 6 17:25:33 2008 From: billj at ieee.org (Bill Janssen) Date: Sun, 06 Jul 2008 14:25:33 -0700 Subject: [time-nuts] Austron 1250A manual archive? In-Reply-To: References: Message-ID: <4871384D.8000407@ieee.org> I have a manual for the Austron 1250A and have answered a couple of questions as to the schematics. I would like to loan my manual to some one that can scan it and make it available on the "NET" Anyone want that chore. I would want the manual returned after it was scanned. Bill K7NOM From had at to-way.com Sun Jul 6 18:34:37 2008 From: had at to-way.com (Had) Date: Sun, 06 Jul 2008 15:34:37 -0700 Subject: [time-nuts] Austron 1250A manual archive? In-Reply-To: <4871384D.8000407@ieee.org> References: <4871384D.8000407@ieee.org> Message-ID: <20080706223440.B8DF9119C39@mail-in03.adhost.com> Bill, I would be happy to do it and add it to the to-way.com T&F manual archive. Had, K7MLR At 02:25 PM 7/6/2008, you wrote: >I have a manual for the Austron 1250A and have answered a couple of >questions as to the > schematics. I would like to loan my manual to some one that can scan it >and make it available on the "NET" > >Anyone want that chore. I would want the manual returned after it was >scanned. > >Bill K7NOM > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From GandalfG8 at aol.com Sun Jul 6 18:35:38 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Sun, 6 Jul 2008 18:35:38 EDT Subject: [time-nuts] Austron 1250A manual archive? Message-ID: In a message dated 06/07/2008 22:26:29 GMT Daylight Time, billj at ieee.org writes: I have a manual for the Austron 1250A and have answered a couple of questions as to the schematics. I would like to loan my manual to some one that can scan it and make it available on the "NET" Anyone want that chore. I would want the manual returned after it was scanned. -------------------- Hi Bill, and All I have a scanned copy of the 1250A manual and will be uploading it to Didier's site shortly. regards Nigel GM8PZR From billj at ieee.org Sun Jul 6 19:10:49 2008 From: billj at ieee.org (Bill Janssen) Date: Sun, 06 Jul 2008 16:10:49 -0700 Subject: [time-nuts] Austron 1250A manual archive? In-Reply-To: References: Message-ID: <487150F9.6030408@ieee.org> GandalfG8 at aol.com wrote: > In a message dated 06/07/2008 22:26:29 GMT Daylight Time, billj at ieee.org > writes: > > I have a manual for the Austron 1250A and have answered a couple of > questions as to the > schematics. I would like to loan my manual to some one that can scan it > and make it available on the "NET" > > Anyone want that chore. I would want the manual returned after it was > scanned. > -------------------- > > > > Hi Bill, and All > > I have a scanned copy of the 1250A manual and will be uploading it to > Didier's site shortly. > > regards > > Nigel > GM8PZR > > > OK Forget my request as it is already in work. Thanks Nigel I will refer any future requests to Didier's site Bill K7NOM From GandalfG8 at aol.com Sun Jul 6 19:23:48 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Sun, 6 Jul 2008 19:23:48 EDT Subject: [time-nuts] Austron 1250A manual archive? Message-ID: In a message dated 07/07/2008 00:12:18 GMT Daylight Time, billj at ieee.org writes: OK Forget my request as it is already in work. Thanks Nigel I will refer any future requests to Didier's site Bill K7NOM ------ Hi Bill I'm having some "fun" uploading it right now but have just realised anyway that mine is a 1250 manual, not 1250A. I'm not sure what the differences are but it might still be well worth while you getting yours scanned, I'd certainly be interested in a copy. regards Nigel GM8PZR From bob.paddock at gmail.com Sun Jul 6 19:34:57 2008 From: bob.paddock at gmail.com (Bob Paddock) Date: Sun, 6 Jul 2008 19:34:57 -0400 Subject: [time-nuts] Thunderbolt and USB to RS232 converters In-Reply-To: <4871342E.5060500@vogel.cx> References: <4871342E.5060500@vogel.cx> Message-ID: > In the device manager, choose "View: Show hidden devices." The grayed > out devices have once been, but are no longer, connected to your > machine. Remove the ones that you no longer care about. You can also > remap the comport-numbers in the properties of the serial port devices, > use the button "Advanced..." there. I'm aware of those, but the next new USB serial device you plug in will still be the next higher number. It is the counter for this number I've not been able to locate. > These are the things that make me happy to be using Linux for most of my > electronics stuff ;-)... At this very moment I'm wearing a T-Shirt that says "Geek by Nature" on the front and "Linux by Choice" on the back. :-) It is only at the day job where IT told me "We are a Windows shop, Linux is nothing but a toy" that I'm forced to use Windows (Resume anyone?). Funny I thought we were a company that made Fire Fighting equipment, not a shop that made Windows... :-< -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ From bob.paddock at gmail.com Sun Jul 6 19:44:07 2008 From: bob.paddock at gmail.com (Bob Paddock) Date: Sun, 6 Jul 2008 19:44:07 -0400 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: References: Message-ID: > A very minimal controller might be an AVR Butterfly. It only has a 6 character display and > joyswitch. Rather not up to the task, There is the newer DB101 with the 128x64 bit map display. http://www.atmel.com/dyn/Products/tools_card.asp?tool_id=4221 I think they really did a botched job on the RS232 interface, but everything else is well buffered. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ From k4cso at charter.net Sun Jul 6 19:48:42 2008 From: k4cso at charter.net (Charles S. Osborne) Date: Sun, 6 Jul 2008 19:48:42 -0400 Subject: [time-nuts] Efratom LPRO Rubidium Message-ID: <004d01c8dfc2$d62bbfe0$7b01a8c0@pari.edu> I have one of the Lucent RFTGm-II-Rb Rubidium cell site standards. It's misbehaving. Knowing the amount of experience on this list, I figured I'd ask before I dive in much deeper where I have no schematics. Initially I believed one of the DC-DC converters was not working after warmup. But after remoting the voltages to test points, they seem to be OK. The system did suffer a lightning strike some years ago, which took out the UT+ GPS receiver in the RFTGm-II-XO. But that's working after the UT+ was replaced. And I doubt the interconnected circuits would have been affected. Power supply for instance was floated across 24VDC of gell cell batteries, which usually can absorb a lightning spike pretty well. The unit powers up about +200 Hz above 10 MHz (mine is modified to no longer put out 15 MHz). After 30 minutes it has dropped slowly to +150 Hz. It briefly shows an online indication then. But a few minutes later that goes off and the fault light comes on. The frequency drops as low as +129 Hz as things continue to heat up. A couple of days later its still in the +129 ~+149 Hz range. I can heat and cool it and move the frequency ( +157 Hz at 90?F inside the Lucent box, +129Hz at 110?F), so the loop definitely isn't in control. I also have its companion RFTGm-II-XO connected to it with the factory wiring harness. The XO is GPS locked and working fine exceeding my ability to read its error accurately but sub-milliHz. Counter is clocked by Z3801A 10 MHz as reference. Lucent diagnostic monitor software says "unit failed", "oscillator maintenance required". My question then, is there anything one can access that might be adjusted to bring the OCXO back within capture range? +140 Hz seems way beyond where it should be. I thought the OCXO tuning range on something like this was normally +/- a few Hz. The unit is circa 1999 vintage. Low mileage, probably has two years online time to date (so likley not an Rb lamp problem). When I bought it, it was new in the box and still in warranty, victim of a cell site buildup deal gone bust and surplused out. At one time the two units would back each other up, switching from one to the other once as they warmed up. Anything user servicable in the LPRO? I assume a trip to the real service center would cost as much as a good used car. So if its something I can't correct, it'll become a dissection learning experience. One final test I haven't run, is removing the LPRO and powering it up stand alone, just in case the C field input is the problem. I assume it should be capable of locking with those inputs floating if the LPRO is indeed OK? Anyone know what: BITE (Built in Test?), Xtal Mon, Lamp volt, and C-Field should be normally? Thanks, Charles Osborne, K4CSO Duluth, GA From kc0vsj at yahoo.com Sun Jul 6 20:41:37 2008 From: kc0vsj at yahoo.com (Tom Clifton) Date: Sun, 6 Jul 2008 17:41:37 -0700 (PDT) Subject: [time-nuts] Thunderbolt Power Question Message-ID: <190082.52492.qm@web37006.mail.mud.yahoo.com> As the requirement is for a few milliamps it appears that All Electgonics has an inexpensive DC DC converter http://www.allelectronics.com/make-a-store/item/DC-32/DC-DC-CONVERTER/-/1.html that runs off of +5v. All I have to do is to run the -19v output throught a negative regualtor and its a done deal. From smace at intt.net Mon Jul 7 00:14:03 2008 From: smace at intt.net (Scott Mace) Date: Sun, 06 Jul 2008 23:14:03 -0500 Subject: [time-nuts] Fury ntp refclock Message-ID: <4871980B.3090503@intt.net> I've created a ntpd refclock driver for the Fury GPS receiver. The refclock is based on the NMEA driver. http://www.intt.net/time-nuts/ntp-fury.diff The driver was created because the Fury does not fully implement the ptime:tcode? T2 string. The output is not on-time and the status fields are always 0. So, it is not going to work with the hpgps refclock. As it turns out the T2 string is rather limiting anyways. Fortunately, the Fury supports a partial NMEA mode, where it will emit on-time $GPGGA sentences. The driver then probes the Fury for other statistics using the GPS? SYNC? DIAG? and MEAS? commands. Also the driver will check for leap second warnings. The stats are concisely output to clockstats. Some logic for handling holdover thresholds and to detect if the Fury is unlocked has been added. flag3 logs the stats, flag4 logs the gpgga sentences output from Fury OEM SMA connector version w/ LPRO-101 54654 13857.011 127.127.45.0 68 1 0 0 2.65e-12 2.10e-09 44.50 1.992863 0.000004 10.53 7 7 1 41 -1 54654 13867.010 127.127.45.0 68 1 0 0 2.67e-12 2.20e-09 44.50 1.993594 0.000004 10.53 7 7 1 41 10 54654 13877.011 127.127.45.0 68 1 0 0 2.99e-12 2.20e-09 44.50 1.993680 0.000004 10.53 7 7 1 41 -13 54654 13887.013 127.127.45.0 68 1 0 0 2.83e-12 2.10e-09 44.50 1.993442 0.000004 10.53 7 7 1 41 -4 lifetime ppslock holdduration holdover fee tint temp efc ocxocurrent ocxovolt sat_vis sat_track pulsestat pulseacc pulsesaw sample ntp.conf: server 127.127.45.0 prefer minpoll 4 maxpoll 4 fudge 127.127.45.0 time1 0.012 #115200 #fudge 127.127.45.0 time1 0.024 #57600 fudge 127.127.45.0 flag3 1 #fudge 127.127.45.0 flag4 1 server 127.127.22.0 minpoll 4 maxpoll 4 tos mindist 0.010 statsdir /var/log/ statistics loopstats peerstats clockstats filegen loopstats file loopstats type day enable filegen peerstats file peerstats type day enable filegen clockstats file clockstats type day enable Scott From hmurray at megapathdsl.net Mon Jul 7 01:51:07 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Sun, 06 Jul 2008 22:51:07 -0700 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: Message from Mark Sims of "Sun, 06 Jul 2008 20:48:27 -0000." Message-ID: <20080707055108.D106EBCCB@ip-64-139-1-69.sjc.megapath.net> > A very minimal controller might be an AVR Butterfly. It only has a 6 > character display and joyswitch. Rather not up to the task, but dirt > cheap (around 20 bucks). It could display a minimal go/nogo type of > indication. Do you actually need a display? How about a LED or 3. My straw man is: off - no power on - OK blink - trouble You can convey a few bits of information with only one LED. Just encode a small integer in the number of blinks. Code 3 would go: blink, blink, blink, pause bling, blink, blink, ... Yes, it's fun to show more information, but if you really want to see more, you probably want to collect that data so you can track things over weeks or months, and you probably have a PC already doing that. -- These are my opinions, not necessarily my employer's. I hate spam. From david at smithfamily.net.au Mon Jul 7 02:10:35 2008 From: david at smithfamily.net.au (David Smith) Date: Mon, 07 Jul 2008 16:10:35 +1000 Subject: [time-nuts] Thunderbolt and USB to RS232 converters In-Reply-To: References: Message-ID: <4871B35B.2040508@smithfamily.net.au> > >> In the device manager, choose "View: Show hidden devices." The grayed >> out devices have once been, but are no longer, connected to your >> machine. Remove the ones that you no longer care about. You can also >> remap the comport-numbers in the properties of the serial port devices, >> use the button "Advanced..." there. > > I'm aware of those, but the next new USB serial device you plug in will > still be the next higher number. It is the counter for this number I've > not been able to locate. > I've just sorted this problem on another thing I was doing, although I was only up to COM14! It seems there are "hidden" hidden devices. Have a look at this: http://support.microsoft.com/kb/315539 So once you clean out the hidden devices and the hidden, hidden devices, then you can remap your USB Com port back to COM3 or whatever, and it'll stay there! Note that even plugging the same USB-RS232 converter into another USB port on a hub will create a "new" COM port. Regards, Dave VK3HZ From namichie at gmail.com Mon Jul 7 02:59:14 2008 From: namichie at gmail.com (Neville Michie) Date: Mon, 7 Jul 2008 16:59:14 +1000 Subject: [time-nuts] Thunderbolt Controllers Message-ID: <138E5863-90B6-48B4-850D-B91B4A783235@gmail.com> On the topic of minimum hardware to use a TBolt, I am interested in observing clock pendulums. WWV is a long way from Australia and only available with good propagation. A GPS receiver will give accurate seconds signals, even if there is some jitter, however it is not easy to identify which second. In the course of a year it is quite believable that a counter may gain or lose one count, what with lightning strikes etc. Minute markers would be sufficient, any clock that can not tell you which minute in the year it is, is not worth observing. The GPS may drop out, so a disciplined oscillator is in order, but how can you get the GPS signals parsed to identify say minute markers without running a computer? All I need is black box which gives seconds pulses and a beep every minute. With a small 4 channel data logger I can then record a clock for a year and its relationship to UTC, temperature and barometric pressure. I would only need a battery backup power supply for the TBolt. cheers, Neville Michie From hmurray at megapathdsl.net Mon Jul 7 04:01:11 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 07 Jul 2008 01:01:11 -0700 Subject: [time-nuts] Thunderbolt Controllers In-Reply-To: Message from Neville Michie of "Mon, 07 Jul 2008 16:59:14 +1000." <138E5863-90B6-48B4-850D-B91B4A783235@gmail.com> Message-ID: <20080707080112.07A56BCCA@ip-64-139-1-69.sjc.megapath.net> > The GPS may drop out, so a disciplined oscillator is in order, but > how can you get the GPS signals parsed to identify say minute markers > without running a computer? There are lots of 8 bit micros that are smart enough to parse the stuff from a TBolt and wiggle a few pins. You have to be happy writing that sort of software. > With a small 4 channel data logger I can then record a clock for a > year and its relationship to UTC, temperature and barometric pressure. > I would only need a battery backup power supply for the TBolt. What are you going to record? How often? What triggers a recording? If you log things with a PC, then it's pretty simple to make your PC track UTC so all you have to do is add a time stamp to each record. Or if your data logger has time but that time isn't good enough, you could make the PC wiggle a pin on the printer port occasionally and make that trigger a recording on the data logger. You would either do it at known times (say top of the hour), or get the PC to record when it does it so you can sort things out later on. -- These are my opinions, not necessarily my employer's. I hate spam. From hmurray at megapathdsl.net Mon Jul 7 04:22:41 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 07 Jul 2008 01:22:41 -0700 Subject: [time-nuts] Efratom LPRO Rubidium In-Reply-To: Message from "Charles S. Osborne" of "Sun, 06 Jul 2008 19:48:42 EDT." <004d01c8dfc2$d62bbfe0$7b01a8c0@pari.edu> Message-ID: <20080707082242.54BD9BCCA@ip-64-139-1-69.sjc.megapath.net> > The unit powers up about +200 Hz above 10 MHz (mine is modified to no > longer put out 15 MHz). After 30 minutes it has dropped slowly to +150 > Hz. It briefly shows an online indication then. But a few minutes > later that goes off and the fault light comes on. The frequency drops > as low as +129 Hz as things continue to heat up. A couple of days > later its still in the +129 ~+149 Hz range. I can heat and cool it and > move the frequency ( +157 Hz at 90?F inside the Lucent box, +129Hz at > 110?F), so the loop definitely isn't in control. My LPRO is 4 or 5 milli Hz high. I can't see any changes with temperature and my setup swings through 15 F p-p during most days. That's with the electrical tuning open and no adjustments to the mechanical tuning. I couldn't find any specs for the mechanical or electrical tuning range in the data sheet. Has anybody measured it? -- These are my opinions, not necessarily my employer's. I hate spam. From namichie at gmail.com Mon Jul 7 05:42:12 2008 From: namichie at gmail.com (Neville Michie) Date: Mon, 7 Jul 2008 19:42:12 +1000 Subject: [time-nuts] Thunderbolt Controllers In-Reply-To: <20080707080112.07A56BCCA@ip-64-139-1-69.sjc.megapath.net> References: <20080707080112.07A56BCCA@ip-64-139-1-69.sjc.megapath.net> Message-ID: My pendulum produces pulses at a rate of one per second. That signal clocks a latch that samples the less significant bits of my reference oscillator (100kHz or 1MHz) in a counter. The latched values drive a 12 bit D-A converter (a R - 2R chain). So I have a phase signal updated every second, and which resolves 10 or 100 microseconds. The data logger samples this every 10 seconds or so and so logs a graph of drifting phase. The data from the logger can then be used in a spread sheet to analyse periodicity of fluctuations and correlation to barometric pressure and temperature. When barometric pressure and temperature are successfully eliminated by compensating the pendulum, I hope to only have planetary resonances, gravity tides and noise disturbing my clock. Currently I have a 1MHz OCXO driving the system, but it drifts significantly. This is a home brew oven, running at about 40*C, consuming about 250mW, quite easy to back up with a 12V battery. The HOBO data logger has 4 inputs of 0 - 2.5 volts and 12 bit resolution, and it runs for 4 years on a lithium cell. It takes a lot more power to run a computer, and then you have to reboot after each power interruption, and so I have not found it worth while to get a machine just for the project. But the overall check of the system is to compare clock time with UTS once in a while to cover the chance of slipped seconds. At the present time I use WWV when I can find it, but what I would really like is a clock showing UTS in a form that can be compared to a clock. That means one second audible pips and a marker on the minute. Just seeing numbers rolling over on a computer is not good enough to check the timing of the second hand of the clock. You need ear - eye coordinated signals. With WWV I can compare to 1/20th of a second. Although I have programmed systems in a variety of languages in my working life, the only languages that have stuck are Fortran and Basic. All the rest are forgotten after a year or two. I do not wish to start again to learn a new system just for one task, and it is obvious that there are so many micros abroad and none of them is going to be universally useful for future tasks. cheers, Neville Michie On 07/07/2008, at 6:01 PM, Hal Murray wrote: > >> The GPS may drop out, so a disciplined oscillator is in order, but >> how can you get the GPS signals parsed to identify say minute markers >> without running a computer? > > There are lots of 8 bit micros that are smart enough to parse the > stuff from > a TBolt and wiggle a few pins. You have to be happy writing that > sort of > software. > > > >> With a small 4 channel data logger I can then record a clock for a >> year and its relationship to UTC, temperature and barometric >> pressure. >> I would only need a battery backup power supply for the TBolt. > > What are you going to record? How often? What triggers a recording? > > If you log things with a PC, then it's pretty simple to make your > PC track > UTC so all you have to do is add a time stamp to each record. > > Or if your data logger has time but that time isn't good enough, > you could > make the PC wiggle a pin on the printer port occasionally and make > that > trigger a recording on the data logger. You would either do it at > known > times (say top of the hour), or get the PC to record when it does > it so you > can sort things out later on. > > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. From df6jb at ulrich-bangert.de Mon Jul 7 07:41:41 2008 From: df6jb at ulrich-bangert.de (Ulrich Bangert) Date: Mon, 7 Jul 2008 13:41:41 +0200 Subject: [time-nuts] Efratom LPRO Rubidium In-Reply-To: <20080707082242.54BD9BCCA@ip-64-139-1-69.sjc.megapath.net> Message-ID: <92591CE6A32A45E78F04283092BC2903@athlon> Hal, > My LPRO is 4 or 5 milli Hz high. I can't see any changes > with temperature and my setup swings through 15 F p-p > during most days. The TC of a LPRO is in the order of -7E-13 / Deg C or even less. That is why you see no changes: They are there but a bit beyond most measurement capabilities. Best regards Ulrich > -----Urspr?ngliche Nachricht----- > Von: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] Im Auftrag von Hal Murray > Gesendet: Montag, 7. Juli 2008 10:23 > An: Discussion of precise time and frequency measurement > Betreff: Re: [time-nuts] Efratom LPRO Rubidium > > > > > The unit powers up about +200 Hz above 10 MHz (mine is > modified to no > > longer put out 15 MHz). After 30 minutes it has dropped > slowly to +150 > > Hz. It briefly shows an online indication then. But a few minutes > > later that goes off and the fault light comes on. The > frequency drops > > as low as +129 Hz as things continue to heat up. A couple of days > > later its still in the +129 ~+149 Hz range. I can heat and > cool it and > > move the frequency ( +157 Hz at 90?F inside the Lucent box, > +129Hz at > > 110?F), so the loop definitely isn't in control. > > My LPRO is 4 or 5 milli Hz high. I can't see any changes > with temperature > and my setup swings through 15 F p-p during most days. > > That's with the electrical tuning open and no adjustments to > the mechanical > tuning. > > > I couldn't find any specs for the mechanical or electrical > tuning range in > the data sheet. Has anybody measured it? > > > > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts > and > follow the instructions there. > From jra at febo.com Mon Jul 7 09:18:23 2008 From: jra at febo.com (John Ackermann N8UR) Date: Mon, 07 Jul 2008 09:18:23 -0400 Subject: [time-nuts] TAPR now open for Thunderbolt orders In-Reply-To: <182285.39028.qm@web62509.mail.re1.yahoo.com> References: <182285.39028.qm@web62509.mail.re1.yahoo.com> Message-ID: <4872179F.7050405@febo.com> Hi Richard -- At the moment we're not taking orders as the demand has outstripped the supply. If -- and there's not much likelihood of this -- we end up having any available, we will first notify those who've already tried to order but were put on hold, and if any are left after that, there will be a notice posted here. But, everyone, please -- don't bother the TAPR office asking if/when there will be more available. There will be a posting here if that happens. John ---- Richard Dabney said the following on 07/05/2008 10:48 PM: > Hi John. The user name and password given do not work. I hope someone didn't screw it up. I would sure like to order one.....tnx.............de Dick W5UFZ > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From holrum at hotmail.com Mon Jul 7 10:59:54 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 7 Jul 2008 14:59:54 +0000 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: References: Message-ID: Yeah, you really do need a display... this is the 21st century... monkeys got better things to do than count blinkenlights (or read a message scrolling across a six character LCD). You need a processor of some sort to decode the TSIP messages. It actually takes a significant amount of code to do it right, so you need a fairly decent one (you could cram it into a small PIC with assembly language, but monkeys got better things to do than all that tedious mucking around in PICspace). Once you have a processor that you can program in a decent language, interfacing it to some sort of LCD display module is rather trivial. Then it can clearly and distinctly tell you the reason your oscillator has gone wobbly. Even a simple two line text display is orders of magnitude better than any blinkenlight. I got 46 seconds of holdover last night. It happened when the two satellites it was tracking got into a bad PDOP/low signal situation and the receiver had to scramble to find something less garbagey to track. That explained that 50ns phase shift in the cesium reference data. It also went through a period of rather high PPS offset (over 20ns, instead of the typical Do you actually need a display? > > How about a LED or 3. My straw man is: > off - no power > on - OK > blink - trouble > > You can convey a few bits of information with only one LED. Just encode a > small integer in the number of blinks. Code 3 would go: > blink, blink, blink, pause > bling, blink, blink, ... > > > Yes, it's fun to show more information, but if you really want to see more, > you probably want to collect that data so you can track things over weeks or > months, and you probably have a PC already doing that. > _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From bruceraymond at ameritech.net Mon Jul 7 11:07:57 2008 From: bruceraymond at ameritech.net (Bruce Raymond) Date: Mon, 07 Jul 2008 11:07:57 -0400 Subject: [time-nuts] Thunderbolt Controllers In-Reply-To: References: <20080707080112.07A56BCCA@ip-64-139-1-69.sjc.megapath.net> Message-ID: <4872314D.5090008@ameritech.net> Hi Neville, As a thought, you might want to look at a Basic Stamp from Parallax. These are PIC chips (at least they used to be) coupled with an EEPROM and are programmed in BASIC. Here's a site for some additional data - http://www.parallax.com/Default.aspx?tabid=295 Regards, Bruce Raymond Neville Michie wrote: > My pendulum produces pulses at a rate of one per second. > That signal clocks a latch that samples the less significant bits of > my reference oscillator (100kHz or 1MHz) > in a counter. > The latched values drive a 12 bit D-A converter (a R - 2R chain). > So I have a phase signal updated every second, and which resolves 10 > or 100 microseconds. > The data logger samples this every 10 seconds or so and so logs a > graph of drifting phase. > The data from the logger can then be used in a spread sheet to > analyse periodicity > of fluctuations and correlation to barometric pressure and temperature. > When barometric pressure and temperature are successfully eliminated > by compensating > the pendulum, I hope to only have planetary resonances, gravity tides > and noise disturbing my clock. > Currently I have a 1MHz OCXO driving the system, but it drifts > significantly. > This is a home brew oven, running at about 40*C, consuming about > 250mW, quite easy to > back up with a 12V battery. > The HOBO data logger has 4 inputs of 0 - 2.5 volts and 12 bit > resolution, and it runs > for 4 years on a lithium cell. > It takes a lot more power to run a computer, and then you have to > reboot after each power > interruption, and so I have not found it worth while to get a machine > just for the project. > > But the overall check of the system is to compare clock time with UTS > once in a while > to cover the chance of slipped seconds. At the present time I use WWV > when I can find it, > but what I would really like is a clock showing UTS in a form that > can be compared to a clock. > That means one second audible pips and a marker on the minute. Just > seeing numbers > rolling over on a computer is not good enough to check the timing of > the second hand of > the clock. You need ear - eye coordinated signals. With WWV I can > compare to 1/20th of a second. > > Although I have programmed systems in a variety of languages in my > working life, the only > languages that have stuck are Fortran and Basic. All the rest are > forgotten after a year or two. > I do not wish to start again to learn a new system just for one task, > and it is obvious that there > are so many micros abroad and none of them is going to be universally > useful for future tasks. > > cheers, Neville Michie > > From hmurray at megapathdsl.net Mon Jul 7 14:40:43 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 07 Jul 2008 11:40:43 -0700 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: Message from Mark Sims of "Mon, 07 Jul 2008 14:59:54 -0000." Message-ID: <20080707184044.0DF68BCCA@ip-64-139-1-69.sjc.megapath.net> > Yeah, you really do need a display... this is the 21st century... > monkeys got better things to do than count blinkenlights (or read a > message scrolling across a six character LCD). A simple blinking LED is handy to alert you that there is a problem. I was probably assuming that you already had a PC setup to log stuff and that you would go look there if you wanted to know what the problem was. About 25 years ago, I worked on a system that used the hack of unary encoding small integers in a blinking LED. That was before small LCDs were inexpensive and readily available. It worked. Yes, it's not great. It (or something similar) might be useful today if you were trying to avoid adding a LCD. -- These are my opinions, not necessarily my employer's. I hate spam. From Arnold.Tibus at gmx.de Mon Jul 7 15:00:54 2008 From: Arnold.Tibus at gmx.de (Arnold Tibus) Date: Mon, 07 Jul 2008 21:00:54 +0200 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: Message-ID: Sorry, I don't like to contradict, but I have different experiences made concerning some statements: On Sun, 6 Jul 2008 20:48:27 +0000, Mark Sims wrote: >The Thunderbolt default config is to not save the survey position. Unless you use some software to save the position, every time you power it up it will do a new survey. This takes from 1 hour to several days to > complete. [...] How that? My Thunderbolt does no self surveying after switch on and does recover in a few minutes, here my report. If I disconnect the antenna and reconnect a few min. later or I disconnect the pwr fully from my Thunderbolt device, let it cool down for about 15 min, after reconnecting Thundertbolt restarts the internal recovery procedure autonomously with my saved position in the EEPROM. the major steps: mode: power up, activity: inactive for about 60 seconds date and time show up, then, mode: power up, activity: osc warm up terminating after 2 min 15 sec then does start the recovery loop function filter init performing after around 3 min 15 sec. recovery loop and filter init ready after 3 min 20 sec. Thunderbolt does work then fully locked and is disciplining again, working nominal, just the almanac alarm is still on for some minutes more. mode (0) normal activity (0) phase locking self survey process 0% it was at no time executed I am running rcvr mode (7) overdet. clock (time) GPS status (0) doing fixes After I had once determined my exact antenna position several times with the self survey function (try a value of more than 2000, perhaps 5000 fixes) I stored this value in 'setup', 'position' as 'accurate position' and did save by klicking 'save segment'. I don't know if it is of importance in this context, I did set the self surveying parameters 'self survey enable' ticked to 'enable' and 'save position flag' to 'don't save'. In this window you can modify the survey length of 2000 fixes (default value). A few minutes later the oscillator is working at about the full precision... > After that you really don't need a controller except for peace of mind that it is working. Mayby once or twice a week I have noticed mine going into holdover mode because of really crappy satellite geometry and signal levels. Without a controller giving a realtime display you would never know your oscillator is undisciplined. I do contemplate with a small control panel, because it is time to think about, that consuming just 100 W during the year does result in 2.4 kWh times 365 equal 876 kWh (not far from 1 MWh!). A few watts shall suffice. And I do not want to take always the Laptop with we (I would need severals). The Laptop or PC shall only be necessary for more detailed setup and control. Such a control panel should me enable to read date and time, the actual coordinates, the DAC-Voltage, the most important warning flags, the correct sat reception, the pps tick and if the oscillator is correctly disciplined. The display may be a 4 line LCD, swapped pages if necessary, together with a few LEDs (blinking or not). As a wish I would like to have the discipline function, fast recovery, man. holdover and restart self survey switchable. >A very minimal controller might be an AVR Butterfly. It only has a 6 character display and joyswitch. Rather not up to the task, but dirt cheap (around 20 bucks). It could display a minimal go/nogo type of indication. >Best is a dedicated cheap old laptop. You can get them for 50 bucks or so with a 1024x768 full color screen, keyboard, and real serial port. I have a nice controller program in the works that displays full unit and satellite status, graphs the DAC voltage, temperature, OSC error, PPS error, and Allan variances. Allows you to control and configure the unit. Disadvantage is size. The Thunderbolt and power supply do fit nicely under a laptop and add an inch or so the the height. >Next best is a dedicated controller based upon the MegaDonkey microcontroller or similar device. It has a 160x80 monochrome LCD with a touch screen and two real serial ports (see mega-donkey.com). Advantage is it allows the Thunderbolt/power supply/controller to be built into a single enclosure to make a stand-alone freq reference with enough display and user input resources to be quite useable. Disadvantage compared to a cheap laptop is cost and the small display. You would have to page though several display screens to get a full take on the unit status. Also the graphs would not be nearly as nice and there is not enough on-chip RAM to do ADEVs, etc. Once I get the laptop program done I'll probably do a controller on the MegaDonkey. >> I find it a good idea to design some (small?) h/w to command the >> Thunderbolt without the need of a PC. >>>Why? Is anything needed? >>>What happens if you just apply power with no PC? I'd expect it would power >>>up and self-survey and after a while, make a good clock. I'm pretty sure >>>mine was working correctly before I got the software working. As I reported already, Thunderbold seem to restart perfectly alone once set properly, until I get a problem.... I have no real control over it, no information about, and for portable use I need always a PC. Did I forget or misunderstand something (I am sure about)? I still do not understand all the details for best setup to optimize the stability... Regards Arnold T. From hmurray at megapathdsl.net Mon Jul 7 15:21:29 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 07 Jul 2008 12:21:29 -0700 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: Message from "Arnold Tibus" of "Mon, 07 Jul 2008 21:00:54 +0200." Message-ID: <20080707192130.9D797BCCA@ip-64-139-1-69.sjc.megapath.net> > As I reported already, Thunderbold seem to restart perfectly alone > once set properly, until I get a problem.... I have no real control > over it, no information about, and for portable use I need always a > PC. I think portable is quite different from stationary. If you move it, you have to tell it the new location or let it do a self-survey. You don't need a PC if you don't store the location in the EEPROM. All you have to do is power off for a while and it will do a self-survey when you turn it back on. That covers the moved case at the disadvantage of a long delay if you didn't move it. -- These are my opinions, not necessarily my employer's. I hate spam. From ne8s at earthlink.net Mon Jul 7 15:58:04 2008 From: ne8s at earthlink.net (NE8S) Date: Mon, 7 Jul 2008 14:58:04 -0500 Subject: [time-nuts] HP 5087A Input Doubler and 10 MHz Ampifiers Needed Message-ID: <003e01c8e06b$c508a620$0e01a8c0@HITACHI> Greetings, all, I am in need of the following Opt PCB's for the HP 5087A: Qty. 3 5087-60011 (5 MHz to 10 MHz Doubler) Qty. 11 5087-60012 (10 MHz Amplfiers) Any spares out there? Please pass the word. TNX Doc NE8S From Arnold.Tibus at gmx.de Mon Jul 7 16:00:43 2008 From: Arnold.Tibus at gmx.de (Arnold Tibus) Date: Mon, 07 Jul 2008 22:00:43 +0200 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: <20080707192130.9D797BCCA@ip-64-139-1-69.sjc.megapath.net> Message-ID: On Mon, 07 Jul 2008 12:21:29 -0700, Hal Murray wrote: >> As I reported already, Thunderbold seem to restart perfectly alone >> once set properly, until I get a problem.... I have no real control >> over it, no information about, and for portable use I need always a >> PC. >I think portable is quite different from stationary. >If you move it, you have to tell it the new location or let it do a >self-survey. >You don't need a PC if you don't store the location in the EEPROM. All you >have to do is power off for a while and it will do a self-survey when you >turn it back on. That covers the moved case at the disadvantage of a long >delay if you didn't move it. Agreed. But with portable I mean to move between different but known locations, even in my own home, or in a friends home etc. Clear, I have to enter the new position parameters (with Laptop) on every new location of use. But then I don't want the need of a PC anymore. Under these a.m. conditions I prefer to keep control without a PC, one need to know wether it still does work reliable. This I would even like to know when the device does steadily run in my 19 inch cabinet - just throwing an eye on it from time to time... Concerning the long start up delay - one can avoid it, just taking the laptop for a moment to read the output of the new self survey result and store it into the memory for this location. Next time you start at this place without the need of further surveys... regards Arnold T. From hmurray at megapathdsl.net Mon Jul 7 17:11:29 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 07 Jul 2008 14:11:29 -0700 Subject: [time-nuts] Thunderbolt Controllers In-Reply-To: Message from Neville Michie of "Mon, 07 Jul 2008 19:42:12 +1000." Message-ID: <20080707211130.9D975BCCA@ip-64-139-1-69.sjc.megapath.net> > My pendulum produces pulses at a rate of one per second. That signal > clocks a latch that samples the less significant bits of my > reference oscillator (100kHz or 1MHz) in a counter. ... > but what I would really like is a clock showing UTS in a form that > can be compared to a clock. > That means one second audible pips and a marker on the minute. Just > seeing numbers rolling over on a computer is not good enough to check > the timing of the second hand of the clock. You need ear - eye > coordinated signals. With WWV I can compare to 1/20th of a second. I haven't quite figured out what that means. How do you feed WWV to your data logger? If you have a TBolt, you get a PPS, a 10 MHz, and a RS232 data stream. If you start a counter with the TBolt PPS and stop it with your pendulum PPS, that will tell you the offset. If you want minute markers, you need to parse the serial data stream. > Although I have programmed systems in a variety of languages in my > working life, the only languages that have stuck are Fortran and > Basic. All the rest are forgotten after a year or two. I do not wish > to start again to learn a new system just for one task, and it is > obvious that there are so many micros abroad and none of them is going > to be universally useful for future tasks. If future tasks are likely to be interesting, then I'd suggest that you pick a manufacturer that looks good and give it a try. Best would be one that a friend uses so you can get some help if you need it. All the manufactures make a broad range of chips with various I/O devices and different sizes of RAM/FLASH and different numbers of pins. Mostly, they are all very similar and use the same tools. Scan the selector chart and pick a chip that has what you need. Or use a bigger one on a board you like. The cost of the chip is tiny relative to everything else. If I was doing what I think you want to do, I'd probably use c in an AVR. That's just because that was the last tiny system I worked on and I have some in my junk box. Another approach would be to horsetrade with a friend who likes writing that sort of software. -- These are my opinions, not necessarily my employer's. I hate spam. From holrum at hotmail.com Mon Jul 7 17:14:15 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 7 Jul 2008 21:14:15 +0000 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: References: Message-ID: As I said: >The Thunderbolt default config is to not save the survey position. Unless you use some software to save the position... The reason your Thunderbolt does no self surveying at power-on is exactly becuase you DID use some software to save the position! The TAPR units were shipped with their brains washed clean of all previous existence. In that state, a stock Thunderbolt will always do a self-survey at each power up and will not save the results. You have to use some sort of software program to cause it to save the survey position. People who just hook up the power and expect it to instantly start cranking out accurate frequency and timing are in for a surprise. My first unit took three days to survey 1400 points. I know of some that took over a week (due to long idled oscillators and/or very bad antenna coverage). Also be aware that with a saved position Thunderbolts gets all upset if you move more than 300 meters. I'm not sure that it would recover without some human intervention... the manual is not clear on the subject and I have not tried to find out. It is a "minor alarm" so I assume it does not totally die. I would never use a PC to control the thing. An obsolete PC compatible laptop makes the optimum controller in terms of user interface and cost. The one that I am using draws less than 20 watts (15V, 1.2A). Even less in power save mode. I paid less than $50 for it. Has a 1024x768 display, 40 gig hard drive, 256 meg ram, etc. The program that I wrote needs none of that. Would work fine booting off a floppy into 512K of RAM (DOS does have its charms). With the 40 gig of hard drive, you can log at one second intervals for 16 years. BTW, on 30 July 2017 your Thunderbolt turns into a pumpkin... its interpretation of the GPS week number fails and it may or may not keep working. At a bare minimum, the time and date will be wrong (see ThunderBoltBook2003.pdf page A-56. I still want to do the MegaDonkey based microcontroller for the Thunderbolt. Makes for a smaller, self contained unit. One just can't do as slick and versatile of a controller with it. It does have the advantage of drawing less than one watt of power. There is a way to hook an SDRAM card / FAT filesystem to it for doing logging, but I think I will just pass log data out the second serial port and let people who are interested in that sort of stuff attach their own recording device. ---------------------------------------- _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From bg at lysator.liu.se Mon Jul 7 17:35:50 2008 From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson) Date: Mon, 07 Jul 2008 23:35:50 +0200 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: References: Message-ID: <1215466550.5912.10.camel@bg-desktop> On Mon, 2008-07-07 at 21:14 +0000, Mark Sims wrote: > > BTW, on 30 July 2017 your Thunderbolt turns into a pumpkin... its > interpretation of the GPS week number fails and it may or may not keep > working. At a bare minimum, the time and date will be wrong (see > ThunderBoltBook2003.pdf page A-56. That is testable with a GPS simulator now. No need to wait for 2017. Would give someone plenty of time to take a look at the flash image and perhaps do a binary patch to move the problem further into the future... -- Bj?rn From rk at timing-consultants.com Mon Jul 7 17:53:13 2008 From: rk at timing-consultants.com (Rob Kimberley) Date: Mon, 7 Jul 2008 22:53:13 +0100 Subject: [time-nuts] Thunderbolt controllers In-Reply-To: References: Message-ID: <1C87CBB742AB4B019E45215EFC4DB01E@Robin> If you look at what a Thunderbolt was originally designed for (a fixed cell site T&F reference), then you are right, they are designed to be powered up and left to sort themselves out - self survey, and then provide T&F outputs when everything has stabilised. Rob K -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Mark Sims Sent: 07 July 2008 22:14 To: time-nuts at febo.com Subject: [time-nuts] Thunderbolt controllers As I said: >The Thunderbolt default config is to not save the survey position. Unless you use some software to save the position... The reason your Thunderbolt does no self surveying at power-on is exactly becuase you DID use some software to save the position! The TAPR units were shipped with their brains washed clean of all previous existence. In that state, a stock Thunderbolt will always do a self-survey at each power up and will not save the results. You have to use some sort of software program to cause it to save the survey position. People who just hook up the power and expect it to instantly start cranking out accurate frequency and timing are in for a surprise. My first unit took three days to survey 1400 points. I know of some that took over a week (due to long idled oscillators and/or very bad antenna coverage). Also be aware that with a saved position Thunderbolts gets all upset if you move more than 300 meters. I'm not sure that it would recover without some human intervention... the manual is not clear on the subject and I have not tried to find out. It is a "minor alarm" so I assume it does not totally die. I would never use a PC to control the thing. An obsolete PC compatible laptop makes the optimum controller in terms of user interface and cost. The one that I am using draws less than 20 watts (15V, 1.2A). Even less in power save mode. I paid less than $50 for it. Has a 1024x768 display, 40 gig hard drive, 256 meg ram, etc. The program that I wrote needs none of that. Would work fine booting off a floppy into 512K of RAM (DOS does have its charms). With the 40 gig of hard drive, you can log at one second intervals for 16 years. BTW, on 30 July 2017 your Thunderbolt turns into a pumpkin... its interpretation of the GPS week number fails and it may or may not keep working. At a bare minimum, the time and date will be wrong (see ThunderBoltBook2003.pdf page A-56. I still want to do the MegaDonkey based microcontroller for the Thunderbolt. Makes for a smaller, self contained unit. One just can't do as slick and versatile of a controller with it. It does have the advantage of drawing less than one watt of power. There is a way to hook an SDRAM card / FAT filesystem to it for doing logging, but I think I will just pass log data out the second serial port and let people who are interested in that sort of stuff attach their own recording device. ---------------------------------------- _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL _Refresh_messenger_video_072008 _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From hmurray at megapathdsl.net Mon Jul 7 19:09:57 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 07 Jul 2008 16:09:57 -0700 Subject: [time-nuts] Fury ntp refclock In-Reply-To: Message from Scott Mace of "Sun, 06 Jul 2008 23:14:03 CDT." <4871980B.3090503@intt.net> Message-ID: <20080707230958.9863DBCCB@ip-64-139-1-69.sjc.megapath.net> smace at intt.net said: > I've created a ntpd refclock driver for the Fury GPS receiver. The > refclock is based on the NMEA driver. Neat/thanks. There is currently a major reluctance to add new drivers to the main ntpd source pool. I think we should add this logic to the hpgps driver. > The driver was created because the Fury does not fully implement the > ptime:tcode? T2 string. The output is not on-time and the status > fields are always 0. So, it is not going to work with the hpgps > refclock. As it turns out the T2 string is rather limiting anyways. Said: Can you make the T2 string be "on time" and/or fix the status fields? Would it be better to invent a T3 string that had everything needed to tell time and also everything people are likely to want logged? Is "everything" a sensible concept? Would that be too much for most people and still not enough for a few? Maybe a mode in the Fury would solve that? Or bit mask? The driver would just log everything after the date/time/status so it doesn't care. (as long as it isn't too long) There is currently a bug/oversight in the hpgps driver. It only gets one sample per poll interval rather than 1 per second. (The refclock interface has a FIFO and code to discard outliers and average the rest.) Fixing this is high on my list. The hpgps driver currently logs a 24x80 status screen if you ask for clock statistics. I'd like an option to record just the interesting parameters. Of course, I have to do this without breaking anything for people who use the current setup. -- These are my opinions, not necessarily my employer's. I hate spam. From smace at intt.net Mon Jul 7 20:07:50 2008 From: smace at intt.net (Scott Mace) Date: Mon, 07 Jul 2008 19:07:50 -0500 Subject: [time-nuts] Fury ntp refclock In-Reply-To: <20080707230958.9863DBCCB@ip-64-139-1-69.sjc.megapath.net> References: <20080707230958.9863DBCCB@ip-64-139-1-69.sjc.megapath.net> Message-ID: <4872AFD6.4090907@intt.net> Maybe just build it into the generic parse refclock? I just needed to get it up and running and a standalone driver was the path of least resistance. The neat thing about the gpgga string is that it happens every second and doesn't rely on ntpd to send a command for it. It gives you a nice trigger to do all the stats gathering after the timecode has been processed. As long as you do the stats collection in less than a second... Jitter will never be low enough for it to be useful without an external pps reference. It would be nice to have a fully functioning short timecode that was emitted every second (instead of polled) that contained all the useful bits that NTP needs, time,sync/lock status, leap status, holdover status. Then add a new command to get a one-line result for all the interesting non-timecode related info that could be polled at whatever interval the user wanted. The gps?,sync?,diag?,meas? results were easier to parse than the system:status? since everything has a prefix. I'm not a fan of a the system:status? command, but it would be nice to get sat signal strength from the gps? command tree. My driver is not ideal, but it works with what the Fury can do with the current firmware. More to come. Scott Hal Murray wrote: > smace at intt.net said: >> I've created a ntpd refclock driver for the Fury GPS receiver. The >> refclock is based on the NMEA driver. > > Neat/thanks. > > There is currently a major reluctance to add new drivers to the main ntpd > source pool. > > I think we should add this logic to the hpgps driver. > > >> The driver was created because the Fury does not fully implement the >> ptime:tcode? T2 string. The output is not on-time and the status >> fields are always 0. So, it is not going to work with the hpgps >> refclock. As it turns out the T2 string is rather limiting anyways. > > Said: Can you make the T2 string be "on time" and/or fix the status fields? > > Would it be better to invent a T3 string that had everything needed to tell > time and also everything people are likely to want logged? > > Is "everything" a sensible concept? Would that be too much for most people > and still not enough for a few? Maybe a mode in the Fury would solve that? > Or bit mask? The driver would just log everything after the date/time/status > so it doesn't care. (as long as it isn't too long) > > > > There is currently a bug/oversight in the hpgps driver. It only gets one > sample per poll interval rather than 1 per second. (The refclock interface > has a FIFO and code to discard outliers and average the rest.) Fixing this > is high on my list. > > The hpgps driver currently logs a 24x80 status screen if you ask for clock > statistics. I'd like an option to record just the interesting parameters. > Of course, I have to do this without breaking anything for people who use the > current setup. > > From kc0vsj at yahoo.com Mon Jul 7 21:32:19 2008 From: kc0vsj at yahoo.com (Tom Clifton) Date: Mon, 7 Jul 2008 18:32:19 -0700 (PDT) Subject: [time-nuts] Thunderbolt Loop Damping Message-ID: <545024.14382.qm@web37001.mail.mud.yahoo.com> The manual doesn't give much direction on tweaking the disciplining parameters. Also, not having anything better to compare results to, I'm pretty handicapped. Has anybody done any tweaking and perhaps can offer any suggestions? Over the weekend I was able to get a GPS antenna on the roof coupled to the receiver in the basement by using an abandoned run of RG6 (Thanks Direct-TV! - The AT&T U-Verse doesn't fade during storms...) Logging of the 10mhz shows it stays pretty much under 0.05ppb. The Excel graphs are easy to generate, but not easy to use if that makes sense. Limited to 32k datapoints per graph and very difficult to zoom in on. Also, Is anybody else as confused as I am by negative ppb numbers??? is 0.00ppb the 10x-11 "baseline" so that -0.01ppb is really 0.009ppb? Tom From ch at murgatroid.com Mon Jul 7 21:55:13 2008 From: ch at murgatroid.com (christopher hoover) Date: Mon, 7 Jul 2008 18:55:13 -0700 Subject: [time-nuts] HP 5087A Input Doubler and 10 MHz Ampifiers In-Reply-To: References: Message-ID: <000601c8e09d$a9930110$fcb90330$@com> "NE8S" wrote: > I am in need of the following Opt PCB's for the HP 5087A: ... > Qty. 11 5087-60012 (10 MHz Amplfiers) Good luck. I like to a have some more of these as well. I have considered doing a run of 60012 boards. This would be straightforward except for one thing: I have been unable to find any spec for the transformers. That part would have be to characterized. Note that you can convert 5MHz boards to 10MHz by changing a couple of discrete component values. -ch From bruce.griffiths at xtra.co.nz Mon Jul 7 22:14:58 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Tue, 08 Jul 2008 14:14:58 +1200 Subject: [time-nuts] Thunderbolt Loop Damping In-Reply-To: <545024.14382.qm@web37001.mail.mud.yahoo.com> References: <545024.14382.qm@web37001.mail.mud.yahoo.com> Message-ID: <4872CDA2.7040204@xtra.co.nz> Tom Clifton wrote: > The manual doesn't give much direction on tweaking the disciplining parameters. Also, not having anything better to compare results to, I'm pretty handicapped. Has anybody done any tweaking and perhaps can offer any suggestions? > > Over the weekend I was able to get a GPS antenna on the roof coupled to the receiver in the basement by using an abandoned run of RG6 (Thanks Direct-TV! - The AT&T U-Verse doesn't fade during storms...) Logging of the 10mhz shows it stays pretty much under 0.05ppb. The Excel graphs are easy to generate, but not easy to use if that makes sense. Limited to 32k datapoints per graph and very difficult to zoom in on. > > Also, Is anybody else as confused as I am by negative ppb numbers??? is 0.00ppb the 10x-11 "baseline" so that -0.01ppb is really 0.009ppb? > > Tom > > Tom Surely the ppb measure just reflects the measured frequency error (actual OCXO frequency - 10.00000000000000000000000MHz ) in parts per billion, so a -ve ppb just means the sign of the error has opp0site that for a +ve ppb number. Bruce From jmiles at pop.net Mon Jul 7 22:18:15 2008 From: jmiles at pop.net (John Miles) Date: Mon, 7 Jul 2008 19:18:15 -0700 Subject: [time-nuts] HP 5087A Input Doubler and 10 MHz Ampifiers In-Reply-To: <000601c8e09d$a9930110$fcb90330$@com> Message-ID: There is nothing special about the 5087A's amplifier cards. The 5087A design is not especially quiet; in fact, it will degrade the broadband floor of a Thunderbolt by a good 7 or 8 dB from what I have seen. I'd say grab some PCB prototyping stock and a Dremel tool, and surf through Bruce's notes and references at http://www.ko4bb.com/~bruce/IsolationAmplifiers.html for some ideas. -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On > Behalf Of christopher hoover > Sent: Monday, July 07, 2008 6:55 PM > To: time-nuts at febo.com > Subject: Re: [time-nuts] HP 5087A Input Doubler and 10 MHz Ampifiers > > > > "NE8S" wrote: > > I am in need of the following Opt PCB's for the HP 5087A: > .... > > Qty. 11 5087-60012 (10 MHz Amplfiers) > > Good luck. I like to a have some more of these as well. > > I have considered doing a run of 60012 boards. This would be > straightforward except for one thing: I have been unable to find any spec > for the transformers. That part would have be to characterized. > > Note that you can convert 5MHz boards to 10MHz by changing a couple of > discrete component values. > > -ch > From holrum at hotmail.com Mon Jul 7 23:49:39 2008 From: holrum at hotmail.com (Mark Sims) Date: Tue, 8 Jul 2008 03:49:39 +0000 Subject: [time-nuts] Thunderbolt Loop Damping In-Reply-To: References: Message-ID: The Thunderbolt attempts to align the specified PPS and OSC edges with the GPS satellite time signal. The PPB parameter is its estimate of the error of the oscillator edge from where it needs to be. They specify it in mysterious parts-per-billion, but never really say billions of what. They do say positive values mean the 10MHz signal is running slow relative to GPS time. My ADEV plotter takes the PPS error in nanoseconds and adds 1.0 to it to get a per-second phase error. To get comparable values from the OSC PPB value, divide it by 1E9 and multiply by 100. Add that to 1.0 seconds to get a per-second phase errorof the OSC signal. The resulting ADEV plots of PPS and OSC PPB are off by a decade below 20 tau, and match very closely above 100 tau. The OSC PPB is worse below 100 tau (4.5e-9 vs 4.5 e-10 at 1 tau, both around 4e-11 at 100 tau) by 10,000 tau the OSC PPB is slightly better than the PPS signal (both in the 5e-13 range). As far as messing with the discilining constants, I figure Trimble has them fairly well optimized for their OXCO. They probably only need to be changed if you graft a different OCXO onto the unit. ---------------------------------------- _________________________________________________________________ It?s a talkathon ? but it?s not just talk. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_JustTalk From w1ksz at earthlink.net Tue Jul 8 00:23:47 2008 From: w1ksz at earthlink.net (Richard W. Solomon) Date: Tue, 8 Jul 2008 00:23:47 -0400 (EDT) Subject: [time-nuts] Thunderbolt Loop Damping Message-ID: <24320305.1215491027833.JavaMail.root@elwamui-cypress.atl.sa.earthlink.net> Did your zero key stick ?? If I counted all them zeros correctly I get 1 part in 10e24 ??? Man thats some rock !! 73, Dick, W1KSZ -----Original Message----- >From: Bruce Griffiths >Sent: Jul 7, 2008 10:14 PM >To: Discussion of precise time and frequency measurement >Subject: Re: [time-nuts] Thunderbolt Loop Damping > >Tom Clifton wrote: >> The manual doesn't give much direction on tweaking the disciplining parameters. Also, not having anything better to compare results to, I'm pretty handicapped. Has anybody done any tweaking and perhaps can offer any suggestions? >> >> Over the weekend I was able to get a GPS antenna on the roof coupled to the receiver in the basement by using an abandoned run of RG6 (Thanks Direct-TV! - The AT&T U-Verse doesn't fade during storms...) Logging of the 10mhz shows it stays pretty much under 0.05ppb. The Excel graphs are easy to generate, but not easy to use if that makes sense. Limited to 32k datapoints per graph and very difficult to zoom in on. >> >> Also, Is anybody else as confused as I am by negative ppb numbers??? is 0.00ppb the 10x-11 "baseline" so that -0.01ppb is really 0.009ppb? >> >> Tom >> >> >Tom > >Surely the ppb measure just reflects the measured frequency error >(actual OCXO frequency - 10.00000000000000000000000MHz ) in parts per >billion, so a -ve ppb just means the sign of the error has opp0site that >for a +ve ppb number. > >Bruce > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From bruce.griffiths at xtra.co.nz Tue Jul 8 00:39:44 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Tue, 08 Jul 2008 16:39:44 +1200 Subject: [time-nuts] HP 5087A Input Doubler and 10 MHz Ampifiers In-Reply-To: References: Message-ID: <4872EF90.7@xtra.co.nz> John Miles wrote: > There is nothing special about the 5087A's amplifier cards. The 5087A > design is not especially quiet; in fact, it will degrade the broadband floor > of a Thunderbolt by a good 7 or 8 dB from what I have seen. > > I'd say grab some PCB prototyping stock and a Dremel tool, and surf through > Bruce's notes and references at > http://www.ko4bb.com/~bruce/IsolationAmplifiers.html for some ideas. > > -- john, KE5FX > > Just watch for the odd error in those references. eg in the first reference (.../498.pdf) the captions for figure 2 and figure 3 should be swapped. If anyone wants to try it, I have an even quieter, lower distortion 3 transistor isolation amplifier design that runs from a 12V supply. I'll add it to that page in the next few days. It has a 50 ohm input impedance and can be driven from a splitter which is in turn driven by another such amplifier to form a high reverse isolation and channel to channel isolation, low noise distribution amplifier. Whatever you do don't copy JPL's isolation amplifier designs they are relatively noisy particularly in the flicker noise region. Bruce From jmiles at pop.net Tue Jul 8 00:58:34 2008 From: jmiles at pop.net (John Miles) Date: Mon, 7 Jul 2008 21:58:34 -0700 Subject: [time-nuts] HP 5087A Input Doubler and 10 MHz Ampifiers In-Reply-To: <4872EF90.7@xtra.co.nz> Message-ID: > > > Just watch for the odd error in those references. > eg in the first reference (.../498.pdf) the captions for figure 2 and > figure 3 should be swapped. > > If anyone wants to try it, I have an even quieter, lower distortion 3 > transistor isolation amplifier design that runs from a 12V supply. > I'll add it to that page in the next few days. It has a 50 ohm input > impedance and can be driven from a splitter which is in turn driven by > another such amplifier to form a high reverse isolation and channel to > channel isolation, low noise distribution amplifier. Certainly, put it up there -- that's a handy collection of ideas. I'd like to add a couple of low-noise outputs to my 5087A at some point, actually. There's a lot of empty space on the front panel that bugs me. -- john, KE5FX From SAIDJACK at aol.com Tue Jul 8 01:45:44 2008 From: SAIDJACK at aol.com (SAIDJACK at aol.com) Date: Tue, 8 Jul 2008 01:45:44 EDT Subject: [time-nuts] Fury ntp refclock Message-ID: Hi guys, We formatted the syst:stat? command on the Fury GPSDO so as to be compatible to GPSCon, that meant following a very rigorous syntax (including the exact number of spaces etc), it's not pretty - but works perfectly with GPSCon. One note of interest to the group in general: some of our future products have a new, very high performance mobile GPS on them that will actually track and output 16 Sats and more simultaneously (well, if it could see the Sats it would receive more than 30 channels) to GPSCon. A far cry from the 8-sat Oncore days, and this is causing some grief for GPSCon (not the entire list of Sat's can be shown by GPSCon without overflowing the page etc). We can't reveal the GPS details just yet though, please don't ask :) Seems the web interface of GPSCon works well with any number of Sats though, see for example: _http://www.jackson-labs.com/images/gpsstat.htm_ (http://www.jackson-labs.com/images/gpsstat.htm) We are working hard on a set of new products right now, so the ptime command changes will have to be put on a slightly lower priority for now unfortunately. Seems your driver is working well right now though from what I can gather in the email thread. Thanks for your hard work on this, bye, Said In a message dated 7/8/2008 02:09:12 W. Europe Daylight Time, smace at intt.net writes: The gps?,sync?,diag?,meas? results were easier to parse than the system:status? since everything has a prefix. I'm not a fan of a the system:status? command, but it would be nice to get sat signal strength from the gps? command tree. My driver is not ideal, but it works with what the Fury can do with the current firmware. More to come. Scott **************Gas prices getting you down? Search AOL Autos for fuel-efficient used cars. (http://autos.aol.com/used?ncid=aolaut00050000000007) From bruce.griffiths at xtra.co.nz Tue Jul 8 01:49:20 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Tue, 08 Jul 2008 17:49:20 +1200 Subject: [time-nuts] HP 5087A Input Doubler and 10 MHz Ampifiers In-Reply-To: References: Message-ID: <4872FFE0.3060401@xtra.co.nz> John Miles wrote: >> Just watch for the odd error in those references. >> eg in the first reference (.../498.pdf) the captions for figure 2 and >> figure 3 should be swapped. >> >> If anyone wants to try it, I have an even quieter, lower distortion 3 >> transistor isolation amplifier design that runs from a 12V supply. >> I'll add it to that page in the next few days. It has a 50 ohm input >> impedance and can be driven from a splitter which is in turn driven by >> another such amplifier to form a high reverse isolation and channel to >> channel isolation, low noise distribution amplifier. >> > > Certainly, put it up there -- that's a handy collection of ideas. I'd like > to add a couple of low-noise outputs to my 5087A at some point, actually. > There's a lot of empty space on the front panel that bugs me. > > -- john, KE5FX > > John Will add the general configuration shortly and follow up with a 5087 specific version that is tailored for the 5087 +18V supply. Have been looking at the 5087 amplifier schematics and it appears that most of the noise is due to the fact that the various output amplifiers have a gain of somewhere around 10x or so judging by the waveform amplitudes given on the schematic. The amplifiers have a fixed gain (for a given load) and large amplitude inputs are accommodated by attenuating them. Lower noise for high amplitude inputs is achieved if the amplifier gain is adjusted to suit the input signal level rather than attenuating the input to suit the amplifier. You will also need to change the 5087A input amplifier - although its a relatively low noise emitter follower it wont drive a 50 ohm load or several in parallel especially with a +13dB input signal. For those who like to use wide bandwidth opamps I'll indicate how to achieve a phase noise floor within 6-12 dB of a low noise discrete design. As NIST have shown there is no need to use particularly exotic transistors for 10MHz distribution amplifiers. Bruce From chris.kuethe at gmail.com Tue Jul 8 02:03:08 2008 From: chris.kuethe at gmail.com (Chris Kuethe) Date: Mon, 7 Jul 2008 23:03:08 -0700 Subject: [time-nuts] Fury ntp refclock In-Reply-To: References: Message-ID: <91981b3e0807072303m72b41a69q547dc55b5d8cdf71@mail.gmail.com> On Mon, Jul 7, 2008 at 10:45 PM, wrote: > One note of interest to the group in general: some of our future products > have a new, very high performance mobile GPS on them that will actually track > and output 16 Sats and more simultaneously (well, if it could see the Sats it > would receive more than 30 channels) to GPSCon. A far cry from the 8-sat > Oncore days, and this is causing some grief for GPSCon (not the entire list of > Sat's can be shown by GPSCon without overflowing the page etc). We can't reveal > the GPS details just yet though, please don't ask :) Those ublox chips are nice, aren't they? ;) -- GDB has a 'break' feature; why doesn't it have 'fix' too? From smace at intt.net Tue Jul 8 02:26:55 2008 From: smace at intt.net (Scott Mace) Date: Tue, 08 Jul 2008 01:26:55 -0500 Subject: [time-nuts] Fury ntp refclock In-Reply-To: References: Message-ID: <487308AF.8010207@intt.net> This is on a net4501 with the TMRIN mod running FreeBSD 7.0 (nanobsd). Fury 1.18 firmware with a surplus LPRO-101 packaged up in an old 1U Datum 670x rubidium reference chassis. > ntptime ntp_gettime() returns code 0 (OK) time cc1d84fd.0fbd3800 Tue, Jul 8 2008 6:17:33.061, (.061481758), maximum error 1480 us, estimated error 15 us, TAI offset 0 ntp_adjtime() returns code 0 (OK) modes 0x0 (), offset -0.014 us, frequency -0.040 ppm, interval 1 s, maximum error 1480 us, estimated error 15 us, status 0x2001 (PLL,NANO), time constant 4, precision 0.001 us, tolerance 496 ppm, > > ntpq -c peers remote refid st t when poll reach delay offset jitter ============================================================================== +REFCLK(45,0) .GPS. 0 l 13 16 377 0.000 -1.152 3.108 oPPS(0) .PPS. 0 l 4 16 377 0.000 0.000 0.015 > clockstats: 54655 22687.015 127.127.45.0 94 1 0 0 5.09e-12 -1.10e-09 46.10 1.994153 0.000004 10.53 8 9 1 38 10 54655 22697.016 127.127.45.0 94 1 0 0 4.59e-12 -1.40e-09 46.00 1.994255 0.000004 10.53 8 9 1 38 10 54655 22707.017 127.127.45.0 94 1 0 0 4.29e-12 -1.60e-09 46.10 1.994454 0.000004 10.53 8 9 1 38 -11 54655 22717.017 127.127.45.0 94 1 0 0 3.56e-12 -1.90e-09 46.10 1.994834 0.000004 10.53 9 9 1 38 4 54655 22727.018 127.127.45.0 94 1 0 0 3.29e-12 -2.10e-09 46.10 1.994912 0.000004 10.53 9 9 1 36 -6 54655 22737.010 127.127.45.0 94 1 0 0 2.35e-12 -2.30e-09 46.10 1.994695 0.000004 10.53 9 9 1 36 -14 54655 22747.010 127.127.45.0 94 1 0 0 2.08e-12 -2.60e-09 46.10 1.994872 0.000004 10.53 9 9 1 36 -13 54655 22757.011 127.127.45.0 94 1 0 0 1.43e-12 -2.80e-09 46.10 1.995252 0.000004 10.53 9 9 1 36 0 54655 22767.012 127.127.45.0 94 1 0 0 1.16e-12 -3.00e-09 46.10 1.995357 0.000004 10.53 9 9 1 36 -5 54655 22777.012 127.127.45.0 94 1 0 0 8.07e-13 -3.20e-09 46.10 1.995337 0.000004 10.53 9 9 1 36 3 54655 22787.014 127.127.45.0 94 1 0 0 5.83e-13 -3.40e-09 46.10 1.995080 0.000004 10.53 9 9 1 36 -8 Scott SAIDJACK at aol.com wrote: > Hi guys, > > We formatted the syst:stat? command on the Fury GPSDO so as to be compatible > to GPSCon, that meant following a very rigorous syntax (including the exact > number of spaces etc), it's not pretty - but works perfectly with GPSCon. > > One note of interest to the group in general: some of our future products > have a new, very high performance mobile GPS on them that will actually track > and output 16 Sats and more simultaneously (well, if it could see the Sats it > would receive more than 30 channels) to GPSCon. A far cry from the 8-sat > Oncore days, and this is causing some grief for GPSCon (not the entire list of > Sat's can be shown by GPSCon without overflowing the page etc). We can't reveal > the GPS details just yet though, please don't ask :) > > Seems the web interface of GPSCon works well with any number of Sats though, > see for example: > > _http://www.jackson-labs.com/images/gpsstat.htm_ > (http://www.jackson-labs.com/images/gpsstat.htm) > > > We are working hard on a set of new products right now, so the ptime command > changes will have to be put on a slightly lower priority for now > unfortunately. Seems your driver is working well right now though from what I can gather > in the email thread. > > Thanks for your hard work on this, > bye, > Said > > > > > In a message dated 7/8/2008 02:09:12 W. Europe Daylight Time, smace at intt.net > writes: > > > The gps?,sync?,diag?,meas? results were easier to parse than the > system:status? > since everything has a prefix. > > I'm not a fan of a the system:status? command, but it would be nice to get > sat signal strength from the gps? command tree. > > My driver is not ideal, but it works with what the Fury can do with the > current > firmware. More to come. > > Scott > > > > > > **************Gas prices getting you down? Search AOL Autos for > fuel-efficient used cars. (http://autos.aol.com/used?ncid=aolaut00050000000007) > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From tvb at LeapSecond.com Tue Jul 8 09:55:04 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Tue, 8 Jul 2008 06:55:04 -0700 Subject: [time-nuts] Thunderbolt Loop Damping References: Message-ID: <002f01c8e102$3a412070$0800a8c0@pc52> Mark Sims writes: > My ADEV plotter takes the PPS error in nanoseconds and > adds 1.0 to it to get a per-second phase error. To get I'm not sure why you would add 1.0 here? The PPS error is a per-second time-interval (phase) error already, no? > comparable values from the OSC PPB value, divide it by > 1E9 and multiply by 100. Add that to 1.0 seconds to get a > per-second phase error of the OSC signal. The resulting > ADEV plots of PPS and OSC PPB are off by a decade > below 20 tau, and match very closely above 100 tau. The > OSC PPB is worse below 100 tau (4.5e-9 vs 4.5 e-10 at > 1 tau, both around 4e-11 at 100 tau) by 10,000 tau the > OSC PPB is slightly better than the PPS signal (both in the > 5e-13 range). It's not clear what you're doing here. Are you comparing your TBolt to an external reference (Rb or Cs or other GPSDO)? Or are you just processing the internal TBolt numbers and assuming you can derive ADEV stability numbers of GPS or the GPSDO or the OCXO itself from that? > As far as messing with the discilining constants, I figure > Trimble has them fairly well optimized for their OXCO. They > probably only need to be changed if you graft a different > OCXO onto the unit. Yes, it's quite flexible and you can have a lot of fun replacing the OCXO. I'm assuming a number of you will be trying this in the coming months. But even with the onboard OCXO, it allows you to change the time constant which can make a noticeable difference in the mid-term stability of the GPSDO. I'll dig out plots I made last year if you're interested. /tvb From Arnold.Tibus at gmx.de Tue Jul 8 12:01:15 2008 From: Arnold.Tibus at gmx.de (Arnold Tibus) Date: Tue, 08 Jul 2008 18:01:15 +0200 Subject: [time-nuts] Thunderbolt Loop Damping In-Reply-To: <002f01c8e102$3a412070$0800a8c0@pc52> Message-ID: On Tue, 8 Jul 2008 06:55:04 -0700, Tom Van Baak wrote: [...] >Yes, it's quite flexible and you can have a lot of fun replacing >the OCXO. I'm assuming a number of you will be trying this >in the coming months. >But even with the onboard OCXO, it allows you to change the >time constant which can make a noticeable difference in the >mid-term stability of the GPSDO. I'll dig out plots I made last >year if you're interested. >/tvb Perhaps there is not much to earn with it, but I thought as well about to replace the OCXO with a 10811 for test purpose etc. I am very much interested as well to see how to set the time constant in conjunction with the damping factor properly with the original onboard oscillator and, if already performed by somebody, with an other type. Would be great if you and others would share your/ their experience! What are the parameters to be watched with TBoltmon, what are the goals, to get the lowest variation on the 10 MHz ppb indication? What about the PPS value in ns UTC? If I do slight modifications specially on the time constant I get the indication drifting very slowly away, but the 10 MHz ppb does not vary much... Under this circumstance I do not see how to set the ns offset for pps. Is it necessary to compensate for the antenna cable delay and how I can do it? (pps offset?) I guess that the outcome will be to not make much modifications !? Arnold T. From holrum at hotmail.com Tue Jul 8 12:11:46 2008 From: holrum at hotmail.com (Mark Sims) Date: Tue, 8 Jul 2008 16:11:46 +0000 Subject: [time-nuts] Thunderbolt Loop Damping In-Reply-To: References: Message-ID: I am calculating plotting the ADEVs (or OADEVs) of the Thunderbolt's own PPS and OSC error estimates. The values are its estimate in the error of the PPS signal edge/OSC zero crossing to GPS time. I have queue of 22000 entries that tracks the last 22000 values of PPS and OSC errors. Every 10 seconds, it calculates and displays the ADEV or OADEVs of all the data in the queue (both a table and a plot). By the time the queue fills up it gives values out to 10,000 tau. Yeah, it's kinda flakey to rely on the device to compare its output signals to its own interpretation of GPS time, but it's free and requires no external equipment. The adding of the 1.0 second to the error estimate values (and the multiplying of the OSC ppb value by 100) was to simulate the values that an external time interval counter would produce if it was measuring the signals. Not really needed, but the code was lifted from another application and it was useful for doing some comparisons to some existing data. (BTW, the ADEV code was based upon your ADEV1.C) _________________________________________________________________ It?s a talkathon ? but it?s not just talk. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_JustTalk From tvb at LeapSecond.com Tue Jul 8 12:48:26 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Tue, 8 Jul 2008 09:48:26 -0700 Subject: [time-nuts] Thunderbolt Loop Damping References: Message-ID: <002001c8e11a$74bb7260$0200a8c0@pc52> > Yeah, it's kinda flakey to rely on the device to compare > its output signals to its own interpretation of GPS time, > but it's free and requires no external equipment. Just because something is free doesn't mean it has any meaning. Stop and think about what your "statistics" are showing. > The adding of the 1.0 second to the error estimate values > (and the multiplying of the OSC ppb value by 100) was to You can't use the same ADEV algorithm for the TI values as the ppb values; one is phase, the other frequency. > simulate the values that an external time interval counter > would produce if it was measuring the signals. Not really > needed, but the code was lifted from another application > and it was useful for doing some comparisons to some > existing data. (BTW, the ADEV code was based upon > your ADEV1.C) I'm still confused and now also worried. The time interval values that adev1.c takes as input are very small numbers, like microseconds or nanoseconds. These are time *interval* measurements, as one would obtain when comparing the 1PPS of a reference against the 1PPS of a GPSDO. At best there is no need to add a fixed constant to these numbers. Note that the adev code will effectively eliminate a constant phase bias. But at worst, adding a constant that is millions or even billions of times greater than your data can cause floating point loss of precision errors. So keep the numbers small; think time error measurements, not time measurements. Second, use ADEV1 only on time interval or phase data. If you have frequency data you need to change the tool, or integrate frequency error back to phase error before you run the tool. /tvb From david.partridge at dsl.pipex.com Tue Jul 8 12:49:42 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Tue, 8 Jul 2008 17:49:42 +0100 Subject: [time-nuts] PCB costs and suggestions for suppliers Message-ID: I'm looking to get a PCB made up for my frequency divider circuit. I'm based in the UK. So far the best price I've found is about 160 Euro plus tax and delivery for one 5" (127mm) by 3.5" (88.9mm) 4-layer board (from PCB-Pool). As I've not had a PCB made up in the last twenty odd years, I don't know if this is typical, or whether I should be able to get a better price. I tried setting it up as a two layer board, but it was far too much pain - I wanted an unbroken ground plane, and couldn't come up with a workable routing. If I get it made in the USA, the saving will need to be significant to cover the additional shipping costs and UK import duty, tax and handling charges. Any guidance on where to go, and what level of pricing I should expect is greatly appreciated. Cheers, David Partridge From optomatic at rogers.com Tue Jul 8 13:07:00 2008 From: optomatic at rogers.com (Patrick) Date: Tue, 08 Jul 2008 13:07:00 -0400 Subject: [time-nuts] PCB costs and suggestions for suppliers In-Reply-To: References: Message-ID: <48739EB4.5080205@rogers.com> Hey David I asked a similar question about a couple of months ago in this thread: [time-nuts] PCB design questions thread II I got lots of great answers. I copied some samples for you below. Please let me now if you need the whole thread forwarded-Patrick ------------------------------------------------------------------------ Cheapest place I've come across for easy boards with 10mil or large lines is this one, but I've not used them yet (probably next month I will): http://www.futurlec.com/PCBService.shtml ------------------------------------------------------------------------ for guaranteed product quality, including choice of material (FR4 choices, Getec, etc), tight impedance control, cleanliness (to reduce loss tangent especially for high-frequency performance), and documentation including solder-samples and cross-sections etc, try: _http://www.titanpcb.com/about_us/Titan_West.asp_ (http://www.titanpcb.com/about_us/Titan_West.asp) Not the cheapest, but great for "professional" proto's when quality trumps cost (above 1GHz, one source FR4 is totally different from another sources FR4...) expresspcb.com works well for low cost, quick-turn proto's. ------------------------------------------------------------------------ I've had good experiences with www.pcbex.com. A little cheaper than pcbfabexpress (which I've also used and recommend). Batchpcb (which someone else mentioned) has been good for 1-off boards if they aren't too big -- sometimes I've gotten boards which aren't sheared quite square, but that's basically a cosmetic problem. ------------------------------------------------------------------------ These are the ones we've used. I am sure there are many others. Prototypes -- www.pcbfabexpress.com Production -- www.pcbnet.com ------------------------------------------------------------------------ For one-off PCBs, I've had good luck with www.batchpcb.com . They work by panelizing different orders together ------------------------------------------------------------------------ http://www.pcb123.com/ http://www.expresspcb.com/index.htm David C. Partridge wrote: > I'm looking to get a PCB made up for my frequency divider circuit. I'm > based in the UK. So far the best price I've found is about 160 Euro plus > tax and delivery for one 5" (127mm) by 3.5" (88.9mm) 4-layer board (from > PCB-Pool). As I've not had a PCB made up in the last twenty odd years, I > don't know if this is typical, or whether I should be able to get a better > price. > > I tried setting it up as a two layer board, but it was far too much pain - I > wanted an unbroken ground plane, and couldn't come up with a workable > routing. > > If I get it made in the USA, the saving will need to be significant to cover > the additional shipping costs and UK import duty, tax and handling charges. > > Any guidance on where to go, and what level of pricing I should expect is > greatly appreciated. > > Cheers, > David Partridge > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From harry at hindriks.demon.nl Tue Jul 8 13:14:45 2008 From: harry at hindriks.demon.nl (Harry Hindriks) Date: Tue, 8 Jul 2008 19:14:45 +0200 Subject: [time-nuts] PCB costs and suggestions for suppliers In-Reply-To: References: Message-ID: <00b201c8e11e$211a4f60$634eee20$@demon.nl> Hi David, You can try www.eurocircuits.com A quick calculation for your board gives 137 Euro plus tax, but including delivery. Regards, Harry Hindriks -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of David C. Partridge Sent: dinsdag 8 juli 2008 18:50 To: 'Discussion of precise time and frequency measurement' Subject: [time-nuts] PCB costs and suggestions for suppliers I'm looking to get a PCB made up for my frequency divider circuit. I'm based in the UK. So far the best price I've found is about 160 Euro plus tax and delivery for one 5" (127mm) by 3.5" (88.9mm) 4-layer board (from PCB-Pool). As I've not had a PCB made up in the last twenty odd years, I don't know if this is typical, or whether I should be able to get a better price. I tried setting it up as a two layer board, but it was far too much pain - I wanted an unbroken ground plane, and couldn't come up with a workable routing. If I get it made in the USA, the saving will need to be significant to cover the additional shipping costs and UK import duty, tax and handling charges. Any guidance on where to go, and what level of pricing I should expect is greatly appreciated. Cheers, David Partridge _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From attila at kinali.ch Tue Jul 8 13:45:49 2008 From: attila at kinali.ch (Attila Kinali) Date: Tue, 8 Jul 2008 19:45:49 +0200 Subject: [time-nuts] Learning HF / low noise electronic design Message-ID: <20080708194549.a10450fe.attila@kinali.ch> Moin, While we are at building our own circuits, can you recommend me any good resources (websites, magazines, books, ...) to learn HF and/or low noise design? Power supplies and audio electronics are easy to find, but somehow i wasn't able to find anything in the HF field that covers more than just the very basics. Thanks in advance Attila Kinali -- It is the unknown we fear when we look upon death and darkness, nothing more. -- Albus P. W. B. Dumbledore From phk at phk.freebsd.dk Tue Jul 8 13:53:47 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Tue, 08 Jul 2008 17:53:47 +0000 Subject: [time-nuts] PCB costs and suggestions for suppliers In-Reply-To: Your message of "Tue, 08 Jul 2008 17:49:42 +0100." Message-ID: <65360.1215539627@critter.freebsd.dk> In message , "David C. Partridge" writ es: >I'm looking to get a PCB made up for my frequency divider circuit. I'm >based in the UK. I've used olimex.com for a couple of two-layer boards and I'm happy with the results. One advantage for me was that they took EagleCad files directly, so that I did't have to worry about inverted gerbers and all that. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From holrum at hotmail.com Tue Jul 8 14:01:22 2008 From: holrum at hotmail.com (Mark Sims) Date: Tue, 8 Jul 2008 18:01:22 +0000 Subject: [time-nuts] Thunderbolt Loop Damping In-Reply-To: References: Message-ID: I do modify the OSC ppb value to morph it into nanoseconds of error before I feed it to the ADEV code (at least I think I do... the documentation is not really clear on what the value really is). The constant 1 second offset that I added to the data makes absolutely no difference in the results (I tried it both ways). It was just there for consistency with another program that I have. The Trimble numbers are 32 bit floats, my 1 second offset number is a 64 bit double, it can handle the value just fine without losing any precision. The ADEV code subtracts pairs of values, so that constant value gets removed automatically (and to quell your concerns, I have removed it from the code). As far as what the statistics are showing... well they show the ADEV values of the Thunderbolt's own measurements of the signal errors (auto ADEV?). How those compare to measurements against an external reference is left as an exercise to the reader. The curves do seem to make some sense. I am seeing curves with distinct breaks in the slope at points that correspond to slope changes in your Thunderbolt ADEV plots. The main difference is below around 50 tau where a "normal" adev curve shows rising values then begins to fall. The plots on the Thunderbolt data show constantly falling adevs with distinct breaks in the slope. If the numbers were totally meaningless one would expect to see a line of constant slope as tau increases. Past 50 tau or so, the ADEV values seem to agree with what one would expect. ---------------------------------------- _________________________________________________________________ The i?m Talkaton. Can 30-days of conversation change the world? http://www.imtalkathon.com/?source=EML_WLH_Talkathon_ChangeWorld From holrum at hotmail.com Tue Jul 8 14:11:36 2008 From: holrum at hotmail.com (Mark Sims) Date: Tue, 8 Jul 2008 18:11:36 +0000 Subject: [time-nuts] PCB costs and suggestions for suppliers In-Reply-To: References: Message-ID: I have used mylydia.com before for some projects. Their prices are very good, but they have a 2000 square inch minimum. For a 4 layer board there is a $300 setup charge and 20 cents per square inch for the boards. So for $700 or so you would get 100 4x5 inch boards. This price is compares well with what a lot of proto houses would charge for a 5-10 piece run, and mayby twice what a single piece run would be. If you trust your layout it can be the way to go. ---------------------------------------- _________________________________________________________________ The i?m Talkaton. Can 30-days of conversation change the world? http://www.imtalkathon.com/?source=EML_WLH_Talkathon_ChangeWorld From tvb at LeapSecond.com Tue Jul 8 14:34:18 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Tue, 8 Jul 2008 11:34:18 -0700 Subject: [time-nuts] Thunderbolt Loop Damping References: Message-ID: <001701c8e129$3f6a50e0$0200a8c0@pc52> > As far as what the statistics are showing... well they show > the ADEV values of the Thunderbolt's own measurements > of the signal errors (auto ADEV?). How those compare to > measurements against an external reference is left as an > exercise to the reader. What you're calculating is the combined ADEV of the GPS ref, the internal measurement system, including internal any filtering, and the OCXO. Your numbers can't show GPS, or the measurement system, or the OCXO by themselves, nor do your numbers reflect the actual GPSDO output signal performance as compared to a real reference clock. That's why it sort of looks like what you have left "as an exercise to the reader" is pretty much the entire exercise. Do have access to a Rb that you can use as a reference? Send me email offline if you'd like to borrow one. Still, one thing you could do now is see the effect of varying the loop time constant. With a tight loop the sdev or adev of TI and ppb will be very small; the looser the loop the wider the variance of those values. That's my guess at least. /tvb From harry at hindriks.demon.nl Tue Jul 8 14:38:59 2008 From: harry at hindriks.demon.nl (Harry Hindriks) Date: Tue, 8 Jul 2008 20:38:59 +0200 Subject: [time-nuts] PCB costs and suggestions for suppliers In-Reply-To: <65360.1215539627@critter.freebsd.dk> References: Your message of "Tue, 08 Jul 2008 17:49:42 +0100." <65360.1215539627@critter.freebsd.dk> Message-ID: <00c701c8e129$e5741d40$b05c57c0$@demon.nl> I used Olimex for some boards, but since they are in European Community the prices increased. 2 Years ago US$ 99,- for 320x200mm, now 120 Euro plus VAT. But when you need a lot of different small boards it is a good option (Panel). Harry Hindriks -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Poul-Henning Kamp Sent: dinsdag 8 juli 2008 19:54 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] PCB costs and suggestions for suppliers In message , "David C. Partridge" writ es: >I'm looking to get a PCB made up for my frequency divider circuit. I'm >based in the UK. I've used olimex.com for a couple of two-layer boards and I'm happy with the results. One advantage for me was that they took EagleCad files directly, so that I did't have to worry about inverted gerbers and all that. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From w1ksz at earthlink.net Tue Jul 8 15:00:24 2008 From: w1ksz at earthlink.net (Richard W. Solomon) Date: Tue, 8 Jul 2008 15:00:24 -0400 (EDT) Subject: [time-nuts] Trimble T-Bolt Dumb Question Message-ID: <20034192.1215543624602.JavaMail.root@mswamui-backed.atl.sa.earthlink.net> How does one determine that they are "locked" to the GPS system ? If I look at TboltMon I see lots of data, but nowhere do I find a specific statement that I am locked. The output frequency is accurate and stable enough to be locked and I see I have anywhere from 5 to 8 satellites tracked, but .... Thanks, Dick, W1KSZ From imp at bsdimp.com Tue Jul 8 15:39:36 2008 From: imp at bsdimp.com (M. Warner Losh) Date: Tue, 08 Jul 2008 13:39:36 -0600 (MDT) Subject: [time-nuts] Trimble T-Bolt Dumb Question In-Reply-To: <20034192.1215543624602.JavaMail.root@mswamui-backed.atl.sa.earthlink.net> References: <20034192.1215543624602.JavaMail.root@mswamui-backed.atl.sa.earthlink.net> Message-ID: <20080708.133936.1159184467.imp@bsdimp.com> In message: <20034192.1215543624602.JavaMail.root at mswamui-backed.atl.sa.earthlink.net> "Richard W. Solomon" writes: : How does one determine that they are "locked" to the GPS system ? : If I look at TboltMon I see lots of data, but nowhere do I find a : specific statement that I am locked. : : The output frequency is accurate and stable enough to be locked and : I see I have anywhere from 5 to 8 satellites tracked, but .... Usually "locked to a GPS system" just means that the oscillator that's controlled by the GPS is operating within some set of prescribed parameters and that the GPS receiver itself is a 'good enough' source of time. The exact definition of good enough varies quite a bit from system to system. You basically have to look at the numbers from your control loop, as well as self diagnostics from the GPS receiver to know if there's a lock or not. Warner From Arnold.Tibus at gmx.de Tue Jul 8 15:51:44 2008 From: Arnold.Tibus at gmx.de (Arnold Tibus) Date: Tue, 08 Jul 2008 21:51:44 +0200 Subject: [time-nuts] Trimble T-Bolt Dumb Question In-Reply-To: <20034192.1215543624602.JavaMail.root@mswamui-backed.atl.sa.earthlink.net> Message-ID: On Tue, 8 Jul 2008 15:00:24 -0400 (EDT), Richard W. Solomon wrote: >How does one determine that they are "locked" to the GPS system ? >If I look at TboltMon I see lots of data, but nowhere do I find a >specific statement that I am locked. >The output frequency is accurate and stable enough to be locked and >I see I have anywhere from 5 to 8 satellites tracked, but .... >Thanks, Dick, W1KSZ At the bottom window section of Thunderbolt Monitor subwindow 'Disciplining Status' you will see Mode '(0) Normal ' and Activity '(0) Phase Locking' In the subwindow 'Minor Alarms' the 'LED' 'Oscillator Disciplining' switches from yellow to green, when finally everything is stabilized all Alarm Indicators will have switched from yellow to green. regards Arnold T. From didier at cox.net Tue Jul 8 18:03:15 2008 From: didier at cox.net (Didier Juges) Date: Tue, 8 Jul 2008 17:03:15 -0500 Subject: [time-nuts] PCB costs and suggestions for suppliers In-Reply-To: <65360.1215539627@critter.freebsd.dk> References: Your message of "Tue, 08 Jul 2008 17:49:42 +0100." <65360.1215539627@critter.freebsd.dk> Message-ID: <004c01c8e146$6cb71fc0$0a01a8c0@didierhp> I have used Olimex also, from the US. Good quality, reasonable price and delivery, painless transaction overall. Only problem the last time I wanted to buy from them: they were on vacation and they simply did not reply or acknowledge my email until 2 weeks later when they came back... In the mean time, I had bought my PWBs from somewhere else, and I am sorry that I did because it ended up costing more and taking longer, because the other guys (US based, who shall remain nameless) blew their projected delivery by a bunch. Olimex will get my business again next time. Didier KO4BB > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Poul-Henning Kamp > Sent: Tuesday, July 08, 2008 12:54 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] PCB costs and suggestions for suppliers > > In message , "David > C. Partridge" writ > es: > > >I'm looking to get a PCB made up for my frequency divider > circuit. I'm > >based in the UK. > > I've used olimex.com for a couple of two-layer boards and I'm > happy with the results. > > One advantage for me was that they took EagleCad files > directly, so that I did't have to worry about inverted > gerbers and all that. > > Poul-Henning > From j-shank at comcast.net Tue Jul 8 21:41:29 2008 From: j-shank at comcast.net (jshank) Date: Tue, 8 Jul 2008 21:41:29 -0400 Subject: [time-nuts] Z3801A & ThunderBolt USING SAME ANTENNA? References: <20080617.214819.152643227461335425.cfmd@bredband.net> <27D659381D97425BAE55C71FC532FC9A@DESKTOP> Message-ID: Hi, I am trying to set up a Z3801A and a ThunderBolt to operate off of one symmetricom 58532A antenna using a symmetricom 4-port smartsplitter. The Z3801A manual suggest using LMR 400 cable which is a 50 ohm cable which is compatible with the antenna. The thunderbolt which I receive has a type F connector and the thunderbolt manual suggest using 75 ohm rg59 cable. Will I have a problem connecting the thunderbolt to the smartsplitter using LRM400 50 ohm cable? The thunderbolt which I received came with a type f to bnc connector, but isn't a bnc connector underrated to handle the 1.5 GHz signal? Thanks, Jeff From j-shank at comcast.net Tue Jul 8 21:44:37 2008 From: j-shank at comcast.net (jshank) Date: Tue, 8 Jul 2008 21:44:37 -0400 Subject: [time-nuts] Z3801A & ThunderBolt USING SAME ANTENNA? References: Message-ID: Hi, I am trying to set up a Z3801A and a ThunderBolt to operate off of one symmetricom 58532A antenna using a symmetricom 4-port smartsplitter. The Z3801A manual suggest using LMR 400 cable which is a 50 ohm cable which is compatible with the antenna. The thunderbolt which I receive has a type F connector and the thunderbolt manual suggest using 75 ohm rg59 cable. Will I have a problem connecting the thunderbolt to the smartsplitter using LRM400 50 ohm cable? The thunderbolt which I received came with a type f to bnc connector, but isn't a bnc connector underrated to handle the 1.5 GHz signal? Thanks, Jeff From bruce.griffiths at xtra.co.nz Tue Jul 8 21:54:39 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Wed, 09 Jul 2008 13:54:39 +1200 Subject: [time-nuts] Z3801A & ThunderBolt USING SAME ANTENNA? In-Reply-To: References: Message-ID: <48741A5F.8050708@xtra.co.nz> jshank wrote: > Hi, > > I am trying to set up a Z3801A and a ThunderBolt to operate off of one > symmetricom 58532A antenna using a symmetricom 4-port smartsplitter. The > Z3801A manual suggest using LMR 400 cable which is a 50 ohm cable which is > compatible with the antenna. The thunderbolt which I receive has a type F > connector and the thunderbolt manual suggest using 75 ohm rg59 cable. Will I > have a problem connecting the thunderbolt to the smartsplitter using LRM400 > 50 ohm cable? The thunderbolt which I received came with a type f to bnc > connector, but isn't a bnc connector underrated to handle the 1.5 GHz > signal? > > Thanks, > > Jeff > Jeff The 50 ohm BNC connector is rated up to 4GHz, the 75 ohm version to 2GHz. The F connector performance degrades above 1GHz but is still useful to several GHz. Both originated in the early 1950's. The Thunderbolt should work well with 50 ohm cable as its far from a precision match to either 50 or 75 ohm cable. Bruce From didier at cox.net Tue Jul 8 21:59:44 2008 From: didier at cox.net (Didier Juges) Date: Tue, 8 Jul 2008 20:59:44 -0500 Subject: [time-nuts] Z3801A & ThunderBolt USING SAME ANTENNA? In-Reply-To: References: Message-ID: <008a01c8e167$756e8ec0$0a01a8c0@didierhp> If the cable is long enough, the discontinuities brought by using a BNC connector should not be too much of a problem, unless you are trying to extract the very last ounce of performance from the Thunderbolt. A long cable will have significant attenuation, and that will absorb most of the reflections caused by the impedance mismatch and bring them down to the noise level. This subject has been covered at length not very long ago (a few months?), so a look through the archives might bring back the thread. You might want to read the Thunderbolt manual to get Trimble's official position on the subject. Trimble has done a good job of confusing people by specifying their equipment for 50 ohm operation but recommending 75 ohm cable and using F connectors on the Thunderbolt and the Bullet antenna. I surmise that for the Thunderbolt's intended application (cell site synchronization), the difference was not worth worrying about. For the true Time-Nuts, that may not be good enough. Didier KO4BB > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of jshank > Sent: Tuesday, July 08, 2008 8:45 PM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] Z3801A & ThunderBolt USING SAME ANTENNA? > > Hi, > > I am trying to set up a Z3801A and a ThunderBolt to operate > off of one symmetricom 58532A antenna using a symmetricom > 4-port smartsplitter. The Z3801A manual suggest using LMR > 400 cable which is a 50 ohm cable which is compatible with > the antenna. The thunderbolt which I receive has a type F > connector and the thunderbolt manual suggest using 75 ohm > rg59 cable. Will I have a problem connecting the thunderbolt > to the smartsplitter using LRM400 50 ohm cable? The > thunderbolt which I received came with a type f to bnc > connector, but isn't a bnc connector underrated to handle the > 1.5 GHz signal? > > Thanks, > > Jeff > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From jim77742 at gmail.com Tue Jul 8 22:10:52 2008 From: jim77742 at gmail.com (Jim Palfreyman) Date: Wed, 9 Jul 2008 12:10:52 +1000 Subject: [time-nuts] Double ovened 10811-60158 on ebay Message-ID: Sorry to pollute the list but some people here may be interested and I think this might be a good buy. Ebay item 250268030266 a bunch of 10811-60158 wrapped up in a second oven that have been pulled from a bunch of HP 58503A. There are 21 units available at US$50 Buy It Now. Postage seems reasonable too. I've bought one and so if anyone knows where I can get the cabling requirements please let me know. Regards, Jim Palfreyman From bob.paddock at gmail.com Tue Jul 8 22:46:47 2008 From: bob.paddock at gmail.com (Bob Paddock) Date: Tue, 8 Jul 2008 22:46:47 -0400 Subject: [time-nuts] Thunderbolt and USB to RS232 converters In-Reply-To: <4871B35B.2040508@smithfamily.net.au> References: <4871B35B.2040508@smithfamily.net.au> Message-ID: <200807082246.47237.bob.paddock@gmail.com> On Monday 07 July 2008 02:10:35 am David Smith wrote: > > I'm aware of those, but the next new USB serial device you plug in will > > still be the next higher number. It is the counter for this number I've > > not been able to locate. > > I've just sorted this problem on another thing I was doing, although I > was only up to COM14! > > It seems there are "hidden" hidden devices. Have a look at this: > http://support.microsoft.com/kb/315539 "Been There Done That", some time ago, but thanks for reminding me. I want to get all of these tips on my website related to this USB COM port saga. > Note that even plugging the same USB-RS232 converter into another USB > port on a hub will create a "new" COM port. I've dug into it enough that I understand why, but I'm still looking for where that "new" COM port number is coming from. Still trying to find that counter. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ From bruce.griffiths at xtra.co.nz Tue Jul 8 22:58:00 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Wed, 09 Jul 2008 14:58:00 +1200 Subject: [time-nuts] Z3801A & ThunderBolt USING SAME ANTENNA? Message-ID: <48742938.8020608@xtra.co.nz> jshank wrote: > Bruce, > > Do I need to spend the extra $ for LMR400 cable or could I just use > rg58 for a total run of 60 feet. > Jeff Jeff A conservative approach would be to use a cable that has an attenuation of no more than 10dB (the attenuation of the cable supplied in the Trimble Thunderbolt starter kit). For standard RG58 this can mean no more than about 30ft. This only applies if the antenna preamp gain is similar to that of the Trimble bullet antenna. _Minimum Antenna gain for Thunderbolt_ http://trl.trimble.com/docushare/dsweb/Get/Document-30908/Product Bullentin 200213.pdf Above link specifies a minimum of 20dB gain at Thunderbolt input. Thus with 23 dBattenuation (cable plus active splitter) you would need to use an antenna with at least 43dB gain preferably a little more. With 10dB of cable attenuation and 3dB maximum splitter loss the antenna preamp gain should be at least 33dB. The 5V Bullet III antenna has 35dB gain and thus allows a maximum attenuation (cable plus splitter) of about 15dB, preferably a little less, when used with a Thunderbolt. GPS Timing antennas with higher gains (50dB) are available. Bruce From holrum at hotmail.com Tue Jul 8 23:55:31 2008 From: holrum at hotmail.com (Mark Sims) Date: Wed, 9 Jul 2008 03:55:31 +0000 Subject: [time-nuts] Thunderbolt Power Question In-Reply-To: References: Message-ID: An earlier question concerned whether the Thunderbolt could be put into battery backup mode without the -12V supply. The definitive answer is NO! The Thunderbolt OCXO is controlled via a DAC voltage that can range from -5V to 5V (the standard oscillator control is -5Hz/V. All mine are operating at around 0.35V). The -5V DAC reference depends upon the -12V input supply. Also the Thunderbolt monitors all three supply voltages and it will throw a critical alarm condition when any are out of whack. _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From hmurray at megapathdsl.net Wed Jul 9 03:12:14 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Wed, 09 Jul 2008 00:12:14 -0700 Subject: [time-nuts] Z3801A & ThunderBolt USING SAME ANTENNA? In-Reply-To: Message from "jshank" of "Tue, 08 Jul 2008 21:44:37 EDT." Message-ID: <20080709071215.6AD38BCCB@ip-64-139-1-69.sjc.megapath.net> > Will I have a problem connecting the thunderbolt to the smartsplitter > using LRM400 50 ohm cable? Try whatever cable you have handy. It's not likely to break anything. I'm assuming you have some way to monitor your Thunderbolt and see if it's working well enough. -- These are my opinions, not necessarily my employer's. I hate spam. From magnus at rubidium.dyndns.org Wed Jul 9 05:55:41 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Wed, 09 Jul 2008 11:55:41 +0200 (CEST) Subject: [time-nuts] Z3801A & ThunderBolt USING SAME ANTENNA? In-Reply-To: <48741A5F.8050708@xtra.co.nz> References: <48741A5F.8050708@xtra.co.nz> Message-ID: <20080709.115541.415917433278915411.cfmd@bredband.net> From: Bruce Griffiths Subject: Re: [time-nuts] Z3801A & ThunderBolt USING SAME ANTENNA? Date: Wed, 09 Jul 2008 13:54:39 +1200 Message-ID: <48741A5F.8050708 at xtra.co.nz> Bruce, > The 50 ohm BNC connector is rated up to 4GHz, the 75 ohm version to 2GHz. Modern 75 Ohm BNC and cable is rated for 4.5 GHz. Used for 2.97 Gb/s HD-SDI. See Trumpeter and Belden cables. > The F connector performance degrades above 1GHz but is still useful to > several GHz. > Both originated in the early 1950's. > The Thunderbolt should work well with 50 ohm cable as its far from a > precision match to either 50 or 75 ohm cable. Cheers, Magnus From wje at quackers.net Wed Jul 9 07:10:40 2008 From: wje at quackers.net (wje) Date: Wed, 09 Jul 2008 07:10:40 -0400 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: Message-ID: <48749CB0.7060109@quackers.net> www.hparchive.com/Manuals/HP-10811AB-Manual.pdf These seem to be a slight variation on the 10811B, but I imagine the pinouts are the same, other than the connectors. Hmm... I think I'll get one. Bill Ezell ---------- They said 'Windows or better' so I used Linux. Jim Palfreyman wrote: Sorry to pollute the list but some people here may be interested and I think this might be a good buy. Ebay item 250268030266 a bunch of 10811-60158 wrapped up in a second oven that have been pulled from a bunch of HP 58503A. There are 21 units available at US$50 Buy It Now. Postage seems reasonable too. I've bought one and so if anyone knows where I can get the cabling requirements please let me know. Regards, Jim Palfreyman _______________________________________________ time-nuts mailing list -- [1]time-nuts at febo.com To unsubscribe, go to [2]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:time-nuts at febo.com 2. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts From attila at kinali.ch Wed Jul 9 08:06:59 2008 From: attila at kinali.ch (Attila Kinali) Date: Wed, 9 Jul 2008 14:06:59 +0200 Subject: [time-nuts] PCB costs and suggestions for suppliers In-Reply-To: References: Message-ID: <20080709140659.4f7fecf9.attila@kinali.ch> On Tue, 8 Jul 2008 17:49:42 +0100 "David C. Partridge" wrote: > I'm looking to get a PCB made up for my frequency divider circuit. I'm > based in the UK. So far the best price I've found is about 160 Euro plus > tax and delivery for one 5" (127mm) by 3.5" (88.9mm) 4-layer board (from > PCB-Pool). As I've not had a PCB made up in the last twenty odd years, I > don't know if this is typical, or whether I should be able to get a better > price. The price sounds reasonable, depending on what options you choose from. The cost of a PCB is mostly dependend on the smallest feature size, which not only includes track width, but also the spacing between tracks or pads. Also keep the number of different sized holes at a minimum (the number itself isn't very much important unless you have 100s of them). Also keep in mind that most of these PCB services use some unspecified FR4 whith very varying quality. Ie you should either design for tracks without specific impedance or choose a better base material. Attila Kinali -- It is the unknown we fear when we look upon death and darkness, nothing more. -- Albus P. W. B. Dumbledore From stanley_reynolds at yahoo.com Wed Jul 9 10:38:11 2008 From: stanley_reynolds at yahoo.com (Stanley Reynolds) Date: Wed, 9 Jul 2008 07:38:11 -0700 (PDT) Subject: [time-nuts] Use of Austron 2100F "Phase Corrected Output" Message-ID: <307405.1821.qm@web30303.mail.mud.yahoo.com> As mesured with a HP-5334A and GPS DO as reference: The phase corrected output does jump around a bit most of the time? (+- .2 Hz) and on occasion (< 100 Hz > 50 Hz). A 100 sample average looks much better but still need logic to throw out the big variations and average more samples. Stanley ----- Original Message ---- From: Stanley Reynolds To: Discussion of precise time and frequency measurement Sent: Tuesday, July 1, 2008 3:05:01 PM Subject: Re: [time-nuts] Use of Austron 2100F "Phase Corrected Output" I would like to know as well. My experiment in the thread "Calibrating the Lucent RFG-M-XO Efratom 10MHz OCXO Oscillator w/ EFC" using the phase corrected output has failed twice, not sure of the reason could be a problem with my lack of knowledge abt the Lucent error correcting oscillator or the 2100F.? It takes > 10 hours for it to fail think this could be related to the?rate the Austron updates. The chart output is also available to steer the disciplined oscillator but with my unit this output jumps around quite a bit. Either output could be processed / filtered to slow the skew. Stanley? ----- Original Message ---- From: Jim Robbins To: time-nuts at febo.com Sent: Sunday, June 29, 2008 9:16:25 PM Subject: [time-nuts] Use of Austron 2100F "Phase Corrected Output" Hi all, I believe I read that it was a mistake to use the "Phase Corrected Output" 10 MHz signal from the 2100F as the time base source for other equipment?? Something about the corrections being in steps.? Has anyone else had any experience with this?? If so, what is the problem with the output?? Thanks. Jim Robbins, N1JR _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ? ? ? _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From Arnold.Tibus at gmx.de Wed Jul 9 12:42:31 2008 From: Arnold.Tibus at gmx.de (Arnold Tibus) Date: Wed, 09 Jul 2008 18:42:31 +0200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: Message-ID: On Wed, 9 Jul 2008 12:10:52 +1000, Jim Palfreyman wrote: >Sorry to pollute the list but some people here may be interested and I think >this might be a good buy. >Ebay item 250268030266 a bunch of 10811-60158 wrapped up in a second oven >that have been pulled from a bunch of HP 58503A. >There are 21 units available at US$50 Buy It Now. Postage seems reasonable >too. >I've bought one and so if anyone knows where I can get the cabling >requirements please let me know. >Regards, >Jim Palfreyman Jim, have a look into the manual GPS Disciplined 10 MHz Frequency Standard by James Miller G3RUH http://www.jrmiller.demon.co.uk/projects/freqstd/manual.pdf he did apply this type and describe the connections. Good luck! Regards, Arnold Tibus From time at johnea.net Thu Jul 10 02:15:52 2008 From: time at johnea.net (time at johnea.net) Date: Wed, 9 Jul 2008 23:15:52 -0700 Subject: [time-nuts] viewing the upcoming leapsecond with XDaliClock In-Reply-To: References: Message-ID: <20080710061552.GA34986@mail.johnea.net> Hello to everyone, I'm new to the list and would like to ask about displaying the upcoming leap second on a linux workstation. I use a PC running linux 2.6.24 and the djb clockspeed daemon periodically synchronized with a couple of different NTP servers. I usually have a correct reading within ~10ms (I know, it's not atomic time 8-) I also use the "right/America/Los_Angeles" time zoneinfo file for correct synchronization with TAI, and installed the new leapsecond.dat file for 2008 in /etc. (and I restarted clockspeed) I'm on the pacific coast of the US and as such the leapsecond occurs here just before 4pm. I've used the date command to set the time of my computer to Dec 31 2008 15:58 PDT and watched as the hour rolled over: No LeapSecond! It goes from 15:59:59 to 16:00:00 I've been using XDaliClock as the display, which uses the unix localtime() call to retrieve the time from the system. I've done quite a bit of scroogling in an attempt to determine how the time is kept in the kernel and how it makes it's way through to userspace for applications like date and xdaliclock to access. I didn't determine 8-( Can anyone advise me as to the feasibility of using this configuration to display the leapsecond to a crowd of eager viewers at the end of this year? Thank you so much for your consideration of my noobish question, and for maintaining an active interest in something just because you like it! ciao bella... johnea From hmurray at megapathdsl.net Thu Jul 10 03:10:00 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Thu, 10 Jul 2008 00:10:00 -0700 Subject: [time-nuts] viewing the upcoming leapsecond with XDaliClock In-Reply-To: Message from time@johnea.net of "Wed, 09 Jul 2008 23:15:52 PDT." <20080710061552.GA34986@mail.johnea.net> Message-ID: <20080710071001.C6C2FBCCD@ip-64-139-1-69.sjc.megapath.net> > I'm new to the list and would like to ask about displaying the > upcoming leap second on a linux workstation. Stick around. There will be a big party. You might check the archives to see the discussion from the last one. > I've done quite a bit of scroogling in an attempt to determine how > the time is kept in the kernel and how it makes it's way through > to userspace for applications like date and xdaliclock to access. The kernel works in UTC. Conversion to/from local time is done in userspace, usually in the c library. Daylight time is a nightmare because politicians keep changing the rules. There is a project that tries to keep track of things. Essentially, all of the open source projects use it. http://en.wikipedia.org/wiki/Zoneinfo The default conversion info is stored in /etc/localtime There is an environment variable, TZ (I think) so you can use your preference rather than the default. This might be handy if you dial in to a system in another zone. -- These are my opinions, not necessarily my employer's. I hate spam. From j.koegel5 at gmail.com Thu Jul 10 04:36:23 2008 From: j.koegel5 at gmail.com (=?ISO-8859-1?Q?J=FCrg_K=F6gel?=) Date: Thu, 10 Jul 2008 10:36:23 +0200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <48749CB0.7060109@quackers.net> References: <48749CB0.7060109@quackers.net> Message-ID: <390229150807100136v4f4e98afp3a3e5e5e694fe1d@mail.gmail.com> 2008/7/9 wje : > www.hparchive.com/Manuals/HP-10811AB-Manual.pdf > These seem to be a slight variation on the 10811B, but I imagine the > pinouts are the same, other than the connectors. > Hmm... I think I'll get one. > Bill Ezell > ---------- > They said 'Windows or better' > so I used Linux. > > Jim Palfreyman wrote: > > Sorry to pollute the list but some people here may be interested and I think > this might be a good buy. > > Ebay item 250268030266 a bunch of 10811-60158 wrapped up in a second oven > that have been pulled from a bunch of HP 58503A. > > There are 21 units available at US$50 Buy It Now. Postage seems reasonable > too. > > I've bought one and so if anyone knows where I can get the cabling > requirements please let me know. > > > Regards, > > Jim Palfreyman > _______________________________________________ > time-nuts mailing list -- [1]time-nuts at febo.com > To unsubscribe, go to [2]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > References > > 1. mailto:time-nuts at febo.com > 2. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > Also have a look at http://homepage.sunrise.ch/mysunrise/shegnauer/Z3801A/Power%20Supply/z3801a_power_supply.htm http://homepage.sunrise.ch/mysunrise/shegnauer/Z3801A/Outer%20Oven%20Controller/z3801a_outer_oven_description.htm Regards Juerg From david.partridge at dsl.pipex.com Thu Jul 10 16:30:56 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Thu, 10 Jul 2008 21:30:56 +0100 Subject: [time-nuts] Frequency divider design critique request Message-ID: As I've mentioned before, I've been working on the design of a frequency divider to go with my TB. The idea is 10MHz sine in from TB, output 2.5Vp-p 50% duty cycle square wave into 50R (5V into 1M), at 10Mhz, 5MHz, 1MHz and decade selectable 100kHz down to 1Hz. All rising edges synchronised to the 10MHz clock rising edge (or as near as I can get with 74AC logic). With a considerable amount of constructive criticism from Bruce Griffiths (thank you again Bruce) I believe the design now to be complete. The aim is to have as low a level of nasties as possible (i.e. fit for time-nuts). All faults are my own - no blame attaches to Bruce! I've not yet subjected this design to the ultimate simulation tool (PCB, parts and solder) yet, and I have no means to test it for levels of jitter (phase noise) or similar nasties. I think that it's now the right time to open the design up for critique from a wider audience before I commit it to copper. I'm therefore attaching the design as a PDF file for your comments. A few comments are in order: 1) The 5Mhz and 1MHz outputs are re-clocked TWICE deliberately to delay them by one clock cycle so they line up with the 1MHz and lower outputs. 2) The selected output (at the '4051 mux) from the ripple counter chain is re-clocked to 1MHz before re-clocking to 10MHz as the worst-case delay in the chain of '4017s is large enough that the lower frquencies wouldn't reliably re-clock directly to 10MHz. I have also done a PCB layout (4-layer) and I'm happy to send a print of the top/bottom layers to anyone who feels that they want to comment on that (inner layers are ground and power). Let the brick-bats be thrown! Cheers Dave No virus found in this outgoing message. Checked by AVG - http://www.avg.com Version: 8.0.138 / Virus Database: 270.4.7/1544 - Release Date: 10/07/2008 07:37 -------------- next part -------------- A non-text attachment was scrubbed... Name: Frequency Divider 2.pdf Type: application/pdf Size: 44459 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080710/01222309/attachment-0001.pdf From wb6bnq at cox.net Thu Jul 10 16:58:16 2008 From: wb6bnq at cox.net (WB6BNQ) Date: Thu, 10 Jul 2008 13:58:16 -0700 Subject: [time-nuts] Frequency divider design critique request References: Message-ID: <487677E8.3B70552D@cox.net> In my best "HAL 9000" voice; Hi Dave. Dave, what are you doing ? Dave we need BNC connectors. Those SMB's are hard to work with. Dave, are you intending to have those SMB's stick out through a panel ? Dave ? Dave, let me suggest that you layout the connector pattern so either one can be used and stick out a panel. Dave ? Dave ? Why are you unplugging my internet feeeeeee-------- Bill....WB6BNQ "David C. Partridge" wrote: > As I've mentioned before, I've been working on the design of a frequency > divider to go with my TB. > > The idea is 10MHz sine in from TB, output 2.5Vp-p 50% duty cycle square wave > into 50R (5V into 1M), at 10Mhz, 5MHz, 1MHz and decade selectable 100kHz > down to 1Hz. All rising edges synchronised to the 10MHz clock rising edge > (or as near as I can get with 74AC logic). With a considerable amount of > constructive criticism from Bruce Griffiths (thank you again Bruce) I > believe the design now to be complete. > > The aim is to have as low a level of nasties as possible (i.e. fit for > time-nuts). > > All faults are my own - no blame attaches to Bruce! > > I've not yet subjected this design to the ultimate simulation tool (PCB, > parts and solder) yet, and I have no means to test it for levels of jitter > (phase noise) or similar nasties. > > I think that it's now the right time to open the design up for critique from > a wider audience before I commit it to copper. > > I'm therefore attaching the design as a PDF file for your comments. > > A few comments are in order: > > 1) The 5Mhz and 1MHz outputs are re-clocked TWICE deliberately to delay them > by one clock cycle so they line up with the 1MHz and lower outputs. > > 2) The selected output (at the '4051 mux) from the ripple counter chain is > re-clocked to 1MHz before re-clocking to 10MHz as the worst-case delay in > the chain of '4017s is large enough that the lower frquencies wouldn't > reliably re-clock directly to 10MHz. > > I have also done a PCB layout (4-layer) and I'm happy to send a print of the > top/bottom layers to anyone who feels that they want to comment on that > (inner layers are ground and power). > > Let the brick-bats be thrown! > > Cheers > Dave > No virus found in this outgoing message. > Checked by AVG - http://www.avg.com > Version: 8.0.138 / Virus Database: 270.4.7/1544 - Release Date: 10/07/2008 > 07:37 > > ------------------------------------------------------------------------ > Name: Frequency Divider 2.pdf > Frequency Divider 2.pdf Type: Portable Document Format (application/pdf) > Encoding: base64 > > ------------------------------------------------------------------------ > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From jmiles at pop.net Thu Jul 10 17:19:24 2008 From: jmiles at pop.net (John Miles) Date: Thu, 10 Jul 2008 14:19:24 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <487677E8.3B70552D@cox.net> Message-ID: I am not a big fan of BNC connectors on the PC board itself, because I am not a big fan of attaching PC boards directly to panels in most cases. There are usually some BNC bulkhead connectors on eBay that terminate in SMA/SMB/SMC pigtails, which are great for panel mounting. http://cgi.ebay.com/eBayISAPI.dll?ViewItem&item=280222636701 fr'instance. That being said, it doesn't matter, because this board has a fault which will cause it to go a hundred percent failure within 72 hours. It is still within operational limits right now, though, and it will stay that way until it fails. :-P -- john, KE5FX > In my best "HAL 9000" voice; > > Hi Dave. Dave, what are you doing ? Dave we need BNC > connectors. Those SMB's > are hard to work with. Dave, are you intending to have those > SMB's stick out > through a panel ? Dave ? Dave, let me suggest that you layout > the connector > pattern so either one can be used and stick out a panel. > > Dave ? Dave ? Why are you unplugging my internet feeeeeee-------- > > Bill....WB6BNQ > From magnus at rubidium.dyndns.org Thu Jul 10 18:06:30 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Fri, 11 Jul 2008 00:06:30 +0200 (CEST) Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: Message-ID: <20080711.000630.415917433278911752.cfmd@bredband.net> From: "David C. Partridge" Subject: [time-nuts] Frequency divider design critique request Date: Thu, 10 Jul 2008 21:30:56 +0100 Message-ID: David, > As I've mentioned before, I've been working on the design of a frequency > divider to go with my TB. > > The idea is 10MHz sine in from TB, output 2.5Vp-p 50% duty cycle square wave > into 50R (5V into 1M), at 10Mhz, 5MHz, 1MHz and decade selectable 100kHz > down to 1Hz. All rising edges synchronised to the 10MHz clock rising edge > (or as near as I can get with 74AC logic). Good initial concept. > With a considerable amount of constructive criticism from Bruce Griffiths > (thank you again Bruce) I believe the design now to be complete. > > The aim is to have as low a level of nasties as possible (i.e. fit for > time-nuts). > > All faults are my own - no blame attaches to Bruce! The one thing I would do is to hook caps over at R24 to R26, say 10 nF, to make the thumb wheel leads less susceptible to noise and less of areal for the edges from the CMOS. The thumb-wheel either keep them floating in one end or didged hard to +5V. To avoid both E and H fields, a series-resistor should be included. > I've not yet subjected this design to the ultimate simulation tool (PCB, > parts and solder) yet, and I have no means to test it for levels of jitter > (phase noise) or similar nasties. I am sure we can come up with some arrangement for that. Several handy time-nuts around. > I think that it's now the right time to open the design up for critique from > a wider audience before I commit it to copper. > > I'm therefore attaching the design as a PDF file for your comments. > > A few comments are in order: > > 1) The 5Mhz and 1MHz outputs are re-clocked TWICE deliberately to delay them > by one clock cycle so they line up with the 1MHz and lower outputs. Neat. > 2) The selected output (at the '4051 mux) from the ripple counter chain is > re-clocked to 1MHz before re-clocking to 10MHz as the worst-case delay in > the chain of '4017s is large enough that the lower frquencies wouldn't > reliably re-clock directly to 10MHz. Good thinking! > I have also done a PCB layout (4-layer) and I'm happy to send a print of the > top/bottom layers to anyone who feels that they want to comment on that > (inner layers are ground and power). ... and you say they are not of interest? > Let the brick-bats be thrown! I have a lots of bricks around me (my summerhouse is build with old handmade bricks) but I wont toss them. So far, only the thumbwheel is the only minor flaw that I could come up with. I need to check some more... I rather have a few questions on why you did not include certain features... In my experience, having a few extra 10 MHz signals to feed Ext Ref on instruments is a good thing. That way you can keep these others at hand for various setups you need to do. I would consider a dedicated 1 PPS output. I would consider a synchronise feature with a PPS/synchronise input. It should be wise to not directly wire it to the counter resets, but provide an arm button and maybe a very simple arrangement to indicate "left", "on mark" and "right" with red, gren, red LEDs. Just a tought. The arm button could also have an electrical input, but I am running into creaping featurism here. I think however that synchronisation might be a good thing. That way you can shift the phase of the signal to fit your need. Pulling and inserting the 10 MHz cable is a very crude way of doing it. Maybe it would be just too much fuzz for too little gain, what do I know, but I know I would enjoy seeing it. A pulse-add/pulse-swallow technique (with a shift in initial divide by 10) could be used to provide inc/dec functionality for a manual movement of phase. Cheers, Magnus From bruce.griffiths at xtra.co.nz Thu Jul 10 18:57:21 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 11 Jul 2008 10:57:21 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <20080711.000630.415917433278911752.cfmd@bredband.net> References: <20080711.000630.415917433278911752.cfmd@bredband.net> Message-ID: <487693D1.5090604@xtra.co.nz> Hej Magnus Magnus Danielson wrote: > David, > > >> As I've mentioned before, I've been working on the design of a frequency >> divider to go with my TB. >> >> The idea is 10MHz sine in from TB, output 2.5Vp-p 50% duty cycle square wave >> into 50R (5V into 1M), at 10Mhz, 5MHz, 1MHz and decade selectable 100kHz >> down to 1Hz. All rising edges synchronised to the 10MHz clock rising edge >> (or as near as I can get with 74AC logic). >> > > Good initial concept. > > >> With a considerable amount of constructive criticism from Bruce Griffiths >> (thank you again Bruce) I believe the design now to be complete. >> >> The aim is to have as low a level of nasties as possible (i.e. fit for >> time-nuts). >> >> All faults are my own - no blame attaches to Bruce! >> > > The one thing I would do is to hook caps over at R24 to R26, say 10 nF, to > make the thumb wheel leads less susceptible to noise and less of areal for > the edges from the CMOS. The thumb-wheel either keep them floating in one > end or didged hard to +5V. To avoid both E and H fields, a series-resistor > should be included. > > You mean?: 1) Connect a 10nF capacitor from each multiplexer digital control input to ground. 2) Connect a series resistor (10k?) from multiplexer control input to the thumbwheel connector pin. 3) Connect a pullup/pulldown resistor from the thumbwheel connector pin to GND or VCC as required. >> I've not yet subjected this design to the ultimate simulation tool (PCB, >> parts and solder) yet, and I have no means to test it for levels of jitter >> (phase noise) or similar nasties. >> > > I am sure we can come up with some arrangement for that. Several handy > time-nuts around. > > >> I think that it's now the right time to open the design up for critique from >> a wider audience before I commit it to copper. >> >> I'm therefore attaching the design as a PDF file for your comments. >> >> A few comments are in order: >> >> 1) The 5Mhz and 1MHz outputs are re-clocked TWICE deliberately to delay them >> by one clock cycle so they line up with the 1MHz and lower outputs. >> > > Neat. > > >> 2) The selected output (at the '4051 mux) from the ripple counter chain is >> re-clocked to 1MHz before re-clocking to 10MHz as the worst-case delay in >> the chain of '4017s is large enough that the lower frquencies wouldn't >> reliably re-clock directly to 10MHz. >> > > Good thinking! > > >> I have also done a PCB layout (4-layer) and I'm happy to send a print of the >> top/bottom layers to anyone who feels that they want to comment on that >> (inner layers are ground and power). >> > > ... and you say they are not of interest? > > >> Let the brick-bats be thrown! >> > > I have a lots of bricks around me (my summerhouse is build with old handmade > bricks) but I wont toss them. > > So far, only the thumbwheel is the only minor flaw that I could come up with. > > I need to check some more... > > I rather have a few questions on why you did not include certain features... > > In my experience, having a few extra 10 MHz signals to feed Ext Ref on > instruments is a good thing. That way you can keep these others at hand for > various setups you need to do. > > I would consider a dedicated 1 PPS output. > > I would consider a synchronise feature with a PPS/synchronise input. It should > be wise to not directly wire it to the counter resets, but provide an arm > button and maybe a very simple arrangement to indicate "left", "on mark" and > "right" with red, gren, red LEDs. Just a tought. The arm button could also > have an electrical input, but I am running into creaping featurism here. > I think however that synchronisation might be a good thing. That way you can > shift the phase of the signal to fit your need. Pulling and inserting the > 10 MHz cable is a very crude way of doing it. > Maybe it would be just too much fuzz for too little gain, what do I know, but > I know I would enjoy seeing it. > A pulse-add/pulse-swallow technique (with a shift in initial divide by 10) > could be used to provide inc/dec functionality for a manual movement of phase. > > The only minor problem is that shifting phase by 1sec or so at the 1pps output will take quite a while if one were to delete 1 pulse per second (to maintain 100ns resolution via pushbutton). A variable phase adjustment rate would work but that adds considerable complication. One method is to allow phase shifting decade by decade. Another way to handle large phase adjustments is to use 2 divider chains, the master is clocked continuously without phase adjustments. The slave is adjusted by preloading it with the desired phase shift when the master divider rolls over. This is easiest to do with synchronous decade counters like the 74XX160/2, however these seem to be hard to find. However this adds considerable complexity and would be much easier to implement in a CPLD or FPGA. External resynchronising/reclocking flipflops would be required to minimise phase modulation of higher frequency outputs by lower frequency outputs. > Cheers, > Magnus > Bruce From time at johnea.net Thu Jul 10 19:15:18 2008 From: time at johnea.net (time at johnea.net) Date: Thu, 10 Jul 2008 16:15:18 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: Message-ID: <20080710231518.GA40432@mail.johnea.net> Hi David, It looks like your design is pretty far along, so maybe it's too late for this suggestion, but one thing you might consider is replacing the 7400 series logic with a 5V CPLD programmable logic device. This could offer several advantages: 1) any issues (such as jitter) could be addressed by reflashing the CPLD and may let you avoid hardware PCB changes. 2) new features or applications (specially created triggers or unusual pulse outputs) that may come up in the future could possibly be added, again without PCB changes. 3) a full simulation of the design could performed prior to construction Xilinx offers a free (as in free beer, not as in free speech) complete programmable logic design simulation and synthesis tool for download from their website. It's called ISE WebPACK. There's a version for windows or linux host: http://www.xilinx.com/ise/logic_design_prod/webpack.htm This tool is quite an amazing free download. I had to go through a few gyrations to get the USB "cable", as they call the downloader, to build for linux: http://wiki.archlinux.org/index.php/Xilinx_ISE_WebPACK_10.1_wUSB_cable_on_ArchLinux-2.6.24 But I'm sure it's easier on windows. The CPLD's (unlike the FPGAs) are single chip solutions. The XC9500 family is 5V logic compatible and could fit into something as small as a 44 pin package. The ISE design tool offers built in Verilog, VHDL or CUPL programming laguages, or (and this really amazed me) a built in schematic editor tool! This lets you capture the design, just as you have, in a schematic, and then synthesize the logic and perform a complete simulation of your captured schematic. You could even just download the tool, capture your existing schematic (there are logic elements for 7400 series logic devices) and use the tool as a simulation engine to test your design. Even if you ultimately plan to use the 7400 parts. No, I don't work for Xilinx 8-) but I did just finish a design using this tool and was suitably impressed. While I write quite a bit of code in my day to day work, I hadn't designed programmable logic since the old PAL days (way back in the early 80's 8-) I used the schematic capture feature of ISE to input the design and then found my way into writing the control state machines in verilog. Then simulated the functionality and when we built the hardware the whole thing just worked, right out of the box! (The design ran an A/D converter, captured the results into a static ram, and then allowed SPI access to the ram from an AVR microcontroller) I know going to programmable logic can seem like a big unknown, but perhaps it's worth just downloading the tool and checking it out. The CPLD wouldn't replace any of your signal conditioning, fusing, etc, but it could replace the core counters, muxes, etc and give you something that could continue to grow as the years go by. Very Cool Project! johnea On Thu, Jul 10, 2008 at 09:30:56PM +0100, David C. Partridge wrote: > As I've mentioned before, I've been working on the design of a frequency > divider to go with my TB. > > The idea is 10MHz sine in from TB, output 2.5Vp-p 50% duty cycle square wave > into 50R (5V into 1M), at 10Mhz, 5MHz, 1MHz and decade selectable 100kHz > down to 1Hz. All rising edges synchronised to the 10MHz clock rising edge > (or as near as I can get with 74AC logic). With a considerable amount of > constructive criticism from Bruce Griffiths (thank you again Bruce) I > believe the design now to be complete. > > The aim is to have as low a level of nasties as possible (i.e. fit for > time-nuts). > > All faults are my own - no blame attaches to Bruce! > > I've not yet subjected this design to the ultimate simulation tool (PCB, > parts and solder) yet, and I have no means to test it for levels of jitter > (phase noise) or similar nasties. > > I think that it's now the right time to open the design up for critique from > a wider audience before I commit it to copper. > > I'm therefore attaching the design as a PDF file for your comments. > > A few comments are in order: > > 1) The 5Mhz and 1MHz outputs are re-clocked TWICE deliberately to delay them > by one clock cycle so they line up with the 1MHz and lower outputs. > > 2) The selected output (at the '4051 mux) from the ripple counter chain is > re-clocked to 1MHz before re-clocking to 10MHz as the worst-case delay in > the chain of '4017s is large enough that the lower frquencies wouldn't > reliably re-clock directly to 10MHz. > > I have also done a PCB layout (4-layer) and I'm happy to send a print of the > top/bottom layers to anyone who feels that they want to comment on that > (inner layers are ground and power). > > Let the brick-bats be thrown! > > Cheers > Dave > No virus found in this outgoing message. > Checked by AVG - http://www.avg.com > Version: 8.0.138 / Virus Database: 270.4.7/1544 - Release Date: 10/07/2008 > 07:37 > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From bruce.griffiths at xtra.co.nz Thu Jul 10 19:33:53 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 11 Jul 2008 11:33:53 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <20080710231518.GA40432@mail.johnea.net> References: <20080710231518.GA40432@mail.johnea.net> Message-ID: <48769C61.5000501@xtra.co.nz> time at johnea.net wrote: > Hi David, > > It looks like your design is pretty far along, so maybe it's too late for this suggestion, but one thing you might consider is replacing the 7400 series logic with a 5V CPLD programmable logic device. > > This could offer several advantages: > > 1) any issues (such as jitter) could be addressed by reflashing the CPLD and may let you avoid hardware PCB changes. > You cannot "fix" modulation of the higher frequency divider outputs by lower frequency outputs by reprogramming a CPLD or FPGA. External reclocking/resynchronising flipflops (one per output frequency) are required > 2) new features or applications (specially created triggers or unusual pulse outputs) that may come up in the future could possibly be added, again without PCB changes. > > 3) a full simulation of the design could performed prior to construction > > Xilinx offers a free (as in free beer, not as in free speech) complete programmable logic design simulation and synthesis tool for download from their website. It's called ISE WebPACK. There's a version for windows or linux host: > > http://www.xilinx.com/ise/logic_design_prod/webpack.htm > > This tool is quite an amazing free download. I had to go through a few gyrations to get the USB "cable", as they call the downloader, to build for linux: > > http://wiki.archlinux.org/index.php/Xilinx_ISE_WebPACK_10.1_wUSB_cable_on_ArchLinux-2.6.24 > > But I'm sure it's easier on windows. > > The CPLD's (unlike the FPGAs) are single chip solutions. The XC9500 family is 5V logic compatible and could fit into something as small as a 44 pin package. > > The ISE design tool offers built in Verilog, VHDL or CUPL programming laguages, or (and this really amazed me) a built in schematic editor tool! This lets you capture the design, just as you have, in a schematic, and then synthesize the logic and perform a complete simulation of your captured schematic. > > You could even just download the tool, capture your existing schematic (there are logic elements for 7400 series logic devices) and use the tool as a simulation engine to test your design. Even if you ultimately plan to use the 7400 parts. > > Just dont use this method to implement the dividers etc in the CPLD. Its better to use a fully synchronous decade divider chain if possible as this eliminates all the realignment logic required with ripple clocked divider chains. Another issue with some (but not all) CPLDs are the power supply requirements, at least with CMOS the divider (when not driving too many outputs) has a low power supply current making battery operation feasible. > No, I don't work for Xilinx 8-) but I did just finish a design using this tool and was suitably impressed. While I write quite a bit of code in my day to day work, I hadn't designed programmable logic since the old PAL days (way back in the early 80's 8-) I used the schematic capture feature of ISE to input the design and then found my way into writing the control state machines in verilog. Then simulated the functionality and when we built the hardware the whole thing just worked, right out of the box! > > (The design ran an A/D converter, captured the results into a static ram, and then allowed SPI access to the ram from an AVR microcontroller) > > I know going to programmable logic can seem like a big unknown, but perhaps it's worth just downloading the tool and checking it out. > > The CPLD wouldn't replace any of your signal conditioning, fusing, etc, but it could replace the core counters, muxes, etc and give you something that could continue to grow as the years go by. > > Very Cool Project! > > johnea > Bruce From bruce.griffiths at xtra.co.nz Thu Jul 10 19:40:37 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 11 Jul 2008 11:40:37 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <20080711.000630.415917433278911752.cfmd@bredband.net> References: <20080711.000630.415917433278911752.cfmd@bredband.net> Message-ID: <48769DF5.7040001@xtra.co.nz> Magnus Danielson wrote: > I would consider a dedicated 1 PPS output. > > I would consider a synchronise feature with a PPS/synchronise input. It should > be wise to not directly wire it to the counter resets, but provide an arm > button and maybe a very simple arrangement to indicate "left", "on mark" and > "right" with red, gren, red LEDs. Just a tought. The arm button could also > have an electrical input, but I am running into creaping featurism here. > I think however that synchronisation might be a good thing. That way you can > shift the phase of the signal to fit your need. Pulling and inserting the > 10 MHz cable is a very crude way of doing it. > Maybe it would be just too much fuzz for too little gain, what do I know, but > I know I would enjoy seeing it. > A pulse-add/pulse-swallow technique (with a shift in initial divide by 10) > could be used to provide inc/dec functionality for a manual movement of phase. > > Cheers, > Magnus > > Hej Magnus The easiest way to add a synchronise feature is to use a shift register clocked at 10MHz (if the input PPS pulse width is sufficient > 1us?) as the synchroniser. The various shift register taps can be used to generate a synchronous preload pulse for the input divider and a wider reset pulse for the 74HC4017's. If narrower sync pulses are likely then use the sync pulse to toggle a flipflop than connect the flipflop output to the shift register input and use 74XX86 XOR gates to generate the preload and REST pulses from the shift register taps. Bruce From bob.paddock at gmail.com Thu Jul 10 19:57:01 2008 From: bob.paddock at gmail.com (Bob Paddock) Date: Thu, 10 Jul 2008 19:57:01 -0400 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <20080710231518.GA40432@mail.johnea.net> References: <20080710231518.GA40432@mail.johnea.net> Message-ID: > The CPLD's (unlike the FPGAs) are single chip solutions. There are many single chip FPGA solutions today from several different companies. If you are in the US and near a Avnet office you can pick up a Actel Igloo Icicle eval. board/programmer for $49. They are giving them out at the Actel Power seminars being held in July and August. I'll be at the one in Cleveland next week if anyone is there. Don't know if this URL will work or not: http://www.em.avnet.com/evs/home/0,4582,CID%253D47005%2526CCD%253DUSA%2526SID%253D32214%2526DID%253DDF2%2526LID%253D32233%2526BID%253DDF2%2526CTP%253DEVS,00.html?SUL=actellowpower -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ From time at johnea.net Thu Jul 10 20:08:05 2008 From: time at johnea.net (time at johnea.net) Date: Thu, 10 Jul 2008 17:08:05 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <48769C61.5000501@xtra.co.nz> References: <20080710231518.GA40432@mail.johnea.net> <48769C61.5000501@xtra.co.nz> Message-ID: <20080711000805.GA40723@mail.johnea.net> On Fri, Jul 11, 2008 at 11:33:53AM +1200, Bruce Griffiths wrote: > time at johnea.net wrote: > > Hi David, > > > > It looks like your design is pretty far along, so maybe it's too late for this suggestion, but one thing you might consider is replacing the 7400 series logic with a 5V CPLD programmable logic device. > > > > This could offer several advantages: > > > > 1) any issues (such as jitter) could be addressed by reflashing the CPLD and may let you avoid hardware PCB changes. > > > You cannot "fix" modulation of the higher frequency divider outputs by > lower frequency outputs by reprogramming a CPLD or FPGA. > External reclocking/resynchronising flipflops (one per output frequency) > are required Flip flops within the CPLD can be clocked with completely asynchronous clocks and perform the exact function of devices external to the CPLD. > > > > The ISE design tool offers built in Verilog, VHDL or CUPL programming laguages, or (and this really amazed me) a built in schematic editor tool! This lets you capture the design, just as you have, in a schematic, and then synthesize the logic and perform a complete simulation of your captured schematic. > > > > You could even just download the tool, capture your existing schematic (there are logic elements for 7400 series logic devices) and use the tool as a simulation engine to test your design. Even if you ultimately plan to use the 7400 parts. > > > > > Just dont use this method to implement the dividers etc in the CPLD. > Its better to use a fully synchronous decade divider chain if possible > as this eliminates all the realignment logic required with ripple > clocked divider chains. > Excellent point. While you could capture your existing design in it's exact form for simulation purposes, if you intended to use the CPLD as the final target device, a fully synchronous divider would be best. The symbol libraries contain a very nice full look ahead counter which is cascadable to arbitrary width. In fact Bruce's point of using synchronous design practices really applies equally to designs within a CPLD/FPGA or implimented using discrete components. > Another issue with some (but not all) CPLDs are the power supply > requirements, at least with CMOS the divider (when not driving too many > outputs) has a low power supply current making battery operation feasible. I would expect that replacing the many 74HCxx logic devices with one CPLD would provide a power consumption benefit. BTW, Altera also offers a very full featured design tool for their programmable logic devices viia free download, but I haven't tried it as it's available for windows only. johnea From w1ksz at earthlink.net Thu Jul 10 20:33:21 2008 From: w1ksz at earthlink.net (Richard W. Solomon) Date: Thu, 10 Jul 2008 17:33:21 -0700 (GMT-07:00) Subject: [time-nuts] Frequency divider design critique request Message-ID: <24641672.1215736401407.JavaMail.root@elwamui-muscovy.atl.sa.earthlink.net> The TrueTime XL-AK Time & Frequency Receiver does just what you want plus a few more outputs. Unfortunately they do not provide schematics in the manual. 73, Dick, W1KSZ -----Original Message----- >From: "David C. Partridge" >Sent: Jul 10, 2008 1:30 PM >To: 'Discussion of precise time and frequency measurement' >Subject: [time-nuts] Frequency divider design critique request > >As I've mentioned before, I've been working on the design of a frequency >divider to go with my TB. > >The idea is 10MHz sine in from TB, output 2.5Vp-p 50% duty cycle square wave >into 50R (5V into 1M), at 10Mhz, 5MHz, 1MHz and decade selectable 100kHz >down to 1Hz. All rising edges synchronised to the 10MHz clock rising edge >(or as near as I can get with 74AC logic). With a considerable amount of >constructive criticism from Bruce Griffiths (thank you again Bruce) I >believe the design now to be complete. > >The aim is to have as low a level of nasties as possible (i.e. fit for >time-nuts). > >All faults are my own - no blame attaches to Bruce! > >I've not yet subjected this design to the ultimate simulation tool (PCB, >parts and solder) yet, and I have no means to test it for levels of jitter >(phase noise) or similar nasties. > >I think that it's now the right time to open the design up for critique from >a wider audience before I commit it to copper. > >I'm therefore attaching the design as a PDF file for your comments. > >A few comments are in order: > >1) The 5Mhz and 1MHz outputs are re-clocked TWICE deliberately to delay them >by one clock cycle so they line up with the 1MHz and lower outputs. > >2) The selected output (at the '4051 mux) from the ripple counter chain is >re-clocked to 1MHz before re-clocking to 10MHz as the worst-case delay in >the chain of '4017s is large enough that the lower frquencies wouldn't >reliably re-clock directly to 10MHz. > >I have also done a PCB layout (4-layer) and I'm happy to send a print of the >top/bottom layers to anyone who feels that they want to comment on that >(inner layers are ground and power). > >Let the brick-bats be thrown! > >Cheers >Dave >No virus found in this outgoing message. >Checked by AVG - http://www.avg.com >Version: 8.0.138 / Virus Database: 270.4.7/1544 - Release Date: 10/07/2008 >07:37 From ch at murgatroid.com Thu Jul 10 22:25:49 2008 From: ch at murgatroid.com (christopher hoover) Date: Thu, 10 Jul 2008 19:25:49 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: Message-ID: <000301c8e2fd$6f50d1f0$4df275d0$@com> John Miles wrote: > I am not a big fan of BNC connectors on the PC board itself, because I > am not a big fan of attaching PC boards directly to panels in most cases. > > There are usually some BNC bulkhead connectors on eBay that terminate > in SMA/SMB/SMC pigtails, which are great for panel mounting. I strongly concur. Using SMA/SMC connectors also makes the board more reusable as part of a bigger system. I like to use vertical SMA/SMC connectors on boards and right-angle connectors on any coax going to a board. With this configuration, you can cram a lot of boards in a box even at 1U height and use the remaining vertical space for cross-connections. -ch From ch at murgatroid.com Thu Jul 10 22:37:48 2008 From: ch at murgatroid.com (christopher hoover) Date: Thu, 10 Jul 2008 19:37:48 -0700 Subject: [time-nuts] Re Frequency divider design critique request In-Reply-To: References: Message-ID: <000601c8e2ff$1bdfaa80$539eff80$@com> Bruce wrote. > However this adds considerable complexity and would be much easier to > implement in a CPLD or FPGA. John and I have a design sketch based on a CoolRunner-2 CPLD that we have been kicking around as a potential TAPR board. The CR2 is nice in that the flip flops can be clocked on both rising and falling edges, so doubling any input signal is trivial, if you need that. I have VHDL (that I'm happy to share) that implements most of the functionality that has been discussed. I use it with some frequency (ha ha!) on several different dev boards and often on the Refclock II board (which has SMA connectors, I should note). John and I have both been preoccupied with Life over the last N months and haven't gotten back to the project yet. -ch From bill at iaxs.net Thu Jul 10 23:10:49 2008 From: bill at iaxs.net (Bill Hawkins) Date: Thu, 10 Jul 2008 22:10:49 -0500 Subject: [time-nuts] Re Frequency divider design critique request In-Reply-To: <000601c8e2ff$1bdfaa80$539eff80$@com> References: <000601c8e2ff$1bdfaa80$539eff80$@com> Message-ID: <000001c8e303$b84d7470$021ba8c0@cyrus> christopher hoover wrote, in part, "John and I have both been preoccupied with Life over the last N months and haven't gotten back to the project yet." I can identify with that. Back in the 70's, Life was a cellular automata display on primitive computers. I wrote a routine to plot the population numbers on an HP plotter that came with a very large FORTRAN package (we used about 3% of it). Fascinating to see the way some populations would approach extinction and come roaring back. What have you done with Life using modern computers? I mean, life is a function of time, no? Right on topic, yes? Bill Hawkins From stanley_reynolds at yahoo.com Fri Jul 11 00:32:27 2008 From: stanley_reynolds at yahoo.com (Stanley Reynolds) Date: Thu, 10 Jul 2008 21:32:27 -0700 (PDT) Subject: [time-nuts] Patriot Missile bug Message-ID: <22882.52317.qm@web30307.mail.mud.yahoo.com> Old news but is an example of the real word consequences of bad time keeping / bad programing. http://www.cs.usyd.edu.au/~alum/patriot_bug.html From rk at timing-consultants.com Fri Jul 11 03:00:58 2008 From: rk at timing-consultants.com (Rob Kimberley) Date: Fri, 11 Jul 2008 08:00:58 +0100 Subject: [time-nuts] UK GPS Jamming Exercises Message-ID: <75B94C795B204D8DAE6F34D9BFDE0C48@Robin> For our UK readers... GPS Jamming exercises announced by OFCOM Dates: 22 to 26 September 2008. Times: Short periods of three minutes up to three hours per day between 08:00 and 17:00 hrs. Location: Sennybridge Training Area - N52? 01.181' W003? 36.684' Contact (during jamming exercise only) - 07766 134520 Dates: 13 to 24 October 2008. Times: between 09:00 and 17:00 hrs. Location: Sennybridge Training Area - within 5 km of N52? 01.181' W003? 36.684' Contact (during jamming exercise only) - 07766 134520 Rob Kimberley From bob.paddock at gmail.com Fri Jul 11 06:13:51 2008 From: bob.paddock at gmail.com (Bob Paddock) Date: Fri, 11 Jul 2008 06:13:51 -0400 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <000301c8e2fd$6f50d1f0$4df275d0$@com> References: <000301c8e2fd$6f50d1f0$4df275d0$@com> Message-ID: >> There are usually some BNC bulkhead connectors on eBay that terminate >> in SMA/SMB/SMC pigtails, which are great for panel mounting. Not directly related to this design, but it made me wonder about something. If you are building a multiple output system and channel phase to channel phase was important, would pigtails like this cause problems due to different delay times because of slight variations in length? From bruce.griffiths at xtra.co.nz Fri Jul 11 06:27:53 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 11 Jul 2008 22:27:53 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: <000301c8e2fd$6f50d1f0$4df275d0$@com> Message-ID: <487735A9.6000809@xtra.co.nz> Bob Paddock wrote: >>> There are usually some BNC bulkhead connectors on eBay that terminate >>> in SMA/SMB/SMC pigtails, which are great for panel mounting. >>> > > Not directly related to this design, but it made me wonder about something. > > If you are building a multiple output system and channel phase to channel phase > was important, would pigtails like this cause problems due to > different delay times > because of slight variations in length? > > Yes, but matching cable delays to 10ps or even 1ps or better isnt too difficult. The skew between outputs due to propagation delay mismatches between ICs and PCB track propagation delay mismatches. If all flipflops are in the same package then crosstalk between outputs will phase modulate the higher output frequencies at all the lower output frequencies. Bruce From kc0vsj at yahoo.com Fri Jul 11 09:22:24 2008 From: kc0vsj at yahoo.com (Tom Clifton) Date: Fri, 11 Jul 2008 06:22:24 -0700 (PDT) Subject: [time-nuts] Thunderbolt Data Plotting Message-ID: <813804.48035.qm@web37005.mail.mud.yahoo.com> Well - I have lots and lots of raw numbers, and no really good way of plottinng it. I'm hardly a linux guru, but would gnuplot be a suitable tool for graphing data like the snipper below? 374741 -0.5 0.00 0.7314587 32.10 0 130 18.2 158 4.0 12 1.8 132 3.2 157 9.0 152 5.8 138 12.0 133 6.2 374742 -0.4 0.00 0.7314491 32.10 0 130 18.0 158 4.4 12 1.8 132 3.4 157 9.0 152 5.8 138 12.0 133 6.4 374743 -0.3 0.00 0.7314491 32.10 0 130 18.2 158 4.4 12 1.8 132 3.4 157 9.2 152 5.8 138 12.2 133 6.2 374744 -0.2 0.01 0.7314491 32.10 0 130 18.0 158 4.6 12 1.8 132 3.4 157 9.2 152 5.8 138 12.0 133 6.0 374745 -0.2 0.02 0.7314491 32.10 0 130 18.0 158 4.8 12 1.8 132 3.2 157 9.2 152 5.6 138 12.2 133 6.2 374746 -0.1 -0.01 0.7314491 32.10 0 130 17.8 158 4.8 12 1.8 132 3.6 157 9.2 152 5.6 138 11.8 133 6.2 374747 0.0 0.01 0.7314491 32.10 0 130 17.4 158 4.8 12 1.8 132 3.4 157 9.4 152 5.8 138 12.2 133 6.6 From rvassar at rob-vassar.com Fri Jul 11 10:26:30 2008 From: rvassar at rob-vassar.com (Robert Vassar) Date: Fri, 11 Jul 2008 09:26:30 -0500 Subject: [time-nuts] Thunderbolt Data Plotting In-Reply-To: <813804.48035.qm@web37005.mail.mud.yahoo.com> References: <813804.48035.qm@web37005.mail.mud.yahoo.com> Message-ID: Tom, Gnuplot is perfectly suitable for stuff like this. You just need to describe what you want to graph, and set some bounds and ranges, output type, etc... Somewhere on my home server, is a backup of it's predecessor, I have a Gnuplot script suitable for running out of cron as a daily job that makes a xy-plot of seconds vs. offset and dumps it in a png file. I'll see if I can find it. I'm sure half a dozen other members here have something similar. Rob On Jul 11, 2008, at 8:22 AM, Tom Clifton wrote: > Well - I have lots and lots of raw numbers, and no really good way > of plottinng it. I'm hardly a linux guru, but would gnuplot be a > suitable tool for graphing data like the snipper below? > > 374741 -0.5 0.00 0.7314587 32.10 0 130 18.2 158 4.0 12 1.8 132 3.2 > 157 9.0 152 5.8 138 12.0 133 6.2 > 374742 -0.4 0.00 0.7314491 32.10 0 130 18.0 158 4.4 12 1.8 132 3.4 > 157 9.0 152 5.8 138 12.0 133 6.4 > 374743 -0.3 0.00 0.7314491 32.10 0 130 18.2 158 4.4 12 1.8 132 3.4 > 157 9.2 152 5.8 138 12.2 133 6.2 > 374744 -0.2 0.01 0.7314491 32.10 0 130 18.0 158 4.6 12 1.8 132 3.4 > 157 9.2 152 5.8 138 12.0 133 6.0 > 374745 -0.2 0.02 0.7314491 32.10 0 130 18.0 158 4.8 12 1.8 132 3.2 > 157 9.2 152 5.6 138 12.2 133 6.2 > 374746 -0.1 -0.01 0.7314491 32.10 0 130 17.8 158 4.8 12 1.8 132 3.6 > 157 9.2 152 5.6 138 11.8 133 6.2 > 374747 0.0 0.01 0.7314491 32.10 0 130 17.4 158 4.8 12 1.8 132 3.4 > 157 9.4 152 5.8 138 12.2 133 6.6 > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. From besten at gmail.com Fri Jul 11 12:10:53 2008 From: besten at gmail.com (Remco den Besten) Date: Fri, 11 Jul 2008 18:10:53 +0200 Subject: [time-nuts] FE5680A signal output Message-ID: <00ad01c8e370$b276edc0$1343892c@kalium> I recently obtained a FEI FE-5680A Rb standard Revision: B. After powering it up 'out of the box', a lock @ 50.25505.. MHz was obtained within a few minutes, confirmed by measuring the lock indicator on pin 3 of J1 and listening to the signal on my FT 857 receiver. Nice to hear it sweeping before locking ;-) Here te levels at pin3 of J1 are: unlocked +4V, locked +1.5V A 1PPS signal could not be detected with a multimeter, so I connected a scope. I consider the signal levels somewhat peculiar and am curious if FE 5680A owners here have the same experience. E.g. the amplitude of the PPS signal at pin6 is superimposed on a DC offset of ca. 170 mV and amounts (only?) 25 mV. It is visible as a small spike here (depending upon the time base of course). My perception of a '1PPS' signal is a signal with TTL levels or open collector out or something, and a pulse width of 10 - 200 ms.. I connected a 2k2 resistor between pin6 and pin1 (pull up) but could not see any improvement. The top-top amplitude remained ca. 25 mV. Pin6 (measured with scope) spikes with t = 1 sec: 200mV | | | 170mV ------|------|------| The signal above will be hard to interface, but I feel that perhaps the PPS output is not 'set' or perhaps broken. After powering up, the unit draws 1.6A which gradually decreases to 800mA. This looks normal. Anyone any ideas? From ik1odo at spin-it.com Fri Jul 11 12:22:30 2008 From: ik1odo at spin-it.com (Marco IK1ODO -2) Date: Fri, 11 Jul 2008 18:22:30 +0200 Subject: [time-nuts] Re Frequency divider design critique request In-Reply-To: <000001c8e303$b84d7470$021ba8c0@cyrus> References: <000601c8e2ff$1bdfaa80$539eff80$@com> <000001c8e303$b84d7470$021ba8c0@cyrus> Message-ID: At 05.10 11/07/2008, Bill wrote: >What have you done with Life using modern computers? Er... not so modern, but... I wrote a Life program in Z80 assembler to exercise the emulator on an HP 64000A development system... it was in 1981 :-) Life was ideated by J.H. Conway in 1970. See http://en.wikipedia.org/wiki/Conway%27s_Game_of_Life . Fascinating (to me) as it was 27 years ago. Sorry for the OT! 73 - Marco IK1ODO / AI4YF From phk at phk.freebsd.dk Fri Jul 11 12:58:56 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Fri, 11 Jul 2008 16:58:56 +0000 Subject: [time-nuts] Re Frequency divider design critique request In-Reply-To: Your message of "Fri, 11 Jul 2008 18:22:30 +0200." Message-ID: <94980.1215795536@critter.freebsd.dk> In message , Marco IK1ODO -2 writes: >Life was ideated by J.H. Conway in 1970. See >http://en.wikipedia.org/wiki/Conway%27s_Game_of_Life . Fascinating >(to me) as it was 27 years ago. Sorry for the OT! Actually, the idea is much older (WWII), and like so much else, comes from the productive mind of John Von Neumann: http://en.wikipedia.org/wiki/Von_Neumann_cellular_automata http://en.wikipedia.org/wiki/Von_Neumann_Universal_Constructor And where Conway was merely toying with computers, JVN was plotting how to mine all the metals in the moon :-) Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From time at johnea.net Fri Jul 11 13:20:54 2008 From: time at johnea.net (time at johnea.net) Date: Fri, 11 Jul 2008 10:20:54 -0700 Subject: [time-nuts] Thunderbolt Data Plotting In-Reply-To: <813804.48035.qm@web37005.mail.mud.yahoo.com> References: <813804.48035.qm@web37005.mail.mud.yahoo.com> Message-ID: <20080711172054.GA45736@mail.johnea.net> I used a package recently called ploticus: http://ploticus.sourceforge.net/doc/welcome.html It has some builtin "prefabs" for doing date/time based plots that made it pretty easy to use. GnuPlot is the granddaddy of all plotting packages. I'm sure it could do the job. johnea On Fri, Jul 11, 2008 at 06:22:24AM -0700, Tom Clifton wrote: > Well - I have lots and lots of raw numbers, and no really good way of plottinng it. I'm hardly a linux guru, but would gnuplot be a suitable tool for graphing data like the snipper below? > > 374741 -0.5 0.00 0.7314587 32.10 0 130 18.2 158 4.0 12 1.8 132 3.2 157 9.0 152 5.8 138 12.0 133 6.2 > 374742 -0.4 0.00 0.7314491 32.10 0 130 18.0 158 4.4 12 1.8 132 3.4 157 9.0 152 5.8 138 12.0 133 6.4 > 374743 -0.3 0.00 0.7314491 32.10 0 130 18.2 158 4.4 12 1.8 132 3.4 157 9.2 152 5.8 138 12.2 133 6.2 > 374744 -0.2 0.01 0.7314491 32.10 0 130 18.0 158 4.6 12 1.8 132 3.4 157 9.2 152 5.8 138 12.0 133 6.0 > 374745 -0.2 0.02 0.7314491 32.10 0 130 18.0 158 4.8 12 1.8 132 3.2 157 9.2 152 5.6 138 12.2 133 6.2 > 374746 -0.1 -0.01 0.7314491 32.10 0 130 17.8 158 4.8 12 1.8 132 3.6 157 9.2 152 5.6 138 11.8 133 6.2 > 374747 0.0 0.01 0.7314491 32.10 0 130 17.4 158 4.8 12 1.8 132 3.4 157 9.4 152 5.8 138 12.2 133 6.6 > From wje at quackers.net Fri Jul 11 13:18:48 2008 From: wje at quackers.net (wje) Date: Fri, 11 Jul 2008 13:18:48 -0400 Subject: [time-nuts] FE5680A signal output In-Reply-To: <00ad01c8e370$b276edc0$1343892c@kalium> References: <00ad01c8e370$b276edc0$1343892c@kalium> Message-ID: <487795F8.7080400@quackers.net> If I remember correctly, the 1PPS pulse width is only about 100 ns. There are two possibilities: 1) you can't see the pulse height properly at the very low sweep rate you're using. Trigger on it at a much higher sweep rate, crank up the intensity on your scope, and look carefully. 2) the output is dead. This happens occasionally. I had to replace the 74ac240 buffer in mine. Bill Ezell ---------- They said 'Windows or better' so I used Linux. Remco den Besten wrote: > I recently obtained a FEI FE-5680A Rb standard Revision: B. > > After powering it up 'out of the box', a lock @ 50.25505.. MHz was obtained > within > a few minutes, confirmed by measuring the lock indicator on pin 3 of J1 and > listening to the signal on my FT 857 receiver. Nice to hear it sweeping > before locking ;-) > Here te levels at pin3 of J1 are: unlocked +4V, locked +1.5V > > A 1PPS signal could not be detected with a multimeter, so I connected a > scope. > > I consider the signal levels somewhat peculiar and am curious if FE 5680A > owners > here have the same experience. E.g. the amplitude of the PPS signal at pin6 > is superimposed on a DC offset of ca. 170 mV and amounts (only?) 25 mV. > It is visible as a small spike here (depending upon the time base of > course). > My perception of a '1PPS' signal is a signal with TTL levels or open > collector out or something, and a pulse width of 10 - 200 ms.. > I connected a 2k2 resistor between pin6 and pin1 (pull up) but could not see > any improvement. The top-top amplitude remained ca. 25 mV. > > Pin6 (measured with scope) spikes with t = 1 sec: > > 200mV | | | > 170mV ------|------|------| > > The signal above will be hard to interface, but I feel that perhaps the PPS > output is not 'set' or perhaps broken. > > After powering up, the unit draws 1.6A which gradually decreases to 800mA. > This looks normal. > > Anyone any ideas? > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > From david.partridge at dsl.pipex.com Fri Jul 11 13:41:52 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Fri, 11 Jul 2008 18:41:52 +0100 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <20080711.000630.415917433278911752.cfmd@bredband.net> References: <20080711.000630.415917433278911752.cfmd@bredband.net> Message-ID: Magnus Danielson: 1) Please could you clarify what you're proposing with the series resistors? I get the idea about 10nF in parallel with R24-R26, though I'm not sure what the benefit is? Those MUX control pins are going to sit pretty hard on 5V or pulled down to ground. 2) You said: >I am sure we can come up with some arrangement for that. Several handy time-nuts around. Are you suggesting that I get more than one PCB made up, or that I get 1 prototype made up and built to confirm it works mostly as I expect, and then get a batch made up for the group to play with? Obviously if there's enough interest I could get a batch made, but it's a bit of a risk if I find problems when I build the first one! Extra features - well I guess I could have added a distribution amplifier as well, but I think that's a different project. 1pps isn't needed as the TB already provides that. Synchronising with the TB 1ppS output - hey, come on, this is my first digital design project. The impossible we do immediately, unfortunately miracles take a bit longer! All, CPLD - wassat? OK, OK I have some idea, but that's about all I know. Anyway these are probably BGA stuff which I couldn't hope to hand solder anyway - it's enough of a stretch for me to think of hand soldering this SMT board. Chris Hoover, You mean you've got something that does all that and more and you've kept quiet about it! Shame on you! Or is it really only in the early stages of gestation? Cheers Dave From preynaert at yahoo.com Fri Jul 11 14:22:03 2008 From: preynaert at yahoo.com (Patrick Reynaert) Date: Fri, 11 Jul 2008 11:22:03 -0700 (PDT) Subject: [time-nuts] Thunderbolt - temperature Message-ID: <984649.39209.qm@web58805.mail.re1.yahoo.com> Hello, I have a question regarding the temperature reading in the Thunderbolt Monitor program of the Trimble Thunderbolt GPSDO. Is this the temperature of the board or the temperature of the crystal? Related to this: does it help to put the Thunderbolt in an isolated box or is this an overkill? Thanks. Patrick Belgium. From preynaert at yahoo.com Fri Jul 11 14:29:39 2008 From: preynaert at yahoo.com (Patrick Reynaert) Date: Fri, 11 Jul 2008 11:29:39 -0700 (PDT) Subject: [time-nuts] Allan variance of Thunderbolt Message-ID: <654182.14362.qm@web58806.mail.re1.yahoo.com> Hello, a question regarding the Allan Deviation of the Thunderbolt. the curve at gives a deviation of 1.5e-12 at tau=1s whereas from the Trimble datasheet: at tau=1s, the deviation is 9e-10 ... Is the data-sheet a worse-case scenario? Regards, Patrick From hmurray at megapathdsl.net Fri Jul 11 14:41:39 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Fri, 11 Jul 2008 11:41:39 -0700 Subject: [time-nuts] Thunderbolt Data Plotting In-Reply-To: Message from Tom Clifton of "Fri, 11 Jul 2008 06:22:24 PDT." <813804.48035.qm@web37005.mail.mud.yahoo.com> Message-ID: <20080711184140.838C2BCCD@ip-64-139-1-69.sjc.megapath.net> > Well - I have lots and lots of raw numbers, and no really good way of > plottinng it. I'm hardly a linux guru, but would gnuplot be a suitable > tool for graphing data like the snipper below? It's what I use. gnuplot has zillions of options. You will probably have to read (or at least skim) the whoie manual to get a feel for how to do things. Once you know what you are looking for, the online help works pretty well. An important question is how to organize your raw data. I copied the setup from ntpd's "day" mode. It uses 1 file per day with filenames like loopstats.20080628. The first two columns of the file are the modified julian day and seconds within the current day. For example: 54658 64083.850 -0.000002000 118.700 0.000016330 0.009421 9 54658 64149.858 -0.000022000 118.700 0.000016849 0.008813 9 54658 64215.865 -0.000040000 118.699 0.000016956 0.008251 9 54658 64280.873 -0.000049000 118.698 0.000016187 0.007726 9 54658 64346.881 -0.000064000 118.697 0.000015979 0.007236 9 You can also link loopstats (no date) to the latest one so tail loopstats gets you the latest/current one without bothering to figure out what the date is. I generally set things up so I can easily plot the last two files. That gives somewhere between 24 and 48 hours so I always have some context if an interesting quirk happens at the start of a day. I have a handful of scripts that grab log files from several machines and setup links to the latest two. For example, foo-loop goes to foo/loopstats.20080711 and foo-loop-1 goes to foo/loopstats.20080710 Then the gnuplot include files just refer to foo-loop and foo-oop-1 When making graphs, I ignore the first column and add a 24 hour offset on one file to the plot command. That generally works OK for looking at events with a time scale of hours. I haven't tried looking for long term (days, months) trends. If/when I want to do that, I'll probably do some pre-processing and make a new file with one line per day or hour. -- These are my opinions, not necessarily my employer's. I hate spam. From magnus at rubidium.dyndns.org Fri Jul 11 15:01:41 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Fri, 11 Jul 2008 21:01:41 +0200 (CEST) Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: <20080711.000630.415917433278911752.cfmd@bredband.net> Message-ID: <20080711.210141.407454645627545389.cfmd@bredband.net> From: "David C. Partridge" Subject: Re: [time-nuts] Frequency divider design critique request Date: Fri, 11 Jul 2008 18:41:52 +0100 Message-ID: Hej David, > Magnus Danielson: > > 1) Please could you clarify what you're proposing with the series resistors? > I get the idea about 10nF in parallel with R24-R26, though I'm not sure what > the benefit is? Those MUX control pins are going to sit pretty hard on 5V > or pulled down to ground. OK. I was thinking EMC here. You may think that this is a DC part of the design but infact you have "DC-signals" hitting a board with sharp edges, so you could very well have transmitter antennas here. Also, the succeptability of those inputs to E or H field disturbance will affect the output of the mux, so attempting to reduce the efficiency as E and H field antenna should be a benefit for the stability. Bypassing the input connection from the push- button to ground with caps just where deas leads hit the board will make the E-field susceptability low, but the low loop area over to the resistors and chip will also make the H-field susceptability low. Trying to analyze such a problem would take either a good feeling about things, luck or experience to quickly pinpoint. It is cheap enought to reduce the problem, even if I don't think the risk is imminent. Do you follow my lines of thought? > 2) You said: > > >I am sure we can come up with some arrangement for that. Several handy > time-nuts around. > > Are you suggesting that I get more than one PCB made up, or that I get 1 > prototype made up and built to confirm it works mostly as I expect, and then > get a batch made up for the group to play with? > > Obviously if there's enough interest I could get a batch made, but it's a > bit of a risk if I find problems when I build the first one! Why not? It basically solves a problem most of us has, and only a few tweaks away and it solves it fairly generically. The only think it doesn't do well is handling 5 MHz souces rather than 10 MHz. Having that would solve many problems. While not achieving full metrological levels of stability, I am sure it could be handy for several time-nuts never the less. Only a few need that upper level anyway. A good prooven design for enought stability and decent money might be right. I would certainly not mind having a pair of those lying around and I am sure I could put a few into continous use. Now that is my lab alone... > Extra features - well I guess I could have added a distribution amplifier as > well, but I think that's a different project. 1pps isn't needed as the TB > already provides that. My point was that it was an output section away.... The PPS was since you do produce the signal and you can the same box to divide down to PPS and say 1 kHz as being used by other designs. Think of a separate 10 MHz source... like a Rb or so. 1 kHz for the loop comparision and PPSes for performance measurements. > Synchronising with the TB 1ppS output - hey, come on, this is my first > digital design project. The impossible we do immediately, unfortunately > miracles take a bit longer! Oh, I seem to expect alot. But really, the extra features was really thinking out loud after asking the question "What would annoy me most when using such a box that I only *almost* can do?". If using counters with loadable initial state, setting it up to come out correctly at synchronisation is not that hard. > All, > > CPLD - wassat? OK, OK I have some idea, but that's about all I know. > Anyway these are probably BGA stuff which I couldn't hope to hand solder > anyway - it's enough of a stretch for me to think of hand soldering this SMT > board. With CPLD you don't need to do BGA. One form of FlatPACK as I recall it. Not too hard to solder. Look at the lower end from Xilinx for instance... I agree with Bruce that resynchroniserz would be expected. The TTL/CMOS you have is however more stable in availability, but so far this has not been much of a problem with CPLDs that I have tracked. Cheers, Magnus From tvb at LeapSecond.com Fri Jul 11 15:03:21 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Fri, 11 Jul 2008 12:03:21 -0700 Subject: [time-nuts] Allan variance of Thunderbolt References: <654182.14362.qm@web58806.mail.re1.yahoo.com> Message-ID: <000e01c8e388$c9f0d480$0800a8c0@pc52> > Hello, > > a question regarding the Allan Deviation of the Thunderbolt. > > the curve at > > gives a deviation of 1.5e-12 at tau=1s > > whereas from the Trimble datasheet: > > at tau=1s, the deviation is 9e-10 ... > > Is the data-sheet a worse-case scenario? > > Regards, > Patrick All the Thunderbolts I've tested for the TAPR group buy have been in the 1 or 2 or 3 parts in 10^12th at tau 1 s. Very consistent. Right, the plot in the Trimble data sheet looks orders of magnitude worse. It is possible the Trimble measurement system that made the plot did not have sufficient resolution at low tau. But it is also possible that the model we got in the surplus deal is some kind of special high-end version of the model shown on the old data sheet. It's hard to know for sure. Somewhere in the FAQ I note you should ignore the plots in the Trimble data sheet. /tvb From James.P.Lux at jpl.nasa.gov Fri Jul 11 16:27:52 2008 From: James.P.Lux at jpl.nasa.gov (Jim Lux) Date: Fri, 11 Jul 2008 13:27:52 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: <20080711.000630.415917433278911752.cfmd@bredband.net> Message-ID: <6.2.5.6.2.20080711132632.02d249f0@jpl.nasa.gov> At 10:41 AM 7/11/2008, David C. Partridge wrote: >M >All, > >CPLD - wassat? OK, OK I have some idea, but that's about all I know. >Anyway these are probably BGA stuff which I couldn't hope to hand solder >anyway - it's enough of a stretch for me to think of hand soldering this SMT >board. CPLD -> small programmable logic device (think like a PAL, but bigger).. not BGAs, typically. Anywhere from a dozen to a couple hundred gate equivalents. Some are really, really fast (e.g. 1 ns prop delays, etc.) From dforbes at dakotacom.net Fri Jul 11 16:38:37 2008 From: dforbes at dakotacom.net (David Forbes) Date: Fri, 11 Jul 2008 13:38:37 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <6.2.5.6.2.20080711132632.02d249f0@jpl.nasa.gov> References: <20080711.000630.415917433278911752.cfmd@bredband.net> <6.2.5.6.2.20080711132632.02d249f0@jpl.nasa.gov> Message-ID: <4877C4CD.2030205@dakotacom.net> Jim Lux wrote: > At 10:41 AM 7/11/2008, David C. Partridge wrote: >> M >> All, >> >> CPLD - wassat? OK, OK I have some idea, but that's about all I know. >> Anyway these are probably BGA stuff which I couldn't hope to hand solder >> anyway - it's enough of a stretch for me to think of hand soldering this SMT >> board. > > CPLD -> small programmable logic device (think like a PAL, but > bigger).. not BGAs, typically. Anywhere from a dozen to a couple > hundred gate equivalents. Some are really, really fast (e.g. 1 ns > prop delays, etc.) > I agree that a CPLD would be an excellent way to make a 10 MHz frequency divider board. The Coolrunner series from Xilinx is available in 44 pin quad flat packs that I have no trouble soldering into place with a regular old soldering iron and some liquid flux. It's easy to solder SMT parts if you have a microscope and the right supplies. The only problem is that the CPLD is programmable. Of course, that's also its strength, until it needs to be reprogrammed and you've lost the programming cable or the source code or the Xilinx tools fail to run on your latest PC or... From didier at cox.net Fri Jul 11 16:47:52 2008 From: didier at cox.net (Didier Juges) Date: Fri, 11 Jul 2008 15:47:52 -0500 Subject: [time-nuts] Monitor for Thunderbolt and other GPS receivers Message-ID: <008701c8e397$641c6b10$0a01a8c0@didierhp> Well, I don't really have much time right now, but I started working on a Monitor for the Trimble ThunderBolt (and other GPS receivers). With 3 TBs here, it would make sense. Here is where I am at the moment: http://www.ko4bb.com/Timing/GPSMonitor/ The idea is to decode the TSIP packets 0x8F-AB (Primary Timing Packet) and 0x8F-AC (Supplemental Timing Packet) which the Thunderbolt sends by default once per second. These packets are defined in the Thunderbolt manual. They provide most of the information of interest to simply monitor the status of the TB. If anyone is interested (or already has a TSIP parser in C) feel free to let me know. I am open to suggestions about what would make the most sense to display. I would like the default screen to have date/time at the top, and disciplining status at the bottom. Other data could be displayed optionaly by pressing a switch. I may also write a NMEA parser for the other GPS receivers I have here. This project uses a Silabs processor, which is part of the 8051 family. Please don't ask me why I am not using a PIC, Atmel, ARM, (put your favorite micro here), processor instead, there is nothing wrong with any of these chips and they all would work. 8051 is what I have tools and code for, and they are cheap enough for me. If there is enough interest, it would not be very hard or expensive to make a small PWB for the processor (the DIP version would be easier to solder), the voltage regulators, the pot (to adjust screen contrast), a push button (to select among a couple or more of screen content) and the RS-232 translator. Didier KO4BB From jra at febo.com Fri Jul 11 17:07:13 2008 From: jra at febo.com (John Ackermann N8UR) Date: Fri, 11 Jul 2008 17:07:13 -0400 Subject: [time-nuts] Getting Hardware Projects to the Masses (Was Re: Monitor for Thunderbolt and other GPS receivers) In-Reply-To: <008701c8e397$641c6b10$0a01a8c0@didierhp> References: <008701c8e397$641c6b10$0a01a8c0@didierhp> Message-ID: <4877CB81.90906@febo.com> There've been some interesting conversations about useful T&F hardware gadgets lately. I'm personally very interested in the 10 MHz divider project (as I've been working, very slowly, on a similar project with several people on the list) and the Tbolt monitor projects. Let me mention, then, that TAPR could very well be interested in handling production and sales of kit or assembled widgets like these. We can provide a lot of "back end" support to help turn a prototype into a marketable product. If you're interested in working with us to bring your T&F project to the masses, drop me a line off-list. John PS -- Just to be clear, TAPR is a non-profit group, primarily aimed at ham radio operators but supporting a wide range of experimenter activities. I'm a past-President and current board member, but don't have any financial interest in the group, other than paying my membership dues. ---- Didier Juges wrote: > Well, I don't really have much time right now, but I started working on a > Monitor for the Trimble ThunderBolt (and other GPS receivers). With 3 TBs > here, it would make sense. > > Here is where I am at the moment: > > http://www.ko4bb.com/Timing/GPSMonitor/ > > The idea is to decode the TSIP packets 0x8F-AB (Primary Timing Packet) and > 0x8F-AC (Supplemental Timing Packet) which the Thunderbolt sends by default > once per second. > These packets are defined in the Thunderbolt manual. > They provide most of the information of interest to simply monitor the > status of the TB. > > If anyone is interested (or already has a TSIP parser in C) feel free to let > me know. > > I am open to suggestions about what would make the most sense to display. I > would like the default screen to have date/time at the top, and disciplining > status at the bottom. Other data could be displayed optionaly by pressing a > switch. > > I may also write a NMEA parser for the other GPS receivers I have here. > > This project uses a Silabs processor, which is part of the 8051 family. > Please don't ask me why I am not using a PIC, Atmel, ARM, (put your favorite > micro here), processor instead, there is nothing wrong with any of these > chips and they all would work. 8051 is what I have tools and code for, and > they are cheap enough for me. > > If there is enough interest, it would not be very hard or expensive to make > a small PWB for the processor (the DIP version would be easier to solder), > the voltage regulators, the pot (to adjust screen contrast), a push button > (to select among a couple or more of screen content) and the RS-232 > translator. > > Didier KO4BB > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From GandalfG8 at aol.com Fri Jul 11 17:15:54 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Fri, 11 Jul 2008 17:15:54 EDT Subject: [time-nuts] Monitor for Thunderbolt and other GPS receivers Message-ID: In a message dated 11/07/2008 21:48:44 GMT Daylight Time, didier at cox.net writes: If there is enough interest, it would not be very hard or expensive to make a small PWB for the processor (the DIP version would be easier to solder), the voltage regulators, the pot (to adjust screen contrast), a push button (to select among a couple or more of screen content) and the RS-232 translator. ------------------ Hi Didier I would certainly be interested, and could also make use of three. regards Nigel GM8PZR From holrum at hotmail.com Fri Jul 11 17:23:20 2008 From: holrum at hotmail.com (Mark Sims) Date: Fri, 11 Jul 2008 21:23:20 +0000 Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: References: Message-ID: The temperature is the electronics temperature. When I put the cover on my red-boxed unit, the temperature went up about 8 C. This would not have happened if them temp was inside the thermostatically controlled oven. ---------------------------------------- _________________________________________________________________ Making the world a better place one message at a time. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_BetterPlace From holrum at hotmail.com Fri Jul 11 17:30:18 2008 From: holrum at hotmail.com (Mark Sims) Date: Fri, 11 Jul 2008 21:30:18 +0000 Subject: [time-nuts] Monitor for Thunderbolt and other GPS receivers In-Reply-To: References: Message-ID: Hello Dieder, I posted the source to a ThunderBolt data dumper a while back. It has a full TSIP parser in it. John Miles also posted his tweaks to make it win-32 compatible. Since then I have combined the two and tweaked it some here and there. I also have a new program that does graphing of the various parameters in real time. It also allows you to control most of the various options in the unit from the keyboard. Right now it requires a PC/laptop with a real serial port, a VGA compatible video controller that can run in 1024x768 mode, and OS that lets you talk to the hardware directly (DOS/Win98/?) ---------------------------------------- _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From holrum at hotmail.com Fri Jul 11 17:50:54 2008 From: holrum at hotmail.com (Mark Sims) Date: Fri, 11 Jul 2008 21:50:54 +0000 Subject: [time-nuts] Allan variance of Thunderbolt In-Reply-To: References: Message-ID: The Thunderbolt data sheet says that the unit requires 25mA at 12V. That spec would imply it is for a unit without an OCXO since the oven heater draws considerable current from the 12V power supply. But then, the data sheet says it draws 15 watts cold, 10 watts steady state. That implies the unit has a heater. And if you multiply the published power supply requirements out you get 2 watts, not 10-15 watts. It appears that some of the specs are for an ovenless unit, others are for the ovenized unit. The data sheet also talks about a telecom version with improved holdover performance... this has got to be the ovenized unit. I suspect the Allan variance plot is for the low end unit, but the shape of the curve is funny. It always slopes downward. Almost all GPSDO Allan variance plots show a hump in the graph around 100 seconds. Trimble's numbers and graph shape do seem to relate closely to my "auto-Allan variance" plots of the OSC offset data supplied by the unit (where the tiiming reference is its own interpretation of the GPS time signal). _________________________________________________________________ Need to know now? Get instant answers with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_messenger_072008 From jmiles at pop.net Fri Jul 11 18:20:19 2008 From: jmiles at pop.net (John Miles) Date: Fri, 11 Jul 2008 15:20:19 -0700 Subject: [time-nuts] Allan variance of Thunderbolt In-Reply-To: Message-ID: I believe the Allan variance graph in Trimble's data sheet was taken before Selective Availability was turned off. I'm not sure what impact this would have; I wouldn't expect any at all at tau << 100s. A pronounced hump in the ADEV plot could suggest that the disciplining loop is underdamped. Ideally you wouldn't be able to tell where the OCXO's influence ends and GPS's begins. -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On > Behalf Of Mark Sims > Sent: Friday, July 11, 2008 2:51 PM > To: time-nuts at febo.com > Subject: Re: [time-nuts] Allan variance of Thunderbolt > > > > The Thunderbolt data sheet says that the unit requires 25mA at > 12V. That spec would imply it is for a unit without an OCXO > since the oven heater draws considerable current from the 12V > power supply. But then, the data sheet says it draws 15 watts > cold, 10 watts steady state. That implies the unit has a heater. > And if you multiply the published power supply requirements out > you get 2 watts, not 10-15 watts. It appears that some of the > specs are for an ovenless unit, others are for the ovenized unit. > > The data sheet also talks about a telecom version with improved > holdover performance... this has got to be the ovenized unit. I > suspect the Allan variance plot is for the low end unit, but the > shape of the curve is funny. It always slopes downward. Almost > all GPSDO Allan variance plots show a hump in the graph around > 100 seconds. > > Trimble's numbers and graph shape do seem to relate closely to my > "auto-Allan variance" plots of the OSC offset data supplied by > the unit (where the tiiming reference is its own interpretation > of the GPS time signal). > From didier at cox.net Fri Jul 11 18:23:51 2008 From: didier at cox.net (Didier Juges) Date: Fri, 11 Jul 2008 17:23:51 -0500 Subject: [time-nuts] Monitor for Thunderbolt and other GPS receivers In-Reply-To: References: Message-ID: <009901c8e3a4$ccbe1490$0a01a8c0@didierhp> Found it, I'll look at it. I remember that thread now. I have been a little preoccupied lately, hence the need for a diversion in the form of writing software. However, it plays games with my short term memory :-) Thanks Didier > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Mark Sims > Sent: Friday, July 11, 2008 4:30 PM > To: time-nuts at febo.com > Subject: Re: [time-nuts] Monitor for Thunderbolt and other > GPS receivers > > > Hello Dieder, > > I posted the source to a ThunderBolt data dumper a while > back. It has a full TSIP parser in it. John Miles also > posted his tweaks to make it win-32 compatible. Since then I > have combined the two and tweaked it some here and there. > > I also have a new program that does graphing of the various > parameters in real time. It also allows you to control most > of the various options in the unit from the keyboard. Right > now it requires a PC/laptop with a real serial port, a VGA > compatible video controller that can run in 1024x768 mode, > and OS that lets you talk to the hardware directly (DOS/Win98/?) > ---------------------------------------- > From pe1rks at xs4all.nl Fri Jul 11 18:28:58 2008 From: pe1rks at xs4all.nl (S. Nestra) Date: Sat, 12 Jul 2008 00:28:58 +0200 Subject: [time-nuts] Looking for an amplifier IC to repair my HP 8662A Generator. Message-ID: <4877DEAA.6010108@xs4all.nl> Hi group, Sorry that it's a bit off-topic but I know that there are a lot of people on this list who also own these beasts and other HP gear. For the repair of my 8662A signal generator I'm looking for a 1826-0372 amplifier. Anybody has one or knows about an available substitute? Sincerely, Stijn Nestra -- Real radios have motors. From didier at cox.net Fri Jul 11 18:37:55 2008 From: didier at cox.net (Didier Juges) Date: Fri, 11 Jul 2008 17:37:55 -0500 Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: <984649.39209.qm@web58805.mail.re1.yahoo.com> References: <984649.39209.qm@web58805.mail.re1.yahoo.com> Message-ID: <009a01c8e3a6$c373c680$0a01a8c0@didierhp> Monitoring the crystal temperature would probably be extremely boring. I would expect it to be absolutely stable, as far as the internal TB temperature monitor is capable of displaying it. Monitoring the electronics temperature is useful because it relates to the ambient and allows you to plot the dependancy of frequency to ambient, and indirectly verify that the air conditioning is working. Putting the TB in an isolated box may be counterproductive, because the ~10W of average dissipation has to go somewhere, otherwise the TB will cook itself crisp. On the other hand, I think it would be very well advised to place the unit in a quiet area with minimal temperature changes, like you would do to keep a good bottle of wine. A while back I plotted the current consumption of an HP 10811 as a function of ambient temperature in my not-very-well regulated ham shack (http://www.ko4bb.com/Test_Equipment/HP10811-Current.png). It was as predicted, considering the ~80 degree operating temperature of the oven. Keeping the unit at constant ambient reduces the need for the oven to draw more or less current. No matter how well the oven is decoupled from the crystal, nothing is ever perfect, so minimizing the ambient variations has got to be a good thing. Didier KO4BB > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Patrick Reynaert > Sent: Friday, July 11, 2008 1:22 PM > To: time-nuts at febo.com > Subject: [time-nuts] Thunderbolt - temperature > > Hello, > > I have a question regarding the temperature reading in the > Thunderbolt Monitor program of the Trimble Thunderbolt GPSDO. > Is this the temperature of the board or the temperature of > the crystal? > > Related to this: does it help to put the Thunderbolt in an > isolated box or is this an overkill? > > Thanks. > > Patrick > Belgium. > From tvb at LeapSecond.com Fri Jul 11 18:39:29 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Fri, 11 Jul 2008 15:39:29 -0700 Subject: [time-nuts] Allan variance of Thunderbolt References: Message-ID: <01a401c8e3a6$fedc8400$0200a8c0@pc52> > The Thunderbolt data sheet says that the unit requires 25mA at > 12V. That spec would imply it is for a unit without an OCXO > since the oven heater draws considerable current from the 12V > power supply. But then, the data sheet says it draws 15 watts > cold, 10 watts steady state. That implies the unit has a heater. > And if you multiply the published power supply requirements out > you get 2 watts, not 10-15 watts. It appears that some of the > specs are for an ovenless unit, others are for the ovenized unit. See actual power requirements for the TAPR Thunderbolt: http://www.leapsecond.com/pages/tbolt/power.htm So, yes, these are OCXO versions. Very nice OCXO. > The data sheet also talks about a telecom version with improved > holdover performance... this has got to be the ovenized unit. I > suspect the Allan variance plot is for the low end unit, but the > shape of the curve is funny. It always slopes downward. Almost > all GPSDO Allan variance plots show a hump in the graph around > 100 seconds. Right. Ignore the ADEV plot on the Trimble data sheet; it's not quite the same unit as the TAPR deal. Please read the FAQ: http://www.leapsecond.com/tbolt-faq.htm /tvb From holrum at hotmail.com Fri Jul 11 19:13:04 2008 From: holrum at hotmail.com (Mark Sims) Date: Fri, 11 Jul 2008 23:13:04 +0000 Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: References: Message-ID: My Thunerbolt is sitting on the floor. It is covered by an upside down cardboard box. This added mayby 1 C to the temperature reading. It hovers around 40C (when my unit in the red metal box was open, it was around 32C). My temperature plot typically shows a sine wave shape with around 300 millidegrees peak-peak cycles lasting around 30 minutes or so. A strange anomaly shows up occasionally in the temperature plot. You occasionally see a 100 millidegree instantaneous positive spike in the data. The temperature then decays over 30 seconds back to the original curve. This occurs on all of my units. They are all different revisions with different power supplies. The spikes seem uncorrelated with any external events. _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From holrum at hotmail.com Fri Jul 11 19:20:53 2008 From: holrum at hotmail.com (Mark Sims) Date: Fri, 11 Jul 2008 23:20:53 +0000 Subject: [time-nuts] Precision temperature measurement - Time-nuts style In-Reply-To: References: Message-ID: In the beforetimes, I built several precision temperature systems using the Analog Devices AD537 voltage-to-frequency converter. This chip has an on board temperature sensor and makes a very nice precision thermometer. Due to its size and thermal mass it is good for fairly slow response curves. For faster response you can use a small thermistor as the sensor. You can get microdegree resolution in fairly simple systems. One system that I built was a long term data logger that measured temperatures in mines, caves, and lakes. They were built in iron plumbing pipe sealed with teflon tape and pipe ends. The original unit, built by a friend, used discrete logic to wake up, do a sample, save it to eeprom, and go back to sleep. The frequency measurement was a synchronized gate counting scheme. It has a couple dozen chips and would record for a couple of years. It's replacement used two PIC chips. One was the wake-up timer on a 32KHz crystal, the other was clocked with a 16MHz xtal and did the frequency measurement and logging to a serial EEPROM. It gave millidegree resolution. Another system was a fast response system with a tiny (almost microscopic) thermistor. It would log temperature changes as it was lowered into wells and boreholes. From the temperature changes one could deduce the rock strata, etc of the hole. The counting scheme was basically recording time tags from a high frequency clock/counter. It had microdegree resolution. The thermistor was mounted in a piece of stainless hypodermic needle tube protected by a slotted steel shroud. You could only log a hole once in a long time because just lowering the probe through the hole disturbed the temperature profile. Both units were calibrated to absolute temperatures as a complete system. One group thought that that they had a problem with a unit. They mounted it in a (supposedly) well nsulated box and were seeing unexplained temperature gradients. Turned out to be body heat from people entering and leaving the lab. You could easily count bodies in the data. _________________________________________________________________ Need to know now? Get instant answers with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_messenger_072008 From James.P.Lux at jpl.nasa.gov Fri Jul 11 19:21:45 2008 From: James.P.Lux at jpl.nasa.gov (Jim Lux) Date: Fri, 11 Jul 2008 16:21:45 -0700 Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: <009a01c8e3a6$c373c680$0a01a8c0@didierhp> References: <984649.39209.qm@web58805.mail.re1.yahoo.com> <009a01c8e3a6$c373c680$0a01a8c0@didierhp> Message-ID: <6.2.5.6.2.20080711162001.02d440f8@jpl.nasa.gov> At 03:37 PM 7/11/2008, Didier Juges wrote: >On the other hand, I think it would be very well advised to place the unit >in a quiet area with minimal temperature changes, like you would do to keep >a good bottle of wine. I knew that putting my Z8301 in the wine locker in the garage was a good idea. It was the coax gods who caused that to be the only place that I could put it which the cable from the antenna would reach, but clearly, they were thinking ahead. Jim From bruce.griffiths at xtra.co.nz Fri Jul 11 19:32:29 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 12 Jul 2008 11:32:29 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <20080711.210141.407454645627545389.cfmd@bredband.net> References: <20080711.000630.415917433278911752.cfmd@bredband.net> <20080711.210141.407454645627545389.cfmd@bredband.net> Message-ID: <4877ED8D.5000906@xtra.co.nz> Magnus Danielson wrote: > Hej David, > > >> Magnus Danielson: >> >> 1) Please could you clarify what you're proposing with the series resistors? >> I get the idea about 10nF in parallel with R24-R26, though I'm not sure what >> the benefit is? Those MUX control pins are going to sit pretty hard on 5V >> or pulled down to ground. >> > > OK. I was thinking EMC here. You may think that this is a DC part of the design > but infact you have "DC-signals" hitting a board with sharp edges, so you could > very well have transmitter antennas here. Also, the succeptability of those > inputs to E or H field disturbance will affect the output of the mux, so > attempting to reduce the efficiency as E and H field antenna should be a > benefit for the stability. Bypassing the input connection from the push- > button to ground with caps just where deas leads hit the board will make the > E-field susceptability low, but the low loop area over to the resistors and > chip will also make the H-field susceptability low. Trying to analyze such a > problem would take either a good feeling about things, luck or experience to > quickly pinpoint. It is cheap enought to reduce the problem, even if I don't > think the risk is imminent. > > Do you follow my lines of thought? > > Hej Magnus The attached circuit should be a little easier on the relatively delicate thumbwheel switch contacts (particularly if the capacitance of the filter caps is large) whilst still providing adequate filtering. The 74HC14 is merely indicative of logic with a low dc input current. The circuit is essentially a low pass filter which rejects any high frequency pickup in the switch wiring. Typical thumbwheel switches are have either closed or open contacts. When closed the associated wiring acts as a loop antenna picking up any hf magnetic fields. When the switch is open the wire acts as a short whip antenna terminated by the pullup (or pulldown) resistor picking up any hf electric field. Bruce -------------- next part -------------- A non-text attachment was scrubbed... Name: SwitchFiltering.gif Type: image/gif Size: 3159 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080712/d59dba5b/attachment-0001.gif From hmurray at megapathdsl.net Fri Jul 11 19:33:16 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Fri, 11 Jul 2008 16:33:16 -0700 Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: Message from Mark Sims of "Fri, 11 Jul 2008 23:13:04 -0000." Message-ID: <20080711233317.3C32FBCCD@ip-64-139-1-69.sjc.megapath.net> > A strange anomaly shows up occasionally in the temperature plot. You > occasionally see a 100 millidegree instantaneous positive spike in the > data. The temperature then decays over 30 seconds back to the > original curve. This occurs on all of my units. They are all > different revisions with different power supplies. The spikes seem > uncorrelated with any external events. Here is a guess. Maybe the CPU is doing a bunch of work, like shifting to a different set of satellites. Can you monitor the power it's using? Or check the satellites before/after a step? -- These are my opinions, not necessarily my employer's. I hate spam. From GandalfG8 at aol.com Fri Jul 11 19:47:04 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Fri, 11 Jul 2008 19:47:04 EDT Subject: [time-nuts] Thunderbolt - temperature Message-ID: In a message dated 12/07/2008 00:14:13 GMT Daylight Time, holrum at hotmail.com writes: when my unit in the red metal box was open, it was around 32C -------------- I'm intrigued by this and similar earlier references. I've only seen Thunderbolts in gold coloured aluminium boxes, where did the red boxed version come from? regards Nigel GM8PZR From holrum at hotmail.com Fri Jul 11 19:59:52 2008 From: holrum at hotmail.com (Mark Sims) Date: Fri, 11 Jul 2008 23:59:52 +0000 Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: References: Message-ID: You can see a picture of the "red box" unit in the Thunderbolt data sheet: http://trl.trimble.com/docushare/dsweb/Get/Document-10015/ I got mine off of Ebay. It has a builit in telecom style power supply that takes from 32-72 volts. It came with a input power cable that "or"ed two input supplies together with diodes. An earlier comment implied that the red box units had the crappy oscillator. Mine seems to be the best of the three that I have... definitely an OCXO. As far as the spikes in the temperature data, they occur instantly. One second the curve is curving gently. The next second it has spiked 50-100 millidegrees. I doubt that any CPU heat could reach and effect the temperature sensor that quickly. I am plotting satellite constellation changes along with other parameters... spikes seem uncorrelated with anything. _________________________________________________________________ Making the world a better place one message at a time. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_BetterPlace From bruce.griffiths at xtra.co.nz Fri Jul 11 20:11:03 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 12 Jul 2008 12:11:03 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <20080711.210141.407454645627545389.cfmd@bredband.net> References: <20080711.000630.415917433278911752.cfmd@bredband.net> <20080711.210141.407454645627545389.cfmd@bredband.net> Message-ID: <4877F697.2040700@xtra.co.nz> Magnus Danielson wrote: > Why not? It basically solves a problem most of us has, and only a few tweaks > away and it solves it fairly generically. The only think it doesn't do well is > handling 5 MHz souces rather than 10 MHz. Having that would solve many > problems. While not achieving full metrological levels of stability, I am sure > it could be handy for several time-nuts never the less. Only a few need that > upper level anyway. A good prooven design for enought stability and decent > money might be right. I would certainly not mind having a pair of those lying > around and I am sure I could put a few into continous use. Now that is my lab > alone... > > > Magnus A minimalist approach for the 5MHz to 10MHz doubler could use a full wave (diode, BJT or JFET) doubler followed by a series tuned 5MHz shunt trap to minimise the 5MHz content in the output. If the doubler components were perfectly matched (unlikely) the fundamental trap could be omitted. The other harmonics are of little concern as the comparator output is a square wave and the rectified sinewave waveform would produce a duty cycle of around 44% at the comparator output. The diode turn on threshold will alter the duty cycle somewhat but it should still be acceptable at least for clocking the flipflops and dividers. If desired a threshold feedback loop could be used to stabilise the comparator duty cycle at 50%. However such a duty cycle stabiliser only works when the input signal waveform is sinusoidal, rectified sinewave or any other signal with a slow enough slew rate. Bruce From GandalfG8 at aol.com Fri Jul 11 20:18:15 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Fri, 11 Jul 2008 20:18:15 EDT Subject: [time-nuts] Thunderbolt - temperature Message-ID: In a message dated 12/07/2008 01:01:27 GMT Daylight Time, holrum at hotmail.com writes: You can see a picture of the "red box" unit in the Thunderbolt data sheet: _http://trl.trimble.com/docushare/dsweb/Get/Document-10015/_ (http://trl.trimble.com/docushare/dsweb/Get/Document-10015/) --------------------------------------- Oh, OK, I understand now, but guess we have different ideas of what a "red box" might be. regards Nigel GM8PZR From billj at ieee.org Fri Jul 11 20:29:06 2008 From: billj at ieee.org (Bill Janssen) Date: Fri, 11 Jul 2008 17:29:06 -0700 Subject: [time-nuts] TAPR and Thunderbolt orders In-Reply-To: <000e01c8e388$c9f0d480$0800a8c0@pc52> References: <654182.14362.qm@web58806.mail.re1.yahoo.com> <000e01c8e388$c9f0d480$0800a8c0@pc52> Message-ID: <4877FAD2.4030005@ieee.org> I was one of those who was lucky enough to get my order in for a Thunderbolt before the order machine was shut down. Now I am wondering what my status is in the queue for shipping. Does anyone know how many thunderbolt units there are still to be tested and to be shipped? I don't want to bother TAPR as I am sure they have more pressing problems to deal with. Just wondering if I can expect to get one. Bill K7NOM From tvb at LeapSecond.com Fri Jul 11 21:03:42 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Fri, 11 Jul 2008 18:03:42 -0700 Subject: [time-nuts] TAPR and Thunderbolt orders References: <654182.14362.qm@web58806.mail.re1.yahoo.com><000e01c8e388$c9f0d480$0800a8c0@pc52> <4877FAD2.4030005@ieee.org> Message-ID: <001d01c8e3bb$254c5c50$0200a8c0@pc52> > I was one of those who was lucky enough to get my order in for a > Thunderbolt before the order machine was shut down. Now I am And it will open up again when/if a new large batch materializes from the telecom salvage firm. So don't despair if you missed out last month. > wondering what my status is in the queue or shipping. > > Does anyone know how many thunderbolt units there are still to be tested > and to be shipped? About a hundred. > I don't want to bother TAPR as I am sure they have more pressing > problems to deal with. > > Just wondering if I can expect to get one. They're going out at the rate of 20 or more per week. /tvb From bruce.griffiths at xtra.co.nz Fri Jul 11 22:45:00 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 12 Jul 2008 14:45:00 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <4877F697.2040700@xtra.co.nz> References: <20080711.000630.415917433278911752.cfmd@bredband.net> <20080711.210141.407454645627545389.cfmd@bredband.net> <4877F697.2040700@xtra.co.nz> Message-ID: <48781AAC.2050100@xtra.co.nz> > Magnus > > A minimalist approach for the 5MHz to 10MHz doubler could use a full > wave (diode, BJT or JFET) doubler followed by a series tuned 5MHz shunt > trap to minimise the 5MHz content in the output. > If the doubler components were perfectly matched (unlikely) the > fundamental trap could be omitted. > The other harmonics are of little concern as the comparator output is a > square wave and the rectified sinewave waveform would produce a duty > cycle of around 44% at the comparator output. > The diode turn on threshold will alter the duty cycle somewhat but it > should still be acceptable at least for clocking the flipflops and dividers. > > If desired a threshold feedback loop could be used to stabilise the > comparator duty cycle at 50%. > However such a duty cycle stabiliser only works when the input signal > waveform is sinusoidal, rectified sinewave or any other signal with a > slow enough slew rate. > > Bruce > Attached circuit schematics illustrate the simple doubler configuration I had in mind. The series tuned shunt traps eliminate Fin and its odd harmonics due to diode mismatch and transformer imbalance. In principle the series tuned shunt traps tuned to the odd harmonics of the input frequency can all be replaced by a length of open circuited 1/4 wave (at Fin) low loss transmission line. However the 50ns of delay line (required for Fin = 5MHz) takes a lot of space. The circuit driving the 74AC14 illustrates how the doubler output may be biased with a dc level of Vcc/2. In practice either a duty cycle stabilising feedback loop or a pot may be used to adjust the output duty cycle to 50%. A similar circuit can be used to drive a comparator. Bruce -------------- next part -------------- A non-text attachment was scrubbed... Name: SimpleDoublerForHighZLoad.gif Type: image/gif Size: 10923 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080712/a96670df/attachment-0002.gif -------------- next part -------------- A non-text attachment was scrubbed... Name: SimpleFrequencyDoublerDrivingSchmitt.gif Type: image/gif Size: 5241 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080712/a96670df/attachment-0003.gif From ch at murgatroid.com Fri Jul 11 23:18:32 2008 From: ch at murgatroid.com (christopher hoover) Date: Fri, 11 Jul 2008 20:18:32 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: Message-ID: <005501c8e3cd$f6ed0b30$e4c72190$@com> David Partridge wrote: > CPLD - wassat? OK, OK I have some idea, but that's about all I know. > Anyway these are probably BGA stuff which I couldn't hope to hand solder anyway Many CPLD's are leaded. Only the high-pin count CPLD/FPGA's are BGA. > Chris Hoover, Christopher, per favor. > You mean you've got something that does all that and more and you've > kept quiet about it! Shame on you! Or is it really only in the early > stages of gestation? We don't have a board yet, but the code works fine on the Digilent proto board and the REFLOCK II board. The latter is Altera rather than Xilinx, but the same code works on both, but you have to tweak the pin assignments naturally. As I said, I am happy to make the VHDL available. I ought to put under revision control somewhere. -ch From richard at karlquist.com Fri Jul 11 23:58:15 2008 From: richard at karlquist.com (Richard (Rick) Karlquist) Date: Fri, 11 Jul 2008 20:58:15 -0700 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: Message-ID: <48782BD7.9050805@karlquist.com> Well, the good news is (if you buy one of these) is that the worst that can happen is that you unwrap all that 2nd oven junk and you are left with a 10811 for $50. I remember when they were designing that double oven 10811. There are so many things wrong with the design that I wouldn't know where to start. Besides, do you really need more thermal gain for an oscillator in a benign environment? Rick Karlquist N6RK Jim Palfreyman wrote: > Sorry to pollute the list but some people here may be interested and I think > this might be a good buy. > > Ebay item 250268030266 a bunch of 10811-60158 wrapped up in a second oven > that have been pulled from a bunch of HP 58503A. > > There are 21 units available at US$50 Buy It Now. Postage seems reasonable > too. > > I've bought one and so if anyone knows where I can get the cabling > requirements please let me know. > > > Regards, > > Jim Palfreyman > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From magnus at rubidium.dyndns.org Sat Jul 12 04:18:33 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Sat, 12 Jul 2008 10:18:33 +0200 (CEST) Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: References: Message-ID: <20080712.101833.415917433278923569.cfmd@bredband.net> From: Mark Sims Subject: Re: [time-nuts] Thunderbolt - temperature Date: Fri, 11 Jul 2008 21:23:20 +0000 Message-ID: > > The temperature is the electronics temperature. When I put the cover on my red-boxed unit, the temperature went up about 8 C. This would not have happened if them temp was inside the thermostatically controlled oven. The temperature in the oven would also shift, but not by that amount. The numbers I have seen seems to indicate electronics temperature, and this is more usefull if a single temperature is given. Cheers, Magnus From bruce.griffiths at xtra.co.nz Sat Jul 12 04:36:15 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 12 Jul 2008 20:36:15 +1200 Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: <20080712.101833.415917433278923569.cfmd@bredband.net> References: <20080712.101833.415917433278923569.cfmd@bredband.net> Message-ID: <48786CFF.4070400@xtra.co.nz> Magnus Danielson wrote: >> The temperature is the electronics temperature. When I put the cover on my red-boxed unit, the temperature went up about 8 C. This would not have happened if them temp was inside the thermostatically controlled oven. >> > > The temperature in the oven would also shift, but not by that amount. The > numbers I have seen seems to indicate electronics temperature, and this is > more usefull if a single temperature is given. > > Cheers, > Magnus > > The ambient air temperature at a specific point within the enclosure or the temperature of a specific component? i.e. any pictures of the temperature sensor and its location. Are the apparent rapid temperature fluctuations observed by some real or are they the result of inadvertent detection of an intermittent burst of EMI from a switching supply? Bruce From magnus at rubidium.dyndns.org Sat Jul 12 04:37:44 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Sat, 12 Jul 2008 10:37:44 +0200 (CEST) Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <4877F697.2040700@xtra.co.nz> References: <20080711.210141.407454645627545389.cfmd@bredband.net> <4877F697.2040700@xtra.co.nz> Message-ID: <20080712.103744.152643227461331398.cfmd@bredband.net> From: Bruce Griffiths Subject: Re: [time-nuts] Frequency divider design critique request Date: Sat, 12 Jul 2008 12:11:03 +1200 Message-ID: <4877F697.2040700 at xtra.co.nz> > Magnus Danielson wrote: > > Why not? It basically solves a problem most of us has, and only a few tweaks > > away and it solves it fairly generically. The only think it doesn't do well is > > handling 5 MHz souces rather than 10 MHz. Having that would solve many > > problems. While not achieving full metrological levels of stability, I am sure > > it could be handy for several time-nuts never the less. Only a few need that > > upper level anyway. A good prooven design for enought stability and decent > > money might be right. I would certainly not mind having a pair of those lying > > around and I am sure I could put a few into continous use. Now that is my lab > > alone... > > > > > > > Magnus > > A minimalist approach for the 5MHz to 10MHz doubler could use a full > wave (diode, BJT or JFET) doubler followed by a series tuned 5MHz shunt > trap to minimise the 5MHz content in the output. Actually, it depends on weither you would like to get a 10 MHz or not. Another solution would be to run the first divider to /5 rather than /10 and only use the doubler for the 10 MHz output. Ah well. > If the doubler components were perfectly matched (unlikely) the > fundamental trap could be omitted. Agreed. If the zero of the shunt trap is made low-Q the tuning of the shunt becomes almost unnecessary. Also, temperature shifts on components would not shift phase as much. > The other harmonics are of little concern as the comparator output is a > square wave and the rectified sinewave waveform would produce a duty > cycle of around 44% at the comparator output. Unless the duty cycle is important, the overtones help to keep the slew rate high and this avoids adding too much jitter. > The diode turn on threshold will alter the duty cycle somewhat but it > should still be acceptable at least for clocking the flipflops and dividers. Agreed. > If desired a threshold feedback loop could be used to stabilise the > comparator duty cycle at 50%. Good thought. Should be a trivial thing. > However such a duty cycle stabiliser only works when the input signal > waveform is sinusoidal, rectified sinewave or any other signal with a > slow enough slew rate. Indeed. I was only thinking that maybe there ought to be a buffer from the input to the rectifier, or else higher frequency energy will escape out towards the source. At least some isolation should be there. Cheers, Magnus From magnus at rubidium.dyndns.org Sat Jul 12 05:05:32 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Sat, 12 Jul 2008 11:05:32 +0200 (CEST) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <48782BD7.9050805@karlquist.com> References: <48782BD7.9050805@karlquist.com> Message-ID: <20080712.110532.393020591912107318.cfmd@bredband.net> From: "Richard (Rick) Karlquist" Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay Date: Fri, 11 Jul 2008 20:58:15 -0700 Message-ID: <48782BD7.9050805 at karlquist.com> > Well, the good news is (if you buy one of these) is that the worst > that can happen is that you unwrap all that 2nd oven junk and > you are left with a 10811 for $50. My thought exactly. > I remember when they were designing that double oven 10811. There are so > many things wrong with the design that I wouldn't know where to start. > Besides, do you really need more thermal gain for an oscillator > in a benign environment? Please, let me just grab a cup of coffie, and off you can go... I keep wondering if not a passive oven (metal box, insulation, metal box) would be sufficient. Worst case temperature change rates would be significantly reduced such that the oven loop can track it better. The remaining temperature shift will be less. Basically acts like a lowpass filter. What strikes me is the lack of isolation between the oven shells. Oh yes, they have tried to bring the heating around the outer shell, but never the less. Well, at least they did not put a fan in that (Z3801A) box. Cheers, Magnus From bruce.griffiths at xtra.co.nz Sat Jul 12 05:06:33 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 12 Jul 2008 21:06:33 +1200 Subject: [time-nuts] Frequency divider design critique request Message-ID: <48787419.8080307@xtra.co.nz> Magnus >> Magnus >> >> A minimalist approach for the 5MHz to 10MHz doubler could use a full >> wave (diode, BJT or JFET) doubler followed by a series tuned 5MHz >> shunt trap to minimise the 5MHz content in the output. >> > > Actually, it depends on weither you would like to get a 10 MHz or not. > Another solution would be to run the first divider to /5 rather than /10 > and only use the doubler for the 10 MHz output. Ah well. > > > >> The other harmonics are of little concern as the comparator output is >> a square wave and the rectified sinewave waveform would produce a >> duty cycle of around 44% at the comparator output. >> > > Unless the duty cycle is important, the overtones help to keep the > slew rate > high and this avoids adding too much jitter. > > Yes, its only necessary to ensure that the odd harmonics of the 5MHz input are low the even harmonics need not be removed. > > Good thought. Should be a trivial thing. > > Except that with a Schmitt trigger device in the loop the duty stabiliser will oscillate at a low frequency in the absence of an input signal. This may or may not be a problem. In fact if one uses a comparator with a totem pole output the loop is practically guaranteed to oscillate at low frequency in the absence of an input signal. One could always disable the duty cycle stabiliser unless the input signal is large enough (requires an RF detector and another comparator). >> However such a duty cycle stabiliser only works when the input signal >> waveform is sinusoidal, rectified sinewave or any other signal with a >> slow enough slew rate. >> > > Indeed. > > I was only thinking that maybe there ought to be a buffer from the input > to the rectifier, or else higher frequency energy will escape out > towards the > source. At least some isolation should be there. > > For suitable designs see: http://www.ko4bb.com/~bruce/IsolationAmplifiers.html If the phase noise performance isnt too critical a low noise wideband opamp could be used. Alternatively if 30 dB or so reverse isolation is OK use an emitter follower (if the relatively high collector current required is acceptable) or better still cascade a couple for improved isolation. > Cheers, > Magnus > > Bruce From bruce.griffiths at xtra.co.nz Sat Jul 12 05:16:41 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 12 Jul 2008 21:16:41 +1200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <20080712.110532.393020591912107318.cfmd@bredband.net> References: <48782BD7.9050805@karlquist.com> <20080712.110532.393020591912107318.cfmd@bredband.net> Message-ID: <48787679.80108@xtra.co.nz> Magnus Danielson wrote: > > I keep wondering if not a passive oven (metal box, insulation, metal box) > would be sufficient. Worst case temperature change rates would be significantly > reduced such that the oven loop can track it better. The remaining temperature > shift will be less. Basically acts like a lowpass filter. > > What strikes me is the lack of isolation between the oven shells. Oh yes, they > have tried to bring the heating around the outer shell, but never the less. > > > > Cheers, > Magnus > > Magnus A box with multilayer walls: insulator/metal/insulator/ metal etc does a much better job of attenuating thermal fluctuations. The insulator layer only need be significantly poorer at conducting heat than the metal layer. Tufnol sheets are OK for the insulator layers, they bond well to aluminium sheets with epoxy. You just need to remove the few watts of heat from the OCXO without too large an internal temperature rise. Bruce From magnus at rubidium.dyndns.org Sat Jul 12 05:31:40 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Sat, 12 Jul 2008 11:31:40 +0200 (CEST) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <48787679.80108@xtra.co.nz> References: <48782BD7.9050805@karlquist.com> <20080712.110532.393020591912107318.cfmd@bredband.net> <48787679.80108@xtra.co.nz> Message-ID: <20080712.113140.65400060287978620.cfmd@bredband.net> From: Bruce Griffiths Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay Date: Sat, 12 Jul 2008 21:16:41 +1200 Message-ID: <48787679.80108 at xtra.co.nz> Hej Bruce, > A box with multilayer walls: insulator/metal/insulator/ metal etc does a > much better job of attenuating thermal fluctuations. > The insulator layer only need be significantly poorer at conducting heat > than the metal layer. > Tufnol sheets are OK for the insulator layers, they bond well to > aluminium sheets with epoxy. Well, it was not about doing the perfect box in any sense, but just "casing" an OCXO within a box can have rather noticeable effects on the OCXOs ability to handle temperature changes. The degree of the filter can then be varied at need. > You just need to remove the few watts of heat from the OCXO without too > large an internal temperature rise. Indeed, but the over will not burn as much as it's immediate surrounding is hotter than if it was sitting there alone in the box. Providing a too good insulation is certainly a concern. The trick is really to make the insulation-heatmass-insulation-heatmass stages. Just adding one such stage can be sufficient. Cheers, Magnus From holrum at hotmail.com Sat Jul 12 07:06:33 2008 From: holrum at hotmail.com (Mark Sims) Date: Sat, 12 Jul 2008 11:06:33 +0000 Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: References: Message-ID: I suspect that the fluctuation is some sort of noise or software glitch (but one of my systems is powered by a very nice linear supply so probably not power related). What is strange is the decay. If it was a noise glitch, one would expect it to last one sample. But, it decays back to the original curve over 30 seconds or so. I suspect that there is some kind of filtering of the A/D going on, but one would expect a filter with a 30 second time constant to smooth out the rising edge also. Perhaps it is seeing a very large glitch, which gets filtered down to a smaller instantaneous transient response. That then gets filtered out over the next 30 seconds. I saw a couple more of the spikes last night... no apparent correlation with any of the other parameters. Also no disturbances in any of the other values. ---------------------------------------- . Are the apparent rapid temperature fluctuations observed by some real or are they the result of inadvertent detection of an intermittent burst of EMI from a switching supply? _________________________________________________________________ Making the world a better place one message at a time. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_BetterPlace From df6jb at ulrich-bangert.de Sat Jul 12 07:09:55 2008 From: df6jb at ulrich-bangert.de (Ulrich Bangert) Date: Sat, 12 Jul 2008 13:09:55 +0200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <20080712.110532.393020591912107318.cfmd@bredband.net> Message-ID: <769FE70BC9AD430CA6506EEEC90E3B8B@athlon> Magnus, > I keep wondering if not a passive oven (metal box, > insulation, metal box) would be sufficient. Worst case > temperature change rates would be significantly reduced such > that the oven loop can track it better. The remaining > temperature shift will be less. Basically acts like a lowpass filter. I have been thinking pretty much the same and therefore I built me an "outer" box for my 10811 that has abt. 2-3 cm of free air between the outer surface of the 10811 and the inner surface of the box to make the 10811's temperature regulation "look" into the same "thermal leakage impedance" that the designers may have in mind when they decided for the controller's parameters. Then comes 2 cm of massive aluminium which's heat capacity - in conjunction with the surrounding air's thermal resistance - is expected to give the desired "lowpass filter" effect. Due to the nature of my disciplining system I have been able to measure the overall effect of this shielding quite precise: The lowpass effect is well defined by a) an increase of "phase delay" between temperature changes outside and changes of the oscillator's frequency that is now in the order of some hours. b) the frequency changes (as far as they seem to be related to temperature) appear to be "smoother" and more predictable Nevertheless I have been a bit disappointed that the overall frequency changes along the diurnal changes of the surrounding temperature in my flat have been pretty much the same in terms of amplitude with the above mentioned phase delay. I have then started to compute what thermal time constant may be expected from this arrangement. This is not trivial stuff because in contrast to the aluminium's thermal properties their counterparts for the surrounding air are not well defined. As far as I remember, a BEST case assumption gave a result of 2-3 hours that seems to match the empirical results. If you are out for time constants that are able to smooth diurnal changes I guess you will have to throw in MUCH more material. Best regards Ulrich > -----Ursprungliche Nachricht----- > Von: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] Im Auftrag von Magnus Danielson > Gesendet: Samstag, 12. Juli 2008 11:06 > An: time-nuts at febo.com; richard at karlquist.com > Betreff: Re: [time-nuts] Double ovened 10811-60158 on ebay > > > From: "Richard (Rick) Karlquist" > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > Date: Fri, 11 Jul 2008 20:58:15 -0700 > Message-ID: <48782BD7.9050805 at karlquist.com> > > > Well, the good news is (if you buy one of these) is that the worst > > that can happen is that you unwrap all that 2nd oven junk > and you are > > left with a 10811 for $50. > > My thought exactly. > > > I remember when they were designing that double oven 10811. > There are > > so many things wrong with the design that I wouldn't know where to > > start. Besides, do you really need more thermal gain for an > oscillator > > in a benign environment? > > Please, let me just grab a cup of coffie, and off you can go... > > I keep wondering if not a passive oven (metal box, > insulation, metal box) would be sufficient. Worst case > temperature change rates would be significantly reduced such > that the oven loop can track it better. The remaining > temperature shift will be less. Basically acts like a lowpass filter. > > What strikes me is the lack of isolation between the oven > shells. Oh yes, they have tried to bring the heating around > the outer shell, but never the less. > > Well, at least they did not put a fan in that (Z3801A) box. > > Cheers, > Magnus > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts > and > follow the instructions there. > From marc at msys.ch Sat Jul 12 07:55:08 2008 From: marc at msys.ch (Marc Balmer) Date: Sat, 12 Jul 2008 13:55:08 +0200 Subject: [time-nuts] precise external reference time for a PC Message-ID: <20080712115508.GA25432@mail.msys.ch> Hi all, for an upcoming experiment I am looking for precise external time reference, preferrably an atomic clock that I can hook up to a computer running a Unix variant. I should be able to read out the time with a low latency, e.g. over PCI or PCI-e bus. The time reference will serve me as a, well reference, to calibrate a series of various radio clocks. I am looking for used equipment, it should fit in a hobbyists budget, sth. in the 1000-5000$ range would be nice, but it should be as precise as possible. If you have ideas or pointers for me, that would be very welcome. Thanks, Marc Balmer, HB9SSB From bob.paddock at gmail.com Sat Jul 12 08:19:05 2008 From: bob.paddock at gmail.com (Bob Paddock) Date: Sat, 12 Jul 2008 08:19:05 -0400 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <20080712.110532.393020591912107318.cfmd@bredband.net> References: <48782BD7.9050805@karlquist.com> <20080712.110532.393020591912107318.cfmd@bredband.net> Message-ID: > I keep wondering if not a passive oven (metal box, insulation, metal box) > would be sufficient. Large metal reflectively lined thermos bottles are worth considering. You do end up with a lot of long skinny circuit boards that way. Peltier based thermoelectric cooler's from Big Box Stores can also be pressed into service as temperature cycling oven, or stable temperature environment, with the addition of proper regulation loop. See this long outdated paper: http://www.designer-iii.com/cco/HBridge.pdf http://focus.ti.com/lit/an/slua202a/slua202a.pdf "Closed-Loop Temperature Regulation Using the UC3638 H-Bridge Motor Controller and a Thermoelectric Cooler". Next time you have to endure shopping with your wife keep your mind busy by asking "What can I use 'that' for?" for everything you see... The Preface to Murphy's Law: We, the willing, Lead by the unknowing. Are doing the impossible for the ungrateful... We have done so much for so long... With so little... We are now qualified to do anything... With nothing... Forever! -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ From magnus at rubidium.dyndns.org Sat Jul 12 08:49:31 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Sat, 12 Jul 2008 14:49:31 +0200 (CEST) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <769FE70BC9AD430CA6506EEEC90E3B8B@athlon> References: <20080712.110532.393020591912107318.cfmd@bredband.net> <769FE70BC9AD430CA6506EEEC90E3B8B@athlon> Message-ID: <20080712.144931.152643227461335821.cfmd@bredband.net> From: "Ulrich Bangert" Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay Date: Sat, 12 Jul 2008 13:09:55 +0200 Message-ID: <769FE70BC9AD430CA6506EEEC90E3B8B at athlon> Ulrich, > > I keep wondering if not a passive oven (metal box, > > insulation, metal box) would be sufficient. Worst case > > temperature change rates would be significantly reduced such > > that the oven loop can track it better. The remaining > > temperature shift will be less. Basically acts like a lowpass filter. > > I have been thinking pretty much the same and therefore I built me an > "outer" box for my 10811 that has abt. 2-3 cm of free air between the > outer surface of the 10811 and the inner surface of the box to make the > 10811's temperature regulation "look" into the same "thermal leakage > impedance" that the designers may have in mind when they decided for the > controller's parameters. > > Then comes 2 cm of massive aluminium which's heat capacity - in > conjunction with the surrounding air's thermal resistance - is expected > to give the desired "lowpass filter" effect. > > Due to the nature of my disciplining system I have been able to measure > the overall effect of this shielding quite precise: The lowpass effect > is well defined by > > a) an increase of "phase delay" between temperature changes outside and > changes of the oscillator's frequency that is now in the order of some > hours. Which does not as a big supprice but rather confirms the expected. > b) the frequency changes (as far as they seem to be related to > temperature) appear to be "smoother" and more predictable Which also matches expected and other measurements done. > Nevertheless I have been a bit disappointed that the overall frequency > changes along the diurnal changes of the surrounding temperature in my > flat have been pretty much the same in terms of amplitude with the above > mentioned phase delay. Your time-constant for the lowpass filter does not do much to the diurnal frequency. The temperature changes still go through. The point with the passive oven is that it does smooth things out, and could potentially make the oven design inside it an easier task. If temperature changes is the main problem then it may be all that is needed to get the extra margin. It is certainly not a perfect solution, but an interesting exercise which may be of help for some cases. > I have then started to compute what thermal time > constant may be expected from this arrangement. This is not trivial > stuff because in contrast to the aluminium's thermal properties their > counterparts for the surrounding air are not well defined. As far as I > remember, a BEST case assumption gave a result of 2-3 hours that seems > to match the empirical results. If you are out for time constants that > are able to smooth diurnal changes I guess you will have to throw in > MUCH more material. You would also like to build multiple stages to form a higher degree filter. The outermost box is really there to create the chamber around the isolating air and in there your heavy mass (big cap) is gets heated (charged) and chilled (discharged) through the air and black-body radiation. Having the heavy mass fairly directly exposed to the surrounding air will provide better conductivity through drag... Oh, humidity will change the heat conductivity of the air noticeably. Cheers, Magnus From df6jb at ulrich-bangert.de Sat Jul 12 09:00:22 2008 From: df6jb at ulrich-bangert.de (Ulrich Bangert) Date: Sat, 12 Jul 2008 15:00:22 +0200 Subject: [time-nuts] precise external reference time for a PC In-Reply-To: <20080712115508.GA25432@mail.msys.ch> Message-ID: <8C899FF87BBE4E3E9C277400AFC3A18F@athlon> Marc, > ...preferrably an atomic clock that I can hook.... if you need the stability and precision of an atomic clock you will of course not come around to REALLY use one! However, for everything else I would do it like that: Generate a 14.318 MHz signal phase locked or DDS synthesized from the atomic standard and feed this signal directly into the motherboard. Every motherboard features timers that can be read out regardless of operating system and preferred programming language that are clocked by this 14.318 MHz signal. You will save lots of expenses that an otherwise hardware based low latency clock may cost. > I am looking for used equipment, it should fit in a hobbyists > budget, sth. in the 1000-5000$ range would be nice, but it > should be as precise as possible. Most interesting note from Switzerland! Is this your weekly or monthly hobbyist budget? What are your current immigration rules? 73s and my best regards Ulrich, DF6JB > -----Ursprungliche Nachricht----- > Von: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] Im Auftrag von Marc Balmer > Gesendet: Samstag, 12. Juli 2008 13:55 > An: time-nuts at febo.com > Betreff: [time-nuts] precise external reference time for a PC > > > Hi all, > > for an upcoming experiment I am looking for precise external > time reference, preferrably an atomic clock that I can hook > up to a computer running a Unix variant. > > I should be able to read out the time with a low latency, > e.g. over PCI or PCI-e bus. > > The time reference will serve me as a, well reference, to > calibrate a series of various radio clocks. > > I am looking for used equipment, it should fit in a hobbyists > budget, sth. in the 1000-5000$ range would be nice, but it > should be as precise as possible. > > If you have ideas or pointers for me, that would be very welcome. > > Thanks, > Marc Balmer, HB9SSB > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts > and > follow the instructions there. > From phk at phk.freebsd.dk Sat Jul 12 09:04:54 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Sat, 12 Jul 2008 13:04:54 +0000 Subject: [time-nuts] precise external reference time for a PC In-Reply-To: Your message of "Sat, 12 Jul 2008 13:55:08 +0200." <20080712115508.GA25432@mail.msys.ch> Message-ID: <28489.1215867894@critter.freebsd.dk> In message <20080712115508.GA25432 at mail.msys.ch>, Marc Balmer writes: >I should be able to read out the time with a low latency, e.g. >over PCI or PCI-e bus. Read my timecounter paper, find a cheap PCI-FPGA development board, learn basic VHDL, enjoy :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From didier at cox.net Sat Jul 12 09:49:43 2008 From: didier at cox.net (Didier Juges) Date: Sat, 12 Jul 2008 08:49:43 -0500 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <20080712.144931.152643227461335821.cfmd@bredband.net> References: <20080712.110532.393020591912107318.cfmd@bredband.net><769FE70BC9AD430CA6506EEEC90E3B8B@athlon> <20080712.144931.152643227461335821.cfmd@bredband.net> Message-ID: <00b901c8e426$246fb550$0a01a8c0@didierhp> My understanding of thermal regulation is that one of the more difficult thing to do is precisely to know what is the temperature of the components you are trying to stabilize. If you have one oven (even double oven), you have one temperature sensor. The best you can do is keep the sensor at a constant temperature. Assuming the temperature sensor is kept at a perfectly stable temperature, how constant will the temperature of other components be will be a matter of hardware design and layout. I.e. the components you are trying to stabilize should be closely thermally coupled to the sensor. Because there are more than one component to stabilize, not just the crystal, it is a difficult task. The issue is not just static regulation, but also regulation in the presence of a temperature gradient. We understand that if you change the ambient temperature by X, the oven will react to keep the sensor's temperature constant, but the distribution of that heat flux will change dynamically (particularly it will be affected by the masses that are in the way, between the source of heat and the components that are to be stabilized), and even if you have perfect static regulation, in most cases there will be a non-zero dynamic response (a transient). The designers of the HP E1938 (which never went to full production) went through pains to try and keep the gradient evenly distributed precisely for that reason. My guess is that it you take the cover out from the E1938, you will find a perfectly symmetrical layout around the center, where the thermistor is located. A large massive cover over the OCXO will go a long way to reduce the transient and allow the oven controller loop to react smoothly, but as long as the time constant is less than the period of variation (a day?), the peak to peak frequency variations will not change much, but they should be more predictable and may be compensated by a feed-forward mechanism, or a Kalman filter. Didier > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Magnus Danielson > Sent: Saturday, July 12, 2008 7:50 AM > To: time-nuts at febo.com > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > > From: "Ulrich Bangert" > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > Date: Sat, 12 Jul 2008 13:09:55 +0200 > Message-ID: <769FE70BC9AD430CA6506EEEC90E3B8B at athlon> > > Ulrich, > > > > I keep wondering if not a passive oven (metal box, > insulation, metal > > > box) would be sufficient. Worst case temperature change > rates would > > > be significantly reduced such that the oven loop can track it > > > better. The remaining temperature shift will be less. > Basically acts > > > like a lowpass filter. > > > > I have been thinking pretty much the same and therefore I > built me an > > "outer" box for my 10811 that has abt. 2-3 cm of free air > between the > > outer surface of the 10811 and the inner surface of the box to make > > the 10811's temperature regulation "look" into the same "thermal > > leakage impedance" that the designers may have in mind when they > > decided for the controller's parameters. > > > > Then comes 2 cm of massive aluminium which's heat capacity - in > > conjunction with the surrounding air's thermal resistance - is > > expected to give the desired "lowpass filter" effect. > > > > Due to the nature of my disciplining system I have been able to > > measure the overall effect of this shielding quite precise: The > > lowpass effect is well defined by > > > > a) an increase of "phase delay" between temperature changes outside > > and changes of the oscillator's frequency that is now in > the order of > > some hours. > > Which does not as a big supprice but rather confirms the expected. > > > b) the frequency changes (as far as they seem to be related to > > temperature) appear to be "smoother" and more predictable > > Which also matches expected and other measurements done. > > > Nevertheless I have been a bit disappointed that the > overall frequency > > changes along the diurnal changes of the surrounding > temperature in my > > flat have been pretty much the same in terms of amplitude with the > > above mentioned phase delay. > > Your time-constant for the lowpass filter does not do much to > the diurnal frequency. The temperature changes still go > through. The point with the passive oven is that it does > smooth things out, and could potentially make the oven design > inside it an easier task. If temperature changes is the main > problem then it may be all that is needed to get the extra > margin. It is certainly not a perfect solution, but an > interesting exercise which may be of help for some cases. > > > I have then started to compute what thermal time constant may be > > expected from this arrangement. This is not trivial stuff > because in > > contrast to the aluminium's thermal properties their > counterparts for > > the surrounding air are not well defined. As far as I > remember, a BEST > > case assumption gave a result of 2-3 hours that seems to match the > > empirical results. If you are out for time constants that > are able to > > smooth diurnal changes I guess you will have to throw in MUCH more > > material. > > You would also like to build multiple stages to form a higher > degree filter. > The outermost box is really there to create the chamber > around the isolating air and in there your heavy mass (big > cap) is gets heated (charged) and chilled > (discharged) through the air and black-body radiation. > > Having the heavy mass fairly directly exposed to the > surrounding air will provide better conductivity through drag... > > Oh, humidity will change the heat conductivity of the air noticeably. > > Cheers, > Magnus > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, > go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From didier at cox.net Sat Jul 12 10:01:14 2008 From: didier at cox.net (Didier Juges) Date: Sat, 12 Jul 2008 09:01:14 -0500 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <00b901c8e426$246fb550$0a01a8c0@didierhp> References: <20080712.110532.393020591912107318.cfmd@bredband.net><769FE70BC9AD430CA6506EEEC90E3B8B@athlon><20080712.144931.152643227461335821.cfmd@bredband.net> <00b901c8e426$246fb550$0a01a8c0@didierhp> Message-ID: <00bb01c8e427$bf669e10$0a01a8c0@didierhp> By having only one sensor, in the case of the double oven that is obviously not true, but what I meant was that even with a double oven, you only have one sensor near the components you try to regulate, the other sensor regulates the outside temperature of the first oven. Didier > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Didier Juges > Sent: Saturday, July 12, 2008 8:50 AM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > > My understanding of thermal regulation is that one of the > more difficult thing to do is precisely to know what is the > temperature of the components you are trying to stabilize. > > If you have one oven (even double oven), you have one > temperature sensor. > The best you can do is keep the sensor at a constant > temperature. Assuming the temperature sensor is kept at a > perfectly stable temperature, how constant will the > temperature of other components be will be a matter of > hardware design and layout. I.e. the components you are > trying to stabilize should be closely thermally coupled to > the sensor. Because there are more than one component to > stabilize, not just the crystal, it is a difficult task. > > The issue is not just static regulation, but also regulation > in the presence of a temperature gradient. We understand that > if you change the ambient temperature by X, the oven will > react to keep the sensor's temperature constant, but the > distribution of that heat flux will change dynamically > (particularly it will be affected by the masses that are in > the way, between the source of heat and the components that > are to be stabilized), and even if you have perfect static > regulation, in most cases there will be a non-zero dynamic > response (a transient). > > The designers of the HP E1938 (which never went to full > production) went through pains to try and keep the gradient > evenly distributed precisely for that reason. My guess is > that it you take the cover out from the E1938, you will find > a perfectly symmetrical layout around the center, where the > thermistor is located. > > A large massive cover over the OCXO will go a long way to > reduce the transient and allow the oven controller loop to > react smoothly, but as long as the time constant is less than > the period of variation (a day?), the peak to peak frequency > variations will not change much, but they should be more > predictable and may be compensated by a feed-forward > mechanism, or a Kalman filter. > > Didier > > > -----Original Message----- > > From: time-nuts-bounces at febo.com > > [mailto:time-nuts-bounces at febo.com] On Behalf Of Magnus Danielson > > Sent: Saturday, July 12, 2008 7:50 AM > > To: time-nuts at febo.com > > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > > > > From: "Ulrich Bangert" > > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > > Date: Sat, 12 Jul 2008 13:09:55 +0200 > > Message-ID: <769FE70BC9AD430CA6506EEEC90E3B8B at athlon> > > > > Ulrich, > > > > > > I keep wondering if not a passive oven (metal box, > > insulation, metal > > > > box) would be sufficient. Worst case temperature change > > rates would > > > > be significantly reduced such that the oven loop can track it > > > > better. The remaining temperature shift will be less. > > Basically acts > > > > like a lowpass filter. > > > > > > I have been thinking pretty much the same and therefore I > > built me an > > > "outer" box for my 10811 that has abt. 2-3 cm of free air > > between the > > > outer surface of the 10811 and the inner surface of the > box to make > > > the 10811's temperature regulation "look" into the same "thermal > > > leakage impedance" that the designers may have in mind when they > > > decided for the controller's parameters. > > > > > > Then comes 2 cm of massive aluminium which's heat capacity - in > > > conjunction with the surrounding air's thermal resistance - is > > > expected to give the desired "lowpass filter" effect. > > > > > > Due to the nature of my disciplining system I have been able to > > > measure the overall effect of this shielding quite precise: The > > > lowpass effect is well defined by > > > > > > a) an increase of "phase delay" between temperature > changes outside > > > and changes of the oscillator's frequency that is now in > > the order of > > > some hours. > > > > Which does not as a big supprice but rather confirms the expected. > > > > > b) the frequency changes (as far as they seem to be related to > > > temperature) appear to be "smoother" and more predictable > > > > Which also matches expected and other measurements done. > > > > > Nevertheless I have been a bit disappointed that the > > overall frequency > > > changes along the diurnal changes of the surrounding > > temperature in my > > > flat have been pretty much the same in terms of amplitude > with the > > > above mentioned phase delay. > > > > Your time-constant for the lowpass filter does not do much to the > > diurnal frequency. The temperature changes still go > through. The point > > with the passive oven is that it does smooth things out, and could > > potentially make the oven design inside it an easier task. If > > temperature changes is the main problem then it may be all that is > > needed to get the extra margin. It is certainly not a perfect > > solution, but an interesting exercise which may be of help for some > > cases. > > > > > I have then started to compute what thermal time constant may be > > > expected from this arrangement. This is not trivial stuff > > because in > > > contrast to the aluminium's thermal properties their > > counterparts for > > > the surrounding air are not well defined. As far as I > > remember, a BEST > > > case assumption gave a result of 2-3 hours that seems to > match the > > > empirical results. If you are out for time constants that > > are able to > > > smooth diurnal changes I guess you will have to throw in > MUCH more > > > material. > > > > You would also like to build multiple stages to form a > higher degree > > filter. > > The outermost box is really there to create the chamber around the > > isolating air and in there your heavy mass (big > > cap) is gets heated (charged) and chilled > > (discharged) through the air and black-body radiation. > > > > Having the heavy mass fairly directly exposed to the > surrounding air > > will provide better conductivity through drag... > > > > Oh, humidity will change the heat conductivity of the air > noticeably. > > > > Cheers, > > Magnus > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, > go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From james.p.lux at jpl.nasa.gov Sat Jul 12 10:26:23 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Sat, 12 Jul 2008 07:26:23 -0700 Subject: [time-nuts] precise external reference time for a PC In-Reply-To: <20080712115508.GA25432@mail.msys.ch> References: <20080712115508.GA25432@mail.msys.ch> Message-ID: <20080712072623.bbp3rb8c0swsso04@webmail.jpl.nasa.gov> Quoting Marc Balmer , on Sat 12 Jul 2008 04:55:08 AM PDT: > Hi all, > > for an upcoming experiment I am looking for precise external > time reference, preferrably an atomic clock that I can hook > up to a computer running a Unix variant. > > I should be able to read out the time with a low latency, e.g. > over PCI or PCI-e bus. > > The time reference will serve me as a, well reference, to > calibrate a series of various radio clocks. > > I am looking for used equipment, it should fit in a hobbyists > budget, sth. in the 1000-5000$ range would be nice, but it > should be as precise as possible. > > If you have ideas or pointers for me, that would be very > welcome. there are a variety of cards made that can generate/receive timecode or sync pulses that plug into a PC. True-Time (now Symmetricom) used to make an IRIG timecode card for ISA bus, for instance. I imagine these are in the $1000 range. For instance the National Instruments PCI-6601 counter timer card is about $350 Then, drive that with Rb standard from Stanford Research (I seem to recall seeing ads on the back of Electronic Design or some such for $1795)... That's all brand new. One can do much better if one hunts down surplus or used. Jim > > Thanks, > Marc Balmer, HB9SSB > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From tvb at LeapSecond.com Sat Jul 12 10:47:26 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Sat, 12 Jul 2008 07:47:26 -0700 Subject: [time-nuts] precise external reference time for a PC References: <20080712115508.GA25432@mail.msys.ch> Message-ID: <000501c8e42e$38857cc0$0200a8c0@pc52> > Hi all, > > for an upcoming experiment I am looking for precise external > time reference, preferrably an atomic clock that I can hook > up to a computer running a Unix variant. > > I should be able to read out the time with a low latency, e.g. > over PCI or PCI-e bus. > > The time reference will serve me as a, well reference, to > calibrate a series of various radio clocks. Are you sure you want or need a PC-based card for this? This sort of precise calibration is often much easier with a simple frequency or time interval counter. Have a look at: Clock Powers of Ten http://www.leapsecond.com/ten/ 1.8 ppm frequency error in a Junghans WWVB radio clock http://www.leapsecond.com/pages/Junghans/ Decoding WWVB atomic time radio controlled clock http://www.leapsecond.com/pages/sony-wwvb/ /tvb From holrum at hotmail.com Sat Jul 12 12:12:34 2008 From: holrum at hotmail.com (Mark Sims) Date: Sat, 12 Jul 2008 16:12:34 +0000 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: Message-ID: Remember that heat flow is proportional to the FOURTH power of the temperature difference. Insulation is generally a linear function. The combination makes thermal stabilization over even small ambient temperature ranges rather problematic. _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From richard at karlquist.com Sat Jul 12 12:14:50 2008 From: richard at karlquist.com (Richard (Rick) Karlquist) Date: Sat, 12 Jul 2008 09:14:50 -0700 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <00b901c8e426$246fb550$0a01a8c0@didierhp> References: <20080712.110532.393020591912107318.cfmd@bredband.net><769FE70BC9AD430CA6506EEEC90E3B8B@athlon> <20080712.144931.152643227461335821.cfmd@bredband.net> <00b901c8e426$246fb550$0a01a8c0@didierhp> Message-ID: <4878D87A.2030005@karlquist.com> Didier Juges wrote: > The designers of the HP E1938 (which never went to full production) went > through pains to try and keep the gradient evenly distributed precisely for > that reason. My guess is that it you take the cover out from the E1938, you > will find a perfectly symmetrical layout around the center, where the > thermistor is located. Actually, something like 30,000 E1938A's were built. Maybe the glass is not full, but it is not exactly empty. As I explained in my 1997 FCS paper, the oven is very symmetrical, etc. We routinely achieved a thermal gain of several 100,000. During design testing, we could often get the thermal gain up to well over 1 million. This is the thermal gain to the crystal. Of course, the gain to the electronics was less. The thermal gain of a good 10811 is around 1,000, by comparison. Rick Karlquist N6RK E1938A designer From chris.cheney at tesco.net Sat Jul 12 13:03:03 2008 From: chris.cheney at tesco.net (Chris Cheney) Date: Sat, 12 Jul 2008 18:03:03 +0100 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: , Message-ID: <4878F1D7.28413.18F4BF8@chris.cheney.tesco.net> On 12 Jul 2008 at 16:12, Mark Sims wrote: > > Remember that heat flow is proportional to the FOURTH power of the > temperature difference. This is Stefan's Law - it applies only to radiation. Heat transfer by conduction and convection are linearly proportional to temperature difference. Chris From mark.amos at toast.net Sat Jul 12 13:13:36 2008 From: mark.amos at toast.net (Mark Amos) Date: Sat, 12 Jul 2008 13:13:36 -0400 Subject: [time-nuts] thermal transfer - even a little further OT Message-ID: <9b1132d6fd0e4866a04d29f6e2ee4959.mark.amos@toast.net> Timenuts, In introductory texts regarding the FFT there is some mention of Fourier's studies having had something to do with heat transfer. Yet most of the FFT work I've been exposed to has to do with decomposing signals into component sinusoids, translating between time and frequency domain, etc. Does anyone have a "layman's" explanation of how this relates to what Fourier was trying to do with heat transfer? I suspect my problem is mostly one of "student density", but I can't make the connection between heat transfer and what I think of when I think of FFT (unless I were to relate it to infrared radiation, which I don't suppose Fourier would have been thinking about...) Thanks, in advance, Mark "An error does not become truth by reason of multiplied propagation, nor does truth become error because nobody sees it." -- Mohandas Gandhi From ed_palmer at sasktel.net Sat Jul 12 13:20:57 2008 From: ed_palmer at sasktel.net (Ed Palmer) Date: Sat, 12 Jul 2008 11:20:57 -0600 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: Message-ID: <4878E7F9.2080309@sasktel.net> Jim, I see that the same vendor has a few more units for sale. He has also included a picture that labels all the connections. Ed > Message: 2 > Date: Wed, 9 Jul 2008 12:10:52 +1000 > From: "Jim Palfreyman" > Subject: [time-nuts] Double ovened 10811-60158 on ebay > To: time-nuts at febo.com > Message-ID: > > Content-Type: text/plain; charset=ISO-8859-1 > > Sorry to pollute the list but some people here may be interested and I think > this might be a good buy. > > Ebay item 250268030266 a bunch of 10811-60158 wrapped up in a second oven > that have been pulled from a bunch of HP 58503A. > > There are 21 units available at US$50 Buy It Now. Postage seems reasonable > too. > > I've bought one and so if anyone knows where I can get the cabling > requirements please let me know. > > > Regards, > > Jim Palfreyman > From james.p.lux at jpl.nasa.gov Sat Jul 12 13:31:03 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Sat, 12 Jul 2008 10:31:03 -0700 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: Message-ID: <20080712103103.naj3s7sz4skosk84@webmail.jpl.nasa.gov> Quoting Mark Sims , on Sat 12 Jul 2008 09:12:34 AM PDT: > > Remember that heat flow is proportional to the FOURTH power of the > temperature difference. Heat transferred by *radiation* goes as the 4th power. Heat transfered by conduction goes linearly. Unless you're in a vacuum, conduction might dominate. From james.p.lux at jpl.nasa.gov Sat Jul 12 13:38:13 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Sat, 12 Jul 2008 10:38:13 -0700 Subject: [time-nuts] thermal transfer - even a little further OT In-Reply-To: <9b1132d6fd0e4866a04d29f6e2ee4959.mark.amos@toast.net> References: <9b1132d6fd0e4866a04d29f6e2ee4959.mark.amos@toast.net> Message-ID: <20080712103813.a05kp46mcgowc04s@webmail.jpl.nasa.gov> Quoting Mark Amos , on Sat 12 Jul 2008 10:13:36 AM PDT: > Timenuts, > > In introductory texts regarding the FFT there is some mention of > Fourier's studies having had something to > do with heat transfer. Yet most of the FFT work I've been exposed > to has to do with decomposing signals > into component sinusoids, translating between time and frequency domain, etc. > > Does anyone have a "layman's" explanation of how this relates to > what Fourier was trying to do with heat > transfer? M. Fourier was looking at the problem of heat transfer in cannon barrels, which, in 2D is a ring (aka a continuous periodic function). http://en.wikipedia.org/wiki/Joseph_Fourier has more info (including the interesting thing that I didn't know before, about his discovery of the greenhouse effect) From david.partridge at dsl.pipex.com Sat Jul 12 13:40:34 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Sat, 12 Jul 2008 18:40:34 +0100 Subject: [time-nuts] 74ac112 and 74ac164 sources and 200 Ohm resistors for frequency divider board? Message-ID: I'm looking for 74ac164 and 74ac112 in SOIC (.15" wide) as the usual suspects (Farnell and RS Components) don't seem to stock these in UK :-( I found most of the other 74AC logic I want. I'm also hunting 200 Ohm 0.25W 1206 case thick film resistors. I can buy a reel of 5000 at about USD34 from RS Components, but don't really need quite as many as that!!! 300 ohm don't seem any easier :-( Yes, I know these aren't in the standard resistor sequence. I'll be using SMA rather than SMB connectors - they were easier to find (and I bought some on eBay). Cheers Dave Partridge From hmurray at megapathdsl.net Sat Jul 12 14:07:13 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Sat, 12 Jul 2008 11:07:13 -0700 Subject: [time-nuts] precise external reference time for a PC In-Reply-To: Message from Marc Balmer of "Sat, 12 Jul 2008 13:55:08 +0200." <20080712115508.GA25432@mail.msys.ch> Message-ID: <20080712180714.A5913BCCD@ip-64-139-1-69.sjc.megapath.net> > for an upcoming experiment I am looking for precise external time > reference, preferrably an atomic clock that I can hook up to a > computer running a Unix variant. How good a clock do you want/expect? If you are using a computer, you have a layer of jitter from things like interrupts and cache misses. PCI adds more jitter from things like DMA activity. How stable is your thermal environment? Have you experimented with ntpd and a simple GPS unit? That turns the problem from hardware to software. I'd expect you could get the system clock to within a few 10s of microseconds. That may take luck and work. Quirks will vary from OS to OS and from release to release, both of OS and ntpd, and maybe from motherboard to board. -- These are my opinions, not necessarily my employer's. I hate spam. From mccorkle at ptialaska.net Sat Jul 12 14:57:00 2008 From: mccorkle at ptialaska.net (Richard H McCorkle) Date: Sat, 12 Jul 2008 10:57:00 -0800 (AKDT) Subject: [time-nuts] 74ac112 and 74ac164 sources and 200 Ohm resistors for frequency divider board? In-Reply-To: References: Message-ID: <28139.206.174.39.163.1215889020.squirrel@mymail.acsalaska.net> Hi Dave, Try www.mouser.com who list both 74ac devices in SOIC and have them in stock. Richard > I'm looking for 74ac164 and 74ac112 in SOIC (.15" wide) as the usual > suspects (Farnell and RS Components) don't seem to stock these in UK :-( > > I found most of the other 74AC logic I want. > > I'm also hunting 200 Ohm 0.25W 1206 case thick film resistors. I can buy a > reel of 5000 at about USD34 from RS Components, but don't really need quite > as many as that!!! 300 ohm don't seem any easier :-( > > Yes, I know these aren't in the standard resistor sequence. > > I'll be using SMA rather than SMB connectors - they were easier to find (and > I bought some on eBay). > > Cheers > Dave Partridge > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From t_list_1_only at braw.co.uk Sat Jul 12 15:45:40 2008 From: t_list_1_only at braw.co.uk (David ) Date: Sat, 12 Jul 2008 20:45:40 +0100 Subject: [time-nuts] 8. 74ac112 and 74ac164 sources and 200 Ohm resistors (time-nuts Digest, Vol 48, Issue 35) In-Reply-To: Message-ID: <004801c8e457$e169bcb0$0200a8c0@hp6110> An easy answer to : > I'm also hunting 200 Ohm 0.25W 1206 case thick film > resistors. I can buy a reel of 5000 at about USD34 from RS > Components, but don't really need quite > as many as that!!! 300 ohm don't seem any easier :-( > > Yes, I know these aren't in the standard resistor sequence. Using standard E12 values: 220R in parallel with 2k2 is exactly 200R. 330R in parallel with 3k3 is exactly 300R. Just stack the two parts on the single footprint, sadly I knew the answers without calculating, need to get out more.... David From alan.melia at btinternet.com Sat Jul 12 15:46:27 2008 From: alan.melia at btinternet.com (Alan Melia) Date: Sat, 12 Jul 2008 20:46:27 +0100 Subject: [time-nuts] 74ac112 and 74ac164 sources and 200 Ohm resistors for frequency divider board? References: <28139.206.174.39.163.1215889020.squirrel@mymail.acsalaska.net> Message-ID: <007801c8e458$0fb90da0$0900a8c0@AM> Hi Dave Rapid Electronics in Colchester do SMBs ....the eaiest way to get 200 ohms might be 2 by 100ohm in series..though it wont fit a ready made 1206 size pcb :-(( www.rapidelectronics.co.uk or www.rapidonline.com is one they quote now I think both work. I dont think you will get 74ACs there though Alan G3NYK >------snip > > I'm looking for 74ac164 and 74ac112 in SOIC (.15" wide) as the usual > > suspects (Farnell and RS Components) don't seem to stock these in UK :-( > > > > I found most of the other 74AC logic I want. > > > > I'm also hunting 200 Ohm 0.25W 1206 case thick film resistors. I can buy a > > reel of 5000 at about USD34 from RS Components, but don't really need quite > > as many as that!!! 300 ohm don't seem any easier :-( > > > > Yes, I know these aren't in the standard resistor sequence. > > > > I'll be using SMA rather than SMB connectors - they were easier to find (and > > I bought some on eBay). > > > > Cheers > > Dave Partridge > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts at febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From kc0vsj at yahoo.com Sat Jul 12 16:03:43 2008 From: kc0vsj at yahoo.com (Tom Clifton) Date: Sat, 12 Jul 2008 13:03:43 -0700 (PDT) Subject: [time-nuts] Thunderbolt temperature spikes Message-ID: <702160.14826.qm@web37007.mail.mud.yahoo.com> I too am seeing them - four or five events during a 24 hour time period. Below are 50 temp readings before and after an event. 32.82 32.82 32.82 32.82 32.82 32.82 32.82 32.82 32.82 32.83 32.92 32.91 32.90 32.89 32.89 32.88 32.87 32.87 32.87 32.86 32.86 32.85 32.85 32.85 32.85 32.84 32.84 32.84 32.84 32.84 32.84 32.84 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 32.83 From bruce.griffiths at xtra.co.nz Sat Jul 12 17:43:11 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sun, 13 Jul 2008 09:43:11 +1200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: Message-ID: <4879256F.2060300@xtra.co.nz> Mark Sims wrote: > Remember that heat flow is proportional to the FOURTH power of the temperature difference. Insulation is generally a linear function. The combination makes thermal stabilization over even small ambient temperature ranges rather problematic. > > > Nonsense. The radiative transfer between 2 bodies at different temperatures is proportional to the difference between the 4th powers of their absolute temperatures. However this requires a medium between the 2 bodies that is transparent to the wavelenghts of interest and emissivity that is constant with wavelength. In a practical situation convection and conduction are also significant. Conductive heat flow is proportional to the temperature difference between the 2 bodies. Bruce From bruce.griffiths at xtra.co.nz Sat Jul 12 19:03:15 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sun, 13 Jul 2008 11:03:15 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <48787419.8080307@xtra.co.nz> References: <48787419.8080307@xtra.co.nz> Message-ID: <48793833.20407@xtra.co.nz> Bruce Griffiths wrote: >> I was only thinking that maybe there ought to be a buffer from the input >> to the rectifier, or else higher frequency energy will escape out >> towards the >> source. At least some isolation should be there. >> >> >> If one uses a common base stage to drive the diode frequency doubler transformer primary, then the high impedance drive minimises the effect of diode thresholds and mismatches, however it is necessary to connect a resistor in parallel with the shunt inductor in the diode doubler to provide a well defined relatively low load impedance at the 10MHz output frequency. Reverse isolation of 40dB or so is possible when using a common base stage at frequencies of around 10MHz or so. Bruce From richard at karlquist.com Sat Jul 12 22:48:06 2008 From: richard at karlquist.com (Rick Karlquist) Date: Sat, 12 Jul 2008 19:48:06 -0700 (PDT) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <4879256F.2060300@xtra.co.nz> References: <4879256F.2060300@xtra.co.nz> Message-ID: <4330.69.12.192.152.1215917286.squirrel@webmail.sonic.net> Bruce Griffiths wrote: > Mark Sims wrote: >> Remember that heat flow is proportional to the FOURTH power of the >> temperature difference. Insulation is generally a linear function. The >> combination makes thermal stabilization over even small ambient >> temperature ranges rather problematic. >> >> >> > > Nonsense. > The radiative transfer between 2 bodies at different temperatures is > proportional to the difference between the 4th powers of their absolute > temperatures. And this quantity is approximately equal to the THIRD power of the temperature difference for small temperature differences. (A simple calculus problem!) Rick Karlquist N6RK From bruce.griffiths at xtra.co.nz Sat Jul 12 23:03:24 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sun, 13 Jul 2008 15:03:24 +1200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <4330.69.12.192.152.1215917286.squirrel@webmail.sonic.net> References: <4879256F.2060300@xtra.co.nz> <4330.69.12.192.152.1215917286.squirrel@webmail.sonic.net> Message-ID: <4879707C.3040505@xtra.co.nz> Rick Karlquist wrote: > Bruce Griffiths wrote: > >> Mark Sims wrote: >> >>> Remember that heat flow is proportional to the FOURTH power of the >>> temperature difference. Insulation is generally a linear function. The >>> combination makes thermal stabilization over even small ambient >>> temperature ranges rather problematic. >>> >>> >>> >>> >> Nonsense. >> The radiative transfer between 2 bodies at different temperatures is >> proportional to the difference between the 4th powers of their absolute >> temperatures. >> > > And this quantity is approximately equal to the THIRD power of > the temperature difference for small temperature differences. > (A simple calculus problem!) > > Rick Karlquist N6RK > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > Rick For small temperature differences its always linearly proportional to the temperature difference not its third power. Heat radiation is proportional to (T2)^4 - (T1)^4 which for small T2-T1 ~ (T2-T1)*T^3 where T ~ T1~T2 and T2-T1 is small. Bruce From bruce.griffiths at xtra.co.nz Sat Jul 12 23:19:19 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sun, 13 Jul 2008 15:19:19 +1200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <4330.69.12.192.152.1215917286.squirrel@webmail.sonic.net> References: <4879256F.2060300@xtra.co.nz> <4330.69.12.192.152.1215917286.squirrel@webmail.sonic.net> Message-ID: <48797437.7090402@xtra.co.nz> Rick Karlquist wrote: > Bruce Griffiths wrote: > >> Mark Sims wrote: >> >>> Remember that heat flow is proportional to the FOURTH power of the >>> temperature difference. Insulation is generally a linear function. The >>> combination makes thermal stabilization over even small ambient >>> temperature ranges rather problematic. >>> >>> >>> >>> >> Nonsense. >> The radiative transfer between 2 bodies at different temperatures is >> proportional to the difference between the 4th powers of their absolute >> temperatures. >> > > And this quantity is approximately equal to the THIRD power of > the temperature difference for small temperature differences. > (A simple calculus problem!) > > Rick Karlquist N6RK > > The Taylor series expansion gives: (T+h)^4 - T^4 = 4*h*(T^3) + 6*(h^2)*(T^2) + 4*(h^3)*T + h^4 The largest term of which is 4*h*T^3 for small h, and large T(absolute temperature). where ^ denotes the power of and * denotes multiplication. That is for small temperature difference the radiative heat transfer is proportional to the PRODUCT of the temperature difference and the THIRD power of the absolute temperature. Bruce From didier at cox.net Sun Jul 13 01:24:13 2008 From: didier at cox.net (Didier Juges) Date: Sun, 13 Jul 2008 00:24:13 -0500 Subject: [time-nuts] Thunderbolt Monitor Message-ID: <000001c8e4a8$b0b1a550$0a00a8c0@d400> Firmware version 0.0.4 is usable and has been uploaded, read the details and download the firmware from my Wiki page: http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:gps_monitor Some user interface (to select which information to display) would be nice. 2 lines of 16 characters is definitely a limitation when dealing with so much information. I am open to suggestions about what you guys think would be the most useful information to display. A few LEDs would not be out of the question. The processor has 17 available IO pins, the LCD uses 7 and the serial port uses 2, so at the moment, there are 8 left. I will probably make a NMEA version at some point, for non-Trimble GPS. Didier KO4BB From hmurray at megapathdsl.net Sun Jul 13 04:43:02 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Sun, 13 Jul 2008 01:43:02 -0700 Subject: [time-nuts] Old Loran Message-ID: <20080713084303.F3D5BBCCE@ip-64-139-1-69.sjc.megapath.net> I found this interesting. It's a chunk of the memoirs of a Coast Guard Captain who was in charge of Loran in Japan from 1961-1964. http://www.uscg.mil/history/WEBORALHISTORY/CAPT_David_Sinclair_29.html It's half Coast Guard history/nostalgia, half his memories of Japan, and a little bit of Loran. But I thought that little bit was neat. How good were crystals back in WW II time frame? Does anybody know anything about early Loran? I'm guessing that the secondary stations listened to the primary and sent their pulse X microseconds after they heard a pulse. How did they implement that delay? What sort of filter/PLL did they have on receiving the primary station? What is current Loran navigation accuracy? What was it like in the old days? -- These are my opinions, not necessarily my employer's. I hate spam. From max at maxsmusicplace.com Sun Jul 13 13:22:33 2008 From: max at maxsmusicplace.com (Max Robinson) Date: Sun, 13 Jul 2008 12:22:33 -0500 Subject: [time-nuts] Old Loran References: <20080713084303.F3D5BBCCE@ip-64-139-1-69.sjc.megapath.net> Message-ID: <006001c8e50d$0bb1b3f0$6401a8c0@BACKROOM> Hal Murray wrote. >How good were crystals back in WW II time frame? >Does anybody know anything about early Loran? I'm guessing that the >secondary stations listened to the primary and sent their pulse X >microseconds after they heard a pulse. How did they implement that delay? >What sort of filter/PLL did they have on receiving the primary station? >What is current Loran navigation accuracy? What was it like in the old >days? Each station in the old loran system used a different pulse rate. You could hear the pulses walking across one another giving a rising and falling sense of rate. There was some frequency diversity as well. I never really understood how the old system worked. In the 60s a carefully designed ovened crystal oscillator could do about 1 part in ten to the ninth. In WWII I suspect it was an order of magnitude worse. Regards. Max. K 4 O D S. Email: max at maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscribe at yahoogroups.com ----- Original Message ----- From: "Hal Murray" To: Sent: Sunday, July 13, 2008 3:43 AM Subject: [time-nuts] Old Loran > > I found this interesting. It's a chunk of the memoirs of a Coast Guard > Captain who was in charge of Loran in Japan from 1961-1964. > > http://www.uscg.mil/history/WEBORALHISTORY/CAPT_David_Sinclair_29.html > > It's half Coast Guard history/nostalgia, half his memories of Japan, and a > little bit of Loran. But I thought that little bit was neat. > > How good were crystals back in WW II time frame? > > Does anybody know anything about early Loran? I'm guessing that the > secondary stations listened to the primary and sent their pulse X > microseconds after they heard a pulse. How did they implement that delay? > What sort of filter/PLL did they have on receiving the primary station? > > What is current Loran navigation accuracy? What was it like in the old > days? > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From phk at phk.freebsd.dk Sun Jul 13 14:55:40 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Sun, 13 Jul 2008 18:55:40 +0000 Subject: [time-nuts] Old Loran In-Reply-To: Your message of "Sun, 13 Jul 2008 12:22:33 EST." <006001c8e50d$0bb1b3f0$6401a8c0@BACKROOM> Message-ID: <33848.1215975340@critter.freebsd.dk> In message <006001c8e50d$0bb1b3f0$6401a8c0 at BACKROOM>, "Max Robinson" writes: >Hal Murray wrote. >>Does anybody know anything about early Loran? You should find and read J.A.Pierce's book in the radiation lab series, it explains how all the WWII systems works, then read his memoir (it used to be on the web), that explains (lightly) Omega, Loran-A..C It was news to me that a LORAN-D was ever worked on, but Dave Mills thesis may also have been the only work ever done on it. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From magnus at rubidium.dyndns.org Sun Jul 13 15:13:04 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Sun, 13 Jul 2008 21:13:04 +0200 (CEST) Subject: [time-nuts] Old Loran In-Reply-To: <33848.1215975340@critter.freebsd.dk> References: <006001c8e50d$0bb1b3f0$6401a8c0@BACKROOM> <33848.1215975340@critter.freebsd.dk> Message-ID: <20080713.211304.415917433278919178.cfmd@bredband.net> From: "Poul-Henning Kamp" Subject: Re: [time-nuts] Old Loran Date: Sun, 13 Jul 2008 18:55:40 +0000 Message-ID: <33848.1215975340 at critter.freebsd.dk> > In message <006001c8e50d$0bb1b3f0$6401a8c0 at BACKROOM>, "Max Robinson" writes: > >Hal Murray wrote. > > >>Does anybody know anything about early Loran? > > You should find and read J.A.Pierce's book in the radiation lab series, > it explains how all the WWII systems works, then read his memoir (it > used to be on the web), that explains (lightly) Omega, Loran-A..C > > It was news to me that a LORAN-D was ever worked on, but Dave Mills > thesis may also have been the only work ever done on it. Considering the modernizing of LORAN-C with data subcarrier and modernized transmitter equipment it could be argued that it to some degree is a LORAN-D. Would love to learn more on Omega and Loran-A through D. I enjoyed the info on the Russian woodpecker online (google, it is great fun and not something you just arbitrarilly have on the back yard). Cheers, Magnus From phk at phk.freebsd.dk Sun Jul 13 15:22:00 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Sun, 13 Jul 2008 19:22:00 +0000 Subject: [time-nuts] Old Loran In-Reply-To: Your message of "Sun, 13 Jul 2008 21:13:04 +0200." <20080713.211304.415917433278919178.cfmd@bredband.net> Message-ID: <33937.1215976920@critter.freebsd.dk> In message <20080713.211304.415917433278919178.cfmd at bredband.net>, Magnus Danie lson writes: >Considering the modernizing of LORAN-C with data subcarrier and modernized >transmitter equipment it could be argued that it to some degree is a LORAN-D. No, Loran-D was a (tactical ?) system with 16 pulses instead of 8 for improved S/N ratio. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From magnus at rubidium.dyndns.org Sun Jul 13 15:26:35 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Sun, 13 Jul 2008 21:26:35 +0200 (CEST) Subject: [time-nuts] Old Loran In-Reply-To: <33937.1215976920@critter.freebsd.dk> References: <20080713.211304.415917433278919178.cfmd@bredband.net> <33937.1215976920@critter.freebsd.dk> Message-ID: <20080713.212635.152643227461323752.cfmd@bredband.net> From: "Poul-Henning Kamp" Subject: Re: [time-nuts] Old Loran Date: Sun, 13 Jul 2008 19:22:00 +0000 Message-ID: <33937.1215976920 at critter.freebsd.dk> > In message <20080713.211304.415917433278919178.cfmd at bredband.net>, Magnus Danie > lson writes: > > >Considering the modernizing of LORAN-C with data subcarrier and modernized > >transmitter equipment it could be argued that it to some degree is a LORAN-D. > > No, Loran-D was a (tactical ?) system with 16 pulses instead of 8 for improved > S/N ratio. Certainly, but if that never happend, then the modernized Loran-C is what we got instead. That was what I tried to say... Loran-D was probably canceled since GPS happend instead. Several projects was canceled or moved into GPS. Both the air force and navy was looking at similar enought things. Cheers, Magnus From bg at lysator.liu.se Sun Jul 13 15:34:55 2008 From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson) Date: Sun, 13 Jul 2008 21:34:55 +0200 Subject: [time-nuts] Old Loran In-Reply-To: <33937.1215976920@critter.freebsd.dk> References: <33937.1215976920@critter.freebsd.dk> Message-ID: <1215977695.5846.8.camel@bg-desktop> On Sun, 2008-07-13 at 19:22 +0000, Poul-Henning Kamp wrote: > In message <20080713.211304.415917433278919178.cfmd at bredband.net>, Magnus Danie > lson writes: > > >Considering the modernizing of LORAN-C with data subcarrier and modernized > >transmitter equipment it could be argued that it to some degree is a LORAN-D. > > No, Loran-D was a (tactical ?) system with 16 pulses instead of 8 for improved > S/N ratio. > eLORAN is used for the current (coming) improved LORAN-C. -- Bj?rn From phk at phk.freebsd.dk Sun Jul 13 15:54:29 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Sun, 13 Jul 2008 19:54:29 +0000 Subject: [time-nuts] Old Loran In-Reply-To: Your message of "Sun, 13 Jul 2008 21:26:35 +0200." <20080713.212635.152643227461323752.cfmd@bredband.net> Message-ID: <34140.1215978869@critter.freebsd.dk> In message <20080713.212635.152643227461323752.cfmd at bredband.net>, Magnus Danie lson writes: >Loran-D was probably canceled since GPS happend instead. Several projects was >canceled or moved into GPS. Both the air force and navy was looking at similar >enought things. No, Loran-D predated GPS by about 10 years. My guess is that it was just not workable. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From namichie at gmail.com Sun Jul 13 19:19:12 2008 From: namichie at gmail.com (Neville Michie) Date: Mon, 14 Jul 2008 09:19:12 +1000 Subject: [time-nuts] Old Loran In-Reply-To: <20080713084303.F3D5BBCCE@ip-64-139-1-69.sjc.megapath.net> References: <20080713084303.F3D5BBCCE@ip-64-139-1-69.sjc.megapath.net> Message-ID: The technology of that era is quite interesting. 1961 I was working on an Australian air navigation system called DME, which measured the distance to a selected airport transponder. Oscilloscopes were very crude by today's standards. A 1MHz LC oscillator was adjusted to zero beat a 1MHz xtal osc. The 1MHz oscillator was then pulsed to start with the synch pulse of the CRO to superimpose little microsecond pips on top of the signal being viewed. (only single beam CROs then, using a 5BP1 tube). That way we had a scope calibrated in microseconds. Stable delays were either a row of maybe 40 capacitors and coils to make a lumped constant delay line, or a box with 100s of yards of coax and a pair of connectors on top. Phase detection was done by a Miller integrator circuit "Phantastron" which created a slowly increasing voltage or ramp which delayed the firing of two monostables. These monostables "gated" (logic was called "pulse technique" in those days) the returned pulses, switching the phantastron from a rising to falling ramp or visa versa so that the phantastron voltage tracked and could be used as the time of flight distance from the beacon. A missing pulse circuit left the phantastron in a static condition until pulses arrived or the timeout circuit reset and the scan from zero delay would start again. Some elements of these ideas are still probably useful, cheers, Neville Michie On 13/07/2008, at 6:43 PM, Hal Murray wrote: > > I found this interesting. It's a chunk of the memoirs of a Coast > Guard > Captain who was in charge of Loran in Japan from 1961-1964. > > http://www.uscg.mil/history/WEBORALHISTORY/CAPT_David_Sinclair_29.html > > It's half Coast Guard history/nostalgia, half his memories of > Japan, and a > little bit of Loran. But I thought that little bit was neat. > > How good were crystals back in WW II time frame? > > Does anybody know anything about early Loran? I'm guessing that the > secondary stations listened to the primary and sent their pulse X > microseconds after they heard a pulse. How did they implement that > delay? > What sort of filter/PLL did they have on receiving the primary > station? > > What is current Loran navigation accuracy? What was it like in the > old days? > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. From didier at cox.net Sun Jul 13 20:55:15 2008 From: didier at cox.net (Didier Juges) Date: Sun, 13 Jul 2008 19:55:15 -0500 Subject: [time-nuts] Thunderbolt Monitor Message-ID: <001f01c8e54c$48a5cdc0$0a00a8c0@d400> I have uploaded version 0.0.8. Alarms (if any) are decoded and displayed in succession on the second line of the display, alternated with the Disciplining Status. The archive has been fixed, there was a problem with v004. If you downloaded it and had problems, I am sorry... Check the Wiki for details: http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:gps_monitor Didier KO4BB From holrum at hotmail.com Mon Jul 14 12:28:07 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 14 Jul 2008 16:28:07 +0000 Subject: [time-nuts] Thunderbolt temperature spikes In-Reply-To: References: Message-ID: I set up my ThunderBolt data logger to flag temperature spikes. Over a 10 hour run last night it caught five of them (TOW magnitude): 104416 0.097 deg 104898 0.022 deg 115715 0.087 deg 135298 0.098 deg 138564 0.041 deg ---------------------------------------- _________________________________________________________________ Making the world a better place one message at a time. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_BetterPlace From danrae at verizon.net Mon Jul 14 12:44:25 2008 From: danrae at verizon.net (Dan Rae) Date: Mon, 14 Jul 2008 09:44:25 -0700 Subject: [time-nuts] Thunderbolt temperature spikes In-Reply-To: References: Message-ID: <487B8269.2010201@verizon.net> Mark Sims wrote: > I set up my ThunderBolt data logger to flag temperature spikes. Over a 10 hour run last night it caught five of them (TOW magnitude): > 104416 0.097 deg > 104898 0.022 deg > 115715 0.087 deg > 135298 0.098 deg > 138564 0.041 deg > ---------------------------------------- > > This is a "spike"? Surely this kind of tiny temperature variation on the unit's board somewhere outside the oven does not have a lot of relevance or effect on anything inside the oven where it is all happening. And what is the tolerance and resolution of the temperature measuring device anyway? Or am I missing something fundamental here? I have long since stopped monitoring mine since it seems quite happy to be left alone, but I used to see diurnal variations in temperature reading several orders of magnitude greater than those "spikes". Dan From holrum at hotmail.com Mon Jul 14 14:02:42 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 14 Jul 2008 18:02:42 +0000 Subject: [time-nuts] Thunderbolt temperature spikes In-Reply-To: References: Message-ID: Yes indeed, those are spikes... and rather big ones at that. They may seem small, but they occur over a one second period. Normally I do not see more than 1 millidegree of change over that time interval. These spikes are 20 to 100 times that. After the spike, the temperature reading decays back to normal over 10-30 seconds. Whatever they are, they should not be there. The oven only affects the crystal stability. All the frequency comparison, EFC DAC voltage, etc logic are outside the oven and are affected by temperature. The Thunderbolt uses the ambient temperature readings to help compensate for these effects, discipline the oscillator, and to train the holdover compensation Kalman filter. The ThunderBolt A/D has at least a 20 bit resolution (probably 24 bit). It reports temperature with microdegree resolution. They would not be using such a high resolution A/D if ambient temperature was not a major factor in performance. Although they are fairly infrequent, the spikes do have the potential to affect the disciplining and holdover performance. My plots of ThunderBolt temperature usually show a 200 millidegree or so peak-peak sinewave shape with a 30 minute or so period (probably corresponding to air conditioning cycles). Over a full day, the reported temperature is 40C +/- 0.5C. The unit I am monitoring right now is sitting on the floor, next to the back door, and next to a floor mounted AC vent. It is covered by a corrugated cardboard box. I go though that door rather frequently (it is 100 F outside and 74F inside) but have not seen any influence on the temperature plots. ---------------------------------------- This is a "spike"? Surely this kind of tiny temperature variation on the unit's board somewhere outside the oven does not have a lot of relevance or effect on anything inside the oven where it is all happening. And what is the tolerance and resolution of the temperature measuring device anyway? Or am I missing something fundamental here? _________________________________________________________________ The i?m Talkaton. Can 30-days of conversation change the world? http://www.imtalkathon.com/?source=EML_WLH_Talkathon_ChangeWorld From chris.kuethe at gmail.com Mon Jul 14 14:11:48 2008 From: chris.kuethe at gmail.com (Chris Kuethe) Date: Mon, 14 Jul 2008 11:11:48 -0700 Subject: [time-nuts] Thunderbolt temperature spikes In-Reply-To: <487B8269.2010201@verizon.net> References: <487B8269.2010201@verizon.net> Message-ID: <91981b3e0807141111v7764e3e0ia7536c0bf237abdd@mail.gmail.com> On Mon, Jul 14, 2008 at 9:44 AM, Dan Rae wrote: > This is a "spike"? Surely this kind of tiny temperature variation on > the unit's board somewhere outside the oven does not have a lot of > relevance or effect on anything inside the oven where it is all > happening. And what is the tolerance and resolution of the temperature > measuring device anyway? Or am I missing something fundamental here? You are missing something fundamental. This is time-nuts, where we love to quibble over stray picoseconds and definitely get our knickers in a knot over a few nanoseconds. That some part of a timing system suddenly changed by several *hundredths* of a part is an atrocity! :) I'm only half-kidding. I guess it's like large uptimes on unix machines - it's fun to see how long you can keep a system running, and how stable it is. Changes are worth investigating and quantifying. Is this a normal, bounded oscillation? Is this just randomess? Is the cat sleeping on the ovenized oscillator again? Are squirrels chewing on the antenna cables? Generally - what is the state of the system, what forces are affecting it, how can we make the system run better? CK -- GDB has a 'break' feature; why doesn't it have 'fix' too? From holrum at hotmail.com Mon Jul 14 14:20:26 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 14 Jul 2008 18:20:26 +0000 Subject: [time-nuts] HP 10811-60158 and LPRO-101 on Ebay In-Reply-To: References: Message-ID: The seller of this 10811's on Ebay has raised his price to 80 bucks a pop. He also is now listing LPRO-101 rubidiums for $99 (half of what everybody else wants). Also, on his pictures of the connectors, one pin is labeled LOCXO. What is this signal? ---------------------------------------- _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From hmurray at megapathdsl.net Mon Jul 14 14:45:40 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 14 Jul 2008 11:45:40 -0700 Subject: [time-nuts] More on Old Loran Message-ID: <20080714184541.CB2B7BCCE@ip-64-139-1-69.sjc.megapath.net> Lots of good info on hyperbolic navigation aids http://jproc.ca/hyperbolic/index.html In particular, this is a nice description of Loran A http://jproc.ca/hyperbolic/loran_a.html Here is info on how a Phantastron works. It may not make much sense if you don't know how tubes work. http://www.radarpages.co.uk/theory/ap3302/sec2/ch8/sec2ch8p137.htm (Figure 3 is on the next page. Follow the link at the bottom.) -- These are my opinions, not necessarily my employer's. I hate spam. From j.koegel5 at gmail.com Mon Jul 14 15:15:09 2008 From: j.koegel5 at gmail.com (=?ISO-8859-1?Q?J=FCrg_K=F6gel?=) Date: Mon, 14 Jul 2008 21:15:09 +0200 Subject: [time-nuts] HP 10811-60158 and LPRO-101 on Ebay In-Reply-To: References: Message-ID: <390229150807141215u25c20806j3f7edead7393f5be@mail.gmail.com> The LOCXO ist the oven monitor. See on the manual 10811A/B Juerg From holrum at hotmail.com Mon Jul 14 15:49:34 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 14 Jul 2008 19:49:34 +0000 Subject: [time-nuts] Thunderbolt temperature spikes In-Reply-To: References: Message-ID: Looking back through some old logs with my New and Improved Spike Finder (tm), it appears that spikes seem to occur, on average, around every 2-3 hours and their effect shows up in the data for around 20 seconds... so figure on 1 part in 500 of the temperature data is corrupted by their effect. It is almost certain that the spikes are not caused by real temperature changes, but are the effect of some noise or firmware glitch. In a system where performance is measured in parts per trillion, something that effects .2% of a critical parameter's measurement is bound to have an adverse effect. ---------------------------------------- _________________________________________________________________ It?s a talkathon ? but it?s not just talk. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_JustTalk From dave.g0dja at tiscali.co.uk Mon Jul 14 16:03:17 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Mon, 14 Jul 2008 21:03:17 +0100 Subject: [time-nuts] Thunderbolt - On its way! In-Reply-To: References: Message-ID: <487BB105.8010900@tiscali.co.uk> I just received confirmation that my payment has been cleared, so I hope my Thunderbolt is on its way. :-) Thanks to all involved. I hope to be trawling back through the discussions on software soon. From dave.g0dja at tiscali.co.uk Mon Jul 14 16:08:50 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Mon, 14 Jul 2008 21:08:50 +0100 Subject: [time-nuts] Trimble Palisade In-Reply-To: <390229150807141215u25c20806j3f7edead7393f5be@mail.gmail.com> References: <390229150807141215u25c20806j3f7edead7393f5be@mail.gmail.com> Message-ID: <487BB252.6070605@tiscali.co.uk> For a very good price I bought a Trimble Palisade the other day. It came without the multiway plug, so I wonder if there's a source of those anywhere? I did find websites for programs for extracting 1PPS data, and even an add on NMEA board, but I'm not really bothered about that. Does anyone have any useful information on using it, or should I open it up and replace the multiway socket and see if I can do something else other than mount it outside as another time standard? Thanks for any ideas. From hmurray at megapathdsl.net Mon Jul 14 16:09:37 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 14 Jul 2008 13:09:37 -0700 Subject: [time-nuts] Mechanicrawl (San Francisco, July 12th) Message-ID: <20080714200938.E811BBCCE@ip-64-139-1-69.sjc.megapath.net> I was in San Francisco on Sat for the Mechanicrawl. For time-nuts, the Long Now was probably the most interesting place. They are building a mechanical clock that is targeted to run for 10,000 years. They had lots of neat prototype stuff working. I didn't get the big picture. It's half art and half engineering. http://www.longnow.org/ I think the plan is to power the core timekeeping unit from day-night temperature differences and let visitors/tourists provide power for the fancy display stuff. They have a big Fresnel lens that's somehow rigged up with a PLL. They are keeping solar time, not atomic time. Pampanito is a WW II sub. http://www.maritime.org/pamphome.htm They had a TDC (Torpedo Data Computer) on display. It was in the shop where you could see it. (There was another in the sub, but the sub itself was really tight.) The TDC was close to working. It's a mechanical analog computer. Inputs are your speed and direction and (estimates) of the target's bearing, speed, and direction. It sets the bearing on the torpedo's gyrocompass. Being able to track that in real time was a major advance. The guy said they were expecting 40-50 geeks. Word got out. They had 1000 or 2000 visitors. I didn't see it on the tour, but the Pampanito has Loran gear. http://www.maritime.org/radio-das.htm http://www.maritime.org/radiocat.htm says: The DAS-3 LORAN is in the control room. It was used to locate the boats position when close to shore based transmitter stations. A replacement is installed in control room. It powers up, but otherwise the status is unknown since the LORAN signals it uses are no longer transmitted. We would like to simulate these signals with a computer for testing, or find one of the WW II era testing devices. Each pulse is 40 microseconds. At 1.75 to 1.95 MHz, that's about a dozen cycles. My straw man would be a 1 bit D/A from a FPGA and a low pass filter. Maybe 2 bits on a center tapped transformer for better symmetry. Next to the Pampanito is the Jeremia O'Brien, a WW II Liberty ship. http://www.ssjeremiahobrien.org/ The steam engine was running. If size is your criteria, it was clearly the hit of the crawl. I didn't see anything timing related, but they did have a neat counter down in the engine room. It counted rotations. It had a lot of digits. Next time, I'll have to remember to find the clock. There are a lot of distractions though. -- These are my opinions, not necessarily my employer's. I hate spam. From GandalfG8 at aol.com Mon Jul 14 16:30:11 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Mon, 14 Jul 2008 16:30:11 EDT Subject: [time-nuts] Trimble Palisade Message-ID: In a message dated 14/07/2008 21:09:41 GMT Daylight Time, dave.g0dja at tiscali.co.uk writes: Does anyone have any useful information on using it, or should I open it up and replace the multiway socket and see if I can do something else other than mount it outside as another time standard? Thanks for any ideas. ------------------------- I don't know if you've seen this site? _http://www.dc2light.pwp.blueyonder.co.uk/Webpage/GPS_ref.htm_ (http://www.dc2light.pwp.blueyonder.co.uk/Webpage/GPS_ref.htm) I wouldn't recommend taking it apart if you do intend to put it outside. If you can't find the proper connector it shouldn't be difficult to mount individual sockets plus some sleeves on the ends of a multiway cable, although not exactly weatherproof either. It used to be possible to buy D type shells and pins/sockets separately, just as one example, but perhaps a conventional D type connector could be broken apart to provide the sockets? regards Nigel GM8PZR From tvb at LeapSecond.com Mon Jul 14 16:39:38 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Mon, 14 Jul 2008 13:39:38 -0700 Subject: [time-nuts] Trimble Palisade References: <390229150807141215u25c20806j3f7edead7393f5be@mail.gmail.com> <487BB252.6070605@tiscali.co.uk> Message-ID: <000701c8e5f1$c2be2760$0200a8c0@pc52> > Does anyone have any useful information on using it, or should I open it > up and replace the multiway socket and see if I can do something else > other than mount it outside as another time standard? Google for Trimble Palisade or see if this helps: Trimble Palisade GPS 1 PPS time source http://www.leapsecond.com/museum/palisade/ /tvb From kc0vsj at yahoo.com Mon Jul 14 16:50:30 2008 From: kc0vsj at yahoo.com (Tom Clifton) Date: Mon, 14 Jul 2008 13:50:30 -0700 (PDT) Subject: [time-nuts] Thunderbolt temperature spikes Message-ID: <326131.89772.qm@web37003.mail.mud.yahoo.com> My own gut feeling is that it is a glitch making its way through one of the power supplies. Its decay looks like it could be capacitive... Pr thermal..... or (fill in the blank) I'm using the brick power supply povided and it is possible that they generate transients, or poorly react to normal line garbage. I'm off for a week of forced vacation (hernia repair - picked up too many boat anchors at hamfests...) but plan to proceede with building linear supplies with battery backup. Once I'm isolated from the mains the glitches will prove themselves by their presence or absence. If anybody out there has a "red box" Thunderbolt that runs off a single dc supply - could you graph the temperature and see if you have similar spikes? Also, I note that there is a Thunderrbolt "E" out there with a different connector layout (has a BNC connector for the antenna input instead of an F connector) and touts improved holdover times. On the off chance that anybody has one of those, do they also suffer these glitches? From preynaert at yahoo.com Mon Jul 14 16:51:22 2008 From: preynaert at yahoo.com (Patrick Reynaert) Date: Mon, 14 Jul 2008 13:51:22 -0700 (PDT) Subject: [time-nuts] Trimble DAC voltage Message-ID: <808193.81096.qm@web58801.mail.re1.yahoo.com> Over the past 2 days, the DAC voltage of my trimble thunderbolt has increased in a linear mannar from 0.332 to 0.336 or about 2mV per day. I assume this voltage will sooner or later saturate? Or is this effect the aging of the crystal in the OCXO that keeps on going at this rate? If the latter is true, does this mean that within about 2500 days from now, the DAC voltage will hit +5V ? Best regards, Patrick. From bob.b at pobox.com Mon Jul 14 16:58:43 2008 From: bob.b at pobox.com (Robert Berg) Date: Mon, 14 Jul 2008 13:58:43 -0700 Subject: [time-nuts] Trimble Palisade In-Reply-To: <487BB252.6070605@tiscali.co.uk> References: <390229150807141215u25c20806j3f7edead7393f5be@mail.gmail.com> <487BB252.6070605@tiscali.co.uk> Message-ID: I picked up a couple of prewired cables for the Palisade from tiger- tech.biz They had both short (~2 or 3m) and much longer cables in stock. Prices weren't bad, either, as I recall. Bob On Jul 14, 2008, at 1:08 PM, David Ackrill wrote: > For a very good price I bought a Trimble Palisade the other day. > > It came without the multiway plug, so I wonder if there's a source of > those anywhere? > > I did find websites for programs for extracting 1PPS data, and even an > add on NMEA board, but I'm not really bothered about that. > > Does anyone have any useful information on using it, or should I > open it > up and replace the multiway socket and see if I can do something else > other than mount it outside as another time standard? > > Thanks for any ideas. > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From paul at greenrover.demon.co.uk Mon Jul 14 17:12:18 2008 From: paul at greenrover.demon.co.uk (paul at greenrover.demon.co.uk) Date: Mon, 14 Jul 2008 22:12:18 +0100 Subject: [time-nuts] Thunderbolt - On its way! In-Reply-To: <487BB105.8010900@tiscali.co.uk> References: <487BB105.8010900@tiscali.co.uk> Message-ID: <487BC132.20609@greenrover.demon.co.uk> David Ackrill wrote: > I just received confirmation that my payment has been cleared, so I hope > my Thunderbolt is on its way. :-) > > Thanks to all involved. I hope to be trawling back through the > discussions on software soon. Mine arrived safely a few days ago - excellent! My thanks to those who made it possible. -- 73 de Paul GW8IZR IO73TI http://www.gw8izr.com From tvb at LeapSecond.com Mon Jul 14 17:20:06 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Mon, 14 Jul 2008 14:20:06 -0700 Subject: [time-nuts] Trimble DAC voltage References: <808193.81096.qm@web58801.mail.re1.yahoo.com> Message-ID: <000701c8e5f7$66ef70f0$0200a8c0@pc52> > Over the past 2 days, the DAC voltage of my trimble > thunderbolt has increased in a linear mannar from > 0.332 to 0.336 or about 2mV per day. Nice. Keep logging for a few more weeks or even months and tell us what happens, long-term. > I assume this voltage will sooner or later saturate? Or > is this effect the aging of the crystal in the OCXO that > keeps on going at this rate? If the latter is true, does > this mean that within about 2500 days from now, the > DAC voltage will hit +5V ? I guess, yes, if the trend of the past *2* days continues without change for the next *2500* days. But in the real world what happens in a few days doesn't always match what happens over a few weeks or years. If you continue your data collection for the long-term it should make an interesting plot. /tvb From chris.kuethe at gmail.com Mon Jul 14 17:21:15 2008 From: chris.kuethe at gmail.com (Chris Kuethe) Date: Mon, 14 Jul 2008 14:21:15 -0700 Subject: [time-nuts] thunderbolt for ntpd or gpsd In-Reply-To: <48559045.4080703@stnhbr.com> References: <200806151145.58089.w.knowles@xtra.co.nz> <48559045.4080703@stnhbr.com> Message-ID: <91981b3e0807141421j2afb6b60t50a5848d5eadd859@mail.gmail.com> On Sun, Jun 15, 2008 at 2:57 PM, Tim Cwik wrote: > I have discovered the even though cgps does not report position or time > using the Thunderbolt, the stock gpsd is getting enough timing data to > update ntp. Gpsd is selected as the sys.peer with a jitter of about .8. > It looks like the PPS pulse is too narrow to be detected on DCD as i've now got my thunderbolt i can start adding support for it in gpsd. wayne knowles did a nice patch which i'm using as the foundation of my development. the main issue is auto-detecting parity of the serial line since trimble couldn't make up their minds about 8N1 or 8O1. i've noticed two primary complaints (with which i agree) - the PPS output is too short and positions don't seem to be output by default. i'm probably going to add an initializer to make the thunderbolt emit position data and crank up the 1PPS pulse length to something reasonable - at least 1ms. the change will be purely runtime - i won't write it to EEPROM. does that seem reasonable? CK -- GDB has a 'break' feature; why doesn't it have 'fix' too? From holrum at hotmail.com Mon Jul 14 17:26:51 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 14 Jul 2008 21:26:51 +0000 Subject: [time-nuts] Thunderbolt temperature spikes In-Reply-To: References: Message-ID: I have both a red-box unit with the single input power supply (internally it has a AT&T DC-DC converter brick and lots of filtering stuff) and two of the three-supply units. All of them show the same temperature glitches. I have had one running off of a Tektronix PS-503A linear lab supply and one running off the TAPR supply. I have run the red-box one off of batteries. All show the glitches. I'm fairly certain that it is not power related. I also think the decay of the glitch is due to some kind of software filtering of the A/D readings. Also does anybody out there have a ThunderBolt-E? I have added "E-bolt" support to my programs that I would like somebody to test. The major E-bolt difference seems to be a 12 channel receiver .vs. the 8 channel one in the older ThunderBolts. Also, the E-bolt does not supply per-satellite clock bias error estimates and has some different version and receiver health status messages. ---------------------------------------- _________________________________________________________________ Use video conversation to talk face-to-face with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_Refresh_messenger_video_072008 From holrum at hotmail.com Mon Jul 14 17:39:11 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 14 Jul 2008 21:39:11 +0000 Subject: [time-nuts] Trimble DAC voltage In-Reply-To: References: Message-ID: That seem to be fairly normal for an oscillator to undergo some initial quick aging after being powered on after a long rest. It should settle down after a week or so. My FTS-4060 cesium unit was aging at about 40mV a day. After a week it was down to around 10mV. After two weeks, it stabilized to where the control voltage more or less follows temperature with around +/- 2mV change over a day. The ThunderBolt DAC voltage plot mirrors the PPS error estimate. As one goes up, the other goes down. They show discontinuities whenever the tracked satellite constellation changes. The DAC voltage usually wanders +/- 250 microvolts over an hour. The PPS error plot is generally a smooth curve. The DAC voltage plot is more of a stair-step curve. ---------------------------------------- > Over the past 2 days, the DAC voltage of my trimble > thunderbolt has increased in a linear mannar from > 0.332 to 0.336 or about 2mV per day. _________________________________________________________________ Making the world a better place one message at a time. http://www.imtalkathon.com/?source=EML_WLH_Talkathon_BetterPlace From hmurray at megapathdsl.net Mon Jul 14 17:51:34 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 14 Jul 2008 14:51:34 -0700 Subject: [time-nuts] Thunderbolt temperature spikes In-Reply-To: Message from Mark Sims of "Mon, 14 Jul 2008 19:49:34 -0000." Message-ID: <20080714215136.16E8DBCCE@ip-64-139-1-69.sjc.megapath.net> > Looking back through some old logs with my New and Improved Spike > Finder (tm), it appears that spikes seem to occur, on average, around > every 2-3 hours and their effect shows up in the data for around 20 > seconds... so figure on 1 part in 500 of the temperature data is > corrupted by their effect. It is almost certain that the spikes are > not caused by real temperature changes, but are the effect of some > noise or firmware glitch. In a system where performance is measured > in parts per trillion, something that effects .2% of a critical > parameter's measurement is bound to have an adverse effect. What do you mean by "not caused by real temperature changes"? Do you mean the external temperature isn't changing so you don't expect the internal temperature to change? Or do you think there is a bug in the temperature measuring stuff? It would be interesting to add a couple more sensors on nearby chips. My guess would be either of 2 events: The CPU is doing some extra work. There is a bug (hardware, firmware, both...) such that there is an occasional bus clash for a short period. If the CPU is doing the work, then the temperature of the CPU should show the spikes, and maybe the memory chips too. If it's a bus clash, then the spikes should appear on the pair of chips involved in the fight. -- These are my opinions, not necessarily my employer's. I hate spam. From hmurray at megapathdsl.net Mon Jul 14 18:26:29 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Mon, 14 Jul 2008 15:26:29 -0700 Subject: [time-nuts] thunderbolt for ntpd or gpsd In-Reply-To: Message from "Chris Kuethe" of "Mon, 14 Jul 2008 14:21:15 PDT." <91981b3e0807141421j2afb6b60t50a5848d5eadd859@mail.gmail.com> Message-ID: <20080714222630.C7D1DBCCE@ip-64-139-1-69.sjc.megapath.net> > i've noticed two primary complaints (with which i agree) - the PPS > output is too short and positions don't seem to be output by default. > i'm probably going to add an initializer to make the thunderbolt emit > position data and crank up the 1PPS pulse length to something > reasonable - at least 1ms. the change will be purely runtime - i won't > write it to EEPROM. does that seem reasonable? That seems reasonable to me. I haven't found any way to adjust the length of the PPS. Please let me know if you find it. -- These are my opinions, not necessarily my employer's. I hate spam. From holrum at hotmail.com Mon Jul 14 18:34:19 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 14 Jul 2008 22:34:19 +0000 Subject: [time-nuts] Thunderbolt temperature spikes In-Reply-To: References: Message-ID: The nature of the spikes are that they show an instantaneous impulse 100mV rise in the temperature readings between two 1 second samples. The rise exists for one sample then decays over around 20 seconds. There is no way that any CPU (or bus) activity can generate a heat pulse that would propogate to the temperature sensor in such a manner... there is just too much thermal mass/spacing involved. Also the spikes appear to occur randomly and are not correlated with any specific CPU activity. I have seen two spikes with five minutes. I have also seen 8 hours go by without any spikes. I think they are related to some glitch in the temperature sensor system... my bet is something in the firmware rather than the hardware. The way the pulse decays looks a whole lot like there is some software filtering of the readings going on. -------------------- >What do you mean by "not caused by real temperature changes"? _________________________________________________________________ The i?m Talkaton. Can 30-days of conversation change the world? http://www.imtalkathon.com/?source=EML_WLH_Talkathon_ChangeWorld From holrum at hotmail.com Mon Jul 14 18:39:08 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 14 Jul 2008 22:39:08 +0000 Subject: [time-nuts] thunderbolt for ntpd or gpsd In-Reply-To: References: Message-ID: The ThunderBolt does not seem to have a way to control the width of the 1PPS pulse in software... My data dumper program for the thing requests and processes just about every message the thing can handle (and a few that it cannot) and I have not seen any messages that can control the pulse width. Do you have any info on how to do it? ----------------------------------------- > i'm probably going to add an initializer to make the thunderbolt emit > position data and crank up the 1PPS pulse length to something > reasonable - at least 1ms. the change will be purely runtime - i won't > write it to EEPROM. does that seem reasonable? _________________________________________________________________ The i?m Talkaton. Can 30-days of conversation change the world? http://www.imtalkathon.com/?source=EML_WLH_Talkathon_ChangeWorld From holrum at hotmail.com Mon Jul 14 19:46:57 2008 From: holrum at hotmail.com (Mark Sims) Date: Mon, 14 Jul 2008 23:46:57 +0000 Subject: [time-nuts] 5071A on Ebay In-Reply-To: References: Message-ID: Well, for only $29K you can KNOW what time it is... and it has the high performance cesium slinger. Or for $200 +/- you can get pretty darn close with a ThunderBolt... ---------------------------------------- _________________________________________________________________ Need to know now? Get instant answers with Windows Live Messenger. http://www.windowslive.com/messenger/connect_your_way.html?ocid=TXT_TAGLM_WL_messenger_072008 From jmiles at pop.net Mon Jul 14 20:02:24 2008 From: jmiles at pop.net (John Miles) Date: Mon, 14 Jul 2008 17:02:24 -0700 Subject: [time-nuts] 5071A on Ebay In-Reply-To: Message-ID: eBay has partitioned itself lately into items with excessive starting bids, and items which are real bargains. But yeah, I already paid for all the Cs/Rb sources flying around overhead, damned if I'm not going to use 'em! -- john > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On > Behalf Of Mark Sims > Sent: Monday, July 14, 2008 4:47 PM > To: time-nuts at febo.com > Subject: [time-nuts] 5071A on Ebay > > > > Well, for only $29K you can KNOW what time it is... and it has > the high performance cesium slinger. > > Or for $200 +/- you can get pretty darn close with a ThunderBolt... > ---------------------------------------- > > _________________________________________________________________ > Need to know now? Get instant answers with Windows Live Messenger. > http://www.windowslive.com/messenger/connect_your_way.html?ocid=TX > T_TAGLM_WL_messenger_072008 > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From didier at cox.net Tue Jul 15 00:47:23 2008 From: didier at cox.net (Didier Juges) Date: Mon, 14 Jul 2008 23:47:23 -0500 Subject: [time-nuts] Thunderbolt monitor Message-ID: <004401c8e635$e04bd360$0a01a8c0@didierhp> I made a second version (same firmware) of the Thunderbolt monitor. This one uses the plastic DIP version of the processor mounted on a small Radio Shack proto board and it uses a gorgeous Noritake Vacuum Fluorescent display. The interface between the Noritake and any ordinary LCD display is the same ( as far as pin-out is concerned), except that the Noritake does not have a contrast adjustment. Otherwise, the firmware is the same, once the differences are accounted for. The Noritake is generally much faster than most 2 line LCDs when updating the data, but requires a little more time to initialize themselves at power up. My software can drive either display without modification. The Noritake displays have a software command to adjust the brightness down to half, and that's it. My firmware does not take advantage of that feature, which I find relatively useless, but may prolong the life of the display. The VFDs only have a few years of life under continuous operation, so dimming the display or turning it off altogether when not needed might be a good idea. See pictures at http://www.ko4bb.com/Timing/GPSMonitor/ Didier KO4BB From hmurray at megapathdsl.net Tue Jul 15 03:42:31 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Tue, 15 Jul 2008 00:42:31 -0700 Subject: [time-nuts] 300 ms offset glitch from TBolt Message-ID: <20080715074232.C16AFBCCE@ip-64-139-1-69.sjc.megapath.net> Has anybody seen anything like this? The data below is from ntpd's clockstats file. There is no PPS on this system, but it's synced to a nearby machine that does keep good time. The TBolt is using the serial port in noselect (aka monitor) mode. I'm just collecting data like this rather than using it for timekeeping. The second column is the time the message arrived from the TBolt. The 50 ms offset is typical. The 360 ms offset runs for 24 minutes, then it fixes itself. ... 54661 65939.051 127.127.29.0 2008 196 18:18:59.000000 54661 65955.051 127.127.29.0 2008 196 18:19:15.000000 54661 65971.052 127.127.29.0 2008 196 18:19:31.000000 54661 65987.054 127.127.29.0 2008 196 18:19:47.000000 54661 66003.052 127.127.29.0 2008 196 18:20:03.000000 54661 66019.051 127.127.29.0 2008 196 18:20:19.000000 54661 66035.054 127.127.29.0 2008 196 18:20:35.000000 54661 66051.054 127.127.29.0 2008 196 18:20:51.000000 54661 66067.052 127.127.29.0 2008 196 18:21:07.000000 54661 66083.053 127.127.29.0 2008 196 18:21:23.000000 54661 66099.053 127.127.29.0 2008 196 18:21:39.000000 54661 66115.053 127.127.29.0 2008 196 18:21:55.000000 54661 66130.362 127.127.29.0 2008 196 18:22:10.000000 54661 66146.363 127.127.29.0 2008 196 18:22:26.000000 54661 66162.363 127.127.29.0 2008 196 18:22:42.000000 54661 66178.361 127.127.29.0 2008 196 18:22:58.000000 54661 66194.363 127.127.29.0 2008 196 18:23:14.000000 54661 66210.363 127.127.29.0 2008 196 18:23:30.000000 54661 66226.363 127.127.29.0 2008 196 18:23:46.000000 54661 66242.361 127.127.29.0 2008 196 18:24:02.000000 54661 66258.361 127.127.29.0 2008 196 18:24:18.000000 54661 66274.360 127.127.29.0 2008 196 18:24:34.000000 54661 66290.360 127.127.29.0 2008 196 18:24:50.000000 ... 54661 67410.365 127.127.29.0 2008 196 18:43:30.000000 54661 67426.364 127.127.29.0 2008 196 18:43:46.000000 54661 67442.363 127.127.29.0 2008 196 18:44:02.000000 54661 67458.364 127.127.29.0 2008 196 18:44:18.000000 54661 67474.364 127.127.29.0 2008 196 18:44:34.000000 54661 67490.361 127.127.29.0 2008 196 18:44:50.000000 54661 67506.361 127.127.29.0 2008 196 18:45:06.000000 54661 67522.360 127.127.29.0 2008 196 18:45:22.000000 54661 67538.364 127.127.29.0 2008 196 18:45:38.000000 54661 67554.361 127.127.29.0 2008 196 18:45:54.000000 54661 67570.362 127.127.29.0 2008 196 18:46:10.000000 54661 67576.052 127.127.29.0 2008 196 18:46:16.000000 54661 67592.051 127.127.29.0 2008 196 18:46:32.000000 54661 67608.051 127.127.29.0 2008 196 18:46:48.000000 54661 67624.053 127.127.29.0 2008 196 18:47:04.000000 54661 67640.051 127.127.29.0 2008 196 18:47:20.000000 54661 67656.054 127.127.29.0 2008 196 18:47:36.000000 54661 67672.053 127.127.29.0 2008 196 18:47:52.000000 54661 67688.054 127.127.29.0 2008 196 18:48:08.000000 54661 67704.050 127.127.29.0 2008 196 18:48:24.000000 54661 67720.055 127.127.29.0 2008 196 18:48:40.000000 54661 67736.054 127.127.29.0 2008 196 18:48:56.000000 54661 67752.053 127.127.29.0 2008 196 18:49:12.000000 54661 67768.053 127.127.29.0 2008 196 18:49:28.000000 54661 67784.054 127.127.29.0 2008 196 18:49:44.000000 ... -- These are my opinions, not necessarily my employer's. I hate spam. From dave.g0dja at tiscali.co.uk Tue Jul 15 03:47:49 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 15 Jul 2008 08:47:49 +0100 Subject: [time-nuts] Trimble Palisade In-Reply-To: References: Message-ID: <487C5625.8040305@tiscali.co.uk> GandalfG8 at aol.com wrote: > > In a message dated 14/07/2008 21:09:41 GMT Daylight Time, > dave.g0dja at tiscali.co.uk writes: > > Does anyone have any useful information on using it, or should I open it > up and replace the multiway socket and see if I can do something else > other than mount it outside as another time standard? > > Thanks for any ideas. > > > > ------------------------- > I don't know if you've seen this site? > Thanks Nigel, that site was mentioned by the person I bought it from (Ray, GM4CXM) and he did make it clear *not* to try to put it into NMEA mode, but to use the add on board. However, I can use other units for NMEA anyway. I was just interested to see if there were any other modifications or uses without needing add on boards. ;-0 Cheers - Dave From dave.g0dja at tiscali.co.uk Tue Jul 15 03:48:49 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 15 Jul 2008 08:48:49 +0100 Subject: [time-nuts] Trimble Palisade In-Reply-To: <000701c8e5f1$c2be2760$0200a8c0@pc52> References: <390229150807141215u25c20806j3f7edead7393f5be@mail.gmail.com> <487BB252.6070605@tiscali.co.uk> <000701c8e5f1$c2be2760$0200a8c0@pc52> Message-ID: <487C5661.406@tiscali.co.uk> Tom Van Baak wrote: > Google for Trimble Palisade or see if this helps: I did :-) Thanks for the additional site, I'd not seen that. Cheers - Dave From dave.g0dja at tiscali.co.uk Tue Jul 15 03:50:17 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 15 Jul 2008 08:50:17 +0100 Subject: [time-nuts] Trimble Palisade In-Reply-To: References: <390229150807141215u25c20806j3f7edead7393f5be@mail.gmail.com> <487BB252.6070605@tiscali.co.uk> Message-ID: <487C56B9.4000505@tiscali.co.uk> Robert Berg wrote: > I picked up a couple of prewired cables for the Palisade from tiger- > tech.biz > Thanks Bob, I'll follow that up. Cheers - Dave From timenuts at stnhbr.com Tue Jul 15 08:37:28 2008 From: timenuts at stnhbr.com (Tim Cwik) Date: Tue, 15 Jul 2008 08:37:28 -0400 Subject: [time-nuts] thunderbolt for ntpd or gpsd In-Reply-To: <91981b3e0807141421j2afb6b60t50a5848d5eadd859@mail.gmail.com> References: <200806151145.58089.w.knowles@xtra.co.nz> <48559045.4080703@stnhbr.com> <91981b3e0807141421j2afb6b60t50a5848d5eadd859@mail.gmail.com> Message-ID: <487C9A08.9050401@stnhbr.com> Chris Kuethe wrote: > On Sun, Jun 15, 2008 at 2:57 PM, Tim Cwik wrote: > >> I have discovered the even though cgps does not report position or time >> using the Thunderbolt, the stock gpsd is getting enough timing data to >> update ntp. Gpsd is selected as the sys.peer with a jitter of about .8. >> It looks like the PPS pulse is too narrow to be detected on DCD >> > > as i've now got my thunderbolt i can start adding support for it in > gpsd. wayne knowles did a nice patch which i'm using as the foundation > of my development. > > the main issue is auto-detecting parity of the serial line since > trimble couldn't make up their minds about 8N1 or 8O1. > > i've noticed two primary complaints (with which i agree) - the PPS > output is too short and positions don't seem to be output by default. > i'm probably going to add an initializer to make the thunderbolt emit > position data and crank up the 1PPS pulse length to something > reasonable - at least 1ms. the change will be purely runtime - i won't > write it to EEPROM. does that seem reasonable? > > It seems reasonable to me. I think the PPS from the stock unit is also the wrong polarity. I have been using Wayne's patch and the FATPPS circuit from TAPR to stretch and invert the PPS signal and seem to be getting good results. The patch decodes the TB super packet and does output positions. For some reason, the clock SHM(0) is not used by NTP although the PPS output SHM(1) is. ind assID status conf reach auth condition last_event cnt =========================================================== 1 33509 9314 yes yes none outlyer reachable 1 2 33510 9334 yes yes none outlyer reachable 3 3 33511 9114 yes yes none falsetick reachable 1 4 33512 9414 yes yes none candidat reachable 1 5 33513 9414 yes yes none candidat reachable 1 6 33514 8015 yes yes none reject clock expt 1 7 33515 9614 yes yes none sys.peer reachable 1 8 33516 9014 yes yes none reject reachable 1 remote refid st t when poll reach delay offset jitter ============================================================================== -216-55-159-183. 130.126.24.44 3 u 110 64 376 84.945 23.379 76.554 -quandary.cross- 132.239.1.6 2 u 14 64 367 88.128 25.749 83.158 xlashiir.sapros. 64.22.120.68 3 u 58 64 377 62.578 -13.184 63.982 +clock3.redhat.c .CDMA. 1 u 60 64 377 93.040 17.595 55.080 +octopus.stnhbr. .GPS1. 1 u 9 64 377 0.294 34.395 5.584 SHM(0) .GPS. 0 l - 16 0 0.000 0.000 0.001 *SHM(1) .GPS1. 0 l 17 16 377 0.000 -0.019 0.071 LOCAL(0) .LOCL. 10 l 55 64 377 0.000 0.000 0.001 Would it be violating the design spirit of gpsd to ask for some sort of separate status file to be (over)written each second with the information about the internal state of the Thunderbolt (e.g., http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:states_modes_and_alarms ) I would like to be able to monitor this with something like Hobbit, Nagios, or Big Brother. If I set the debug level high enough, the information might be in the log but that would generate very large log files. Thanks for working on this. Tim From stanley_reynolds at yahoo.com Tue Jul 15 10:30:22 2008 From: stanley_reynolds at yahoo.com (Stanley Reynolds) Date: Tue, 15 Jul 2008 07:30:22 -0700 (PDT) Subject: [time-nuts] Use of Austron 2100F "Phase Corrected Output" Message-ID: <196809.23370.qm@web30304.mail.mud.yahoo.com> The strength of the station seems to effect the size of the jumps. I switched from 7980 Master to the Grangeville, LA secondary ( a stronger signal here) and the jumps are much less with the same reference indicating high 8-5?E11 most of the time vs E10 before, same default time constant. ----- Original Message ---- From: Stanley Reynolds To: Discussion of precise time and frequency measurement Sent: Wednesday, July 9, 2008 9:38:11 AM Subject: Re: [time-nuts] Use of Austron 2100F "Phase Corrected Output" As measured with a HP-5334A and GPS DO as reference: The phase corrected output does jump around a bit most of the time? (+- .2 Hz) and on occasion (< 100 Hz > 50 Hz). A 100 sample average looks much better but still need logic to throw out the big variations and average more samples. Stanley ----- Original Message ---- From: Stanley Reynolds To: Discussion of precise time and frequency measurement Sent: Tuesday, July 1, 2008 3:05:01 PM Subject: Re: [time-nuts] Use of Austron 2100F "Phase Corrected Output" I would like to know as well. My experiment in the thread "Calibrating the Lucent RFG-M-XO Efratom 10MHz OCXO Oscillator w/ EFC" using the phase corrected output has failed twice, not sure of the reason could be a problem with my lack of knowledge abt the Lucent error correcting oscillator or the 2100F.? It takes > 10 hours for it to fail think this could be related to the?rate the Austron updates. The chart output is also available to steer the disciplined oscillator but with my unit this output jumps around quite a bit. Either output could be processed / filtered to slow the skew. Stanley? ----- Original Message ---- From: Jim Robbins To: time-nuts at febo.com Sent: Sunday, June 29, 2008 9:16:25 PM Subject: [time-nuts] Use of Austron 2100F "Phase Corrected Output" Hi all, I believe I read that it was a mistake to use the "Phase Corrected Output" 10 MHz signal from the 2100F as the time base source for other equipment?? Something about the corrections being in steps.? Has anyone else had any experience with this?? If so, what is the problem with the output?? Thanks. Jim Robbins, N1JR _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ? ? ? _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ? ? ? _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From david.partridge at dsl.pipex.com Tue Jul 15 13:16:14 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Tue, 15 Jul 2008 18:16:14 +0100 Subject: [time-nuts] Frequency divider design critique request Message-ID: <1CD285B5DEE944BE84372601C13732E7@APOLLO> Magnus, Was the attached what you had in mind? Thanks Dave -----Original Message----- From: Magnus Danielson [mailto:magnus at rubidium.dyndns.org] Sent: 10 July 2008 23:07 To: time-nuts at febo.com; david.partridge at dsl.pipex.com Subject: Re: [time-nuts] Frequency divider design critique request From: "David C. Partridge" Subject: [time-nuts] Frequency divider design critique request Date: Thu, 10 Jul 2008 21:30:56 +0100 Message-ID: David, > As I've mentioned before, I've been working on the design of a > frequency divider to go with my TB. > > The idea is 10MHz sine in from TB, output 2.5Vp-p 50% duty cycle > square wave into 50R (5V into 1M), at 10Mhz, 5MHz, 1MHz and decade > selectable 100kHz down to 1Hz. All rising edges synchronised to the > 10MHz clock rising edge (or as near as I can get with 74AC logic). Good initial concept. > With a considerable amount of constructive criticism from Bruce Griffiths > (thank you again Bruce) I believe the design now to be complete. > > The aim is to have as low a level of nasties as possible (i.e. fit for > time-nuts). > > All faults are my own - no blame attaches to Bruce! The one thing I would do is to hook caps over at R24 to R26, say 10 nF, to make the thumb wheel leads less susceptible to noise and less of areal for the edges from the CMOS. The thumb-wheel either keep them floating in one end or didged hard to +5V. To avoid both E and H fields, a series-resistor should be included. > I've not yet subjected this design to the ultimate simulation tool > (PCB, parts and solder) yet, and I have no means to test it for levels > of jitter (phase noise) or similar nasties. I am sure we can come up with some arrangement for that. Several handy time-nuts around. > I think that it's now the right time to open the design up for > critique from a wider audience before I commit it to copper. > > I'm therefore attaching the design as a PDF file for your comments. > > A few comments are in order: > > 1) The 5Mhz and 1MHz outputs are re-clocked TWICE deliberately to > delay them by one clock cycle so they line up with the 1MHz and lower outputs. Neat. > 2) The selected output (at the '4051 mux) from the ripple counter > chain is re-clocked to 1MHz before re-clocking to 10MHz as the > worst-case delay in the chain of '4017s is large enough that the lower > frquencies wouldn't reliably re-clock directly to 10MHz. Good thinking! > I have also done a PCB layout (4-layer) and I'm happy to send a print > of the top/bottom layers to anyone who feels that they want to comment > on that (inner layers are ground and power). ... and you say they are not of interest? > Let the brick-bats be thrown! I have a lots of bricks around me (my summerhouse is build with old handmade bricks) but I wont toss them. So far, only the thumbwheel is the only minor flaw that I could come up with. I need to check some more... I rather have a few questions on why you did not include certain features... In my experience, having a few extra 10 MHz signals to feed Ext Ref on instruments is a good thing. That way you can keep these others at hand for various setups you need to do. I would consider a dedicated 1 PPS output. I would consider a synchronise feature with a PPS/synchronise input. It should be wise to not directly wire it to the counter resets, but provide an arm button and maybe a very simple arrangement to indicate "left", "on mark" and "right" with red, gren, red LEDs. Just a tought. The arm button could also have an electrical input, but I am running into creaping featurism here. I think however that synchronisation might be a good thing. That way you can shift the phase of the signal to fit your need. Pulling and inserting the 10 MHz cable is a very crude way of doing it. Maybe it would be just too much fuzz for too little gain, what do I know, but I know I would enjoy seeing it. A pulse-add/pulse-swallow technique (with a shift in initial divide by 10) could be used to provide inc/dec functionality for a manual movement of phase. Cheers, Magnus No virus found in this outgoing message. Checked by AVG - http://www.avg.com Version: 8.0.138 / Virus Database: 270.4.7/1546 - Release Date: 11/07/2008 06:47 No virus found in this outgoing message. Checked by AVG - http://www.avg.com Version: 8.0.138 / Virus Database: 270.4.11/1553 - Release Date: 15/07/2008 05:48 -------------- next part -------------- A non-text attachment was scrubbed... Name: Mux wiring changes.pdf Type: application/pdf Size: 12876 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080715/b72512ba/attachment.pdf From jmiles at pop.net Tue Jul 15 13:30:23 2008 From: jmiles at pop.net (John Miles) Date: Tue, 15 Jul 2008 10:30:23 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <1CD285B5DEE944BE84372601C13732E7@APOLLO> Message-ID: I don't know about sending edges that slow into a CMOS chip. Is that considered kosher for HC-series logic? -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com]On Behalf Of David C. Partridge > Sent: Tuesday, July 15, 2008 10:16 AM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] Frequency divider design critique request > > > Magnus, > > Was the attached what you had in mind? > > Thanks > Dave > From rk at timing-consultants.com Tue Jul 15 13:45:09 2008 From: rk at timing-consultants.com (Rob Kimberley) Date: Tue, 15 Jul 2008 18:45:09 +0100 Subject: [time-nuts] More on Old Loran In-Reply-To: <20080714184541.CB2B7BCCE@ip-64-139-1-69.sjc.megapath.net> References: <20080714184541.CB2B7BCCE@ip-64-139-1-69.sjc.megapath.net> Message-ID: <5D7DC7CD6BCD4EA48702D190FEF949EF@Robin> I found the following extract in David Irving's book "Apocalypse" about the bombing of Dresden. Interesting stuff..... Rob Kimberley ....The highest precision in navigation was required; only Loran could provide this. The Royal Air Force's most up-to-date piece of electronic long-range navigation equipment, installed only in a few aircraft, Loran was to be used to make the initial fix on the target area, and Smith was thereafter to rely on low-level visual marking for the attack. Loran, a bulky piece of equipment housed in several metal containers strapped into the already cramped cockpit of nine Mosquito high-speed bombers, was originally designed to be installed in Lancasters and used in long-range attacks in the Pacific theatre of the war. Basically an upgrade of the Gee radio-beam navigation device, which spun an invisible web of beams across the Western European ether, Loran did not suffer from the shortcomings of Gee which permitted its use only within relatively short distances of the transmitter chains. Using reflected radio waves from the 'E'-layer, Loran had a range of some fifteen hundred miles; but the use of the 'E'-layers limited its applicability to night flying only. Before February the R.A.F. had never relied on it for an operation. The crews of the nine Mosquito aircraft fitted with Loran were quickly trained in the operation of their equipment; Bomber Command's navigation chiefs crossed their fingers and hoped that on the night the gear would work perfectly; the English Gee chain's radio beams, even when not jammed by the enemy, petered out some miles west of Dresden; the signals picked up from the mobile Gee transmitters moving up behind the Allied lines were unreliable and even they did not extend to Dresden, the target city. -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Hal Murray Sent: 14 July 2008 19:46 To: time-nuts at febo.com Subject: [time-nuts] More on Old Loran Lots of good info on hyperbolic navigation aids http://jproc.ca/hyperbolic/index.html In particular, this is a nice description of Loran A http://jproc.ca/hyperbolic/loran_a.html Here is info on how a Phantastron works. It may not make much sense if you don't know how tubes work. http://www.radarpages.co.uk/theory/ap3302/sec2/ch8/sec2ch8p137.htm (Figure 3 is on the next page. Follow the link at the bottom.) -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From rk at timing-consultants.com Tue Jul 15 13:48:53 2008 From: rk at timing-consultants.com (Rob Kimberley) Date: Tue, 15 Jul 2008 18:48:53 +0100 Subject: [time-nuts] More on Old Loran In-Reply-To: <5D7DC7CD6BCD4EA48702D190FEF949EF@Robin> References: <20080714184541.CB2B7BCCE@ip-64-139-1-69.sjc.megapath.net> <5D7DC7CD6BCD4EA48702D190FEF949EF@Robin> Message-ID: I missed the last paragraph.... Rob K .....There was however an added complication involved in navigating successfully to Dresden by Loran-because of the curvature of the earth the beams would probably not be picked up below nineteen thousand feet. The Master Bomber and his eight Marker Mosquitoes would have to endure a painful switch back dive from nineteen thousand feet to their normal marking altitude of less than one thousand feet within four or five minutes if they were to arrive at the target area on time. -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Rob Kimberley Sent: 15 July 2008 18:45 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] More on Old Loran I found the following extract in David Irving's book "Apocalypse" about the bombing of Dresden. Interesting stuff..... Rob Kimberley ....The highest precision in navigation was required; only Loran could provide this. The Royal Air Force's most up-to-date piece of electronic long-range navigation equipment, installed only in a few aircraft, Loran was to be used to make the initial fix on the target area, and Smith was thereafter to rely on low-level visual marking for the attack. Loran, a bulky piece of equipment housed in several metal containers strapped into the already cramped cockpit of nine Mosquito high-speed bombers, was originally designed to be installed in Lancasters and used in long-range attacks in the Pacific theatre of the war. Basically an upgrade of the Gee radio-beam navigation device, which spun an invisible web of beams across the Western European ether, Loran did not suffer from the shortcomings of Gee which permitted its use only within relatively short distances of the transmitter chains. Using reflected radio waves from the 'E'-layer, Loran had a range of some fifteen hundred miles; but the use of the 'E'-layers limited its applicability to night flying only. Before February the R.A.F. had never relied on it for an operation. The crews of the nine Mosquito aircraft fitted with Loran were quickly trained in the operation of their equipment; Bomber Command's navigation chiefs crossed their fingers and hoped that on the night the gear would work perfectly; the English Gee chain's radio beams, even when not jammed by the enemy, petered out some miles west of Dresden; the signals picked up from the mobile Gee transmitters moving up behind the Allied lines were unreliable and even they did not extend to Dresden, the target city. -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Hal Murray Sent: 14 July 2008 19:46 To: time-nuts at febo.com Subject: [time-nuts] More on Old Loran Lots of good info on hyperbolic navigation aids http://jproc.ca/hyperbolic/index.html In particular, this is a nice description of Loran A http://jproc.ca/hyperbolic/loran_a.html Here is info on how a Phantastron works. It may not make much sense if you don't know how tubes work. http://www.radarpages.co.uk/theory/ap3302/sec2/ch8/sec2ch8p137.htm (Figure 3 is on the next page. Follow the link at the bottom.) -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From david.partridge at dsl.pipex.com Tue Jul 15 14:06:47 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Tue, 15 Jul 2008 19:06:47 +0100 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: <1CD285B5DEE944BE84372601C13732E7@APOLLO> Message-ID: <61048996F3D7437B9E32B1E017CC0941@APOLLO> John, This is just DC selection of which MUX line is active. Am I missing something here? Dave -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of John Miles Sent: 15 July 2008 18:30 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Frequency divider design critique request I don't know about sending edges that slow into a CMOS chip. Is that considered kosher for HC-series logic? -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com]On Behalf Of David C. Partridge > Sent: Tuesday, July 15, 2008 10:16 AM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] Frequency divider design critique request > > > Magnus, > > Was the attached what you had in mind? > > Thanks > Dave > _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From jmiles at pop.net Tue Jul 15 14:44:11 2008 From: jmiles at pop.net (John Miles) Date: Tue, 15 Jul 2008 11:44:11 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <61048996F3D7437B9E32B1E017CC0941@APOLLO> Message-ID: Right; when the thumbswitches are toggled, the RC integrators will slow down the edges into pins 9-11. Sometimes CMOS parts will latch up or otherwise fail to reliably with slow edges -- it probably comes down to the "complementary" thing, where both halves of a totem pole can turn on erratically during a slow transition. I have seen large capacitors used on TTL MUXes for EMI suppression, but never on CMOS. I have a feeling 100 pF would be safer and still adequate. Probably no big deal, but if you want to be anal about it, it could pay to check the edge-time specs for the HC family. -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On > Behalf Of David C. Partridge > Sent: Tuesday, July 15, 2008 11:07 AM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] Frequency divider design critique request > > > John, > > This is just DC selection of which MUX line is active. > > Am I missing something here? > > Dave > > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On > Behalf Of John Miles > Sent: 15 July 2008 18:30 > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Frequency divider design critique request > > I don't know about sending edges that slow into a CMOS chip. Is that > considered kosher for HC-series logic? > > -- john, KE5FX > > > -----Original Message----- > > From: time-nuts-bounces at febo.com > > [mailto:time-nuts-bounces at febo.com]On Behalf Of David C. Partridge > > Sent: Tuesday, July 15, 2008 10:16 AM > > To: 'Discussion of precise time and frequency measurement' > > Subject: Re: [time-nuts] Frequency divider design critique request > > > > > > Magnus, > > > > Was the attached what you had in mind? > > > > Thanks > > Dave > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From smace at intt.net Tue Jul 15 19:09:18 2008 From: smace at intt.net (Scott Mace) Date: Tue, 15 Jul 2008 18:09:18 -0500 Subject: [time-nuts] Lucent RFTG-m-RB Message-ID: <487D2E1E.80104@intt.net> Has anyone tried to discipline the RFTG-m-RB without the -XO unit from a house PPS feed? I think pins 4 and 8 on J6 are the PPS input. Scott From bruce.griffiths at xtra.co.nz Tue Jul 15 19:21:09 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Wed, 16 Jul 2008 11:21:09 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: Message-ID: <487D30E5.5030504@xtra.co.nz> John Miles wrote: > Right; when the thumbswitches are toggled, the RC integrators will slow down > the edges into pins 9-11. Sometimes CMOS parts will latch up or otherwise > fail to reliably with slow edges -- it probably comes down to the > "complementary" thing, where both halves of a totem pole can turn on > erratically during a slow transition. > > I have seen large capacitors used on TTL MUXes for EMI suppression, but > never on CMOS. I have a feeling 100 pF would be safer and still adequate. > Probably no big deal, but if you want to be anal about it, it could pay to > check the edge-time specs for the HC family. > > -- john, KE5FX > > Maximum recommended transition time for most HCMOS inputs is 500ns. However this is more intended to reduce the time for which both p channel and n channel devices are simultaneously conducting. When both p and n channel devices conduct the power supply current is increased (to around 1mA for HCMOS gates with a 5V power supply), however this current is to low to cause latchup. There should not be an oscillation problem with slow input transition times when using devices that don't incorporate feedback (eg gates, multiplexers). However if there is excessive noise on the a gate input near threshold it may switch on noise spikes leading to an apparent oscillation problem. For flipflops slow clock transition times may cause oscillation problems especially if the clock inputs dont incorporate an internal Schmitt trigger circuit. In synchronous systems employing multiple flipflop or divider packages the maximum clok rise time should be about 2x the individual device clock to output propagation delay to avoid incorrect operation due to clock threshold variations from device to device. If you are concerned about the transition times at the multiplexer inputs then use a 74HC14 hex inverting Schmitt trigger after the RC filters and use pullup resistors instead of pulldown resistors. Schmitt trigger devices are recommended whenever the inpu transition times exceed 500ns. The RC filter network actually attenuates the dc mux inputs by about 10%, its better to use the alternate circuit that I posted earlier that doesnt attenuate the dc levels at the multiplexer inputs. The only major concern with large capacitors connected from the multiplexer inputs to ground is that should the power supply slew rate at turn on or turn off be too large the the multiplexer input protection diode current rating will be exceeded and the protection diodes will fail. If this is likely then use a pair of external clamp diodes connected to Vcc and ground and use a connect a small resistor between the capacitor and the CMOS input. Bruce From bruce.griffiths at xtra.co.nz Wed Jul 16 00:59:27 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Wed, 16 Jul 2008 16:59:27 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: Message-ID: <487D802F.4090905@xtra.co.nz> John Miles wrote: > Right; when the thumbswitches are toggled, the RC integrators will slow down > the edges into pins 9-11. Sometimes CMOS parts will latch up or otherwise > fail to reliably with slow edges -- it probably comes down to the > "complementary" thing, where both halves of a totem pole can turn on > erratically during a slow transition. > > I have seen large capacitors used on TTL MUXes for EMI suppression, but > never on CMOS. I have a feeling 100 pF would be safer and still adequate. > Probably no big deal, but if you want to be anal about it, it could pay to > check the edge-time specs for the HC family. > > -- john, KE5FX > > During a transition a CMOS inverter acts as an amplifier, the gain can be high with a buffered input where 2 or more inverters are cascaded. Thus any noise riding on a slowly slewing input can be amplified considerably as the input signal passes through Vcc/2 where a CMOS inverter small signal gain is maximum. Bruce From bruce.griffiths at xtra.co.nz Wed Jul 16 01:48:34 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Wed, 16 Jul 2008 17:48:34 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: Message-ID: <487D8BB2.1060304@xtra.co.nz> John Miles wrote: > Right; when the thumbswitches are toggled, the RC integrators will slow down > the edges into pins 9-11. Sometimes CMOS parts will latch up or otherwise > fail to reliably with slow edges -- it probably comes down to the > "complementary" thing, where both halves of a totem pole can turn on > erratically during a slow transition. > > I have seen large capacitors used on TTL MUXes for EMI suppression, but > never on CMOS. I have a feeling 100 pF would be safer and still adequate. > Probably no big deal, but if you want to be anal about it, it could pay to > check the edge-time specs for the HC family. > > -- john, KE5FX > What about the common RC switch debouncer using a CMOS Schmitt trigger and an RC filter? Capacitors of 100nF or more are often used in such circuits. When using Phillips HCMOS (there is an internal 100 ohm polysilicon resistor between the input pin and the protection devices.) an external diode (anode to HCMOS input cathode to Vcc) usually suffices to protect the input during turnoff. With other brands you may have to add an external 100 ohm resistor in series with the input pin. Bruce From hmurray at megapathdsl.net Wed Jul 16 05:12:27 2008 From: hmurray at megapathdsl.net (Hal Murray) Date: Wed, 16 Jul 2008 02:12:27 -0700 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: Message from Bruce Griffiths of "Wed, 16 Jul 2008 17:48:34 +1200." <487D8BB2.1060304@xtra.co.nz> Message-ID: <20080716091228.D5B2EBCCE@ip-64-139-1-69.sjc.megapath.net> [Context is filtering on inputs from switches.] Could somebody tell me why we are doing anything fancy at all? What's wrong with just a simple pullup? I can think of two cases that might be interesting. One is signal integrity. There might be enough crosstalk to cause troubles. This is a 4 layer board. Right? Unless the traces from the switch to the mux chip wrap around some high speed signal there isn't likely to be a problem. I'm not a signal integrity wizard, but the ballpark is that you only need a few trace widths of separation between agressor/source and victim/receiver. This case is slightly ugly since the pullup is not low impedance like a typical driver. So the question becomes how small a pullup do we need to maintain good signal integrity? Or how far from a nearby trace do we have to be with a given pullup? If the coupling is primarily capacitive, then we have a C-R high pass filter. I'm not sure that's valid, but it is easy to analyze. I should be smart enough to work this out, but it's late. HC is pretty slow. AC might be fast enough to make things interesting. But this only matters if the switch traces run parallel to a trace that is active for a significant length. What is the (ballpark) output impedance of a CMOS driver? What's the input capacitance on a CMOS gate? (It's in parallel with the R, making a C-C divider at high frequencies.) The other possible complication is trying to keep a clean output signal when the switch changes state. I'm assuming we don't really care what happens while the contacts are bouncing between switch settings. If we do, then we need serious switch debouncing and synchronization. I don't think anybody has mentioned this tangle. All the switch inputs I've worked with recently have been a simple pullup/down. They usually go into a small CPU using the internal pullups and software debouncing. I have heard war stories of cross talk on reset signals. They often wander all over the board and since they are slow, they often get overlooked when checking for crosstalk. -- These are my opinions, not necessarily my employer's. I hate spam. From bruce.griffiths at xtra.co.nz Wed Jul 16 05:56:48 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Wed, 16 Jul 2008 21:56:48 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <20080716091228.D5B2EBCCE@ip-64-139-1-69.sjc.megapath.net> References: <20080716091228.D5B2EBCCE@ip-64-139-1-69.sjc.megapath.net> Message-ID: <487DC5E0.1070006@xtra.co.nz> Hal Murray wrote: > [Context is filtering on inputs from switches.] > > Could somebody tell me why we are doing anything fancy at all? What's wrong > with just a simple pullup? > > Pull down required because of thumbwheel switch encoding. > I can think of two cases that might be interesting. > > One is signal integrity. There might be enough crosstalk to cause troubles. > This is a 4 layer board. Right? Unless the traces from the switch to the > mux chip wrap around some high speed signal there isn't likely to be a > problem. > > The 10MHz clock tracks have been routed well clear of everything else. > I'm not a signal integrity wizard, but the ballpark is that you only need a > few trace widths of separation between agressor/source and victim/receiver. > This case is slightly ugly since the pullup is not low impedance like a > typical driver. > > So the question becomes how small a pullup do we need to maintain good signal > integrity? Or how far from a nearby trace do we have to be with a given > pullup? > > If the coupling is primarily capacitive, then we have a C-R high pass filter. > I'm not sure that's valid, but it is easy to analyze. I should be smart > enough to work this out, but it's late. HC is pretty slow. AC might be fast > enough to make things interesting. But this only matters if the switch > traces run parallel to a trace that is active for a significant length. > > What is the (ballpark) output impedance of a CMOS driver? What's the input > capacitance on a CMOS gate? (It's in parallel with the R, making a C-C > divider at high frequencies.) > > 10-20 ohms. 5-10pF. > The other possible complication is trying to keep a clean output signal when > the switch changes state. I'm assuming we don't really care what happens > while the contacts are bouncing between switch settings. If we do, then we > need serious switch debouncing and synchronization. I don't think anybody > has mentioned this tangle. > > RC filter followed by a Schmitt trigger IC (74HC14) can debounce the switch contacts effectively if RC product is large enough. A shift register (clocked at 1MHz in this case)is required to synchronise each mux control input if synchronisation is required. Using a shift register is slightly simpler than using a dual FF as only need to connect clock plus input and output. > All the switch inputs I've worked with recently have been a simple > pullup/down. They usually go into a small CPU using the internal pullups and > software debouncing. > > No cpu available. > I have heard war stories of cross talk on reset signals. They often wander > all over the board and since they are slow, they often get overlooked when > checking for crosstalk. > > > Using an emitter follower to buffer the reset circuit RC node has led to VHF oscillation problems with capacitive load on emitter (track C) with collector and base at RF ground. Bruce From david.partridge at dsl.pipex.com Wed Jul 16 13:27:51 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Wed, 16 Jul 2008 18:27:51 +0100 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: <487DC5E0.1070006@xtra.co.nz> References: <20080716091228.D5B2EBCCE@ip-64-139-1-69.sjc.megapath.net> <487DC5E0.1070006@xtra.co.nz> Message-ID: I'm waiting to see what Magnus Danielson has to say, as it was he after all who suggested adding caps in parallel to the pull-downs, and also series resistors. Thinking about it retrospect, I think he may have meant the series resistors to go between the pull-downs and the chip, rather than where the schematic fragment showed them. I don't *think* switch bounce is an issue here, as it will all settle to the right answer pretty sharply. Magnus, are you there? Cheers Dave From bg at lysator.liu.se Wed Jul 16 13:59:08 2008 From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson) Date: Wed, 16 Jul 2008 19:59:08 +0200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: <20080716091228.D5B2EBCCE@ip-64-139-1-69.sjc.megapath.net> <487DC5E0.1070006@xtra.co.nz> Message-ID: <1216231148.23949.17.camel@bg-desktop> Magnus is on vacation and has some (net) connectivity problems. I would expect him to be back online within a day or two. -- Bj?rn On Wed, 2008-07-16 at 18:27 +0100, David C. Partridge wrote: > I'm waiting to see what Magnus Danielson has to say, as it was he after all > who suggested adding caps in parallel to the pull-downs, and also series > resistors. > > Thinking about it retrospect, I think he may have meant the series resistors > to go between the pull-downs and the chip, rather than where the schematic > fragment showed them. > > I don't *think* switch bounce is an issue here, as it will all settle to the > right answer pretty sharply. > > Magnus, are you there? > > Cheers > Dave > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From bruce.griffiths at xtra.co.nz Wed Jul 16 17:27:16 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Thu, 17 Jul 2008 09:27:16 +1200 Subject: [time-nuts] Frequency divider design critique request In-Reply-To: References: <20080716091228.D5B2EBCCE@ip-64-139-1-69.sjc.megapath.net> <487DC5E0.1070006@xtra.co.nz> Message-ID: <487E67B4.3020704@xtra.co.nz> David C. Partridge wrote: > I'm waiting to see what Magnus Danielson has to say, as it was he after all > who suggested adding caps in parallel to the pull-downs, and also series > resistors. > > Thinking about it retrospect, I think he may have meant the series resistors > to go between the pull-downs and the chip, rather than where the schematic > fragment showed them. > > I don't *think* switch bounce is an issue here, as it will all settle to the > right answer pretty sharply. > > Magnus, are you there? > > Cheers > Dave > > Dave Switch bounce could be an issue if one wished to switch cleanly to another frequency output without incurring extraneous transitions during the changeover from one frequency to another. A hex D(74HC174) or an octal D(74HC374 74HC574) could be used to synchronise debounced multiplexer select inputs. Another issue is that all BCD switch contacts will not make or break at the same time. Also the debounce filters will not all settle simultaneously. Thus a debounced enable pushbutton may also be required. When the enable pushbutton is depressed the current state of the selector switches is latched. In this case only the enable pushbutton need be debounced. Bruce From j-shank at comcast.net Wed Jul 16 21:58:44 2008 From: j-shank at comcast.net (jshank) Date: Wed, 16 Jul 2008 21:58:44 -0400 Subject: [time-nuts] Thunderbolt monitor References: <004401c8e635$e04bd360$0a01a8c0@didierhp> Message-ID: <1C2032F78B14424F81C2E49E3366E765@DESKTOP> The Noritake display looks great. I am hoping that a kit of this proposed Thunderbolt monitor with the Noritake display will be made available through TARP in the near future. I am sure that many of the Thunderbolts which recently became available would benefit from such a kit. Jeff ----- Original Message ----- From: "Didier Juges" To: "Time-Nuts" Sent: Tuesday, July 15, 2008 12:47 AM Subject: [time-nuts] Thunderbolt monitor >I made a second version (same firmware) of the Thunderbolt monitor. This >one > uses the plastic DIP version of the processor mounted on a small Radio > Shack > proto board and it uses a gorgeous Noritake Vacuum Fluorescent display. > > The interface between the Noritake and any ordinary LCD display is the > same > ( as far as pin-out is concerned), except that the Noritake does not have > a > contrast adjustment. Otherwise, the firmware is the same, once the > differences are accounted for. The Noritake is generally much faster than > most 2 line LCDs when updating the data, but requires a little more time > to > initialize themselves at power up. My software can drive either display > without modification. > > The Noritake displays have a software command to adjust the brightness > down > to half, and that's it. My firmware does not take advantage of that > feature, > which I find relatively useless, but may prolong the life of the display. > The VFDs only have a few years of life under continuous operation, so > dimming the display or turning it off altogether when not needed might be > a > good idea. > > See pictures at http://www.ko4bb.com/Timing/GPSMonitor/ > > Didier KO4BB > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From didier at cox.net Wed Jul 16 22:46:50 2008 From: didier at cox.net (Didier Juges) Date: Wed, 16 Jul 2008 21:46:50 -0500 Subject: [time-nuts] Thunderbolt monitor In-Reply-To: <1C2032F78B14424F81C2E49E3366E765@DESKTOP> References: <004401c8e635$e04bd360$0a01a8c0@didierhp> <1C2032F78B14424F81C2E49E3366E765@DESKTOP> Message-ID: <010401c8e7b7$5de8abe0$0a01a8c0@didierhp> One issue with the Noritake display (common to all VFD devices) is that it draws over 100mA of current at 5V. A 3 terminal linear regulator running from 12V will need a reasonable heat sink to operate. A better choice would be a small switching regulator such as the LT1375 which I have used in a great many products. It's a small 8 pin device that requires only a handful of external components to convert 12V to 5 with excellent efficiency (no heat sink required). I may lay out the PWB for both types of regulators, depending on the type of display you want to use. Didier KO4BB > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of jshank > Sent: Wednesday, July 16, 2008 8:59 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Thunderbolt monitor > > The Noritake display looks great. > I am hoping that a kit of this proposed Thunderbolt monitor > with the Noritake display will be made available through TARP > in the near future. I am sure that many of the Thunderbolts > which recently became available would benefit from such a kit. > Jeff > ----- Original Message ----- > From: "Didier Juges" > To: "Time-Nuts" > Sent: Tuesday, July 15, 2008 12:47 AM > Subject: [time-nuts] Thunderbolt monitor > > > >I made a second version (same firmware) of the Thunderbolt monitor. > >This one uses the plastic DIP version of the processor mounted on a > >small Radio Shack proto board and it uses a gorgeous > Noritake Vacuum > >Fluorescent display. > > > > The interface between the Noritake and any ordinary LCD > display is the > > same ( as far as pin-out is concerned), except that the > Noritake does > > not have a contrast adjustment. Otherwise, the firmware is > the same, > > once the differences are accounted for. The Noritake is > generally much > > faster than most 2 line LCDs when updating the data, but requires a > > little more time to initialize themselves at power up. My > software can > > drive either display without modification. > > > > The Noritake displays have a software command to adjust the > brightness > > down to half, and that's it. My firmware does not take advantage of > > that feature, which I find relatively useless, but may prolong the > > life of the display. > > The VFDs only have a few years of life under continuous > operation, so > > dimming the display or turning it off altogether when not > needed might > > be a good idea. > > > > See pictures at http://www.ko4bb.com/Timing/GPSMonitor/ > > > > Didier KO4BB > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, > go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From jpawlan at pawlan.com Wed Jul 16 23:39:36 2008 From: jpawlan at pawlan.com (Jeffrey Pawlan) Date: Wed, 16 Jul 2008 20:39:36 -0700 (PDT) Subject: [time-nuts] Thunderbolt monitor In-Reply-To: <010401c8e7b7$5de8abe0$0a01a8c0@didierhp> Message-ID: Regarding the VFD display, although they may be very different one manufacturer to another, I can definitely dispute a prior statement made that VFDs in general have a short lifetime and become dim. They are universally used in VCRs, DVD players, microwave ovens, and some clocks. I have never had one become dim or burn out. The displays in my appliances are on even when the rest of the appliance is off. I have never seen one become dim even after 15 years of on-time. I look forward to your project. 73, Jeffrey Pawlan, WA6KBL From jmiles at pop.net Thu Jul 17 00:00:11 2008 From: jmiles at pop.net (John Miles) Date: Wed, 16 Jul 2008 21:00:11 -0700 Subject: [time-nuts] Thunderbolt monitor In-Reply-To: Message-ID: Yeah, those Noritake parts are very nice. I wouldn't expect trouble from one. There is a slight possibility of additional EMI versus an LCD, obviously nothing that would cause trouble at the end of an RS232 cable. -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On > Behalf Of Jeffrey Pawlan > Sent: Wednesday, July 16, 2008 8:40 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Thunderbolt monitor > > > Regarding the VFD display, although they may be very different > one manufacturer > to another, I can definitely dispute a prior statement made that > VFDs in general > have a short lifetime and become dim. They are universally used > in VCRs, DVD > players, microwave ovens, and some clocks. I have never had one > become dim or > burn out. The displays in my appliances are on even when the rest of the > appliance is off. I have never seen one become dim even after 15 years of > on-time. > > I look forward to your project. > > > 73, > > Jeffrey Pawlan, WA6KBL > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From ka2cdk at cox.net Thu Jul 17 00:05:42 2008 From: ka2cdk at cox.net (Thomas A. Frank) Date: Thu, 17 Jul 2008 00:05:42 -0400 Subject: [time-nuts] Thunderbolt monitor In-Reply-To: <010401c8e7b7$5de8abe0$0a01a8c0@didierhp> References: <004401c8e635$e04bd360$0a01a8c0@didierhp> <1C2032F78B14424F81C2E49E3366E765@DESKTOP> <010401c8e7b7$5de8abe0$0a01a8c0@didierhp> Message-ID: On Jul 16, 2008, at 10:46 PM, Didier Juges wrote: > One issue with the Noritake display (common to all VFD devices) is > that it > draws over 100mA of current at 5V. A 3 terminal linear regulator > running > from 12V will need a reasonable heat sink to operate. A better > choice would > be a small switching regulator such as the LT1375 which I have used > in a > great many products. It's a small 8 pin device that requires only a > handful > of external components to convert 12V to 5 with excellent > efficiency (no > heat sink required). I may lay out the PWB for both types of > regulators, > depending on the type of display you want to use. > > Didier KO4BB Why would you run this external box off of 12 volts? Do you have portable use in mind? I ask because to my way of thinking, I would provide the display/ processor box with 5 volts straight out of a "wall wart"; I've probably got a dozen in that voltage range lying around (left over from ZIP drives). The only use for 12 volts in the display box would be for the RS232, and that can come from a MAX232 chip. Seems like a simpler approach to me. If I really wanted portable, the 12-5v unit would be external. Tom Frank KA2CDK From didier at cox.net Thu Jul 17 00:43:17 2008 From: didier at cox.net (Didier Juges) Date: Wed, 16 Jul 2008 23:43:17 -0500 Subject: [time-nuts] Thunderbolt monitor In-Reply-To: References: <010401c8e7b7$5de8abe0$0a01a8c0@didierhp> Message-ID: <010801c8e7c7$a2457bf0$0a01a8c0@didierhp> Interesting, I can show you my two VCRs with dim displays (Panasonic and JVC, both about 10 years old and on 24/7), and I have used a number of the Noritake VFDs in an application where the devices have been on 24/7 since 2000. In that application, only 2, 3 or 4 digits are on all the time, the other digits are only used for a special test mode and have probably less than one hour total of operation in 8 years. The digits that are on all the time have dimmed appreciably, but are still readable. The digits that are not normally used are extremely dim when operated, where they are unreadable in normal light. I have not asked the manufacturer about that, since the units are well beyong varranty, we just replace the displays. Didier > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Jeffrey Pawlan > Sent: Wednesday, July 16, 2008 10:40 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Thunderbolt monitor > > Regarding the VFD display, although they may be very > different one manufacturer to another, I can definitely > dispute a prior statement made that VFDs in general have a > short lifetime and become dim. They are universally used in > VCRs, DVD players, microwave ovens, and some clocks. I have > never had one become dim or burn out. The displays in my > appliances are on even when the rest of the appliance is > off. I have never seen one become dim even after 15 years of on-time. > > I look forward to your project. > > > 73, > > Jeffrey Pawlan, WA6KBL > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, > go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From didier at cox.net Thu Jul 17 00:54:15 2008 From: didier at cox.net (Didier Juges) Date: Wed, 16 Jul 2008 23:54:15 -0500 Subject: [time-nuts] Thunderbolt monitor In-Reply-To: References: <004401c8e635$e04bd360$0a01a8c0@didierhp><1C2032F78B14424F81C2E49E3366E765@DESKTOP><010401c8e7b7$5de8abe0$0a01a8c0@didierhp> Message-ID: <010901c8e7c9$2aaf1860$0a01a8c0@didierhp> My preference is usually to have a voltage regulator on the board where the "expensive" electronics is, simply because I use adjustable bench supplies for testing and I also own and use a large number of 9 to 12V wall warts such that I have blown great many parts by inadvertently putting 9 or 12V into a 5V gizmo. Also, most of my processor boards take advantage of the built-in A/D converter, and a local stable 5V source is a good design practice that avoids a number of problems down the road. So it's been my practice to put a 5V regulator, needed or not :-) Now, the Silabs chips run off 3V nominal and have their own, relatively stable 2.5V reference, so that problem also mostly goes away. In this case, since the group buy Thunderbolt comes with a multi-output supply which includes 5V, we could use that directly I guess. It just had not occurred to me to do that... My original "red box" Thunderbolt runs off 28V, so that one will definitely need its own switching regulator. Regarding the RS-232, the monitor only needs to convert the RS-232 to 0-3V logic, so 12V is not needed there either. In any event, a separate supply would be a waste and is not necessary. Didier KO4BB > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Thomas A. Frank > Sent: Wednesday, July 16, 2008 11:06 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Thunderbolt monitor > > On Jul 16, 2008, at 10:46 PM, Didier Juges wrote: > > > One issue with the Noritake display (common to all VFD devices) is > > that it draws over 100mA of current at 5V. A 3 terminal linear > > regulator running from 12V will need a reasonable heat sink to > > operate. A better choice would be a small switching > regulator such as > > the LT1375 which I have used in a great many products. It's > a small 8 > > pin device that requires only a handful of external components to > > convert 12V to 5 with excellent efficiency (no heat sink > required). I > > may lay out the PWB for both types of regulators, depending on the > > type of display you want to use. > > > > Didier KO4BB > > Why would you run this external box off of 12 volts? Do you > have portable use in mind? > > I ask because to my way of thinking, I would provide the > display/ processor box with 5 volts straight out of a "wall > wart"; I've probably got a dozen in that voltage range lying > around (left over from ZIP drives). > > The only use for 12 volts in the display box would be for the > RS232, and that can come from a MAX232 chip. > > Seems like a simpler approach to me. If I really wanted > portable, the 12-5v unit would be external. > > Tom Frank KA2CDK > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, > go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From holrum at hotmail.com Thu Jul 17 06:38:41 2008 From: holrum at hotmail.com (Mark Sims) Date: Thu, 17 Jul 2008 10:38:41 +0000 Subject: [time-nuts] Thunderbolt monitor In-Reply-To: References: Message-ID: All VFD displays (and EL and CCFL LCD backlights) have finite lifetimes. Very few will last over 40,000 hours (5 years). Many start to noticeably degrade after one year. Many EL backlights have lifetimes of less than 5000 hours (ever see a Tektronix 1502/1503B/C TDR with a good backlight?) VFD displays have two main wearout mechanisms... phosphor degradation and cathode (filament) degradation. These displays are essentially the same as CRTs and old fashioned vacuum tubes. They rely on a stream of electrons from a heated filament to hit a phosphor screen. Over time the filament and the phosphor degrade. VFD displays (and EL backlights) typically have a rapid initial drop in brightness (25 percent over the first 100 hours is not uncommon) followed by a slow, fairly linear, drop in brightness. Most spec the lifetime of the device at 50% drop in brightness. I repair quite a few old digital scales from Sartorius and Mettler that use VFD displays. Many of these units are discarded because the displays have become so dim that they are unreadable (and the only source of replacements is another balance). Most of these balances keep the electronics on continuously to keep the units thermally stabilized. The power switch just turns the display on or off. Unfortunately some of the balances just blank the display. They leave the VFD filament energized and this wears out the display about as fast as keeping it lit. ---------------------------------------- _________________________________________________________________ With Windows Live for mobile, your contacts travel with you. http://www.windowslive.com/mobile/overview.html?ocid=TXT_TAGLM_WL_mobile_072008 From dibene at usa.net Thu Jul 17 09:47:38 2008 From: dibene at usa.net (Alberto di Bene) Date: Thu, 17 Jul 2008 15:47:38 +0200 Subject: [time-nuts] Power splitter on the Thunderbolt units In-Reply-To: References: Message-ID: <487F4D7A.7030106@usa.net> What is the power splitter glued on some of the Thunderbolt units meant for ? Apparently it is good up to 500 MHz, so it can't be used for the signal coming from the antenna. Maybe it was just part of complete product which the Thunderbolt was part of. Just curious.... 73 Alberto I2PHD From tvb at LeapSecond.com Thu Jul 17 12:31:51 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Thu, 17 Jul 2008 09:31:51 -0700 Subject: [time-nuts] Power splitter on the Thunderbolt units References: <487F4D7A.7030106@usa.net> Message-ID: <000801c8e82a$a244d6b0$0900a8c0@pc52> > What is the power splitter glued on some of the Thunderbolt units meant for ? > Apparently it is good up to 500 MHz, so it can't be used for the signal coming from the antenna. > Maybe it was just part of complete product which the Thunderbolt was part of. > Just curious.... > > 73 Alberto I2PHD It was used with the 10 MHz output; either to split the output or to combine with a phased locked 10 MHz backup source (we've seen this on other telecom frequency references). Some of the Thunderbolts in the group buy had the splitter removed (those with screws from the outside). Others came with splitters screwed from the inside and it was too much bother to remove the splitter from each unit before shipment. You can remove the thing yourself by opening up the case. /tvb From dave.g0dja at tiscali.co.uk Thu Jul 17 13:10:37 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Thu, 17 Jul 2008 18:10:37 +0100 Subject: [time-nuts] Power splitter on the Thunderbolt units In-Reply-To: <000801c8e82a$a244d6b0$0900a8c0@pc52> References: <487F4D7A.7030106@usa.net> <000801c8e82a$a244d6b0$0900a8c0@pc52> Message-ID: <487F7D0D.9030806@tiscali.co.uk> Tom Van Baak wrote: > > It was used with the 10 MHz output; either to split the output > or to combine with a phased locked 10 MHz backup source > (we've seen this on other telecom frequency references). Sounds like a nice little 'freebe' for some. :-) I can understand that it would be better to remove it to keep P&P costs under control though. Dave (G0DJA) From stanley_reynolds at yahoo.com Thu Jul 17 15:05:47 2008 From: stanley_reynolds at yahoo.com (Stanley Reynolds) Date: Thu, 17 Jul 2008 12:05:47 -0700 (PDT) Subject: [time-nuts] AUSTRON LORAN-C TRF RECEIVER MODEL 2082 Message-ID: <114310.18332.qm@web30303.mail.mud.yahoo.com> Any info available ? ? Name is a little misleading as this unit is?RF filters and preamp. ? Contains?4 adjustable?filters first is switch selectable for peek or null, other 3 are null, and one band pass filter 29Khz to 100Khz. May be similar to 2084 Multifilter one output shared between front and rear panels and no Sferics warning lamp . From smace at intt.net Thu Jul 17 17:43:20 2008 From: smace at intt.net (Scott Mace) Date: Thu, 17 Jul 2008 16:43:20 -0500 Subject: [time-nuts] Lucent RFTG-m-RB In-Reply-To: <487D2E1E.80104@intt.net> References: <487D2E1E.80104@intt.net> Message-ID: <487FBCF8.1010200@intt.net> When you have a RFTG-m-XO and Rb pair, do you connect both J5 and J6 on each unit or just J5? Scott Scott Mace wrote: > Has anyone tried to discipline the RFTG-m-RB without the -XO unit from > a house PPS feed? > > I think pins 4 and 8 on J6 are the PPS input. > > Scott > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From d.seiter at comcast.net Thu Jul 17 18:35:06 2008 From: d.seiter at comcast.net (d.seiter at comcast.net) Date: Thu, 17 Jul 2008 22:35:06 +0000 Subject: [time-nuts] Thunderbolt monitor Message-ID: <071720082235.22631.487FC91A000CB7480000586722058891169D0A9B070A9CD20B@comcast.net> I too have never seen one go dim. In fact, I have a VCR (Beta!) that's been pluged in continously since I got it new in the early '80s. It still looks the same as when I got it except that the display has had a left to right wave going through it since about 1995. So, wavy- but not dim at all. -Dave -------------- Original message -------------- From: Jeffrey Pawlan > Regarding the VFD display, although they may be very different one manufacturer > to another, I can definitely dispute a prior statement made that VFDs in general > have a short lifetime and become dim. They are universally used in VCRs, DVD > players, microwave ovens, and some clocks. I have never had one become dim or > burn out. The displays in my appliances are on even when the rest of the > appliance is off. I have never seen one become dim even after 15 years of > on-time. > > I look forward to your project. > > > 73, > > Jeffrey Pawlan, WA6KBL > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From d.seiter at comcast.net Thu Jul 17 18:35:06 2008 From: d.seiter at comcast.net (d.seiter at comcast.net) Date: Thu, 17 Jul 2008 22:35:06 +0000 Subject: [time-nuts] Thunderbolt monitor Message-ID: <071720082235.22631.487FC91A000CB7480000586722058891169D0A9B070A9CD20B@comcast.net> I too have never seen one go dim. In fact, I have a VCR (Beta!) that's been pluged in continously since I got it new in the early '80s. It still looks the same as when I got it except that the display has had a left to right wave going through it since about 1995. So, wavy- but not dim at all. -Dave -------------- Original message -------------- From: Jeffrey Pawlan > Regarding the VFD display, although they may be very different one manufacturer > to another, I can definitely dispute a prior statement made that VFDs in general > have a short lifetime and become dim. They are universally used in VCRs, DVD > players, microwave ovens, and some clocks. I have never had one become dim or > burn out. The displays in my appliances are on even when the rest of the > appliance is off. I have never seen one become dim even after 15 years of > on-time. > > I look forward to your project. > > > 73, > > Jeffrey Pawlan, WA6KBL > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From namichie at gmail.com Thu Jul 17 18:50:34 2008 From: namichie at gmail.com (Neville Michie) Date: Fri, 18 Jul 2008 08:50:34 +1000 Subject: [time-nuts] Thunderbolt monitor In-Reply-To: <071720082235.22631.487FC91A000CB7480000586722058891169D0A9B070A9CD20B@comcast.net> References: <071720082235.22631.487FC91A000CB7480000586722058891169D0A9B070A9CD20B@comcast.net> Message-ID: From my thermionic valve days, the emmissivity of a filament was greatly extended by under-running them. If the display is pemanently run at a lower current in dim mode, how long could the life be extended by dropping the filament voltage by a small margin? cheers, Neville Michie On 18/07/2008, at 8:35 AM, d.seiter at comcast.net wrote: > I too have never seen one go dim. In fact, I have a VCR (Beta!) > that's been pluged in continously since I got it new in the early > '80s. It still looks the same as when I got it except that the > display has had a left to right wave going through it since about > 1995. So, wavy- but not dim at all. > > -Dave > > > -------------- Original message -------------- > From: Jeffrey Pawlan > >> Regarding the VFD display, although they may be very different one >> manufacturer >> to another, I can definitely dispute a prior statement made that >> VFDs in general >> have a short lifetime and become dim. They are universally used in >> VCRs, DVD >> players, microwave ovens, and some clocks. I have never had one >> become dim or >> burn out. The displays in my appliances are on even when the rest >> of the >> appliance is off. I have never seen one become dim even after 15 >> years of >> on-time. >> >> I look forward to your project. >> >> >> 73, >> >> Jeffrey Pawlan, WA6KBL >> >> >> >> >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts at febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/ >> listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. From billh40 at aol.com Thu Jul 17 21:17:40 2008 From: billh40 at aol.com (billh40 at aol.com) Date: Thu, 17 Jul 2008 21:17:40 -0400 Subject: [time-nuts] change in email address Message-ID: <8CAB68B34B01C27-167C-1AEF@FWM-D20.sysops.aol.com> change in email address: ??? was: ????????????????????????????????????? is: ?? billh40 at aol.com?????????????????????? billh40 at gmail.com Thanks, Bill Hanna From ChrisB at tsogosun.com Fri Jul 18 05:42:45 2008 From: ChrisB at tsogosun.com (Baragwanath, Chris (TSG)) Date: Fri, 18 Jul 2008 11:42:45 +0200 Subject: [time-nuts] TimeNuts Assistance Request In-Reply-To: References: Message-ID: Hi all Time Nuts, I am a 'side line' member of the mailing list, ex Broadcast engineer whose principle fascination is accurate pendulum clocks and as one who has been lucky enough to have been in the presence of the ultimate "Clock" here in South Africa, the SAST (South African Standard Time) cluster. We do not have a "free to air" telephonic Time and Freq service in SA as the NIST does and our principle RF source (ZUO_ has long been discontinued for economic reasons (Other than the distant low power coastal stations the transmit a few mins a day for shipping purposes). The former Govt Labs and Standards Authorities are now privatised to lessen the burden on the fiscus and supposed to be self supporting, so charge and arm and a leg for access to their facilities, that our tax money paid for in the first place) At present, radio propagation conditions are so poor that and of the NIST and other stations are unusable as a tone reference or 1 pulse per second reference, and so have to call the NIST land line number, which is an expensive call from South Africa. As a voluntary / community service, we are trying to establish a freely accessible tone and pulse service and are looking for a donation of any unwanted equipment that will help us get a more stable 440hz and 1 PPS reference running. (The current oscillator is a good old uncompensated crystal British Ferrograph Test Set from broadcast days interrupted by another uncompensated xtal osc which interrupts the tone to prove the PPS output). Any donation of unwanted equipment, especially of more stable equipment or the ultimate, a GPS Rx board with 1 PPS output would be greatly appreciated. If anyone is prepared to help, I would be most grateful and would cover the shipping costs to SA. The mains in SA is 220v 50hz, but do have access to a 120v 60hz sinewave inverter unit to safely power US spec equipment. Many thanks in advance, Kind regards, Chris D Bagwanath "Its About Time" chris at baragwanath.co.za Tel +27 83 700 5057 Fax: +27 11 792 166 From didier at cox.net Fri Jul 18 08:14:18 2008 From: didier at cox.net (Didier Juges) Date: Fri, 18 Jul 2008 07:14:18 -0500 Subject: [time-nuts] TimeNuts Assistance Request In-Reply-To: References: Message-ID: <00a601c8e8cf$ce25fed0$0a01a8c0@didierhp> Chris, What is the 440Hz used for, other than tune instruments? Didier > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Baragwanath, > Chris (TSG) > Sent: Friday, July 18, 2008 4:43 AM > To: time-nuts at febo.com > Subject: [time-nuts] TimeNuts Assistance Request > > Hi all Time Nuts, > > I am a 'side line' member of the mailing list, ex Broadcast > engineer whose principle fascination is accurate pendulum > clocks and as one who has been lucky enough to have been in > the presence of the ultimate "Clock" here in South Africa, > the SAST (South African Standard Time) cluster. > > We do not have a "free to air" telephonic Time and Freq > service in SA as the NIST does and our principle RF source > (ZUO_ has long been discontinued for economic reasons (Other > than the distant low power coastal stations the transmit a > few mins a day for shipping purposes). > The former Govt Labs and Standards Authorities are now > privatised to lessen the burden on the fiscus and supposed to > be self supporting, so charge and arm and a leg for access to > their facilities, that our tax money paid for in the first place) > > At present, radio propagation conditions are so poor that and > of the NIST and other stations are unusable as a tone > reference or 1 pulse per second reference, and so have to > call the NIST land line number, which is an expensive call > from South Africa. > > As a voluntary / community service, we are trying to > establish a freely accessible tone and pulse service and are > looking for a donation of any unwanted equipment that will > help us get a more stable 440hz and 1 PPS reference running. > (The current oscillator is a good old uncompensated crystal > British Ferrograph Test Set from broadcast days interrupted > by another uncompensated xtal osc which interrupts the tone > to prove the PPS output). > > Any donation of unwanted equipment, especially of more stable > equipment or the ultimate, a GPS Rx board with 1 PPS output > would be greatly appreciated. > > If anyone is prepared to help, I would be most grateful and > would cover the shipping costs to SA. > > The mains in SA is 220v 50hz, but do have access to a 120v > 60hz sinewave inverter unit to safely power US spec equipment. > > Many thanks in advance, > > > Kind regards, > > > Chris D Bagwanath > "Its About Time" > > chris at baragwanath.co.za > Tel +27 83 700 5057 > Fax: +27 11 792 166 > > > > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, > go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From pvince at theiet.org Fri Jul 18 13:22:09 2008 From: pvince at theiet.org (Peter Vince) Date: Fri, 18 Jul 2008 18:22:09 +0100 Subject: [time-nuts] Thunderbolt - temperature In-Reply-To: References: Message-ID: I have one of the Trimble Z3801 look-alikes. It only seems to report its temperature in half-degree steps, but I left it running for nearly 27 hours, and saw a couple of 1-second 1 degree spikes during that time - see attached graph. Could this be the same thing you are seeing with your real Thunderbolts? There is no 20-second decay that you are seeing, but then the resolution is very coarse. The item has several part numbers on its label: P/N: NTPX26AB-01 D/C: 9828 P/N: 34304-00 -11 Oscillator "T" (barcode) NNTM74TR0081 and has a small label under the barcode with 1.56 on it - firmware version? Regards, Peter Vince (G8ZZR, London, England) -------------- next part -------------- A non-text attachment was scrubbed... Name: trimble_temperature.gif Type: image/gif Size: 8176 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080718/c00215e6/attachment.gif From w1ksz at earthlink.net Fri Jul 18 19:08:10 2008 From: w1ksz at earthlink.net (Richard W. Solomon) Date: Fri, 18 Jul 2008 16:08:10 -0700 (GMT-07:00) Subject: [time-nuts] Time Nuts Archives Message-ID: <15116200.1216422491090.JavaMail.root@mswamui-backed.atl.sa.earthlink.net> Where are the archives located ? I did a Google search and when I tries entering the febo.com website I got some dire warning of impending doom due to something about a certificate. 73, Dick, W1KSZ From jpradoes at telefonica.net Fri Jul 18 19:14:45 2008 From: jpradoes at telefonica.net (Jose Manuel) Date: Sat, 19 Jul 2008 01:14:45 +0200 Subject: [time-nuts] Time Nuts Archives References: <15116200.1216422491090.JavaMail.root@mswamui-backed.atl.sa.earthlink.net> Message-ID: <011701c8e92c$11a8ff20$2201a8c0@PC2> Try this http://www.febo.com/pipermail/time-nuts/ 73 de Jos?, EA1PX ----- Original Message ----- From: "Richard W. Solomon" To: Sent: Saturday, July 19, 2008 1:08 AM Subject: [time-nuts] Time Nuts Archives > Where are the archives located ? I did a Google search and when I > tries entering the febo.com website I got some dire warning of > impending doom due to something about a certificate. > > 73, Dick, W1KSZ > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > -- > No virus found in this incoming message. > Checked by AVG. > Version: 7.5.526 / Virus Database: 270.5.0 - Release Date: 16/07/2008 0:00 > > From n3izn at aol.com Fri Jul 18 21:42:08 2008 From: n3izn at aol.com (n3izn at aol.com) Date: Fri, 18 Jul 2008 21:42:08 -0400 Subject: [time-nuts] Trimble GPSDO unit for sale In-Reply-To: <485D2F74.1070606@febo.com> References: <485D2F74.1070606@febo.com> Message-ID: <8CAB757CA39ACAB-F34-9AB0@webmail-nh05.sysops.aol.com> Hello all, I hope this is not against the rules but I came across another Trimble unit, like what ever one is calling Thunderbolts. I've had one up and running for a couple of years now and I don't see a need for another one right now. I however have a bunch of projects that need funding. So I have the gold colored unit, About a 2~3" of wire on the power connector. The minicircuits 10 Mhz Splitter and the cables connected to it. Sorry I wasn't thinking and just cut the F connector to TNC (or was it N) cable adapter. So I have a 3-4" F connector on the cable. I can send pics. I will power it up and verify it locks up and puts out 10 Mhz to make my MW equipment happy but I can tell you much more than that. I think the group buy was selling at $115? Would prefer stateside. I need (want) more power on 1296. So if you an amp for 1296 we can work out something. My other project requires a doubler, 2~3 Ghz in, 4~6 Ghz out. Would also work something out. Thanks Chris Interested contact direct. From wje at quackers.net Sat Jul 19 09:48:34 2008 From: wje at quackers.net (wje) Date: Sat, 19 Jul 2008 09:48:34 -0400 Subject: [time-nuts] 5061A and Zeeman freq question Message-ID: <4881F0B2.8070207@quackers.net> My understanding is that the precise cesium hyperfine transition energy, and hence microwave frequency, is dependent upon the applied C-field, and the field setting to select a particular transition is the same for all clocks (which is why these are primary standards). The C-field is set by applying an LF signal at the correct frequency to cause Zeeman splitting, and optimizing the C-field to peak the splitting. So, shouldn't the Zeeman frequency always be 42.82 Khz, which is what I've seen in every reference? But, my 5061A with a high-performance tube has a sticker that says 'Zeeman freq 53.53 Khz'. I can indeed get Zeeman splitting at that frequency with a C-field setting of 3.45, but is this correct? If so, why? (BTW - I don't seem to be able to get any splitting at 42.82 Khz) Confused, Bill -- Bill Ezell ---------- They said 'Windows or better' so I used Linux. From tvb at LeapSecond.com Sat Jul 19 11:09:02 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Sat, 19 Jul 2008 08:09:02 -0700 Subject: [time-nuts] 5061A and Zeeman freq question References: <4881F0B2.8070207@quackers.net> Message-ID: <001201c8e9b1$664f10c0$0900a8c0@pc52> > My understanding is that the precise cesium hyperfine transition energy, > and hence microwave frequency, is dependent upon the applied C-field, > and the field setting to select a particular transition is the same for > all clocks (which is why these are primary standards). The C-field is > set by applying an LF signal at the correct frequency to cause Zeeman > splitting, and optimizing the C-field to peak the splitting. It's the same for all cesium tubes of the same design but over the decades a number of different tubes have been designed. 42.82 kHz (older model 5061) 70.40 kHz (model 5062c) 53.53 kHz (newer 5061A/B and 5071A) See this 2005 time-nuts posting: http://www.mail-archive.com/time-nuts at febo.com/msg00233.html The Zeeman shift would also be different among the one of a kind cesium standards that national laboratories build. But the key is that based on the beam design the zeeman shift can be calculated and thus compensated for. What makes a standard primary is if all the frequency shifts can be calculated (not measured) as well as the magnitude of all error sources. For a great example of this read: http://www.boulder.nist.gov/timefreq/general/pdf/1497.pdf including table 3 and table 4. > So, shouldn't the Zeeman frequency always be 42.82 Khz, which is what > I've seen in every reference? But, my 5061A with a high-performance tube > has a sticker that says 'Zeeman freq 53.53 Khz'. I can indeed get Zeeman > splitting at that frequency with a C-field setting of 3.45, but is this > correct? If so, why? (BTW - I don't seem to be able to get any splitting > at 42.82 Khz) > > Confused, > Bill There's also a nice description here: http://www.leapsecond.com/museum/hp5062c/theory.htm Homemade plots of the 7 cesium hyperfine peaks here: http://www.leapsecond.com/pages/cspeak/ /tvb From stijena at tapko.de Sat Jul 19 11:14:02 2008 From: stijena at tapko.de (Predrag Dukic) Date: Sat, 19 Jul 2008 17:14:02 +0200 Subject: [time-nuts] 5061A and Zeeman freq question In-Reply-To: <4881F0B2.8070207@quackers.net> References: <4881F0B2.8070207@quackers.net> Message-ID: <7.0.1.0.1.20080719170354.01e66b18@tapko.de> Bill, I am not a quantum physicist, but my understanding of Zeeman splitting is a bit different. With applied homogenous DC magnetic field to the atoms on their path You get splitting. Without it You have no Ramsey fringes. There is a formula to calculate mid-fringe offset from defined cesium resonance knowing splitting frequency. So You should always be able to tell the right frequency from the splitting frequency, and that has nothing to do with definition of the cesium as primary standard. The correct field strength and correct splitting frequency, by my opinion have some importance to other parameters; stability, mid fringe width etc, while resonance frequency is tied to split frequency by an exact mathematical equation. All of this under assumption that the field is homogenous. If not, than You have some other problems. Predrag Dukic At 15:48 19.7.2008, you wrote: >My understanding is that the precise cesium hyperfine transition energy, >and hence microwave frequency, is dependent upon the applied C-field, >and the field setting to select a particular transition is the same for >all clocks (which is why these are primary standards). The C-field is >set by applying an LF signal at the correct frequency to cause Zeeman >splitting, and optimizing the C-field to peak the splitting. > >So, shouldn't the Zeeman frequency always be 42.82 Khz, which is what >I've seen in every reference? But, my 5061A with a high-performance tube >has a sticker that says 'Zeeman freq 53.53 Khz'. I can indeed get Zeeman >splitting at that frequency with a C-field setting of 3.45, but is this >correct? If so, why? (BTW - I don't seem to be able to get any splitting >at 42.82 Khz) > >Confused, >Bill > >-- >Bill Ezell >---------- >They said 'Windows or better' >so I used Linux. > > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From aceamusements at mchsi.com Sat Jul 19 11:49:47 2008 From: aceamusements at mchsi.com (aceamusements at mchsi.com) Date: Sat, 19 Jul 2008 15:49:47 +0000 Subject: [time-nuts] Trimble GPSDO unit for sale Message-ID: <071920081549.8295.48820D1B00007D0D00002067219791299503010CD2079C080C03BF9C9B020A030A9C9A030E0A0C0E@mchsi.com> I would be interested if you accept paypal,,would offer 200.00 if new cond.. Dvr20 at aol.com.thanks.. ---------------------- Original Message: --------------------- From: n3izn at aol.com To: time-nuts at febo.com Subject: [time-nuts] Trimble GPSDO unit for sale Date: Sat, 19 Jul 2008 01:43:45 +0000 > > > Hello all, > > I hope this is not against the rules but I came across another Trimble unit, > like what ever one is calling Thunderbolts. I've had one up and running for a > couple of years now > and I don't see a need for another one right now. I however have a bunch of > projects that need funding. > > So I have the gold colored unit, About a 2~3" of wire on the power connector. > The minicircuits 10 Mhz > Splitter and the cables connected to it. Sorry I wasn't thinking and just cut > the F connector > to TNC (or was it N) cable adapter. So I have a 3-4" F connector on the cable. > > > > > > > > > > > > > I can send pics. I will power it up and verify it locks up and puts out 10 Mhz > to make my MW > equipment happy but I can tell you much more than that. > I think the group buy was selling at $115? Would prefer stateside. > I need (want) more power on 1296. So if you an amp for 1296 we can work out > something. > My other project requires a doubler, 2~3 Ghz in, 4~6 Ghz out. Would also work > something out. > Thanks > Chris > Interested contact direct. > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From cdelect at juno.com Sat Jul 19 13:47:29 2008 From: cdelect at juno.com (corby d dawson) Date: Sat, 19 Jul 2008 10:47:29 -0700 Subject: [time-nuts] cesium Zeeman frequencies Message-ID: <20080719.104730.-398201.0.cdelect@juno.com> The Zeeman frequency is calculated by the amount of C-field current you use. If you change the Zeeman then to get the unit "on frequency" you then have to change the synthesizer frequency and the C-field current to compensate. The amount of C-field change is too big for the front panel knobpot so a resistor change on the A15 board is required. The earlier 5061A current (61miiliGauss) resulted in a synthesizer frequency of 12.6317716 Mhz giving a corresponding Zeeman frequency of 48.82Khz. On later 5061A and B units HP decided that using a different current (76 milliGauss) that was more stable which ended up giving you 12.7317725Mhz and 53.53Khz. There is NO difference in the tubes C-field winding (for 5061A/B and 5071A). The current set resistor on the A15 board and the synthesizer frequency are the only change. Corby Dawson ____________________________________________________________ Learn about VA loan programs and benefits. Click now. http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3m3mWguucezHInyDvTMZqPNuZVtJ2PrIg6iEz3xSv6sf8Syt/ From wje at quackers.net Sat Jul 19 16:31:47 2008 From: wje at quackers.net (wje) Date: Sat, 19 Jul 2008 16:31:47 -0400 Subject: [time-nuts] cesium Zeeman frequencies In-Reply-To: <20080719.104730.-398201.0.cdelect@juno.com> References: <20080719.104730.-398201.0.cdelect@juno.com> Message-ID: <48824F33.4060901@quackers.net> Thanks all. I reviewed some physics on this, and now it makes sense. Corby, my 5061A is an oldie, it has the early synthesizer that has the UTC offset correction, which I've set to match atomic time (L2095 on the switches). The tube was replaced in '82. So, I need to verify that the C-field current was also adjusted to match the new 76 mGauss setting, right?. Looks like my synthesizer frequency is 12.6317715, so possibly not. This could also explain the 100ps/sec drift wrt my Z3801A. You don't happen to know the proper value for the resistor, do you? Hmm... I wonder if my synthesizer can do ..725 Mhz. I've been toying with the idea of building a new synthesizer using modern a modern digital PLL, going so far as to lay out a PCB for it. Maybe I should follow through on that. Bill Ezell ---------- They said 'Windows or better' so I used Linux. corby d dawson wrote: > The Zeeman frequency is calculated by the amount of C-field current you > use. > > If you change the Zeeman then to get the unit "on frequency" you then > have to change the synthesizer frequency and the C-field current to > compensate. The amount of C-field change is too big for the front panel > knobpot so a resistor change on the A15 board is required. > > The earlier 5061A current (61miiliGauss) resulted in a synthesizer > frequency of 12.6317716 Mhz giving a corresponding Zeeman frequency of > 48.82Khz. > > On later 5061A and B units HP decided that using a different current (76 > milliGauss) that was more stable which ended up giving you 12.7317725Mhz > and 53.53Khz. > > There is NO difference in the tubes C-field winding (for 5061A/B and > 5071A). The current set resistor on the A15 board and the synthesizer > frequency are the only change. > > Corby Dawson > ____________________________________________________________ > Learn about VA loan programs and benefits. Click now. > http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3m3mWguucezHInyDvTMZqPNuZVtJ2PrIg6iEz3xSv6sf8Syt/ > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > From not.again at btinternet.com Sat Jul 19 17:19:33 2008 From: not.again at btinternet.com (Angus) Date: Sat, 19 Jul 2008 22:19:33 +0100 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <4878E7F9.2080309@sasktel.net> References: <4878E7F9.2080309@sasktel.net> Message-ID: <2cl484t5nhllg7hl97dbqpp2a8ap62hq97@4ax.com> >I see that the same vendor has a few more units for sale. He has also >included a picture that labels all the connections. At least they look to be complete with their outer covers now, which would be useful if anyone did want to add some temp control. Seeing all those oscillators does make me wonder what they came from - a heap of working 58503's going to landfill is close to sacrilege :-) Angus. On Sat, 12 Jul 2008 11:20:57 -0600, you wrote: > >> Message: 2 >> Date: Wed, 9 Jul 2008 12:10:52 +1000 >> From: "Jim Palfreyman" >> Subject: [time-nuts] Double ovened 10811-60158 on ebay >> To: time-nuts at febo.com >> Message-ID: >> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Sorry to pollute the list but some people here may be interested and I think >> this might be a good buy. >> >> Ebay item 250268030266 a bunch of 10811-60158 wrapped up in a second oven >> that have been pulled from a bunch of HP 58503A. >> >> There are 21 units available at US$50 Buy It Now. Postage seems reasonable >> too. >> >> I've bought one and so if anyone knows where I can get the cabling >> requirements please let me know. >> >> >> Regards, >> >> Jim Palfreyman >> > > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From wje at quackers.net Sat Jul 19 17:33:07 2008 From: wje at quackers.net (wje) Date: Sat, 19 Jul 2008 17:33:07 -0400 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <2cl484t5nhllg7hl97dbqpp2a8ap62hq97@4ax.com> References: <4878E7F9.2080309@sasktel.net> <2cl484t5nhllg7hl97dbqpp2a8ap62hq97@4ax.com> Message-ID: <48825D93.2060101@quackers.net> I got one without the outer cover, which isn't quite as useful. I removed all the junk to get down to the orginal non-double-ovened osc. One thing I noticed - I wonder where these were actually deployed? The 10811B itself has a fair amount of corrosion on it, lots of pitting. It still works fine, though. Another thing, the 10811B in mine doesn't have a removable endplate, it's soldered. This makes it a lot more difficult to adjust or repair. Still, I think it's a fine buy for the cost. Now all I have to do is figure out what I really want to do with it. :) Bill Ezell ---------- They said 'Windows or better' so I used Linux. Angus wrote: I see that the same vendor has a few more units for sale. He has also included a picture that labels all the connections. At least they look to be complete with their outer covers now, which would be useful if anyone did want to add some temp control. Seeing all those oscillators does make me wonder what they came from - a heap of working 58503's going to landfill is close to sacrilege :-) Angus. On Sat, 12 Jul 2008 11:20:57 -0600, you wrote: Message: 2 Date: Wed, 9 Jul 2008 12:10:52 +1000 From: "Jim Palfreyman" [1] Subject: [time-nuts] Double ovened 10811-60158 on ebay To: [2]time-nuts at febo.com Message-ID: [3] Content-Type: text/plain; charset=ISO-8859-1 Sorry to pollute the list but some people here may be interested and I think this might be a good buy. Ebay item 250268030266 a bunch of 10811-60158 wrapped up in a second oven that have been pulled from a bunch of HP 58503A. There are 21 units available at US$50 Buy It Now. Postage seems reasonable too. I've bought one and so if anyone knows where I can get the cabling requirements please let me know. Regards, Jim Palfreyman _______________________________________________ time-nuts mailing list -- [4]time-nuts at febo.com To unsubscribe, go to [5]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [6]time-nuts at febo.com To unsubscribe, go to [7]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:jim77742 at gmail.com 2. mailto:time-nuts at febo.com 3. mailto:f616e0f80807081910i38b378b7ic7d9d513cd3026c6 at mail.gmail.com 4. mailto:time-nuts at febo.com 5. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 6. mailto:time-nuts at febo.com 7. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts From mikes at flatsurface.com Sat Jul 19 17:47:57 2008 From: mikes at flatsurface.com (Mike S) Date: Sat, 19 Jul 2008 17:47:57 -0400 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <48825D93.2060101@quackers.net> References: <4878E7F9.2080309@sasktel.net> <2cl484t5nhllg7hl97dbqpp2a8ap62hq97@4ax.com> <48825D93.2060101@quackers.net> Message-ID: <20080719215221.D57D11165C3@hamburg.alientech.net> At 05:33 PM 7/19/2008, wje wrote... > Another thing, the 10811B in mine doesn't have a removable endplate, > it's soldered. This makes it a lot more difficult to adjust or > repair. > Still, I think it's a fine buy for the cost. Well, yea. Maybe Rick Karlquist will pipe in, but I believe that (other than temperature, which is obviously well controlled by a double oven), pressure/humidity are the biggest instability factors. Soldering the case closed mitigates that. From w1ksz at earthlink.net Sat Jul 19 19:10:52 2008 From: w1ksz at earthlink.net (Richard W. Solomon) Date: Sat, 19 Jul 2008 16:10:52 -0700 (GMT-07:00) Subject: [time-nuts] Double ovened 10811-60158 on ebay Message-ID: <1304760.1216509052356.JavaMail.root@mswamui-bichon.atl.sa.earthlink.net> They probably spent most of their life outside. The air pollution over there is horrible !! 73, Dick, W1KSZ -----Original Message----- >From: wje >Sent: Jul 19, 2008 2:33 PM >To: Discussion of precise time and frequency measurement >Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > > I got one without the outer cover, which isn't quite as useful. I > removed all the junk to get down to the orginal non-double-ovened osc. > One thing I noticed - I wonder where these were actually deployed? The > 10811B itself has a fair amount of corrosion on it, lots of pitting. It > still works fine, though. > Another thing, the 10811B in mine doesn't have a removable endplate, > it's soldered. This makes it a lot more difficult to adjust or repair. > Still, I think it's a fine buy for the cost. Now all I have to do is > figure out what I really want to do with it. :) >Bill Ezell >---------- >They said 'Windows or better' >so I used Linux. > > Angus wrote: > >I see that the same vendor has a few more units for sale. He has also >included a picture that labels all the connections. > > > >At least they look to be complete with their outer covers now, which >would be useful if anyone did want to add some temp control. > >Seeing all those oscillators does make me wonder what they came from - >a heap of working 58503's going to landfill is close to sacrilege :-) > >Angus. > > >On Sat, 12 Jul 2008 11:20:57 -0600, you wrote: > > > >Message: 2 >Date: Wed, 9 Jul 2008 12:10:52 +1000 >From: "Jim Palfreyman" [1] >Subject: [time-nuts] Double ovened 10811-60158 on ebay >To: [2]time-nuts at febo.com >Message-ID: > [3] >Content-Type: text/plain; charset=ISO-8859-1 > >Sorry to pollute the list but some people here may be interested and I think >this might be a good buy. > >Ebay item 250268030266 a bunch of 10811-60158 wrapped up in a second oven >that have been pulled from a bunch of HP 58503A. > >There are 21 units available at US$50 Buy It Now. Postage seems reasonable >too. > >I've bought one and so if anyone knows where I can get the cabling >requirements please let me know. > > >Regards, > >Jim Palfreyman > > >_______________________________________________ >time-nuts mailing list -- [4]time-nuts at febo.com >To unsubscribe, go to [5]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > > >_______________________________________________ >time-nuts mailing list -- [6]time-nuts at febo.com >To unsubscribe, go to [7]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > >References > > 1. mailto:jim77742 at gmail.com > 2. mailto:time-nuts at febo.com > 3. mailto:f616e0f80807081910i38b378b7ic7d9d513cd3026c6 at mail.gmail.com > 4. mailto:time-nuts at febo.com > 5. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > 6. mailto:time-nuts at febo.com > 7. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From magnus at rubidium.dyndns.org Sat Jul 19 19:21:49 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Sun, 20 Jul 2008 01:21:49 +0200 Subject: [time-nuts] 5061A and Zeeman freq question In-Reply-To: <7.0.1.0.1.20080719170354.01e66b18@tapko.de> References: <4881F0B2.8070207@quackers.net> <7.0.1.0.1.20080719170354.01e66b18@tapko.de> Message-ID: <4882770D.5090503@rubidium.dyndns.org> Predrag Dukic wrote: > Bill, > > I am not a quantum physicist, but my understanding of Zeeman > splitting is a bit different. > > With applied homogenous DC magnetic field to the atoms on their path > You get splitting. Without it You have no Ramsey fringes. Correct, > There is a formula to calculate mid-fringe offset from defined cesium > resonance knowing splitting frequency. Not only that, there is a formulat to describe the shifts of all 7 Rabi pedistals. The "sidebands" depends on the square of the field. The relation between the sidebands separation on the C field and its relation to the shift in frequency of the mid fringe is used on modern Cs beams to create a C field lock loop and autonmous triming, causing a much reduced systematic drift effect. See FTS 4065 manuan for instance. The Zeeman splitting is an arbitrary design aspect and the ease of designing the frequency synthesis controls the selection of nominal C field and thus Zeeman splitting in early designs. With the modern high resolution DDS chips, a more complex method for controling the system became possible. So seek these magic numbers elsewhere than the pure physics, althought they do relate to it. > So You should always be able to tell the right frequency from the > splitting frequency, and that has nothing to do with definition of > the cesium as primary standard. > > The correct field strength and correct splitting frequency, by my > opinion have some importance to other parameters; stability, mid > fringe width etc, > > while resonance frequency is tied to split frequency by an exact > mathematical equation. With the ideal case of exactly 0 as C-field. > All of this under assumption that the field is homogenous. If not, > than You have some other problems. Indeed. Cheers, Magnus From holrum at hotmail.com Sat Jul 19 21:33:45 2008 From: holrum at hotmail.com (Mark Sims) Date: Sun, 20 Jul 2008 01:33:45 +0000 Subject: [time-nuts] Zeeman freq question In-Reply-To: References: Message-ID: I noticed that all the Zeeman freqs seem to be specified to 10 Hz resolution. Were the systems designed with the c-field set to make this happen or are more precise values available? It seems that such an important value would be specifed with greater precision. I have my FEI-5650A program set up to generate these standard Zeeman values. I can get 0.01 Hz resolution if more accurate values are available... ---------------------------------------- _________________________________________________________________ Keep your kids safer online with Windows Live Family Safety. http://www.windowslive.com/family_safety/overview.html?ocid=TXT_TAGLM_WL_family_safety_072008 From cdelect at juno.com Sat Jul 19 21:43:59 2008 From: cdelect at juno.com (corby d dawson) Date: Sat, 19 Jul 2008 18:43:59 -0700 Subject: [time-nuts] 5061 c-field info Message-ID: <20080719.184359.-398201.3.cdelect@juno.com> Bill, 2095 is indeed for 12.6317716 Mhz and a Zeeman of 42.82Khz. If you can't get splitting at 42.82 then change the synthesizer to 12.6317725Mhz and try again using 53.53Khz. If no splitting at 53.53 within the C-field dial range you will need to select a new resistor/s on the A15 board. Set the C-field pot to midrange and the zeeman to 53.53khz and with a resistance decade across R19 reduce the resistance until you get the peak at 53.53Khz. Then solder in a 1% reaistor close to the value you obtained across the existing R19. Now use the C-field pot to repeak at 53.53Khz. Corby ____________________________________________________________ Fly in style. Click here for information on private jets. http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3nMct9uAIj6WAWY5FilTDbYhEVzvENgAGDxSq9ut8HMtDCM5/ From ed_palmer at sasktel.net Sat Jul 19 22:00:45 2008 From: ed_palmer at sasktel.net (Ed Palmer) Date: Sat, 19 Jul 2008 20:00:45 -0600 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: Message-ID: <48829C4D.5020305@sasktel.net> Bill, I picked up a couple of these 'naked' oscillators. I was surprised to hear that you stripped yours down. I'm planning to build it back up to its former glory with a controller for the outer oven and a new cover of some sort. Is there any reason not to do that? Thanks, Ed > Date: Sat, 19 Jul 2008 17:33:07 -0400 > From: wje > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > To: Discussion of precise time and frequency measurement > > Message-ID: <48825D93.2060101 at quackers.net> > Content-Type: text/plain; charset="ISO-8859-1" > > I got one without the outer cover, which isn't quite as useful. I > removed all the junk to get down to the orginal non-double-ovened osc. > One thing I noticed - I wonder where these were actually deployed? The > 10811B itself has a fair amount of corrosion on it, lots of pitting. It > still works fine, though. > Another thing, the 10811B in mine doesn't have a removable endplate, > it's soldered. This makes it a lot more difficult to adjust or repair. > Still, I think it's a fine buy for the cost. Now all I have to do is > figure out what I really want to do with it. :) > Bill Ezell > ---------- > They said 'Windows or better' > so I used Linux From wje at quackers.net Sat Jul 19 22:27:15 2008 From: wje at quackers.net (wje) Date: Sat, 19 Jul 2008 22:27:15 -0400 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <48829C4D.5020305@sasktel.net> References: <48829C4D.5020305@sasktel.net> Message-ID: <4882A283.5050401@quackers.net> Two reasons - I don't have the outer can, and I don't have the controller for the outer oven. The controller was on the Z3801 power supply board (which is what I think these came out of, or something very similar). I really just wanted a good tcxo with an efc input, which the bare osc does nicely. Bill Ezell ---------- They said 'Windows or better' so I used Linux. Ed Palmer wrote: Bill, I picked up a couple of these 'naked' oscillators. I was surprised to hear that you stripped yours down. I'm planning to build it back up to its former glory with a controller for the outer oven and a new cover of some sort. Is there any reason not to do that? Thanks, Ed Date: Sat, 19 Jul 2008 17:33:07 -0400 From: wje [1] Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay To: Discussion of precise time and frequency measurement [2] Message-ID: [3]<48825D93.2060101 at quackers.net> Content-Type: text/plain; charset="ISO-8859-1" I got one without the outer cover, which isn't quite as useful. I removed all the junk to get down to the orginal non-double-ovened osc. One thing I noticed - I wonder where these were actually deployed? The 10811B itself has a fair amount of corrosion on it, lots of pitting. It still works fine, though. Another thing, the 10811B in mine doesn't have a removable endplate, it's soldered. This makes it a lot more difficult to adjust or repair. Still, I think it's a fine buy for the cost. Now all I have to do is figure out what I really want to do with it. :) Bill Ezell ---------- They said 'Windows or better' so I used Linux _______________________________________________ time-nuts mailing list -- [4]time-nuts at febo.com To unsubscribe, go to [5]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:wje at quackers.net 2. mailto:time-nuts at febo.com 3. mailto:48825D93.2060101 at quackers.net 4. mailto:time-nuts at febo.com 5. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts From tvb at LeapSecond.com Sat Jul 19 23:01:23 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Sat, 19 Jul 2008 20:01:23 -0700 Subject: [time-nuts] Zeeman freq question References: Message-ID: <001301c8ea14$e9dd5060$0900a8c0@pc52> > I noticed that all the Zeeman freqs seem to be specified > to 10 Hz resolution. Were the systems designed with the > c-field set to make this happen or are more precise values > available? It seems that such an important value would be > specifed with greater precision. I have my FEI-5650A > program set up to generate these standard Zeeman values. > I can get 0.01 Hz resolution if more accurate values are available... Right, but the precision of the Zeeman frequency has but a small effect on the accuracy of the Cs resonance. As one example, based on the formula under Figure 10 in: http://www.leapsecond.com:80/museum/hp5062c/theory.htm f = 9192631770 + 8.7026x10-10fz2 a 10 Hz Zeeman difference at 42.82 kHz makes only a 0.000745 Hz difference out of 9192631770 Hz, or 8.1e-14. Given that these old standards are only spec'd parts in ten to the 11th to maybe 12th in accuracy the 10 Hz margin for the Zeeman input would appear more than adequate. /tvb From N3IZN at aol.com Sat Jul 19 23:14:55 2008 From: N3IZN at aol.com (N3IZN at aol.com) Date: Sat, 19 Jul 2008 23:14:55 EDT Subject: [time-nuts] Trimble GPSDO unit for sale Message-ID: No problem on PayPal. I just put it where mine was and it started a self survey by itself. I don't have any fancy test equipment but I'll let it drive my 10 Ghz rig and listen to some beacons and see if I can tell any diference. Where are you at? Chris > I would be interested if you accept paypal,,would offer 200.00 if new > cond.. > > Dvr20 at aol.com.thanks.. ************** Get fantasy football with free live scoring. Sign up for FanHouse Fantasy Football today. (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020) From holrum at hotmail.com Sat Jul 19 23:34:41 2008 From: holrum at hotmail.com (Mark Sims) Date: Sun, 20 Jul 2008 03:34:41 +0000 Subject: [time-nuts] Zeeman freq question In-Reply-To: References: Message-ID: 8.1E-14... egad, that's almost 1e-13. We're time nuts... we demand perfection from our imperfect instruments... or at least the illusion/delusion of perfection. My FTS-4060M seems to be drifting from GPS by a fairly consistent 20 ns per day (2.3E-13) (not too shabby for a $600 woogedy old unit that can't admit that it is locked). I have not adjusted the c-field yet so I don't know what, if any, improvement can be coaxed out of it. It would be nice to give it the benefit of as precise a Zeeman freq as possible with today's (well, actually yesterweek's) technology (I can generate 48.xxx KHz to within around a microhertz). ---------------------------------------- a 10 Hz Zeeman difference at 42.82 kHz makes only a 0.000745 Hz difference out of 9192631770 Hz, or 8.1e-14. Given that these old standards are only spec'd parts in ten to the 11th to maybe 12th in accuracy the 10 Hz margin for the Zeeman input would appear more than adequate. _________________________________________________________________ Time for vacation? WIN what you need- enter now! http://www.gowindowslive.com/summergiveaway/?ocid=tag_jlyhm From richard at karlquist.com Sat Jul 19 23:35:38 2008 From: richard at karlquist.com (Rick Karlquist) Date: Sat, 19 Jul 2008 20:35:38 -0700 (PDT) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <20080719215221.D57D11165C3@hamburg.alientech.net> References: <4878E7F9.2080309@sasktel.net> <2cl484t5nhllg7hl97dbqpp2a8ap62hq97@4ax.com> <48825D93.2060101@quackers.net> <20080719215221.D57D11165C3@hamburg.alientech.net> Message-ID: <19613.69.12.192.152.1216524938.squirrel@webmail.sonic.net> Mike S wrote: > At 05:33 PM 7/19/2008, wje wrote... >> Another thing, the 10811B in mine doesn't have a removable endplate, >> it's soldered. This makes it a lot more difficult to adjust or >> repair. >> Still, I think it's a fine buy for the cost. > > Well, yea. Maybe Rick Karlquist will pipe in, but I believe that (other > than temperature, which is obviously well controlled by a double oven), > pressure/humidity are the biggest instability factors. Soldering the > case closed mitigates that. Right. Without hermetic sealing, the double oven would be negated by humidity effects. I tried to discover exactly what component was the major humidity "sensor" in the 10811, but was never able to narrow it down to anything specific. The crystal is not the humidity sensor because it is hermetic in its own package, even in the non-hermetic 10811. Rick Karlquist N6RK From richard at karlquist.com Sat Jul 19 23:40:24 2008 From: richard at karlquist.com (Rick Karlquist) Date: Sat, 19 Jul 2008 20:40:24 -0700 (PDT) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <48829C4D.5020305@sasktel.net> References: <48829C4D.5020305@sasktel.net> Message-ID: <11409.69.12.192.152.1216525224.squirrel@webmail.sonic.net> Ed Palmer wrote: > Bill, > > I picked up a couple of these 'naked' oscillators. I was surprised to > hear that you stripped yours down. I'm planning to build it back up to > its former glory with a controller for the outer oven and a new cover of > some sort. Is there any reason not to do that? The possible reason is that the oven thermal gain isn't all that great (AFAIK), so you go to fair amount of trouble for marginal benefits. You will probably have to use a very long time constant which will sort of rule out a simple analog integrator, forcing a PID digital controller. If you're good with a PIC, it might not be too hard. I'm an analog guy; I don't speak PIC. :-) Rick Karlquist N6RK > > Thanks, > Ed > >> Date: Sat, 19 Jul 2008 17:33:07 -0400 >> From: wje >> Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay >> To: Discussion of precise time and frequency measurement >> >> Message-ID: <48825D93.2060101 at quackers.net> >> Content-Type: text/plain; charset="ISO-8859-1" >> >> I got one without the outer cover, which isn't quite as useful. I >> removed all the junk to get down to the orginal non-double-ovened >> osc. >> One thing I noticed - I wonder where these were actually deployed? >> The >> 10811B itself has a fair amount of corrosion on it, lots of pitting. >> It >> still works fine, though. >> Another thing, the 10811B in mine doesn't have a removable endplate, >> it's soldered. This makes it a lot more difficult to adjust or >> repair. >> Still, I think it's a fine buy for the cost. Now all I have to do is >> figure out what I really want to do with it. :) >> Bill Ezell >> ---------- >> They said 'Windows or better' >> so I used Linux > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From namichie at gmail.com Sun Jul 20 00:09:59 2008 From: namichie at gmail.com (Neville Michie) Date: Sun, 20 Jul 2008 14:09:59 +1000 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <11409.69.12.192.152.1216525224.squirrel@webmail.sonic.net> References: <48829C4D.5020305@sasktel.net> <11409.69.12.192.152.1216525224.squirrel@webmail.sonic.net> Message-ID: Hi, surely an oven that controls to 1*C limits the inner xtal oven from the outside 0 - 50*C, so with a finite gain on the inner oven the oven the XTAL is controlled 50 times as well? Thats why they use double ovens. cheers, Neville Michie On 20/07/2008, at 1:40 PM, Rick Karlquist wrote: > Ed Palmer wrote: >> Bill, >> >> I picked up a couple of these 'naked' oscillators. I was >> surprised to >> hear that you stripped yours down. I'm planning to build it back >> up to >> its former glory with a controller for the outer oven and a new >> cover of >> some sort. Is there any reason not to do that? > > The possible reason is that the oven thermal gain isn't all that > great (AFAIK), so you go to fair amount of trouble for marginal > benefits. You will probably have to use a very long time constant > which will sort of rule out a simple analog integrator, forcing > a PID digital controller. If you're good with a PIC, it might not > be too hard. I'm an analog guy; I don't speak PIC. :-) > > Rick Karlquist N6RK > >> >> Thanks, >> Ed >> >>> Date: Sat, 19 Jul 2008 17:33:07 -0400 >>> From: wje >>> Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay >>> To: Discussion of precise time and frequency measurement >>> >>> Message-ID: <48825D93.2060101 at quackers.net> >>> Content-Type: text/plain; charset="ISO-8859-1" >>> >>> I got one without the outer cover, which isn't quite as useful. I >>> removed all the junk to get down to the orginal non-double-ovened >>> osc. >>> One thing I noticed - I wonder where these were actually >>> deployed? >>> The >>> 10811B itself has a fair amount of corrosion on it, lots of >>> pitting. >>> It >>> still works fine, though. >>> Another thing, the 10811B in mine doesn't have a removable >>> endplate, >>> it's soldered. This makes it a lot more difficult to adjust or >>> repair. >>> Still, I think it's a fine buy for the cost. Now all I have to >>> do is >>> figure out what I really want to do with it. :) >>> Bill Ezell >>> ---------- >>> They said 'Windows or better' >>> so I used Linux >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts at febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. From ed_palmer at sasktel.net Sun Jul 20 01:08:47 2008 From: ed_palmer at sasktel.net (Ed Palmer) Date: Sat, 19 Jul 2008 23:08:47 -0600 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: Message-ID: <4882C85F.5040201@sasktel.net> > Date: Sat, 19 Jul 2008 20:40:24 -0700 (PDT) > From: "Rick Karlquist" > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > To: "Discussion of precise time and frequency measurement" > > Message-ID: > <11409.69.12.192.152.1216525224.squirrel at webmail.sonic.net> > Content-Type: text/plain;charset=iso-8859-1 > > Ed Palmer wrote: > >> Bill, >> >> I picked up a couple of these 'naked' oscillators. I was surprised to >> hear that you stripped yours down. I'm planning to build it back up to >> its former glory with a controller for the outer oven and a new cover of >> some sort. Is there any reason not to do that? >> > > The possible reason is that the oven thermal gain isn't all that > great (AFAIK), so you go to fair amount of trouble for marginal > benefits. You will probably have to use a very long time constant > which will sort of rule out a simple analog integrator, forcing > a PID digital controller. If you're good with a PIC, it might not > be too hard. I'm an analog guy; I don't speak PIC. :-) > > Rick Karlquist N6RK > I wasn't planning on doing anything fancy - just copy the original controller since the schematic is available. And it's all analog. :-) But now that I look around, I can't find anything to tell me that the double-oven version performs any better than the regular version. The 10811 specification document says that the thermal performance of the -60158 version is the same as the regular D/E version. I'm guessing that's when it's _not_ in a double oven configuration. The only differences in specs are things that the double oven wouldn't affect (e.g. aging). It started out as such a nice little project.......... Ed From ed_palmer at sasktel.net Sun Jul 20 01:17:24 2008 From: ed_palmer at sasktel.net (Ed Palmer) Date: Sat, 19 Jul 2008 23:17:24 -0600 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: Message-ID: <4882CA64.3010406@sasktel.net> > Date: Sat, 19 Jul 2008 20:35:38 -0700 (PDT) > From: "Rick Karlquist" > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > To: "Discussion of precise time and frequency measurement" > > Message-ID: > <19613.69.12.192.152.1216524938.squirrel at webmail.sonic.net> > Content-Type: text/plain;charset=iso-8859-1 > > Mike S wrote: > >> At 05:33 PM 7/19/2008, wje wrote... >> >>> Another thing, the 10811B in mine doesn't have a removable endplate, >>> it's soldered. This makes it a lot more difficult to adjust or >>> repair. >>> Still, I think it's a fine buy for the cost. >>> >> Well, yea. Maybe Rick Karlquist will pipe in, but I believe that (other >> than temperature, which is obviously well controlled by a double oven), >> pressure/humidity are the biggest instability factors. Soldering the >> case closed mitigates that. >> > > Right. Without hermetic sealing, the double oven would be negated > by humidity effects. I tried to discover exactly what component > was the major humidity "sensor" in the 10811, but was never able > to narrow it down to anything specific. The crystal is not the > humidity sensor because it is hermetic in its own package, even in > the non-hermetic 10811. > > Rick Karlquist N6RK > If their intent was to hermetically seal the oscillator, why would they leave the screw in the front that covers the adjustment hole (which nobody could possibly get to!)? Would the seal around the screw be good enough to make it worth the effort to seal the rest of the unit? Ed From wb6bnq at cox.net Sun Jul 20 01:22:22 2008 From: wb6bnq at cox.net (WB6BNQ) Date: Sat, 19 Jul 2008 22:22:22 -0700 Subject: [time-nuts] Double ovened 10811-60158 on ebay References: <4882CA64.3010406@sasktel.net> Message-ID: <4882CB8E.316246B9@cox.net> Did it occur to anyone that possibly these units where intended to be used in some very cold country, like the top of Alaska or some similar place wheere a little additional help was necessary ? ? ? Just a thought . . . Bill....WB6BNQ Ed Palmer wrote: > > Date: Sat, 19 Jul 2008 20:35:38 -0700 (PDT) > > From: "Rick Karlquist" > > Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay > > To: "Discussion of precise time and frequency measurement" > > > > Message-ID: > > <19613.69.12.192.152.1216524938.squirrel at webmail.sonic.net> > > Content-Type: text/plain;charset=iso-8859-1 > > > > Mike S wrote: > > > >> At 05:33 PM 7/19/2008, wje wrote... > >> > >>> Another thing, the 10811B in mine doesn't have a removable endplate, > >>> it's soldered. This makes it a lot more difficult to adjust or > >>> repair. > >>> Still, I think it's a fine buy for the cost. > >>> > >> Well, yea. Maybe Rick Karlquist will pipe in, but I believe that (other > >> than temperature, which is obviously well controlled by a double oven), > >> pressure/humidity are the biggest instability factors. Soldering the > >> case closed mitigates that. > >> > > > > Right. Without hermetic sealing, the double oven would be negated > > by humidity effects. I tried to discover exactly what component > > was the major humidity "sensor" in the 10811, but was never able > > to narrow it down to anything specific. The crystal is not the > > humidity sensor because it is hermetic in its own package, even in > > the non-hermetic 10811. > > > > Rick Karlquist N6RK > > > If their intent was to hermetically seal the oscillator, why would they > leave the screw in the front that covers the adjustment hole (which > nobody could possibly get to!)? Would the seal around the screw be good > enough to make it worth the effort to seal the rest of the unit? > > Ed > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From mikes at flatsurface.com Sun Jul 20 06:54:29 2008 From: mikes at flatsurface.com (Mike S) Date: Sun, 20 Jul 2008 06:54:29 -0400 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <4882CA64.3010406@sasktel.net> References: <4882CA64.3010406@sasktel.net> Message-ID: <20080720105430.E103E1165C3@hamburg.alientech.net> At 01:17 AM 7/20/2008, Ed Palmer wrote... >If their intent was to hermetically seal the oscillator, why would >they >leave the screw in the front that covers the adjustment hole (which >nobody could possibly get to!)? Would the seal around the screw be >good >enough to make it worth the effort to seal the rest of the unit? That screw has a silicone (?) o-ring on it. Why do you think that wouldn't make a sufficient seal? From richard at karlquist.com Sun Jul 20 10:14:47 2008 From: richard at karlquist.com (Rick Karlquist) Date: Sun, 20 Jul 2008 07:14:47 -0700 (PDT) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <4882CA64.3010406@sasktel.net> References: <4882CA64.3010406@sasktel.net> Message-ID: <7286.69.12.192.152.1216563287.squirrel@webmail.sonic.net> Ed Palmer wrote: >> If their intent was to hermetically seal the oscillator, why would they > leave the screw in the front that covers the adjustment hole (which > nobody could possibly get to!)? Would the seal around the screw be good > enough to make it worth the effort to seal the rest of the unit? > > Ed Good point. I don't know about the hermeticity of a screw, sounds questionable. It's possible the designers were kidding themselves. I know that I debunked a lot of their theories about what is or is not hermetic. For example, "hermetic" epoxy isn't. Possibly there is a Viton O ring around the screw. I think that might be hermetic. Rick Karlquist N6RK From richard at karlquist.com Sun Jul 20 10:29:07 2008 From: richard at karlquist.com (Rick Karlquist) Date: Sun, 20 Jul 2008 07:29:07 -0700 (PDT) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: <48829C4D.5020305@sasktel.net> <11409.69.12.192.152.1216525224.squirrel@webmail.sonic.net> Message-ID: <15438.69.12.192.152.1216564147.squirrel@webmail.sonic.net> Neville Michie wrote: > Hi, > surely an oven that controls to 1*C limits the inner xtal oven from > the outside 0 - 50*C, > so with a finite gain on the inner oven the oven the XTAL is > controlled 50 times as well? > Thats why they use double ovens. > > cheers, Neville Michie How do you know that the double oven controls to 1 degree? Where is this 1 degree measured? I'm sure it holds the thermistor to 1 degree, but the 10811 is a large object that might have its own temperature gradients. How do you know that the outer oven does not produce gradients that reduce the gain of the inner oven? How much does the 10811 internal oven current vary vs ambient? Rick Karlquist N6RK From namichie at gmail.com Sun Jul 20 10:29:31 2008 From: namichie at gmail.com (Neville Michie) Date: Mon, 21 Jul 2008 00:29:31 +1000 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <20080720105430.E103E1165C3@hamburg.alientech.net> References: <4882CA64.3010406@sasktel.net> <20080720105430.E103E1165C3@hamburg.alientech.net> Message-ID: Silicon rubber is quite transparent to water vapour, at least in the concentrations that are important to the HP 10811. The seal on the screw will only slow the response of the oscillator to humidity. Epoxy is a much better barrier but not perfect. Vapour barriers must be perfect. Water vapour adheres to oxygen atoms, so has an affinity to all metals which have an oxide film. It will also adhere to quartz being SiO2. The glass frequency trim capacitor is a good candidate for humidity sensitivity, but so are all the insulating materials. Solder seals are good against humidity as are glass to metal seals. The way to make a HP10811 immune to humidity is to seal it in a metal container with glass leadthrough seals after it has been flushed with dry nitrogen for a few days. Another method is to seal a small quantity of P2O5 in it as a humidity "getter". An added improvement is to wind two platinum wires on a P2O5 containing fibre glass pad, and electrolyse any water absorbed to oxygen and hydrogen gas after it is sealed. Vacuum tube sealing and evacuation works well. cheers, Neville MIchie On 20/07/2008, at 8:54 PM, Mike S wrote: > At 01:17 AM 7/20/2008, Ed Palmer wrote... >> If their intent was to hermetically seal the oscillator, why would >> they >> leave the screw in the front that covers the adjustment hole (which >> nobody could possibly get to!)? Would the seal around the screw be >> good >> enough to make it worth the effort to seal the rest of the unit? > > That screw has a silicone (?) o-ring on it. Why do you think that > wouldn't make a sufficient seal? > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. From stijena at tapko.de Sun Jul 20 10:35:39 2008 From: stijena at tapko.de (Predrag Dukic) Date: Sun, 20 Jul 2008 16:35:39 +0200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <7286.69.12.192.152.1216563287.squirrel@webmail.sonic.net> References: <4882CA64.3010406@sasktel.net> <7286.69.12.192.152.1216563287.squirrel@webmail.sonic.net> Message-ID: <7.0.1.0.1.20080720163213.01eb0050@tapko.de> Viton is good enough to keep moisture out and air pressure constant. It is however permeable for light hydrocarbons and fluorocarbons. And for hydrogen, (as most metals are also). It is a matter of definition... Predrag Dukic At 16:14 20.7.2008, you wrote: >Ed Palmer wrote: > >> If their intent was to hermetically seal the oscillator, why would they > > leave the screw in the front that covers the adjustment hole (which > > nobody could possibly get to!)? Would the seal around the screw be good > > enough to make it worth the effort to seal the rest of the unit? > > > > Ed > >Good point. I don't know about the hermeticity of a screw, sounds >questionable. It's possible the designers were kidding themselves. >I know that I debunked a lot of their theories about what is or is >not hermetic. For example, "hermetic" epoxy isn't. Possibly there >is a Viton O ring around the screw. I think that might be hermetic. > >Rick Karlquist N6RK > > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From ka2cdk at cox.net Sun Jul 20 11:02:50 2008 From: ka2cdk at cox.net (Thomas A. Frank) Date: Sun, 20 Jul 2008 11:02:50 -0400 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: <4882CA64.3010406@sasktel.net> <20080720105430.E103E1165C3@hamburg.alientech.net> Message-ID: > The way to make a HP10811 immune to humidity is to seal it in a metal > container with glass leadthrough seals > after it has been flushed with dry nitrogen for a few days. Or perhaps pump it down to a vacuum, hold for a couple of hours, then fill with dry nitrogen? Just don't power it during that time. > Another method is to seal a small quantity of P2O5 in it as a > humidity "getter". An added improvement is to wind > two platinum wires on a P2O5 containing fibre glass pad, and > electrolyse any water absorbed to oxygen and hydrogen gas > after it is sealed. Doesn't that pose a minor fire/explosion risk? As the H2 and O2 try to recombine? Tom Frank, KA2CDK From tvb at LeapSecond.com Sun Jul 20 11:10:56 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Sun, 20 Jul 2008 08:10:56 -0700 Subject: [time-nuts] Double ovened 10811-60158 on ebay References: <4882CA64.3010406@sasktel.net> <7286.69.12.192.152.1216563287.squirrel@webmail.sonic.net> Message-ID: <006c01c8ea7a$d2d14960$0900a8c0@pc52> It would seem to me that a perfectly hermetically sealed oscillator is not a requirement for a typical GPSDO. Environmental effects to the oscillator that work slowly will be absorbed by the GPSDO tracking algorithm. If someone wants a fun project -- measure a 10811-60158 while changing the humidity from 10% to 90% and see if the oscillator drifts faster or a lot slower than the GPSDO time constant of the Z3801A. /tvb From phk at phk.freebsd.dk Sun Jul 20 11:21:25 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Sun, 20 Jul 2008 15:21:25 +0000 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: Your message of "Sun, 20 Jul 2008 08:10:56 MST." <006c01c8ea7a$d2d14960$0900a8c0@pc52> Message-ID: <9294.1216567285@critter.freebsd.dk> In message <006c01c8ea7a$d2d14960$0900a8c0 at pc52>, "Tom Van Baak" writes: >It would seem to me that a perfectly hermetically sealed oscillator >is not a requirement for a typical GPSDO. Spot on. All you need to care about, is making the changes slow enough that the GPSDO can deal with them. I think I have mentioned it before, but a really good way to do so is to find an old fridge and put your stuff in that without starting the cooling compressor. The thermal insulation of the fridge will delay any temperature or humidity changes by many hours. Of course there is a limit to how much power you can burn in the fridge without it getting too hot. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From magnus at rubidium.dyndns.org Sun Jul 20 12:39:48 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Sun, 20 Jul 2008 18:39:48 +0200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <7286.69.12.192.152.1216563287.squirrel@webmail.sonic.net> References: <4882CA64.3010406@sasktel.net> <7286.69.12.192.152.1216563287.squirrel@webmail.sonic.net> Message-ID: <48836A54.5040002@rubidium.dyndns.org> Rick Karlquist wrote: > Ed Palmer wrote: >>> If their intent was to hermetically seal the oscillator, why would they >> leave the screw in the front that covers the adjustment hole (which >> nobody could possibly get to!)? Would the seal around the screw be good >> enough to make it worth the effort to seal the rest of the unit? >> >> Ed > > Good point. I don't know about the hermeticity of a screw, sounds > questionable. It's possible the designers were kidding themselves. > I know that I debunked a lot of their theories about what is or is > not hermetic. For example, "hermetic" epoxy isn't. Possibly there > is a Viton O ring around the screw. I think that might be hermetic. The question is what is "hermetical" in this context. While not strictly hermetical the time constant is significantly larger than the open hole. I think it would be illuminating to discuss the effects and what would require strict hermetic environment and what benefits and limits a limited hermeticallity would result in. Cheers, Magnus From Murray.Greenman at rakon.com Sun Jul 20 14:39:18 2008 From: Murray.Greenman at rakon.com (Murray Greenman) Date: Mon, 21 Jul 2008 06:39:18 +1200 Subject: [time-nuts] Thunderbolt etc software? In-Reply-To: References: Message-ID: Hi, I've just acquired a Trimble (Nortel) NTGS50AA GPSTM (another flavour of GPSDO), and it supports the Trimble TSIP protocol, as used by the Thunderbolt. Apart from one message, it works fine with the TBOLTMON software. TBOLTMON Works fine, can post-process using the log, no graphics. TRIMBLE MONITOR Works, but a few items missing. Cool software though! TIMEKEEPER Works well. I'm interested to know if there is any other software out there available for the Thunderbolt, which might work with this unit. I am especially interested in graphical software which would plot the ongoing reference performance. I'm also interested to know if anyone knows the full repertoire of messages the NTGS50AA uses, or knows of Trimble/Nortel software designed for the unit. 73, Murray ZL1BPU From richard at karlquist.com Sun Jul 20 15:42:57 2008 From: richard at karlquist.com (Rick Karlquist) Date: Sun, 20 Jul 2008 12:42:57 -0700 (PDT) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: References: <4882CA64.3010406@sasktel.net> <20080720105430.E103E1165C3@hamburg.alientech.net> Message-ID: <15828.69.12.192.152.1216582977.squirrel@webmail.sonic.net> Neville Michie wrote: > Silicon rubber is quite transparent to water vapour, at least in the I believe it is Viton, not silicone > concentrations that are > important to the HP 10811. The seal on the screw will only slow the > response of the oscillator to humidity. > Epoxy is a much better barrier but not perfect. Vapour barriers must > be perfect. My tests showed that epoxy has no effect whatsoever on humidity. Goes right through it, right away. Viton is certainly a lot better than epoxy. > Water vapour adheres to oxygen atoms, so has an affinity to all > metals which have an oxide film. > It will also adhere to quartz being SiO2. The glass frequency trim > capacitor is a good candidate for humidity sensitivity, > but so are all the insulating materials. Obviously, the first thing I tried was to replace the trimmer with a fixed capacitor. Didn't help. 30 years ago when the 10811 first went into production, the trimmer was a problem, but IIRC the problem was that lubricating oil migrated around causing slow drifing. That trimmer was replaced by one from another vendor. > Solder seals are good against humidity as are glass to metal seals. > The way to make a HP10811 immune to humidity is to seal it in a metal > container with glass leadthrough seals > after it has been flushed with dry nitrogen for a few days. > Another method is to seal a small quantity of P2O5 in it as a > humidity "getter". An added improvement is to wind > two platinum wires on a P2O5 containing fibre glass pad, and > electrolyse any water absorbed to oxygen and hydrogen gas > after it is sealed. > Vacuum tube sealing and evacuation works well. > cheers, Neville MIchie Rick Karlquist N6RK From richard at karlquist.com Sun Jul 20 15:45:28 2008 From: richard at karlquist.com (Rick Karlquist) Date: Sun, 20 Jul 2008 12:45:28 -0700 (PDT) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <006c01c8ea7a$d2d14960$0900a8c0@pc52> References: <4882CA64.3010406@sasktel.net> <7286.69.12.192.152.1216563287.squirrel@webmail.sonic.net> <006c01c8ea7a$d2d14960$0900a8c0@pc52> Message-ID: <5974.69.12.192.152.1216583128.squirrel@webmail.sonic.net> A non sealed 10811 responds to humidity in a few minutes. The speed is nearly limited by the rate of change achievable in the environmental chamber. Rick Ksrlquist N6RK Tom Van Baak wrote: > It would seem to me that a perfectly hermetically sealed oscillator > is not a requirement for a typical GPSDO. Environmental effects > to the oscillator that work slowly will be absorbed by the GPSDO > tracking algorithm. > > If someone wants a fun project -- measure a 10811-60158 while > changing the humidity from 10% to 90% and see if the oscillator > drifts faster or a lot slower than the GPSDO time constant of the > Z3801A. > > /tvb > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From mikes at flatsurface.com Sun Jul 20 17:52:14 2008 From: mikes at flatsurface.com (Mike S) Date: Sun, 20 Jul 2008 17:52:14 -0400 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <15828.69.12.192.152.1216582977.squirrel@webmail.sonic.net> References: <4882CA64.3010406@sasktel.net> <20080720105430.E103E1165C3@hamburg.alientech.net> <15828.69.12.192.152.1216582977.squirrel@webmail.sonic.net> Message-ID: <20080720215356.681DC1165C3@hamburg.alientech.net> At 03:42 PM 7/20/2008, Rick Karlquist wrote... >Obviously, the first thing I tried was to replace the trimmer with >a fixed capacitor. Didn't help. Did you do any testing of encapsulation materials, other than epoxy? Surely 3M has some fairly impermeable stuff in their kit. AIR from last time I was into a 10811, there's no coating on the components/pcb, other than a solder mask. What about polyamide or PTFE PCBs? From dibene at usa.net Sun Jul 20 18:31:35 2008 From: dibene at usa.net (Alberto di Bene) Date: Mon, 21 Jul 2008 00:31:35 +0200 Subject: [time-nuts] Thunderbolt vs Z3801A Message-ID: <4883BCC7.2050900@usa.net> Somebody had to pose this question... given the respective sizes of the Trimble Thunderbolt and the HP Z3801A, the simplicity of the first and the complexity of the second, it comes natural to ask ourselves, what advantages does the HP unit have to justify the differences ? Is the Z3801A really so better than the TB, or simply did Trimble do a much better design ? Alberto I2PHD From richard at karlquist.com Sun Jul 20 18:33:11 2008 From: richard at karlquist.com (Rick Karlquist) Date: Sun, 20 Jul 2008 15:33:11 -0700 (PDT) Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <20080720215356.681DC1165C3@hamburg.alientech.net> References: <4882CA64.3010406@sasktel.net> <20080720105430.E103E1165C3@hamburg.alientech.net> <15828.69.12.192.152.1216582977.squirrel@webmail.sonic.net> <20080720215356.681DC1165C3@hamburg.alientech.net> Message-ID: <13179.69.12.192.152.1216593191.squirrel@webmail.sonic.net> We didn't use the epoxy for encapsulation. We used to in place of soldering to see if we could replace solder with epoxy. Nope. Is polyimide or PTFE board less hygroscopic than FR-4? Anyway, we didn't try that (too much trouble). Rick Karlquist N6RK Mike S wrote: > At 03:42 PM 7/20/2008, Rick Karlquist wrote... >>Obviously, the first thing I tried was to replace the trimmer with >>a fixed capacitor. Didn't help. > > Did you do any testing of encapsulation materials, other than epoxy? > Surely 3M has some fairly impermeable stuff in their kit. AIR from last > time I was into a 10811, there's no coating on the components/pcb, > other than a solder mask. > > What about polyamide or PTFE PCBs? > > From GandalfG8 at aol.com Sun Jul 20 18:54:49 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Sun, 20 Jul 2008 18:54:49 EDT Subject: [time-nuts] Thunderbolt vs Z3801A Message-ID: In a message dated 20/07/2008 23:33:28 GMT Daylight Time, dibene at usa.net writes: Somebody had to pose this question... given the respective sizes of the Trimble Thunderbolt and the HP Z3801A, the simplicity of the first and the complexity of the second, it comes natural to ask ourselves, what advantages does the HP unit have to justify the differences ? Is the Z3801A really so better than the TB, or simply did Trimble do a much better design ? -------------- Hi Alberto Somebody did, no prizes for guessing who, and here's the results:-).. _http://www.leapsecond.com/pages/gpsdo/_ (http://www.leapsecond.com/pages/gpsdo/) regards Nigel GM8PZR From namichie at gmail.com Sun Jul 20 18:58:46 2008 From: namichie at gmail.com (Neville Michie) Date: Mon, 21 Jul 2008 08:58:46 +1000 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <5974.69.12.192.152.1216583128.squirrel@webmail.sonic.net> References: <4882CA64.3010406@sasktel.net> <7286.69.12.192.152.1216563287.squirrel@webmail.sonic.net> <006c01c8ea7a$d2d14960$0900a8c0@pc52> <5974.69.12.192.152.1216583128.squirrel@webmail.sonic.net> Message-ID: If it is only the rapidity of humidity transients that concern you , it is possible to "insulate" the HP10811 against humidity fluctuations. 0.25 inch of wool felt all around the unit will provide a hygral buffer with a time constant, probably as long as 8 hours. Wool has an equilibrium moisture content of 15% moisture at 65%RH, and with fibres of about 20 microns diameter it responds in seconds to any increase or decrease of humidity by absorbing or desorbing moisture from the air. Wool is quite stable up to 100*C and so could be used as the insulation in a double oven system. The hygral sensitivity of wool has a temperature consequence, and latent heat and heat of hydration are released as moisture is absorbed. This usually only adds to the thermal stability of the insulated item, which is why wool is comfortable to wear. Just in case you were interested, Neville Michie On 21/07/2008, at 5:45 AM, Rick Karlquist wrote: > A non sealed 10811 responds to humidity in a few minutes. > The speed is nearly limited by the rate of change achievable > in the environmental chamber. > > Rick Ksrlquist N6RK > > > Tom Van Baak wrote: >> It would seem to me that a perfectly hermetically sealed oscillator >> is not a requirement for a typical GPSDO. Environmental effects >> to the oscillator that work slowly will be absorbed by the GPSDO >> tracking algorithm. >> >> If someone wants a fun project -- measure a 10811-60158 while >> changing the humidity from 10% to 90% and see if the oscillator >> drifts faster or a lot slower than the GPSDO time constant of the >> Z3801A. >> >> /tvb >> >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts at febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. From cfharris at erols.com Sun Jul 20 19:13:32 2008 From: cfharris at erols.com (Chuck Harris) Date: Sun, 20 Jul 2008 19:13:32 -0400 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <15828.69.12.192.152.1216582977.squirrel@webmail.sonic.net> References: <4882CA64.3010406@sasktel.net> <20080720105430.E103E1165C3@hamburg.alientech.net> <15828.69.12.192.152.1216582977.squirrel@webmail.sonic.net> Message-ID: <4883C69C.1060208@erols.com> Hi Rick, Rick Karlquist wrote: > > My tests showed that epoxy has no effect whatsoever on humidity. > Goes right through it, right away. That is not generally possible. Some epoxies will hold a vacuum for an extended period of time. I know of no mechanism whereby epoxy could hold back both nitrogen and oxygen molecules, and not be able to hold back H2O vapor molecules. Epoxy is even a pretty good seal for helium as was shown by its successful use in HeNe lasers. Either your epoxy seals were not properly done (very likely), or there is another mechanism in play. If you did not pressure test your epoxy seals, you really gained no useful information from your tests.... Well, other than the knowledge that you didn't make a successful epoxy hermetic seal. I presume that you saw different behavior with solder seals? If you didn't, then maybe what you were seeing was the difference in thermal resistance between humid air and dry air. -Chuck Harris From magnus at rubidium.dyndns.org Sun Jul 20 19:01:48 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Mon, 21 Jul 2008 01:01:48 +0200 Subject: [time-nuts] Thunderbolt vs Z3801A In-Reply-To: References: Message-ID: <4883C3DC.3070206@rubidium.dyndns.org> GandalfG8 at aol.com wrote: > > In a message dated 20/07/2008 23:33:28 GMT Daylight Time, dibene at usa.net > writes: > > Somebody had to pose this question... given the respective sizes of the > Trimble Thunderbolt and the HP Z3801A, the > simplicity of the first and the complexity of the second, it comes natural > to ask ourselves, what advantages does the HP > unit have to justify the differences ? Is the Z3801A really so better than > the TB, or simply did Trimble do a much > better design ? Depends on what you want: http://www.leapsecond.com/pages/gpsdo/ Cheers, Magnus From magnus at rubidium.dyndns.org Sun Jul 20 18:58:13 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Mon, 21 Jul 2008 00:58:13 +0200 Subject: [time-nuts] Double ovened 10811-60158 on ebay In-Reply-To: <13179.69.12.192.152.1216593191.squirrel@webmail.sonic.net> References: <4882CA64.3010406@sasktel.net> <20080720105430.E103E1165C3@hamburg.alientech.net> <15828.69.12.192.152.1216582977.squirrel@webmail.sonic.net> <20080720215356.681DC1165C3@hamburg.alientech.net> <13179.69.12.192.152.1216593191.squirrel@webmail.sonic.net> Message-ID: <4883C305.5050505@rubidium.dyndns.org> Rick Karlquist wrote: > We didn't use the epoxy for encapsulation. We used to in place > of soldering to see if we could replace solder with epoxy. Nope. > > Is polyimide or PTFE board less hygroscopic than FR-4? Anyway, > we didn't try that (too much trouble). PTFE is very hydrophobic. Also has good RF properties. I think it would handle humidity better than FR4. Reinforced PTFE is another matter. Tossing glas-fibers into PTFE would allow humidity both around the glas fiber as well as asorbed by the glas itself. Glas (silica) fibers absorbs a slight amount of humidity and the hydroxyl absorbtion separates the 1310 nm and 1550 nm bands we use at the higher speeds and lengths. Cheers, Magnus From didier at cox.net Sun Jul 20 20:56:40 2008 From: didier at cox.net (Didier Juges) Date: Sun, 20 Jul 2008 19:56:40 -0500 Subject: [time-nuts] Thunderbolt vs Z3801A In-Reply-To: <4883BCC7.2050900@usa.net> References: <4883BCC7.2050900@usa.net> Message-ID: <012801c8eacc$a3af45e0$0a01a8c0@didierhp> In my unqualified opinion, Trimble did something very smart with the Thunderbolt. Most previous GPSDOs use a stand alone GPS receiver, with its own CPU clock, to generate the 1PPS signal, to which a separate OCXO is servoed via PLL and occasionaly smart software. The basic problem I see with this is that because the GPS receiver is clocked with a (20, 25, 40 MHz, or anything in between, pick your choice) crystal of generally dubious quality, the PPS signal is aligned with one edge of that CPU clock, and therefore the PPS signal error will fluctuate over that 1/f period. The GPS receiver may know by how much the PPS is off (and some tell you so), but it cannot align the PPS between two successive CPU clock edges, it has to choose one, so the PPS is adjusted with quantum leaps of 1/f, typically 20 to 50 nS. Because Trimble integrated the GPS receiver and the OCXO, they use the OCXO as a clock to run the processor, therefore that source of error is not there. The ultimate performance is not better than a perfectly optimized "conventional" GPSDO + OCXO, but excellent performance can be achieved at lower cost, and without having to deal with certain tradeoffs. Now, I am sure there are other, more subtle details that explain why the Z3801A is generally superior to the Thunderbolt, but that I cannot explain... Didier > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Alberto di Bene > Sent: Sunday, July 20, 2008 5:32 PM > To: Time Nuts > Subject: [time-nuts] Thunderbolt vs Z3801A > > Somebody had to pose this question... given the respective > sizes of the Trimble Thunderbolt and the HP Z3801A, the > simplicity of the first and the complexity of the second, it > comes natural to ask ourselves, what advantages does the HP > unit have to justify the differences ? Is the Z3801A really > so better than the TB, or simply did Trimble do a much better design ? > > Alberto I2PHD > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, > go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From magnus at rubidium.dyndns.org Sun Jul 20 21:25:17 2008 From: magnus at rubidium.dyndns.org (Magnus Danielson) Date: Mon, 21 Jul 2008 03:25:17 +0200 Subject: [time-nuts] Thunderbolt vs Z3801A In-Reply-To: <012801c8eacc$a3af45e0$0a01a8c0@didierhp> References: <4883BCC7.2050900@usa.net> <012801c8eacc$a3af45e0$0a01a8c0@didierhp> Message-ID: <4883E57D.1090501@rubidium.dyndns.org> Dear Didier, Didier Juges wrote: > In my unqualified opinion, Trimble did something very smart with the > Thunderbolt. > > Most previous GPSDOs use a stand alone GPS receiver, with its own CPU clock, > to generate the 1PPS signal, to which a separate OCXO is servoed via PLL and > occasionaly smart software. > > The basic problem I see with this is that because the GPS receiver is > clocked with a (20, 25, 40 MHz, or anything in between, pick your choice) > crystal of generally dubious quality, the PPS signal is aligned with one > edge of that CPU clock, and therefore the PPS signal error will fluctuate > over that 1/f period. The GPS receiver may know by how much the PPS is off > (and some tell you so), but it cannot align the PPS between two successive > CPU clock edges, it has to choose one, so the PPS is adjusted with quantum > leaps of 1/f, typically 20 to 50 nS. > > Because Trimble integrated the GPS receiver and the OCXO, they use the OCXO > as a clock to run the processor, therefore that source of error is not > there. First of all, so called sawtooth correction overcome part of this problem, but only to the degree by which the sawtooth correction reports corrections (often in steps of 1 ns) where as the Thunderbolt seems to report in 10 ps steps during locked conditions. There is another aspect to the use of a good OCXO rather than standard TCXOs and that is that the lower noise allows for a better "position" in space and time as there is less noise in the input signal. Especially at lower frequencies/longer times. Locking the LO to the GPS allows for a different kind of clock error handling than normal OEM GPS recievers typically use. > The ultimate performance is not better than a perfectly optimized > "conventional" GPSDO + OCXO, but excellent performance can be achieved at > lower cost, and without having to deal with certain tradeoffs. Certainly. > Now, I am sure there are other, more subtle details that explain why the > Z3801A is generally superior to the Thunderbolt, but that I cannot > explain... It is strange considering the 100 ps resolution TI counter in the Z3801A with the TCXO-GPS beating and high sawtooth error of the Oncore VP. Locking the OCXO up and using the GPS receiver as a phase comparator to GPS time is a more direct approach than the acquward PPS method. You always gain alittle by doing it through the LO. Cheers, Magnus From jim77742 at gmail.com Mon Jul 21 02:10:21 2008 From: jim77742 at gmail.com (Jim Palfreyman) Date: Mon, 21 Jul 2008 16:10:21 +1000 Subject: [time-nuts] Rack flange kit for 5370B and 3325B Message-ID: Hi, I've been looking for a bit with no luck so I thought I'd try here. I wish to mount my HP/Agilent 5370B and 3325B in a rack. Now the HP part 5061-0077 (also known as 3325B-908 or 5370B-908) and called a "Rack Flange Kit" (no handle version - although the handle version would be fine) looks like what I want. Has anyone got a couple of sets of these they are willing to part with or can least point me in the right direction? There are various companies that sell military and aircraft spares but they will charge a hefty minimum price - probably more than I paid for the actual units! I know these flanges aren't precision timing instruments, but they support precision timing instruments and keep them out of harms way - so should be revered in their own right. :-) Jim Palfreyman From ChrisB at tsogosun.com Mon Jul 21 03:07:08 2008 From: ChrisB at tsogosun.com (Baragwanath, Chris (TSG)) Date: Mon, 21 Jul 2008 09:07:08 +0200 Subject: [time-nuts] TimeNuts Assistance Request (Didier Juges) In-Reply-To: References: Message-ID: Hi Didier, Yes, the 440Hz is primarily a reference for tuning musical instruments or calibrating tuners (i.e. PC sound cad based). In doing a little "market research" as to the free frequency service, this freq. was preferred to the normal 500Hz or 600Hz and still just within analog telephone bandwidth. Kind Regards, -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of time-nuts-request at febo.com Sent: 18 July 2008 14:15 To: time-nuts at febo.com Subject: time-nuts Digest, Vol 48, Issue 47 Send time-nuts mailing list submissions to time-nuts at febo.com To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts or, via email, send a message with subject or body 'help' to time-nuts-request at febo.com You can reach the person managing the list at time-nuts-owner at febo.com When replying, please edit your Subject line so it is more specific than "Re: Contents of time-nuts digest..." Today's Topics: 1. Re: Power splitter on the Thunderbolt units (Tom Van Baak) 2. Re: Power splitter on the Thunderbolt units (David Ackrill) 3. AUSTRON LORAN-C TRF RECEIVER MODEL 2082 (Stanley Reynolds) 4. Re: Lucent RFTG-m-RB (Scott Mace) 5. Re: Thunderbolt monitor (d.seiter at comcast.net) 6. Re: Thunderbolt monitor (d.seiter at comcast.net) 7. Re: Thunderbolt monitor (Neville Michie) 8. change in email address (billh40 at aol.com) 9. TimeNuts Assistance Request (Baragwanath, Chris (TSG)) 10. Re: TimeNuts Assistance Request (Didier Juges) ---------------------------------------------------------------------- Message: 1 Date: Thu, 17 Jul 2008 09:31:51 -0700 From: "Tom Van Baak" Subject: Re: [time-nuts] Power splitter on the Thunderbolt units To: "Discussion of precise time and frequency measurement" Message-ID: <000801c8e82a$a244d6b0$0900a8c0 at pc52> Content-Type: text/plain; format=flowed; charset="Windows-1252"; reply-type=original > What is the power splitter glued on some of the Thunderbolt units meant for ? > Apparently it is good up to 500 MHz, so it can't be used for the signal coming from the antenna. > Maybe it was just part of complete product which the Thunderbolt was part of. > Just curious.... > > 73 Alberto I2PHD It was used with the 10 MHz output; either to split the output or to combine with a phased locked 10 MHz backup source (we've seen this on other telecom frequency references). Some of the Thunderbolts in the group buy had the splitter removed (those with screws from the outside). Others came with splitters screwed from the inside and it was too much bother to remove the splitter from each unit before shipment. You can remove the thing yourself by opening up the case. /tvb ------------------------------ Message: 2 Date: Thu, 17 Jul 2008 18:10:37 +0100 From: David Ackrill Subject: Re: [time-nuts] Power splitter on the Thunderbolt units To: Discussion of precise time and frequency measurement Message-ID: <487F7D0D.9030806 at tiscali.co.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Tom Van Baak wrote: > > It was used with the 10 MHz output; either to split the output or to > combine with a phased locked 10 MHz backup source (we've seen this on > other telecom frequency references). Sounds like a nice little 'freebe' for some. :-) I can understand that it would be better to remove it to keep P&P costs under control though. Dave (G0DJA) ------------------------------ Message: 3 Date: Thu, 17 Jul 2008 12:05:47 -0700 (PDT) From: Stanley Reynolds Subject: [time-nuts] AUSTRON LORAN-C TRF RECEIVER MODEL 2082 To: time-nuts at febo.com Message-ID: <114310.18332.qm at web30303.mail.mud.yahoo.com> Content-Type: text/plain; charset=iso-8859-1 Any info available ? ? Name is a little misleading as this unit is?RF filters and preamp. ? Contains?4 adjustable?filters first is switch selectable for peek or null, other 3 are null, and one band pass filter 29Khz to 100Khz. May be similar to 2084 Multifilter one output shared between front and rear panels and no Sferics warning lamp . ------------------------------ Message: 4 Date: Thu, 17 Jul 2008 16:43:20 -0500 From: Scott Mace Subject: Re: [time-nuts] Lucent RFTG-m-RB To: Discussion of precise time and frequency measurement Message-ID: <487FBCF8.1010200 at intt.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed When you have a RFTG-m-XO and Rb pair, do you connect both J5 and J6 on each unit or just J5? Scott Scott Mace wrote: > Has anyone tried to discipline the RFTG-m-RB without the -XO unit from > a house PPS feed? > > I think pins 4 and 8 on J6 are the PPS input. > > Scott > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ------------------------------ Message: 5 Date: Thu, 17 Jul 2008 22:35:06 +0000 From: d.seiter at comcast.net Subject: Re: [time-nuts] Thunderbolt monitor To: Discussion of precise time and frequency measurement , Discussion of precise time and frequency measurement Message-ID: <071720082235.22631.487FC91A000CB7480000586722058891169D0A9B070A9CD20B at c omcast.net> Content-Type: text/plain I too have never seen one go dim. In fact, I have a VCR (Beta!) that's been pluged in continously since I got it new in the early '80s. It still looks the same as when I got it except that the display has had a left to right wave going through it since about 1995. So, wavy- but not dim at all. -Dave -------------- Original message -------------- From: Jeffrey Pawlan > Regarding the VFD display, although they may be very different one > manufacturer to another, I can definitely dispute a prior statement > made that VFDs in general have a short lifetime and become dim. They > are universally used in VCRs, DVD players, microwave ovens, and some > clocks. I have never had one become dim or burn out. The displays in > my appliances are on even when the rest of the appliance is off. I > have never seen one become dim even after 15 years of on-time. > > I look forward to your project. > > > 73, > > Jeffrey Pawlan, WA6KBL > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ------------------------------ Message: 6 Date: Thu, 17 Jul 2008 22:35:06 +0000 From: d.seiter at comcast.net Subject: Re: [time-nuts] Thunderbolt monitor To: Discussion of precise time and frequency measurement , Discussion of precise time and frequency measurement Message-ID: <071720082235.22631.487FC91A000CB7480000586722058891169D0A9B070A9CD20B at c omcast.net> Content-Type: text/plain I too have never seen one go dim. In fact, I have a VCR (Beta!) that's been pluged in continously since I got it new in the early '80s. It still looks the same as when I got it except that the display has had a left to right wave going through it since about 1995. So, wavy- but not dim at all. -Dave -------------- Original message -------------- From: Jeffrey Pawlan > Regarding the VFD display, although they may be very different one > manufacturer to another, I can definitely dispute a prior statement > made that VFDs in general have a short lifetime and become dim. They > are universally used in VCRs, DVD players, microwave ovens, and some > clocks. I have never had one become dim or burn out. The displays in > my appliances are on even when the rest of the appliance is off. I > have never seen one become dim even after 15 years of on-time. > > I look forward to your project. > > > 73, > > Jeffrey Pawlan, WA6KBL > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ------------------------------ Message: 7 Date: Fri, 18 Jul 2008 08:50:34 +1000 From: Neville Michie Subject: Re: [time-nuts] Thunderbolt monitor To: Discussion of precise time and frequency measurement Message-ID: Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed From my thermionic valve days, the emmissivity of a filament was greatly extended by under-running them. If the display is pemanently run at a lower current in dim mode, how long could the life be extended by dropping the filament voltage by a small margin? cheers, Neville Michie On 18/07/2008, at 8:35 AM, d.seiter at comcast.net wrote: > I too have never seen one go dim. In fact, I have a VCR (Beta!) > that's been pluged in continously since I got it new in the early > '80s. It still looks the same as when I got it except that the > display has had a left to right wave going through it since about > 1995. So, wavy- but not dim at all. > > -Dave > > > -------------- Original message -------------- > From: Jeffrey Pawlan > >> Regarding the VFD display, although they may be very different one >> manufacturer to another, I can definitely dispute a prior statement >> made that VFDs in general have a short lifetime and become dim. They >> are universally used in VCRs, DVD players, microwave ovens, and some >> clocks. I have never had one become dim or burn out. The displays in >> my appliances are on even when the rest of the appliance is off. I >> have never seen one become dim even after 15 years of on-time. >> >> I look forward to your project. >> >> >> 73, >> >> Jeffrey Pawlan, WA6KBL >> >> >> >> >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/ >> listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. ------------------------------ Message: 8 Date: Thu, 17 Jul 2008 21:17:40 -0400 From: billh40 at aol.com Subject: [time-nuts] change in email address To: time-nuts at febo.com Message-ID: <8CAB68B34B01C27-167C-1AEF at FWM-D20.sysops.aol.com> Content-Type: text/plain; charset="us-ascii" change in email address: ??? was: ????????????????????????????????????? is: ?? billh40 at aol.com?????????????????????? billh40 at gmail.com Thanks, Bill Hanna ------------------------------ Message: 9 Date: Fri, 18 Jul 2008 11:42:45 +0200 From: "Baragwanath, Chris (TSG)" Subject: [time-nuts] TimeNuts Assistance Request To: Message-ID: Content-Type: text/plain; charset="US-ASCII" Hi all Time Nuts, I am a 'side line' member of the mailing list, ex Broadcast engineer whose principle fascination is accurate pendulum clocks and as one who has been lucky enough to have been in the presence of the ultimate "Clock" here in South Africa, the SAST (South African Standard Time) cluster. We do not have a "free to air" telephonic Time and Freq service in SA as the NIST does and our principle RF source (ZUO_ has long been discontinued for economic reasons (Other than the distant low power coastal stations the transmit a few mins a day for shipping purposes). The former Govt Labs and Standards Authorities are now privatised to lessen the burden on the fiscus and supposed to be self supporting, so charge and arm and a leg for access to their facilities, that our tax money paid for in the first place) At present, radio propagation conditions are so poor that and of the NIST and other stations are unusable as a tone reference or 1 pulse per second reference, and so have to call the NIST land line number, which is an expensive call from South Africa. As a voluntary / community service, we are trying to establish a freely accessible tone and pulse service and are looking for a donation of any unwanted equipment that will help us get a more stable 440hz and 1 PPS reference running. (The current oscillator is a good old uncompensated crystal British Ferrograph Test Set from broadcast days interrupted by another uncompensated xtal osc which interrupts the tone to prove the PPS output). Any donation of unwanted equipment, especially of more stable equipment or the ultimate, a GPS Rx board with 1 PPS output would be greatly appreciated. If anyone is prepared to help, I would be most grateful and would cover the shipping costs to SA. The mains in SA is 220v 50hz, but do have access to a 120v 60hz sinewave inverter unit to safely power US spec equipment. Many thanks in advance, Kind regards, Chris D Bagwanath "Its About Time" chris at baragwanath.co.za Tel +27 83 700 5057 Fax: +27 11 792 166 ------------------------------ Message: 10 Date: Fri, 18 Jul 2008 07:14:18 -0500 From: "Didier Juges" Subject: Re: [time-nuts] TimeNuts Assistance Request To: "'Discussion of precise time and frequency measurement'" Message-ID: <00a601c8e8cf$ce25fed0$0a01a8c0 at didierhp> Content-Type: text/plain; charset="US-ASCII" Chris, What is the 440Hz used for, other than tune instruments? Didier > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Baragwanath, Chris > (TSG) > Sent: Friday, July 18, 2008 4:43 AM > To: time-nuts at febo.com > Subject: [time-nuts] TimeNuts Assistance Request > > Hi all Time Nuts, > > I am a 'side line' member of the mailing list, ex Broadcast engineer > whose principle fascination is accurate pendulum clocks and as one who > has been lucky enough to have been in the presence of the ultimate > "Clock" here in South Africa, the SAST (South African Standard Time) > cluster. > > We do not have a "free to air" telephonic Time and Freq service in SA > as the NIST does and our principle RF source (ZUO_ has long been > discontinued for economic reasons (Other than the distant low power > coastal stations the transmit a few mins a day for shipping purposes). > The former Govt Labs and Standards Authorities are now privatised to > lessen the burden on the fiscus and supposed to be self supporting, so > charge and arm and a leg for access to their facilities, that our tax > money paid for in the first place) > > At present, radio propagation conditions are so poor that and of the > NIST and other stations are unusable as a tone reference or 1 pulse > per second reference, and so have to call the NIST land line number, > which is an expensive call from South Africa. > > As a voluntary / community service, we are trying to establish a > freely accessible tone and pulse service and are looking for a > donation of any unwanted equipment that will help us get a more stable > 440hz and 1 PPS reference running. > (The current oscillator is a good old uncompensated crystal British > Ferrograph Test Set from broadcast days interrupted by another > uncompensated xtal osc which interrupts the tone to prove the PPS > output). > > Any donation of unwanted equipment, especially of more stable > equipment or the ultimate, a GPS Rx board with 1 PPS output would be > greatly appreciated. > > If anyone is prepared to help, I would be most grateful and would > cover the shipping costs to SA. > > The mains in SA is 220v 50hz, but do have access to a 120v 60hz > sinewave inverter unit to safely power US spec equipment. > > Many thanks in advance, > > > Kind regards, > > > Chris D Bagwanath > "Its About Time" > > chris at baragwanath.co.za > Tel +27 83 700 5057 > Fax: +27 11 792 166 > > > > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ------------------------------ _______________________________________________ time-nuts mailing list time-nuts at febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts End of time-nuts Digest, Vol 48, Issue 47 ***************************************** From phk at phk.freebsd.dk Mon Jul 21 03:38:00 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Mon, 21 Jul 2008 07:38:00 +0000 Subject: [time-nuts] TimeNuts Assistance Request (Didier Juges) In-Reply-To: Your message of "Mon, 21 Jul 2008 09:07:08 +0200." Message-ID: <27615.1216625880@critter.freebsd.dk> In message , "Baragwanath, Chris (TSG)" writes: >Yes, the 440Hz is primarily a reference for tuning musical instruments >or calibrating tuners (i.e. PC sound cad based). In doing a little >"market research" as to the free frequency service, this freq. was >preferred to the normal 500Hz or 600Hz and still just within analog >telephone bandwidth. Both analog and digital phone technology may transpose frequencies up to 7 Hz in either directions. It doesnt' happen as much as it did back on old carrier-frequency transmission systems, but there can still be musically significant frequency shifts. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From jltran at worldnet.att.net Mon Jul 21 07:19:49 2008 From: jltran at worldnet.att.net (J. L. Trantham) Date: Mon, 21 Jul 2008 06:19:49 -0500 Subject: [time-nuts] Rack flange kit for 5370B and 3325B In-Reply-To: Message-ID: I, too, have been looking for rack mount ears for similar units (5334B, 3325A, 3335A, 8657A, 5087A, 105B, 8130A, etc.) with no luck. If there is anyone with a source or another idea of how to accomplish rack mounting without the HP ears, I would like to hear about it also. Thanks, Joe -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On Behalf Of Jim Palfreyman Sent: Monday, July 21, 2008 1:10 AM To: time-nuts at febo.com Subject: [time-nuts] Rack flange kit for 5370B and 3325B Hi, I've been looking for a bit with no luck so I thought I'd try here. I wish to mount my HP/Agilent 5370B and 3325B in a rack. Now the HP part 5061-0077 (also known as 3325B-908 or 5370B-908) and called a "Rack Flange Kit" (no handle version - although the handle version would be fine) looks like what I want. Has anyone got a couple of sets of these they are willing to part with or can least point me in the right direction? There are various companies that sell military and aircraft spares but they will charge a hefty minimum price - probably more than I paid for the actual units! I know these flanges aren't precision timing instruments, but they support precision timing instruments and keep them out of harms way - so should be revered in their own right. :-) Jim Palfreyman _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From GandalfG8 at aol.com Mon Jul 21 07:46:14 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Mon, 21 Jul 2008 07:46:14 EDT Subject: [time-nuts] Rack flange kit for 5370B and 3325B Message-ID: In a message dated 21/07/2008 12:22:23 GMT Daylight Time, jltran at worldnet.att.net writes: If there is anyone with a source or another idea of how to accomplish rack mounting without the HP ears, I would like to hear about it also. --------------------- Make your own from aluminium stock angle, or use a rack shelf. regards Nigel GM8PZR From mikes at flatsurface.com Mon Jul 21 07:43:23 2008 From: mikes at flatsurface.com (Mike S) Date: Mon, 21 Jul 2008 07:43:23 -0400 Subject: [time-nuts] Rack flange kit for 5370B and 3325B In-Reply-To: References: Message-ID: <20080721120925.5924B1165C3@hamburg.alientech.net> At 07:19 AM 7/21/2008, J. L. Trantham wrote... >If there is anyone with a source or another idea of how to accomplish >rack >mounting without the HP ears, I would like to hear about it also. Rack shelves. If you need more security, it should be pretty easy to figure out a way to bolt the device to the shelf. Lots on 'em on ebay. From stanley_reynolds at yahoo.com Mon Jul 21 10:11:01 2008 From: stanley_reynolds at yahoo.com (Stanley Reynolds) Date: Mon, 21 Jul 2008 07:11:01 -0700 (PDT) Subject: [time-nuts] Rack flange kit for 5370B and 3325B Message-ID: <780714.2104.qm@web30308.mail.mud.yahoo.com> Would not a piece of aluminum or steel L stock?work with washers or flat stock next to the case ? For an inexpensive source I use metal bed frames painted with primer and epoxy paint after the holes are drilled. I use a abrasive saw instead of a hack saw, less effort to cut them to length or cut notches. ----- Original Message ---- From: J. L. Trantham To: Discussion of precise time and frequency measurement Sent: Monday, July 21, 2008 6:19:49 AM Subject: Re: [time-nuts] Rack flange kit for 5370B and 3325B I, too, have been looking for rack mount ears for similar units (5334B, 3325A, 3335A, 8657A, 5087A, 105B, 8130A, etc.) with no luck. If there is anyone with a source or another idea of how to accomplish rack mounting without the HP ears, I would like to hear about it also. Thanks, Joe -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On Behalf Of Jim Palfreyman Sent: Monday, July 21, 2008 1:10 AM To: time-nuts at febo.com Subject: [time-nuts] Rack flange kit for 5370B and 3325B Hi, I've been looking for a bit with no luck so I thought I'd try here. I wish to mount my HP/Agilent 5370B and 3325B in a rack. Now the HP part 5061-0077 (also known as 3325B-908 or 5370B-908) and called a "Rack Flange Kit" (no handle version - although the handle version would be fine) looks like what I want. Has anyone got a couple of sets of these they are willing to part with or can least point me in the right direction? There are various companies that sell military and aircraft spares but they will charge a hefty minimum price - probably more than I paid for the actual units! I know these flanges aren't precision timing instruments, but they support precision timing instruments and keep them out of harms way - so should be revered in their own right. :-) Jim Palfreyman _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From peterawson at earthlink.net Mon Jul 21 11:49:47 2008 From: peterawson at earthlink.net (Pete) Date: Mon, 21 Jul 2008 09:49:47 -0600 Subject: [time-nuts] Double ovened 10811-60158 on ebay References: <4882CA64.3010406@sasktel.net><20080720105430.E103E1165C3@hamburg.alientech.net><15828.69.12.192.152.1216582977.squirrel@webmail.sonic.net> <20080720215356.681DC1165C3@hamburg.alientech.net> Message-ID: <004b01c8eb49$6af266b0$0200a8c0@BASE1> PCA coatings thin enough & chemically "friendly" enough to permit component replacement simply delay the effects of increasing ambient humidity on the circuits exposed. If the PCA fabrication processes leave the finished surface VERY clean, then several brands of conformal coatings will permit the surface to remain clean as humidity rises and falls. This is not to say the circuit will be unaffected by these changes, just that they become predictable. For most designs, particularly with fiber reinforced substrates, moisture intrusion from untreated edges is often overlooked. PCA cutting processes tend to tear many of the reinforcement fibers, making extended voids along the fiber length. Subsequent chemical processes fill these voids with varying amounts of electrolytes, which cannot be effectively removed. This situation results in difficult to predict response to high humidity. Here's one place where a careful (expensive) application of epoxy would help. Short of complete encapsulation, PCAs should first be designed to work properly at the highest humidity the customer demands: second, be absolutely clean; finally, coated only to stay clean. Pete Rawson From paul at greenrover.demon.co.uk Mon Jul 21 12:10:44 2008 From: paul at greenrover.demon.co.uk (paul at greenrover.demon.co.uk) Date: Mon, 21 Jul 2008 17:10:44 +0100 Subject: [time-nuts] Thunderbolt etc software? In-Reply-To: References: Message-ID: <4884B504.40102@greenrover.demon.co.uk> Murray Greenman wrote: > TIMEKEEPER Works well. > Hello Murray, what is Timekeeper please, I tried searching the Trimble site but failed to find any hits? Regards Paul -- 73 de Paul GW8IZR IO73TI http://www.gw8izr.com From jpradoes at telefonica.net Mon Jul 21 13:33:46 2008 From: jpradoes at telefonica.net (Jose Manuel) Date: Mon, 21 Jul 2008 19:33:46 +0200 Subject: [time-nuts] HP58504A antenna Message-ID: <001701c8eb57$ee4b3f10$2201a8c0@PC2> Hello all, I?d like to repair a HP58504A antenna that don?t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. Does anyone have any experience or data about this antenna? I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? Thanks in advance, Jos?, EA1PX From mfeher at eozinc.com Mon Jul 21 13:54:10 2008 From: mfeher at eozinc.com (Mike Feher) Date: Mon, 21 Jul 2008 13:54:10 -0400 Subject: [time-nuts] HP58504A antenna In-Reply-To: <001701c8eb57$ee4b3f10$2201a8c0@PC2> References: <001701c8eb57$ee4b3f10$2201a8c0@PC2> Message-ID: <011001c8eb5a$ca2a1a40$0201a8c0@gsmacdq14es> Jose - If it is similar to the HP two way GPS power splitter, then the MMIC is a voltage regulator used to deliver 3 volts to the amplifier transistor. In my splitter the MMIC died, so, not having another, I cut it out and soldered in a wire from the 5 volt input to the 3 volt output and then the splitter worked fine again. The 30 ma may be OK, as the antenna has to let the receiver know that it is OK, and it does that by exceeding a current threshold on the 5 volts delivered by the receiver. I doubt if the transistor draws nearly as much. Check the output lead on the active device to see if you have 3 volts on it. From your picture it appears it is the tab that goes to the output filter. 73 - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Jose Manuel Sent: Monday, July 21, 2008 1:34 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] HP58504A antenna Hello all, I?d like to repair a HP58504A antenna that don?t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. Does anyone have any experience or data about this antenna? I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? Thanks in advance, Jos?, EA1PX _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From SAIDJACK at aol.com Mon Jul 21 14:17:41 2008 From: SAIDJACK at aol.com (SAIDJACK at aol.com) Date: Mon, 21 Jul 2008 14:17:41 EDT Subject: [time-nuts] Thunderbolt vs Z3801A Message-ID: Hi Didier, the drawback of this approach is that everything is connected together as one big circuit, and thus processor noise can get into the GPS front end and reduce the sensitivity and cause other errors.. For RF performance, it's probably better to have the GPS receiver sit all by itself in a shielded enclosure with it's own TCXO. Trimble seems to have done a pretty good job at the layout to handle these types of issues though. bye, Said In a message dated 7/20/2008 18:01:11 Pacific Daylight Time, didier at cox.net writes: Because Trimble integrated the GPS receiver and the OCXO, they use the OCXO as a clock to run the processor, therefore that source of error is not there. The ultimate performance is not better than a perfectly optimized "conventional" GPSDO + OCXO, but excellent performance can be achieved at lower cost, and without having to deal with certain tradeoffs. Now, I am sure there are other, more subtle details that explain why the Z3801A is generally superior to the Thunderbolt, but that I cannot explain... Didier **************Get fantasy football with free live scoring. Sign up for FanHouse Fantasy Football today. (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020) From gbusg at comcast.net Mon Jul 21 16:38:33 2008 From: gbusg at comcast.net (Greg Burnett) Date: Mon, 21 Jul 2008 14:38:33 -0600 Subject: [time-nuts] HP 113BR manual scanned References: Message-ID: <008001c8eb71$be6dae30$6501a8c0@gb02> Hi David, As followup to your question, my friend at Agilent tells me they will take scans of any manuals (even for very old instruments) but they probably won't post it until someone asks for it. He says "it's still better to contribute it because it's better to have it than not, even if it does not get posted until someone asks!" He says that manuals at agilent.com is the email address to remember whether wanting to find one or to offer one. Cheers, Greg ----David wrote: Does anyone think Agilent is interested in a manual for something this old, or is this more of an HP Archives sort of boatanchor? I also have a 103AR manual to scan if anyone's interested in this ancient stuff. Let me know. --clip-- From wb6bnq at cox.net Mon Jul 21 16:45:09 2008 From: wb6bnq at cox.net (WB6BNQ) Date: Mon, 21 Jul 2008 13:45:09 -0700 Subject: [time-nuts] HP58504A antenna References: <001701c8eb57$ee4b3f10$2201a8c0@PC2> Message-ID: <4884F555.8B1FA99C@cox.net> Hi Jose, If you trace out the power feed (the bottom direction from the coax connection) it supplies the transistor (most likely a MMIC) and the black 6 legged active device (no idea on it). The silver square looks like a filter device of some sort between what you call the transistor and the 6 legged active device. The silver square has no voltage going to it. The 30 milliamps does not sound out of range to me, but then I have no experience with the hp system. What makes you think it is the antenna that is the problem ? If the voltages appear to be about right (your statement) my guess would be that the antenna might be working correctly. So I would not be shorting anything out without getting a lot more information first. Is there anyone else in your area that has such a system that you could compare with ? Good luck, 73....Bill....WB6BNQ Jose Manuel wrote: > Hello all, > > I?d like to repair a HP58504A antenna that don?t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. > > Does anyone have any experience or data about this antenna? > > I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? > > Thanks in advance, Jos?, EA1PX > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From bruce.griffiths at xtra.co.nz Mon Jul 21 19:00:53 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Tue, 22 Jul 2008 11:00:53 +1200 Subject: [time-nuts] HP58504A antenna In-Reply-To: <4884F555.8B1FA99C@cox.net> References: <001701c8eb57$ee4b3f10$2201a8c0@PC2> <4884F555.8B1FA99C@cox.net> Message-ID: <48851525.2060101@xtra.co.nz> WB6BNQ wrote: > Hi Jose, > > If you trace out the power feed (the bottom direction from the coax connection) it supplies the transistor (most likely a MMIC) and the black 6 legged active device (no idea on it). The silver square looks like a filter > device of some sort between what you call the transistor and the 6 legged active device. The silver square has no voltage going to it. > > The 30 milliamps does not sound out of range to me, but then I have no experience with the hp system. What makes you think it is the antenna that is the problem ? If the voltages appear to be about right (your > statement) my guess would be that the antenna might be working correctly. > > So I would not be shorting anything out without getting a lot more information first. Is there anyone else in your area that has such a system that you could compare with ? > > Good luck, > > 73....Bill....WB6BNQ > > Jose Manuel wrote: > > Actually the 4 leaded input device is more likely to be a depletion mode FET (not Si but GaAs, or other III-V semiconductor) with the gate connected to ground via the . The 2 wide leads are both source connections. The 6 leaded device is likely to be a MMIC. Try an old HP semiconductor (or an Avago) catalog for likely candidates. Bruce From bruce.griffiths at xtra.co.nz Mon Jul 21 20:32:59 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Tue, 22 Jul 2008 12:32:59 +1200 Subject: [time-nuts] HP58504A antenna In-Reply-To: <001701c8eb57$ee4b3f10$2201a8c0@PC2> References: <001701c8eb57$ee4b3f10$2201a8c0@PC2> Message-ID: <48852ABB.2050503@xtra.co.nz> Jose Manuel wrote: > Hello all, > > I?d like to repair a HP58504A antenna that don?t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. > > Does anyone have any experience or data about this antenna? > > I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? > > > > Thanks in advance, Jos?, EA1PX > Jose Its hard to be certain from the picture but is the to end (opposite end to that connected to the input transistor gate track) of the white ceramic cap connected to the antenna input or not? it should be. Bruce From wb6bnq at cox.net Mon Jul 21 20:45:59 2008 From: wb6bnq at cox.net (WB6BNQ) Date: Mon, 21 Jul 2008 17:45:59 -0700 Subject: [time-nuts] HP58504A antenna References: <001701c8eb57$ee4b3f10$2201a8c0@PC2> <48852ABB.2050503@xtra.co.nz> Message-ID: <48852DC7.DC565E6C@cox.net> Hi Bruce, I looked at that also. Using OPERA browser I can zoom in really well and at 400 % you can just make out the trace under the coating and other stuff obscuring the view. Bill....WB6BNQ Bruce Griffiths wrote: > Jose Manuel wrote: > > Hello all, > > > > I?d like to repair a HP58504A antenna that don?t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. > > > > Does anyone have any experience or data about this antenna? > > > > I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? > > > > > > > > Thanks in advance, Jos?, EA1PX > > > Jose > > Its hard to be certain from the picture but is the to end (opposite end > to that connected to the input transistor gate track) of the white > ceramic cap connected to the antenna input or not? > it should be. > > Bruce > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From bruce.griffiths at xtra.co.nz Mon Jul 21 20:46:03 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Tue, 22 Jul 2008 12:46:03 +1200 Subject: [time-nuts] HP58504A antenna In-Reply-To: <001701c8eb57$ee4b3f10$2201a8c0@PC2> References: <001701c8eb57$ee4b3f10$2201a8c0@PC2> Message-ID: <48852DCB.6020602@xtra.co.nz> Jose Manuel wrote: > Hello all, > > I?d like to repair a HP58504A antenna that don?t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. > > The resistive voltage divider feeding (from the +5V supply) the Vcc pin on the MMIC will draw about 15mA by itself plus 6mA for the MMIC is a total of 21 mA. The input stage has a total dc resistance of around 421 ohms to the drain, with 90.5 ohms from the source to ground, should the input transistor have a drain to source short the input stage current would be about 9.7mA giving a total of about 30.7mA. To eliminate the possibility of a drain to source short, the drain to source voltage of the input device needs to be measured (or inferred from resistor measurements with the circuit unpowered and by measuring the voltage drop across the 100 ohm resistor in series with the drain with the circuit powered - this is unlikely to cause parasitic oscillations) without causing it to oscillate. > Does anyone have any experience or data about this antenna? > > I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? > > > > Thanks in advance, Jos?, EA1PX > Bruce From ddabney01 at yahoo.com Mon Jul 21 23:09:45 2008 From: ddabney01 at yahoo.com (Richard Dabney) Date: Mon, 21 Jul 2008 20:09:45 -0700 (PDT) Subject: [time-nuts] Stability vs. Accuracy Message-ID: <658044.97848.qm@web62509.mail.re1.yahoo.com> I'm not a scientist or engineer but have a question to those of you who are. The many recent posts regarding the GPSDOs and comparisons between the various ones? have been comparing stability. How about accuracy compared with the national frequency standard? Are stability and accuracy the same? Stability to E-13.5 with the Thunderbolt. How close to perfect time and frequency?............? Thanks...Dick W5UFZ??? FMT-nut From james.p.lux at jpl.nasa.gov Mon Jul 21 23:22:41 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Mon, 21 Jul 2008 20:22:41 -0700 Subject: [time-nuts] humidity sensitivity of 10811 Message-ID: <20080721202241.4ean6thri804swko@webmail.jpl.nasa.gov> Some mention has been made recently of the sensitivity of the pervasive and ubiquitous 10811 to humidity changes. What sort of general magnitude are we talking about here.. 1E-12, 1E-9, etc. Jim Lux From ch at murgatroid.com Tue Jul 22 00:32:05 2008 From: ch at murgatroid.com (christopher hoover) Date: Mon, 21 Jul 2008 21:32:05 -0700 Subject: [time-nuts] HP58504A antenna In-Reply-To: References: Message-ID: <007301c8ebb3$e57bac60$b0730520$@com> Jose wrote: > I?d like to repair a HP58504A antenna that don?t deliver any output > signal. The current is about 30 mA ( I think too high), and the > transistor (unknown type) and the MMIC (uPC2749TB), seems to be with > correct voltage. > > Does anyone have any experience or data about this antenna? > > I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the > transistor be identified by the color code? I'm assuming correctly that the big blob of solder in the LL is the antenna connection, otherwise please ignore all of this. I suspect that "transistor" is really an MMIC in one of the fancier packages rather than a discrete transistor. It looks to me as if the bias flows through the trace on the BR and then through a couple of 001 R's before the bias setting 221 R. This MMIC is before the filter, so it is probably been selected and biased to avoid IM problems. But I don't think 30 mA sounds too high. -ch From bruce.griffiths at xtra.co.nz Tue Jul 22 00:51:30 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Tue, 22 Jul 2008 16:51:30 +1200 Subject: [time-nuts] HP58504A antenna In-Reply-To: <007301c8ebb3$e57bac60$b0730520$@com> References: <007301c8ebb3$e57bac60$b0730520$@com> Message-ID: <48856752.6040800@xtra.co.nz> christopher hoover wrote: > Jose wrote: > > >> I?d like to repair a HP58504A antenna that don?t deliver any output >> signal. The current is about 30 mA ( I think too high), and the >> transistor (unknown type) and the MMIC (uPC2749TB), seems to be with >> correct voltage. >> >> Does anyone have any experience or data about this antenna? >> >> I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the >> transistor be identified by the color code? >> > > I'm assuming correctly that the big blob of solder in the LL > is the antenna connection, otherwise please ignore all of this. > > I suspect that "transistor" is really an MMIC in one of the > fancier packages rather than a discrete transistor. > > Circuit is exactly that to be expected with a discrete pHEMT or similar device. > It looks to me as if the bias flows through the trace on the BR > and then through a couple of 001 R's before the bias > setting 221 R. > > Nonsense they are 100 ohm resistors text is upside down. 1 ohm resistors wouldn't be particularly effective in the filters, > This MMIC is before the filter, so it is probably been selected > and biased to avoid IM problems. > > Its unlikely to be an MMIC as they generally have all the bias parts internal to the chip other than an output biasing resistor. Also most MMICs do not have the input connected to dc ground. > But I don't think 30 mA sounds too high. > > -ch > > Bruce From bruce.griffiths at xtra.co.nz Tue Jul 22 01:44:46 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Tue, 22 Jul 2008 17:44:46 +1200 Subject: [time-nuts] HP58504A antenna In-Reply-To: <48856752.6040800@xtra.co.nz> References: <007301c8ebb3$e57bac60$b0730520$@com> <48856752.6040800@xtra.co.nz> Message-ID: <488573CE.20204@xtra.co.nz> Correction: Resistor values used are probably: 100 = 10 ohms 560 = 56 ohms or is it 680 = 68 ohms? 101 = 100 ohms 121 = 120 ohms 181 = 180 ohms 221 = 220 ohms 271 = 270 ohms Thus the total resistance from the 5V supply to the output terminal of the input device is actually = 220 + 10 + 10 = 240 ohms. Equivalent resistance from input device "source" terminals to ground = 90 ohms. Voltage divider for Vcc of MMIC is 56 ohms from 5V is series with 270 ohms to ground nominal current ~ 15mA + 6mA? for MMIC, total ~ 21mA. Input device if shorted would have a current drain of 5V/(90+220 + 10 + 10) ~ 15mA. Thus measuring the dc output of the input device and/or measuring its power supply current is required to assist diagnosis. Some pHEMT devices have an absolute drain source voltage limit as low as 3V so the operating drain source voltage of the input device may only be 1/2 that. Typical MMICs have a somewhat larger dc voltage on the output. Bruce From richard at karlquist.com Tue Jul 22 02:47:07 2008 From: richard at karlquist.com (Richard (Rick) Karlquist) Date: Mon, 21 Jul 2008 23:47:07 -0700 Subject: [time-nuts] humidity sensitivity of 10811 In-Reply-To: <20080721202241.4ean6thri804swko@webmail.jpl.nasa.gov> References: <20080721202241.4ean6thri804swko@webmail.jpl.nasa.gov> Message-ID: <4885826B.600@karlquist.com> Moderate humidity changes caused frequency shifts on the order of parts in 10^9. With the environmental chamber on full throttle, I saw parts in 10^8. The E1938A has an unmeasurable humidity coefficient, even unsealed. Rick Karlquist N6RK Jim Lux wrote: > Some mention has been made recently of the sensitivity of the > pervasive and ubiquitous 10811 to humidity changes. What sort of > general magnitude are we talking about here.. 1E-12, 1E-9, etc. > > Jim Lux > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From ian.sheffield1 at tesco.net Tue Jul 22 02:51:54 2008 From: ian.sheffield1 at tesco.net (Ian Sheffield) Date: Tue, 22 Jul 2008 07:51:54 +0100 Subject: [time-nuts] Hameg HM8125 Time/frequency Standard Message-ID: <006001c8ebc7$6ec80280$0300000a@cookie> Hello, Does anyone have a copy of a schematic or service manual for the down-converter for the Hameg HM8125 GPS frequency/time receiver? The receiver and display seems to be working fine, but the separate down-converter appears to have been modified with a capacitor blocking the DC power feed from the receiver and what may be a voltage regulator has been removed. The downconverter appears to do more than just shift frequency, as it has a TDA 1574 FM subsystem chip in it as well as the expected RF circuitry. Any help would be appreciated, or even if someone had a spare downconverter for sale.........? These units do unfortunately, appear to be as scarce as hens' teeth. Thanks in advance, Ian Sheffield From dave.g0dja at tiscali.co.uk Tue Jul 22 05:49:45 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 22 Jul 2008 10:49:45 +0100 Subject: [time-nuts] Thunderbolt PSU Message-ID: <4885AD39.8080304@tiscali.co.uk> The Thunderbolt arrived today. Thanks again to all involved. However, it looks like my PSU is faulty. I carefully cut the outer on the cable, splayed out the coloured inner connectors, so as to avoid short circuits, and noticed that colours of the insulation on the cable cores did not match the colour code given at http://www.leapsecond.com/pages/tbolt/power.htm No problem, I have a multi-meter and was trained as an electrical engineer so I should be able to sort out what was going on. On plugging in a lead there was a slight 'buzz' and, on checking the outputs, no DC volts. Checking the lead showed no AC volts. So, I opened the plug and checked the fuse, a 3 Amp type - too big for the unit output really, but shouldn't have blown... Changing the fuse for a 1 amp type, and plugging back in showed no output voltage again. Checked the business end of the lead and there's AC volts still there. I'm guessing, from experience of these PSUs in the past, that there's a fuse inside the unit which has also blown. If so, I guess I have a faulty PSU? Ah well, a trip to the local PC Store for a +12v/-12v, +5 Volt PSU I guess. Also, I see that the antenna socket on the Thunderbolt is an F-type. Someone has thoughtfully provided an F-Type to BNC adapter. However, the plug on the Motorola GPS antenna is an SMA type. Ah well, I can make a lead which should work instead. :-) Dave From alan.melia at btinternet.com Tue Jul 22 05:50:12 2008 From: alan.melia at btinternet.com (Alan Melia) Date: Tue, 22 Jul 2008 10:50:12 +0100 Subject: [time-nuts] Hameg HM8125 Time/frequency Standard References: <006001c8ebc7$6ec80280$0300000a@cookie> Message-ID: <002601c8ebe0$5d11abe0$0900a8c0@AM> Hi Ian I dont know whether it works for that unit, but try the Hameg site. http://www.hameg.com/66.0.html There are "almost" complete manuals for all the units (well certainly the scopes!) You may find that there are no schematics in the English versions....download the German versions (which you may see are bigger files) and the are often schematics at the back of these....the titles etc are also bilingual. Hope that helps Cheers de Alan G3NYK ----- Original Message ----- From: "Ian Sheffield" To: Sent: Tuesday, July 22, 2008 7:51 AM Subject: [time-nuts] Hameg HM8125 Time/frequency Standard > Hello, > > Does anyone have a copy of a schematic or service manual for the down-converter for the Hameg HM8125 > GPS frequency/time receiver? > > The receiver and display seems to be working fine, but the separate down-converter appears to have been modified with a capacitor blocking the DC power feed from the receiver and what may be a voltage regulator has been removed. The downconverter appears to do more than just shift frequency, as it has a TDA 1574 FM subsystem chip in it as well as the expected RF circuitry. > > Any help would be appreciated, or even if someone had a spare downconverter for sale.........? > > These units do unfortunately, appear to be as scarce as hens' teeth. > > Thanks in advance, > > Ian Sheffield > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From ian.sheffield1 at tesco.net Tue Jul 22 06:43:53 2008 From: ian.sheffield1 at tesco.net (Ian Sheffield) Date: Tue, 22 Jul 2008 11:43:53 +0100 Subject: [time-nuts] Hameg HM8125 Time/frequency Standard References: <006001c8ebc7$6ec80280$0300000a@cookie> <002601c8ebe0$5d11abe0$0900a8c0@AM> Message-ID: <001a01c8ebe7$d6c9eef0$0300000a@cookie> Hi Alan, Tried that, and downloaded the operating manual a while back. Tried your tip and looked at the German version, but no luck either. Thanks for the suggestion though. Cheers, Ian. ----- Original Message ----- From: "Alan Melia" To: "Discussion of precise time and frequency measurement" Sent: Tuesday, July 22, 2008 10:50 AM Subject: Re: [time-nuts] Hameg HM8125 Time/frequency Standard > Hi Ian I dont know whether it works for that unit, but try the Hameg site. > http://www.hameg.com/66.0.html > There are "almost" complete manuals for all the units (well certainly the > scopes!) You may find that there are no schematics in the English > versions....download the German versions (which you may see are bigger > files) and the are often schematics at the back of these....the titles etc > are also bilingual. > > Hope that helps > Cheers de Alan G3NYK > > ----- Original Message ----- > From: "Ian Sheffield" > To: > Sent: Tuesday, July 22, 2008 7:51 AM > Subject: [time-nuts] Hameg HM8125 Time/frequency Standard > > >> Hello, >> >> Does anyone have a copy of a schematic or service manual for the > down-converter for the Hameg HM8125 >> GPS frequency/time receiver? >> >> The receiver and display seems to be working fine, but the separate > down-converter appears to have been modified with a capacitor blocking the > DC power feed from the receiver and what may be a voltage regulator has > been > removed. The downconverter appears to do more than just shift frequency, > as > it has a TDA 1574 FM subsystem chip in it as well as the expected RF > circuitry. >> >> Any help would be appreciated, or even if someone had a spare > downconverter for sale.........? >> >> These units do unfortunately, appear to be as scarce as hens' teeth. >> >> Thanks in advance, >> >> Ian Sheffield >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts at febo.com >> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > No virus found in this incoming message. > Checked by AVG - http://www.avg.com > Version: 8.0.138 / Virus Database: 270.5.3/1565 - Release Date: 7/21/2008 > 18:36 > > > From wje at quackers.net Tue Jul 22 07:03:56 2008 From: wje at quackers.net (wje) Date: Tue, 22 Jul 2008 07:03:56 -0400 Subject: [time-nuts] Stability vs. Accuracy In-Reply-To: <658044.97848.qm@web62509.mail.re1.yahoo.com> References: <658044.97848.qm@web62509.mail.re1.yahoo.com> Message-ID: <4885BE9C.7080600@quackers.net> Simply put, stability is a measure of how much something varies from a constant value. A stable value doesn't mean an accurate value; accuracy is a measure of how close to some standard value a device emits (in this case) or measures, for a meter. So, you could have something that's perfectly stable but not accurate. You can also have something that's accurate but not stable. In theory, they can be perfectly (ok, nearly perfectly) accurate because their lack of stability is averaged out over a long period of time, and the average value is an accurate representation of the time kept by the satellites, which themselves provide an accurate representation of 'true', i.e., NIST time. In practice they wander around a bit, and that wandering is the stability measurement you see. What you can tell from the stability figures is that the unit is that close to perfect accuracy most of the time. The stability figure is really a measure of the statistical probability that at any given time the accuracy is within that bound. Why do they wander? Many factors contribute, ranging from the stability and accuracy of the local VCXO and its control loop to atmospheric propagation variations to variations in the satellite clocks themselves, etc. Bill Ezell ---------- They said 'Windows or better' so I used Linux. Richard Dabney wrote: > I'm not a scientist or engineer but have a question to those of you who are. > > The many recent posts regarding the GPSDOs and comparisons between the various ones have been comparing stability. How about accuracy compared with the national frequency standard? > Are stability and accuracy the same? Stability to E-13.5 with the Thunderbolt. How close to > perfect time and frequency?............ Thanks...Dick W5UFZ FMT-nut > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > From phill.r1 at btinternet.com Tue Jul 22 07:30:47 2008 From: phill.r1 at btinternet.com (Roy Phillips) Date: Tue, 22 Jul 2008 12:30:47 +0100 Subject: [time-nuts] Stability vs. Accuracy References: <658044.97848.qm@web62509.mail.re1.yahoo.com> <4885BE9C.7080600@quackers.net> Message-ID: <000e01c8ebee$64ab4970$4301a8c0@r8909f0aecf524> Bill A very big thank you for what must be a near perfect (accurate) answer to a question that most of us without Degrees have pondered from time to time. I shall paste this into my "book of many answers" Regards Roy Phillips. ----- Original Message ----- From: "wje" To: ; "Discussion of precise time and frequency measurement" Sent: Tuesday, July 22, 2008 12:03 PM Subject: Re: [time-nuts] Stability vs. Accuracy > Simply put, stability is a measure of how much something varies from a > constant value. > A stable value doesn't mean an accurate value; accuracy is a measure of > how close to some standard value a device emits (in this case) or > measures, for a meter. > > So, you could have something that's perfectly stable but not accurate. > You can also have something that's accurate but not stable. > > In theory, they can be perfectly (ok, nearly perfectly) accurate because > their lack of stability is averaged out over a long period of time, and > the average value is an accurate representation of the time kept by the > satellites, which themselves provide an accurate representation of > 'true', i.e., NIST time. > > In practice they wander around a bit, and that wandering is the > stability measurement you see. What you can tell from the stability > figures is that the unit is that close to perfect accuracy most of the > time. The stability figure is really a measure of the statistical > probability that at any given time the accuracy is within that bound. > > Why do they wander? Many factors contribute, ranging from the stability > and accuracy of the local VCXO and its control loop to atmospheric > propagation variations to variations in the satellite clocks themselves, > etc. > > Bill Ezell > ---------- > They said 'Windows or better' > so I used Linux. > > > > Richard Dabney wrote: >> I'm not a scientist or engineer but have a question to those of you who >> are. >> >> The many recent posts regarding the GPSDOs and comparisons between the >> various ones have been comparing stability. How about accuracy compared >> with the national frequency standard? >> Are stability and accuracy the same? Stability to E-13.5 with the >> Thunderbolt. How close to >> perfect time and frequency?............ Thanks...Dick W5UFZ FMT-nut >> >> >> >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts at febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From alan.melia at btinternet.com Tue Jul 22 07:46:12 2008 From: alan.melia at btinternet.com (Alan Melia) Date: Tue, 22 Jul 2008 12:46:12 +0100 Subject: [time-nuts] Hameg HM8125 Time/frequency Standard References: <006001c8ebc7$6ec80280$0300000a@cookie><002601c8ebe0$5d11abe0$0900a8c0@AM> <001a01c8ebe7$d6c9eef0$0300000a@cookie> Message-ID: <006001c8ebf0$e82b7660$0900a8c0@AM> You might try the UK agent who has been quite helpful on scope spares. hameguk at btopenworld.com I can't remember the fellow's name now, but I bought several control knobs to refurb an HM1005 scope. He was very helpful though this adress is not the one on the back of the manuals! Alan G3NYK ----- Original Message ----- From: "Ian Sheffield" To: "Discussion of precise time and frequency measurement" Sent: Tuesday, July 22, 2008 11:43 AM Subject: Re: [time-nuts] Hameg HM8125 Time/frequency Standard > Hi Alan, > > Tried that, and downloaded the operating manual a while back. > Tried your tip and looked at the German version, but no luck either. > > Thanks for the suggestion though. > > Cheers, > > Ian. > > ----- Original Message ----- > From: "Alan Melia" > To: "Discussion of precise time and frequency measurement" > > Sent: Tuesday, July 22, 2008 10:50 AM > Subject: Re: [time-nuts] Hameg HM8125 Time/frequency Standard > > > > Hi Ian I dont know whether it works for that unit, but try the Hameg site. > > http://www.hameg.com/66.0.html > > There are "almost" complete manuals for all the units (well certainly the > > scopes!) You may find that there are no schematics in the English > > versions....download the German versions (which you may see are bigger > > files) and the are often schematics at the back of these....the titles etc > > are also bilingual. > > > > Hope that helps > > Cheers de Alan G3NYK > > > > ----- Original Message ----- > > From: "Ian Sheffield" > > To: > > Sent: Tuesday, July 22, 2008 7:51 AM > > Subject: [time-nuts] Hameg HM8125 Time/frequency Standard > > > > > >> Hello, > >> > >> Does anyone have a copy of a schematic or service manual for the > > down-converter for the Hameg HM8125 > >> GPS frequency/time receiver? > >> > >> The receiver and display seems to be working fine, but the separate > > down-converter appears to have been modified with a capacitor blocking the > > DC power feed from the receiver and what may be a voltage regulator has > > been > > removed. The downconverter appears to do more than just shift frequency, > > as > > it has a TDA 1574 FM subsystem chip in it as well as the expected RF > > circuitry. > >> > >> Any help would be appreciated, or even if someone had a spare > > downconverter for sale.........? > >> > >> These units do unfortunately, appear to be as scarce as hens' teeth. > >> > >> Thanks in advance, > >> > >> Ian Sheffield > >> > >> > >> _______________________________________________ > >> time-nuts mailing list -- time-nuts at febo.com > >> To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts at febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > No virus found in this incoming message. > > Checked by AVG - http://www.avg.com > > Version: 8.0.138 / Virus Database: 270.5.3/1565 - Release Date: 7/21/2008 > > 18:36 > > > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From rfnuts at arcor.de Tue Jul 22 07:48:47 2008 From: rfnuts at arcor.de (Adrian) Date: Tue, 22 Jul 2008 13:48:47 +0200 Subject: [time-nuts] HP58504A antenna In-Reply-To: <001701c8eb57$ee4b3f10$2201a8c0@PC2> References: <001701c8eb57$ee4b3f10$2201a8c0@PC2> Message-ID: <4885C91F.7030201@arcor.de> Hi Jos?, before trying to fix the antenna, please check if it's still working. Connect it through a bias Tee (for feeding 5 V into the antenna cable, and for decoupling DC from the analyzer) to a spectrum analyzer and use a signal generator with a short wire inserted into the output jack. Set both instruments to1575.42 MHz. Put the antenna near the signal generator (1 meter distance would be fine). You should get enough signal in the air to see if the antenna is working or not. If there is no signal, please check the source and drain voltage at the input FET (left side of your picture), Source is the left terminal, drain the upper one. Also check voltages at the output MMIC (6 pin device). Check input (lower left) and output (upper right) as well as the supply pin (lower right), plus the actual voltage that is coming in from the output coax cable, and report back. Adrian Jose Manuel schrieb: > Hello all, > > I?d like to repair a HP58504A antenna that don?t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. > > Does anyone have any experience or data about this antenna? > > I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? > > > > Thanks in advance, Jos?, EA1PX > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From jltran at worldnet.att.net Tue Jul 22 08:16:51 2008 From: jltran at worldnet.att.net (J. L. Trantham) Date: Tue, 22 Jul 2008 07:16:51 -0500 Subject: [time-nuts] HP58504A antenna In-Reply-To: <4885C91F.7030201@arcor.de> Message-ID: I have been reading this thread with interest since I enjoy resurrecting 'dead' instruments. Two questions though: 1. Since I have been out of the loop for many years, what is an 'MMIC'? 2. The picture suggests some corrosion or oxidation near the coax cable connection. Has this been cleaned to eliminate any chance of 'shorting' the signal to ground? Thanks, Joe -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On Behalf Of Adrian Sent: Tuesday, July 22, 2008 6:49 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP58504A antenna Hi Jos?, before trying to fix the antenna, please check if it's still working. Connect it through a bias Tee (for feeding 5 V into the antenna cable, and for decoupling DC from the analyzer) to a spectrum analyzer and use a signal generator with a short wire inserted into the output jack. Set both instruments to1575.42 MHz. Put the antenna near the signal generator (1 meter distance would be fine). You should get enough signal in the air to see if the antenna is working or not. If there is no signal, please check the source and drain voltage at the input FET (left side of your picture), Source is the left terminal, drain the upper one. Also check voltages at the output MMIC (6 pin device). Check input (lower left) and output (upper right) as well as the supply pin (lower right), plus the actual voltage that is coming in from the output coax cable, and report back. Adrian Jose Manuel schrieb: > Hello all, > > I?d like to repair a HP58504A antenna that don?t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. > > Does anyone have any experience or data about this antenna? > > I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? > > > > Thanks in advance, Jos?, EA1PX > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From mikes at flatsurface.com Tue Jul 22 08:53:33 2008 From: mikes at flatsurface.com (Mike S) Date: Tue, 22 Jul 2008 08:53:33 -0400 Subject: [time-nuts] Thunderbolt PSU In-Reply-To: <4885AD39.8080304@tiscali.co.uk> References: <4885AD39.8080304@tiscali.co.uk> Message-ID: <20080722131003.E7F471165C3@hamburg.alientech.net> At 05:49 AM 7/22/2008, David Ackrill wrote... >On plugging in a lead there was a slight 'buzz' and, on checking the >outputs, no DC volts. Checking the lead showed no AC volts. So, I >opened the plug and checked the fuse, a 3 Amp type - too big for the >unit output really, but shouldn't have blown... > >Changing the fuse for a 1 amp type, and plugging back in showed no >output voltage again. Checked the business end of the lead and >there's >AC volts still there. I'm guessing, from experience of these PSUs in >the past, that there's a fuse inside the unit which has also >blown. If >so, I guess I have a faulty PSU? Most switching supplies require a minimum load to operate correctly. If the output is just open, and you don't see any voltage, it doesn't necessarily indicate a problem. I wouldn't use it with the Thunderbolt until you get the issue worked out, though - you don't want to blow it up if there's been a failure in the power supply's protective circuits. According to a previous list message, a running Tbolt takes about 160mA at +12V, 250mA at +5V, and 3mA at -12V. So maybe a 75 Ohm, 2 W resistor across the +12V and a 20 Ohm, 2W resistor across the +5. If those are covered, the -12 can probably be left open without issue. From wje at quackers.net Tue Jul 22 09:15:12 2008 From: wje at quackers.net (wje) Date: Tue, 22 Jul 2008 09:15:12 -0400 Subject: [time-nuts] HP58504A antenna In-Reply-To: References: Message-ID: <4885DD60.4050900@quackers.net> MMIC = Monolithic Microwave Integrated Circuit Bill Ezell ---------- They said 'Windows or better' so I used Linux. J. L. Trantham wrote: I have been reading this thread with interest since I enjoy resurrecting 'dead' instruments. Two questions though: 1. Since I have been out of the loop for many years, what is an 'MMIC'? 2. The picture suggests some corrosion or oxidation near the coax cable connection. Has this been cleaned to eliminate any chance of 'shorting' the signal to ground? Thanks, Joe -----Original Message----- From: [1]time-nuts-bounces at febo.com [[2]mailto:time-nuts-bounces at febo.com]On Behalf Of Adrian Sent: Tuesday, July 22, 2008 6:49 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP58504A antenna Hi Jos?, before trying to fix the antenna, please check if it's still working. Connect it through a bias Tee (for feeding 5 V into the antenna cable, and for decoupling DC from the analyzer) to a spectrum analyzer and use a signal generator with a short wire inserted into the output jack. Set both instruments to1575.42 MHz. Put the antenna near the signal generator (1 meter distance would be fine). You should get enough signal in the air to see if the antenna is working or not. If there is no signal, please check the source and drain voltage at the input FET (left side of your picture), Source is the left terminal, drain the upper one. Also check voltages at the output MMIC (6 pin device). Check input (lower left) and output (upper right) as well as the supply pin (lower right), plus the actual voltage that is coming in from the output coax cable, and report back. Adrian Jose Manuel schrieb: Hello all, I?d like to repair a HP58504A antenna that don?t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. Does anyone have any experience or data about this antenna? I took an inside photo: [3]http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? Thanks in advance, Jos?, EA1PX _______________________________________________ time-nuts mailing list -- [4]time-nuts at febo.com To unsubscribe, go to [5]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [6]time-nuts at febo.com To unsubscribe, go to [7]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [8]time-nuts at febo.com To unsubscribe, go to [9]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:time-nuts-bounces at febo.com 2. mailto:time-nuts-bounces at febo.com 3. http://www.ea1px.es/HP58504A.jpg 4. mailto:time-nuts at febo.com 5. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 6. mailto:time-nuts at febo.com 7. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 8. mailto:time-nuts at febo.com 9. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts From bruce.griffiths at xtra.co.nz Tue Jul 22 09:15:18 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Wed, 23 Jul 2008 01:15:18 +1200 Subject: [time-nuts] HP58504A antenna In-Reply-To: References: Message-ID: <4885DD66.2050804@xtra.co.nz> J. L. Trantham wrote: > I have been reading this thread with interest since I enjoy resurrecting > 'dead' instruments. Two questions though: > > 1. Since I have been out of the loop for many years, what is an 'MMIC'? > > Monolithic Microwave Integrated Circuit. > 2. The picture suggests some corrosion or oxidation near the coax cable > connection. Has this been cleaned to eliminate any chance of 'shorting' the > signal to ground? > > Thanks, > > Joe > > Bruce From dave.g0dja at tiscali.co.uk Tue Jul 22 10:15:56 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 22 Jul 2008 15:15:56 +0100 Subject: [time-nuts] Thunderbolt PSU In-Reply-To: <20080722131003.E7F471165C3@hamburg.alientech.net> References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> Message-ID: <4885EB9C.1060408@tiscali.co.uk> Mike S wrote: > Most switching supplies require a minimum load to operate correctly. If > the output is just open, and you don't see any voltage, it doesn't > necessarily indicate a problem. No, the unit is dead... I managed to get another one locally, a place called JPG in Chesterfield. Almost identical unit, but this one has a 5 way DIN plug on it and the pin outs for the voltages marked on the case. Checking the new one on no load I get volts, and almost the correct level, but as you say the no load voltage is often a bit different. Just to check, I opened the supplied unit and checked inside. as I suspected there's a soldered in fuse in line with the 3 pin input socket. Volts are OK on one side, and nothing on the other. A check with a continuity checker also confirms that the internal fues, A 2.5A type, is open circuit. From the look of the insides, something was short circuit as there's discolouration round a small, vertically mounted, PCB inside. Dave Ackrill From dave.g0dja at tiscali.co.uk Tue Jul 22 10:20:33 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 22 Jul 2008 15:20:33 +0100 Subject: [time-nuts] Thunderbolt PSU In-Reply-To: <20080722131003.E7F471165C3@hamburg.alientech.net> References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> Message-ID: <4885ECB1.2060303@tiscali.co.uk> Oh, for anyone else who has the same PSU as I received, the colours of the output, from the markings I can see on the PCB, are as follows. Brown = Ground (Yes, honestly! The brown wire is soldered to the case in my unit) Black = 12 Volts (I presume nevative) Red = +12 Volts Green = +5 Volts White = Could not see the markings under some electrolytics. I'll see if I can get a better look later. But, I would check for yourselves before connecting up to the Trimble. As ever, i can't accept responsibility if your unit is wired differently from mine. Dave From billj at ieee.org Tue Jul 22 11:28:21 2008 From: billj at ieee.org (Bill Janssen) Date: Tue, 22 Jul 2008 08:28:21 -0700 Subject: [time-nuts] Thunderbolt PSU In-Reply-To: <4885ECB1.2060303@tiscali.co.uk> References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> <4885ECB1.2060303@tiscali.co.uk> Message-ID: <4885FC95.60300@ieee.org> David Ackrill wrote: > Oh, for anyone else who has the same PSU as I received, the colours of > the output, from the markings I can see on the PCB, are as follows. > > Brown = Ground (Yes, honestly! The brown wire is soldered to the case > in my unit) > Black = 12 Volts (I presume nevative) > Red = +12 Volts > Green = +5 Volts > White = Could not see the markings under some electrolytics. I'll see > if I can get a better look later. > > But, I would check for yourselves before connecting up to the Trimble. > As ever, i can't accept responsibility if your unit is wired differently > from mine. > > Dave On my unit White is Common for the other voltage leads and blue is not used. Bill K7NOM From danrae at verizon.net Tue Jul 22 12:08:45 2008 From: danrae at verizon.net (Dan Rae) Date: Tue, 22 Jul 2008 09:08:45 -0700 Subject: [time-nuts] Austron 2100 keypad? Message-ID: <4886060D.20802@verizon.net> My 2100 timing receiver (no suffix) has started to give me problems with what looks like bounce from the keypad switches, with a lot of numbers repeating without being asked. Is this a known problem with these units, and is there a known fix? I don't think the guts of the pad are accessible for cleaning. Thanks, Dan From dave.g0dja at tiscali.co.uk Tue Jul 22 12:17:51 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 22 Jul 2008 17:17:51 +0100 Subject: [time-nuts] Thunderbolt PSU In-Reply-To: <4885FC95.60300@ieee.org> References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> <4885ECB1.2060303@tiscali.co.uk> <4885FC95.60300@ieee.org> Message-ID: <4886082F.2070702@tiscali.co.uk> Bill Janssen wrote: > On my unit White is Common for the other voltage leads and blue is not used. Yes Bill, Now I've had a bit of a poke round, the white is common, it's connected to the ground plane on the main PCB, and the blue wire is cut off just behind the grommet. My Thunderbolt lives! The replacement PSU seems to be working like a charm and my trusty old MF1000 frequency counter (bought in the 1980s) is showing that the 10MHz output is 10.00003MHz. Which I don't think is bad for such an old piece of test gear that has never been recalibrated since I bought it. Next job is to find that software that was mentioned for looking at the output from the 9 pin D socket. Although, I seem to think someone said it was RS442 not RS232? I'm using a 5V powered antenna that I got with some Aisin GPS boards many years ago. Next job is to make an SMA socket to F-Type plug adapter cable for the motorola antenna. Dave (G0DJA) From chris.kuethe at gmail.com Tue Jul 22 12:42:37 2008 From: chris.kuethe at gmail.com (Chris Kuethe) Date: Tue, 22 Jul 2008 09:42:37 -0700 Subject: [time-nuts] Thunderbolt PSU In-Reply-To: <4885AD39.8080304@tiscali.co.uk> References: <4885AD39.8080304@tiscali.co.uk> Message-ID: <91981b3e0807220942o15176ae2m641ff923cbaaa584@mail.gmail.com> On Tue, Jul 22, 2008 at 2:49 AM, David Ackrill wrote: > Also, I see that the antenna socket on the Thunderbolt is an F-type. > Someone has thoughtfully provided an F-Type to BNC adapter. However, > the plug on the Motorola GPS antenna is an SMA type. Ah well, I can > make a lead which should work instead. :-) on that note, I went to fry's and bought an SMA to BNC adapter which works pretty well. they didn't have SMA to F... *sigh* -- GDB has a 'break' feature; why doesn't it have 'fix' too? From dave.g0dja at tiscali.co.uk Tue Jul 22 12:47:01 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 22 Jul 2008 17:47:01 +0100 Subject: [time-nuts] Thunderbolt Lives In-Reply-To: <4886082F.2070702@tiscali.co.uk> References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> <4885ECB1.2060303@tiscali.co.uk> <4885FC95.60300@ieee.org> <4886082F.2070702@tiscali.co.uk> Message-ID: <48860F05.1060509@tiscali.co.uk> Well, setting up the Trimble software was quite straight forward, and I've got nearly all Green on the alarms. The only two yellowed are "Self Survey Activity" and "Stored Possition". I'll do some reading of the manual before I go messing with any of the settings. Next thing to do is save up for the 10GHz transceiver that this will be used to keep on frequency, and think about making some form of portable power supply. Has anyone done any tests as to how far out voltages on the +12 and -12 Volt lines can go before the Thunderbolt goes out of lock? One of the problems with using batteries out in the field is the weight. However, I guess I could probably manage a couple of lightweight 12V Gell Cells in series, and then some voltage regulators to give the 3 rails for the supply. Seeing that the power requirement isn't that great on the mains PSU, I would guess that a well charged, small, pair of gell cells would do? Dave (G0DJA) From ch at murgatroid.com Tue Jul 22 13:07:40 2008 From: ch at murgatroid.com (christopher hoover) Date: Tue, 22 Jul 2008 10:07:40 -0700 Subject: [time-nuts] HP58504A antenna In-Reply-To: References: Message-ID: <000b01c8ec1d$732db080$59891180$@com> Bruce wrote: > Circuit is exactly that to be expected with a discrete pHEMT or similar > device. > > It looks to me as if the bias flows through the trace on the BR > > and then through a couple of 001 R's before the bias > > setting 221 R. > > > > > Nonsense they are 100 ohm resistors text is upside down. Ah! > > This MMIC is before the filter, so it is probably been selected > > and biased to avoid IM problems. > > > > > Its unlikely to be an MMIC as they generally have all the bias parts > internal to the chip other than an output biasing resistor. > Also most MMICs do not have the input connected to dc ground. I stand corrected. -ch From david.partridge at dsl.pipex.com Tue Jul 22 13:17:38 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Tue, 22 Jul 2008 18:17:38 +0100 Subject: [time-nuts] Thunderbolt Lives In-Reply-To: <48860F05.1060509@tiscali.co.uk> References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> <4885ECB1.2060303@tiscali.co.uk> <4885FC95.60300@ieee.org><4886082F.2070702@tiscali.co.uk> <48860F05.1060509@tiscali.co.uk> Message-ID: The self survey will go green after it has completed the survey as will the stored position. Dave -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of David Ackrill Sent: 22 July 2008 17:47 To: Discussion of precise time and frequency measurement Subject: [time-nuts] Thunderbolt Lives Well, setting up the Trimble software was quite straight forward, and I've got nearly all Green on the alarms. The only two yellowed are "Self Survey Activity" and "Stored Possition". I'll do some reading of the manual before I go messing with any of the settings. Next thing to do is save up for the 10GHz transceiver that this will be used to keep on frequency, and think about making some form of portable power supply. Has anyone done any tests as to how far out voltages on the +12 and -12 Volt lines can go before the Thunderbolt goes out of lock? One of the problems with using batteries out in the field is the weight. However, I guess I could probably manage a couple of lightweight 12V Gell Cells in series, and then some voltage regulators to give the 3 rails for the supply. Seeing that the power requirement isn't that great on the mains PSU, I would guess that a well charged, small, pair of gell cells would do? Dave (G0DJA) _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From dave.g0dja at tiscali.co.uk Tue Jul 22 13:32:32 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 22 Jul 2008 18:32:32 +0100 Subject: [time-nuts] Thunderbolt Lives In-Reply-To: References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> <4885ECB1.2060303@tiscali.co.uk> <4885FC95.60300@ieee.org><4886082F.2070702@tiscali.co.uk> <48860F05.1060509@tiscali.co.uk> Message-ID: <488619B0.6050808@tiscali.co.uk> David C. Partridge wrote: > The self survey will go green after it has completed the survey as will the > stored position. > Thanks for the advice Dave, Yes, I can see that it's only 73% through the self survey, so I'll leave it whilst I do the dinner, and see if it's finished by then. Did I see, somewhere, that someone had written another program to collect data from the Thunderbolt? Also, is there a way to get it to keep a PC clock on time (allowing for the GPS leap second difference of course) as that would also be useful for times when I am not in range of the internet, but want to use Amateur Radio modes, like the WSJT modes, that rely upon accurate timing to ensure that you are transmitting and receiving at the correct times each minute? Dave (G0DJA) From cfharris at erols.com Tue Jul 22 14:07:42 2008 From: cfharris at erols.com (Chuck Harris) Date: Tue, 22 Jul 2008 14:07:42 -0400 Subject: [time-nuts] Austron 2100 keypad? In-Reply-To: <4886060D.20802@verizon.net> References: <4886060D.20802@verizon.net> Message-ID: <488621EE.9060104@erols.com> Hi Dan, It is a very well known problem. As the key contacts age and get dirty, they sort of "fry" rather than make a clean contact. You can gain a short term fix by replacing the two 1uf tantalum key debounce caps with a larger value. These capacitors are axial leaded hermetically sealed wet slug types. They are the only two on the front panel board. Their designation is C2 and C5, and they are located right next to the 74C923 keyboard debounce/encoder IC's on the front panel printed circuit board. I have replaced them with 3uf to get a mild improvement, 10uf seems to be a pretty good balance between key press response, and debouncing. Eventually, you will need to replace the keypad switches. They are individually soldered onto the board, and should be available. -Chuck Harris Dan Rae wrote: > My 2100 timing receiver (no suffix) has started to give me problems with > what looks like bounce from the keypad switches, with a lot of numbers > repeating without being asked. Is this a known problem with these > units, and is there a known fix? I don't think the guts of the pad are > accessible for cleaning. > > Thanks, > > Dan > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From jra at febo.com Tue Jul 22 14:11:30 2008 From: jra at febo.com (John Ackermann N8UR) Date: Tue, 22 Jul 2008 14:11:30 -0400 Subject: [time-nuts] Rack flange kit for 5370B and 3325B In-Reply-To: References: Message-ID: <488622D2.2010708@febo.com> It's been a year or so since I shopped for any, but eBay yielded quite a few for me, searching on "rack ears". John ---- J. L. Trantham said the following on 07/21/2008 07:19 AM: > I, too, have been looking for rack mount ears for similar units (5334B, > 3325A, 3335A, 8657A, 5087A, 105B, 8130A, etc.) with no luck. > > If there is anyone with a source or another idea of how to accomplish rack > mounting without the HP ears, I would like to hear about it also. > > Thanks, > > Joe > > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On > Behalf Of Jim Palfreyman > Sent: Monday, July 21, 2008 1:10 AM > To: time-nuts at febo.com > Subject: [time-nuts] Rack flange kit for 5370B and 3325B > > Hi, > > I've been looking for a bit with no luck so I thought I'd try here. > > I wish to mount my HP/Agilent 5370B and 3325B in a rack. Now the HP part > 5061-0077 (also known as 3325B-908 or 5370B-908) and called a "Rack Flange > Kit" (no handle version - although the handle version would be fine) looks > like what I want. > > Has anyone got a couple of sets of these they are willing to part with or > can least point me in the right direction? There are various companies that > sell military and aircraft spares but they will charge a hefty minimum price > - probably more than I paid for the actual units! > > I know these flanges aren't precision timing instruments, but they support > precision timing instruments and keep them out of harms way - so should be > revered in their own right. > > :-) > > Jim Palfreyman > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From jsimmons at rogerstwoway.com Tue Jul 22 15:51:08 2008 From: jsimmons at rogerstwoway.com (John Simmons) Date: Tue, 22 Jul 2008 14:51:08 -0500 Subject: [time-nuts] Efratom model identification Message-ID: <1DFBABF19C16E74B84683D252D3EAAA21BB468@v-ger.rogerstwoway.nymore> I have what I believe to be a rubidium frequency reference made by Efratom. Research with Google has not helped me find info on using it. The unit is a cube about 2"x3"x4" marked "ASSY 100334-004". The unit has a connector that looks identical to the Stanford PRS10. I have the pinout for that. Can anyone please help? Thanks! John A. Simmons Project Management Engineer Roger's Two Way Radio, Inc. (218) 751-3077 (800) 243-3077 Fax (218) 751-0508 www.rogerstwoway.com From had at to-way.com Tue Jul 22 16:07:21 2008 From: had at to-way.com (Had) Date: Tue, 22 Jul 2008 13:07:21 -0700 Subject: [time-nuts] Efratom model identification In-Reply-To: <1DFBABF19C16E74B84683D252D3EAAA21BB468@v-ger.rogerstwoway. nymore> References: <1DFBABF19C16E74B84683D252D3EAAA21BB468@v-ger.rogerstwoway.nymore> Message-ID: <20080722200743.38A71192805@mail-in04.adhost.com> John, Sounds to me like you have a FRS-C. Same pin out as the PRS-10 for the most part. See the FRS-C manual at my T&F site www.to-way.com Hadley At 12:51 PM 7/22/2008, you wrote: >I have what I believe to be a rubidium frequency reference made by >Efratom. Research with Google has not helped me find info on using it. >The unit is a cube about 2"x3"x4" marked "ASSY 100334-004". The unit has >a connector that looks identical to the Stanford PRS10. I have the >pinout for that. > >Can anyone please help? > >Thanks! >John A. Simmons >Project Management Engineer >Roger's Two Way Radio, Inc. >(218) 751-3077 >(800) 243-3077 >Fax (218) 751-0508 >www.rogerstwoway.com >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From rfnuts at arcor.de Tue Jul 22 16:08:57 2008 From: rfnuts at arcor.de (Adrian) Date: Tue, 22 Jul 2008 22:08:57 +0200 Subject: [time-nuts] Efratom model identification In-Reply-To: <1DFBABF19C16E74B84683D252D3EAAA21BB468@v-ger.rogerstwoway.nymore> References: <1DFBABF19C16E74B84683D252D3EAAA21BB468@v-ger.rogerstwoway.nymore> Message-ID: <48863E59.2050806@arcor.de> John, I don't have mine at hands to cross-check if I'm right, but you probably have a Ball Efratom / Symmetricom FRS. Adrian John Simmons schrieb: > I have what I believe to be a rubidium frequency reference made by > Efratom. Research with Google has not helped me find info on using it. > The unit is a cube about 2"x3"x4" marked "ASSY 100334-004". The unit has > a connector that looks identical to the Stanford PRS10. I have the > pinout for that. > > Can anyone please help? > > Thanks! > John A. Simmons > Project Management Engineer > Roger's Two Way Radio, Inc. > (218) 751-3077 > (800) 243-3077 > Fax (218) 751-0508 > www.rogerstwoway.com > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From boyscout at gmail.com Tue Jul 22 16:16:27 2008 From: boyscout at gmail.com (Matt Ettus) Date: Tue, 22 Jul 2008 13:16:27 -0700 Subject: [time-nuts] Test equipment-level phase noise PLLs Message-ID: In looking into extremely low phase noise synthesizers, I have come across the new HMC700LP4 chip from hittite, which seems to have the best figure of merit I have found, -227 dBm/Hz. That gives you -107dBc/Hz at 20 kHz offset at 6 GHz according to the datasheets. That sounds amazingly good, but my R+S signal generator does better. Do they use a different sort of architecture? Do they not use conventional dividers? Some other sort of phase detector? Thanks, Matt From jpradoes at telefonica.net Tue Jul 22 16:19:57 2008 From: jpradoes at telefonica.net (Jose Manuel) Date: Tue, 22 Jul 2008 22:19:57 +0200 Subject: [time-nuts] HP58504A antenna References: <007301c8ebb3$e57bac60$b0730520$@com><48856752.6040800@xtra.co.nz> <488573CE.20204@xtra.co.nz> Message-ID: <002b01c8ec38$503d7db0$2201a8c0@PC2> Thank you very much Bruce and all who replied my previous message, According to measurements made with multimeter I think the MMIC is damaged, because it?s consuming more than 10mA, when its maximum specified current, at 3V, is 8mA, and the typical 6mA; maybe some of its internal transistors are shorted. The measured supply voltage at pin 6, mid point of 270 and 68 ohms resistors, is 2.78V. The input transistor is supplied with 2.61V and biased with 0.69V, the current is 8mA, so I think it?s OK. By the way, my Z3801 only delivers 4.67V to the antenna connector. Datasheet of the MMIC can be seen here: http://www.necel.com/microwave/en/pdf/P13489EJ3V0DS00.pdf Now my problem is where to purchase one of these devices ;-) Best regards....Jos?, EA1PX ----- Original Message ----- From: "Bruce Griffiths" To: "Discussion of precise time and frequency measurement" Sent: Tuesday, July 22, 2008 7:44 AM Subject: Re: [time-nuts] HP58504A antenna > Correction: > Resistor values used are probably: > > 100 = 10 ohms > 560 = 56 ohms or is it 680 = 68 ohms? > 101 = 100 ohms > 121 = 120 ohms > 181 = 180 ohms > 221 = 220 ohms > 271 = 270 ohms > > > > Thus the total resistance from the 5V supply to the output terminal of > the input device is actually = 220 + 10 + 10 = 240 ohms. > Equivalent resistance from input device "source" terminals to ground = > 90 ohms. > Voltage divider for Vcc of MMIC is 56 ohms from 5V is series with 270 > ohms to ground nominal current ~ 15mA + 6mA? for MMIC, total ~ 21mA. > Input device if shorted would have a current drain of 5V/(90+220 + 10 + > 10) ~ 15mA. > > Thus measuring the dc output of the input device and/or measuring its > power supply current is required to assist diagnosis. > Some pHEMT devices have an absolute drain source voltage limit as low as > 3V so the operating drain source voltage of the input device may only be > 1/2 that. > Typical MMICs have a somewhat larger dc voltage on the output. > > Bruce > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > -- > No virus found in this incoming message. > Checked by AVG. > Version: 7.5.526 / Virus Database: 270.5.3/1564 - Release Date: 21/07/2008 > 6:42 > > From dforbes at dakotacom.net Tue Jul 22 16:26:10 2008 From: dforbes at dakotacom.net (David Forbes) Date: Tue, 22 Jul 2008 13:26:10 -0700 Subject: [time-nuts] Test equipment-level phase noise PLLs In-Reply-To: References: Message-ID: <48864262.30608@dakotacom.net> Matt Ettus wrote: > In looking into extremely low phase noise synthesizers, I have come > across the new HMC700LP4 chip from hittite, which seems to have the > best figure of merit I have found, -227 dBm/Hz. That gives you > -107dBc/Hz at 20 kHz offset at 6 GHz according to the datasheets. > > That sounds amazingly good, but my R+S signal generator does better. > Do they use a different sort of architecture? Do they not use > conventional dividers? Some other sort of phase detector? > > Thanks, > Matt Matt, They usually use a microwave mixer heterodyning against a harmonic multiplier driven by the reference frequency, producing an IF in the 30-50 MHz area. Often there will be a dual loop PLL to improve performance. From dave.g0dja at tiscali.co.uk Tue Jul 22 16:49:59 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 22 Jul 2008 21:49:59 +0100 Subject: [time-nuts] Thunderbolt Lives In-Reply-To: References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> <4885ECB1.2060303@tiscali.co.uk> <4885FC95.60300@ieee.org><4886082F.2070702@tiscali.co.uk> <48860F05.1060509@tiscali.co.uk> Message-ID: <488647F7.3020202@tiscali.co.uk> David C. Partridge wrote: > The self survey will go green after it has completed the survey as will the > stored position. The Self Survey has gone green as Self-Survey Progress is at 100% now, and the Thunderbolt is seeing 7 out of the 8 satellites at the moment. However, Stored Position is still coloured yellow. I'll leave it monitoring over night to see what happens. Dave (G0DJA) From rfnuts at arcor.de Tue Jul 22 16:51:36 2008 From: rfnuts at arcor.de (Adrian) Date: Tue, 22 Jul 2008 22:51:36 +0200 Subject: [time-nuts] HP58504A antenna In-Reply-To: <002b01c8ec38$503d7db0$2201a8c0@PC2> References: <007301c8ebb3$e57bac60$b0730520$@com><48856752.6040800@xtra.co.nz> <488573CE.20204@xtra.co.nz> <002b01c8ec38$503d7db0$2201a8c0@PC2> Message-ID: <48864858.9010703@arcor.de> Jos?, 14 mA seems a bit high... but you may check the other pin voltages, too. The UPC2749TB is available here: http://www.mouser.com/ http://search.digikey.com/ Digikey has a sales office in Germany, so you might save on shipping. It's probably easier to ask NEC for 2...3 samples than to order a single device from a supplyer... ...or try it here: http://www.msc-ge.com/frame/d/wir/inhalt_hig.html ... they are also in Madrid and in Barcelona :-) http://www.msc-ge.com/frame/d/wir/inhalt_hig.html How sounds that? Adrian Jose Manuel schrieb: > Thank you very much Bruce and all who replied my previous message, > > > According to measurements made with multimeter I think the MMIC is damaged, > because it?s consuming more than 10mA, when its maximum specified current, > at 3V, is 8mA, and the typical 6mA; maybe some of its internal transistors > are shorted. The measured supply voltage at pin 6, mid point of 270 and 68 > ohms resistors, is 2.78V. > > The input transistor is supplied with 2.61V and biased with 0.69V, the > current is 8mA, so I think it?s OK. > > By the way, my Z3801 only delivers 4.67V to the antenna connector. > > Datasheet of the MMIC can be seen here: > http://www.necel.com/microwave/en/pdf/P13489EJ3V0DS00.pdf > > Now my problem is where to purchase one of these devices ;-) > > > > Best regards....Jos?, EA1PX > > > > > > > > > ----- Original Message ----- > From: "Bruce Griffiths" > To: "Discussion of precise time and frequency measurement" > > Sent: Tuesday, July 22, 2008 7:44 AM > Subject: Re: [time-nuts] HP58504A antenna > > > >> Correction: >> Resistor values used are probably: >> >> 100 = 10 ohms >> 560 = 56 ohms or is it 680 = 68 ohms? >> 101 = 100 ohms >> 121 = 120 ohms >> 181 = 180 ohms >> 221 = 220 ohms >> 271 = 270 ohms >> >> >> >> Thus the total resistance from the 5V supply to the output terminal of >> the input device is actually = 220 + 10 + 10 = 240 ohms. >> Equivalent resistance from input device "source" terminals to ground = >> 90 ohms. >> Voltage divider for Vcc of MMIC is 56 ohms from 5V is series with 270 >> ohms to ground nominal current ~ 15mA + 6mA? for MMIC, total ~ 21mA. >> Input device if shorted would have a current drain of 5V/(90+220 + 10 + >> 10) ~ 15mA. >> >> Thus measuring the dc output of the input device and/or measuring its >> power supply current is required to assist diagnosis. >> Some pHEMT devices have an absolute drain source voltage limit as low as >> 3V so the operating drain source voltage of the input device may only be >> 1/2 that. >> Typical MMICs have a somewhat larger dc voltage on the output. >> >> Bruce >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts at febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> -- >> No virus found in this incoming message. >> Checked by AVG. >> Version: 7.5.526 / Virus Database: 270.5.3/1564 - Release Date: 21/07/2008 >> 6:42 >> >> >> > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From dave.g0dja at tiscali.co.uk Tue Jul 22 17:00:42 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 22 Jul 2008 22:00:42 +0100 Subject: [time-nuts] Thunderbolt Lives In-Reply-To: References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> <4885ECB1.2060303@tiscali.co.uk> <4885FC95.60300@ieee.org><4886082F.2070702@tiscali.co.uk> <48860F05.1060509@tiscali.co.uk> Message-ID: <48864A7A.9090006@tiscali.co.uk> Only 3 sats visible and the Thunderbolt has un-locked. I guess I need to get an external antenna up ouside and clear of as many obstructions as I can make it. Dave (G0DJA) From wbeam at gci.net Tue Jul 22 17:15:18 2008 From: wbeam at gci.net (Bill Beam) Date: Tue, 22 Jul 2008 13:15:18 -0800 Subject: [time-nuts] Thunderbolt Lives Message-ID: <0K4F007DFF1SV0A0@msgmmp-1.gci.net> In this case the Stored Position will never go green since 1) the Self survey has not been configured to store the surveyed position and 2) you have not manually stored a position. You have two choices: 1) Click on Setup, select Position..., fill in an appropriate position and click Save Segment. or 2) Click on Setup, select Self-Survey..., set the Save Position Flag to Save and click Save Segment. Then click on Control and Restart Self-Survey. The unit was shipped configured not to save position after a self-survey. This assures a Self-Survey after power cycle. Regards, Bill (NL7F) On 7/22/2008 12:49:59 PM, David Ackrill (dave.g0dja at tiscali.co.uk) wrote: > David C. Partridge wrote: > > The self survey will go green after it has completed the survey as will > the > > stored position. > > The Self Survey has gone green as Self-Survey Progress is at 100% now, > and the Thunderbolt is seeing 7 out of the 8 satellites at the moment. > However, Stored Position is still coloured yellow. > > I'll leave it monitoring over night to see what happens. > > Dave (G0DJA) > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. Bill Beam NL7F From dave.g0dja at tiscali.co.uk Tue Jul 22 17:59:57 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 22 Jul 2008 22:59:57 +0100 Subject: [time-nuts] Thunderbolt Lives In-Reply-To: <0K4F007DFF1SV0A0@msgmmp-1.gci.net> References: <0K4F007DFF1SV0A0@msgmmp-1.gci.net> Message-ID: <4886585D.9010001@tiscali.co.uk> Bill Beam wrote: > The unit was shipped configured not to save position after a self-survey. This > assures a Self-Survey after power cycle. Thanks Bill, Someone else pointed out my mistake as well. So, I've now set the self-survey up again after doing as you suggested. Thanks - Dave (G0DJA) From dave.g0dja at tiscali.co.uk Tue Jul 22 19:14:41 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Wed, 23 Jul 2008 00:14:41 +0100 Subject: [time-nuts] Thunderbolt SV and AMU Signal levels In-Reply-To: <4886585D.9010001@tiscali.co.uk> References: <0K4F007DFF1SV0A0@msgmmp-1.gci.net> <4886585D.9010001@tiscali.co.uk> Message-ID: <488669E1.4040704@tiscali.co.uk> Sorry to be a bore, but like any kid with a new toy I'm facinated by the changing values on the display... What do the values under SV and AMU mean? Maybe I should recognise them from other GPS satellite days, but they don't seem to be values that I remember. I'm sure it all means that they are to the north, south, east or west of here and to do with signal strength to my location or how good, or bad, the lock to the satellites is.. But, nothing that I can remember, to be honest... The 10MHz output seems, as far as my old Multifunction Counter is concerned, to be to 10.00000MHz within +/-0.00001 MHz. The display showing 10.00003 to 10.00004 MHz all evening. So, my guess is that my poor old counter is +/- 10Hz out, but that may be due to the age and non-calibration of my frequency counter over the years. Or... The Thunderbolt 10MHz output is moving up and down by 0.00001 MHz within a 10MHz band. This is where I start to get to grips with the spectrum analyser that a friend of mine lent to me. I hope... Dave (G0DJA) From chris.kuethe at gmail.com Tue Jul 22 19:25:59 2008 From: chris.kuethe at gmail.com (Chris Kuethe) Date: Tue, 22 Jul 2008 16:25:59 -0700 Subject: [time-nuts] Thunderbolt SV and AMU Signal levels In-Reply-To: <488669E1.4040704@tiscali.co.uk> References: <0K4F007DFF1SV0A0@msgmmp-1.gci.net> <4886585D.9010001@tiscali.co.uk> <488669E1.4040704@tiscali.co.uk> Message-ID: <91981b3e0807221625o27df7417m9ebe98322a8a2c09@mail.gmail.com> On Tue, Jul 22, 2008 at 4:14 PM, David Ackrill wrote: > Sorry to be a bore, but like any kid with a new toy I'm facinated by the > changing values on the display... > > What do the values under SV and AMU mean? SV = space vehicle. mostly irrelevant, unless you care about the serial number of the bit of metal up there. Usually people mean to say PRN, or Pseudo-Random Noise code number - one of the 32 codes transmitted by the satellite. AMU is Amplitude Measurement Unit. Trimble's signal strength measurement. > Maybe I should recognise them from other GPS satellite days, but they > don't seem to be values that I remember. > > I'm sure it all means that they are to the north, south, east or west of > here and to do with signal strength to my location or how good, or bad, > the lock to the satellites is.. But, nothing that I can remember, to be > honest... You're thinking of azimuth and elevation. > The 10MHz output seems, as far as my old Multifunction Counter is > concerned, to be to 10.00000MHz within +/-0.00001 MHz. > > The display showing 10.00003 to 10.00004 MHz all evening. > > So, my guess is that my poor old counter is +/- 10Hz out, but that may > be due to the age and non-calibration of my frequency counter over the > years. > > Or... The Thunderbolt 10MHz output is moving up and down by 0.00001 MHz > within a 10MHz band. > > This is where I start to get to grips with the spectrum analyser that a > friend of mine lent to me. I hope... > > Dave (G0DJA) > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- GDB has a 'break' feature; why doesn't it have 'fix' too? From jmiles at pop.net Tue Jul 22 19:30:00 2008 From: jmiles at pop.net (John Miles) Date: Tue, 22 Jul 2008 16:30:00 -0700 Subject: [time-nuts] Test equipment-level phase noise PLLs In-Reply-To: Message-ID: I've played with the Hittite chips before and obtained PN results in the same ballpark (see http://www.ke5fx.com/hpll.htm ), but at 8 GHz rather than 6 GHz. To save further head-scratching, the figure of merit on these chips works like this: In-band phase noise in dBc/Hz = FOM + 10*log(Fcomp) + 20*log(N) This is the best-case noise level that you will get assuming a perfectly-clean reference and no VCO noise contribution. As usual, Hittite's less-than-ideal data sheet doesn't make that relationship clear. Specifically, the 5.8-GHz integer-N plot in figure 1 appear to have been made with a 50 MHz comparison frequency and N=116. -107 dBc/Hz - 77 - 41 = -225 dBc/Hz. From dave.g0dja at tiscali.co.uk Tue Jul 22 19:31:12 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Wed, 23 Jul 2008 00:31:12 +0100 Subject: [time-nuts] Thunderbolt SV and AMU Signal levels In-Reply-To: <488669E1.4040704@tiscali.co.uk> References: <0K4F007DFF1SV0A0@msgmmp-1.gci.net> <4886585D.9010001@tiscali.co.uk> <488669E1.4040704@tiscali.co.uk> Message-ID: <48866DC0.1010507@tiscali.co.uk> Oh well then, I guess everyone is asleep. So, GN all. Dave (G0DJA) From GandalfG8 at aol.com Tue Jul 22 19:41:39 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Tue, 22 Jul 2008 19:41:39 EDT Subject: [time-nuts] Thunderbolt SV and AMU Signal levels Message-ID: In a message dated 23/07/2008 00:15:51 GMT Daylight Time, dave.g0dja at tiscali.co.uk writes: The 10MHz output seems, as far as my old Multifunction Counter is concerned, to be to 10.00000MHz within +/-0.00001 MHz. The display showing 10.00003 to 10.00004 MHz all evening. So, my guess is that my poor old counter is +/- 10Hz out, but that may be due to the age and non-calibration of my frequency counter over the years. Or... The Thunderbolt 10MHz output is moving up and down by 0.00001 MHz within a 10MHz band. This is where I start to get to grips with the spectrum analyser that a friend of mine lent to me. I hope... ------------- Hi Dave One of the problems with becoming a time-nut is that the first step, whatever that might be, is fatal. And after that it just gets worse:-) Unless your Thunderbolt is very unwell, which I doubt, it won't be moving anywhere near that much. Not only is the reference in your counter likley to be off frequency but it's also likely that the stability of the reference is much worse than what you're trying to measure, and this is where the downward spiral really begins. Earlier this year I bought an HP 53132A counter to give me the resolution I'd decided I needed and promptly used it to measure the 10MHz output of a Thunderbolt. The result was similar to what you're seeing and a great disappointment, especially as I didn't know at first whether to trust the counter or the Thunderbolt. However, using another Thunderbolt to drive the external reference input on the counter gave a very different result, and immediately any variation became just a few figures in the 10th decimal place. It turned out that the basic reference as fitted to the 3132A was fine to demonstrate that the counter was working, but that was it. If your counter will accept an external reference I'd suggest using the Thunderbolt for that and just trusting the results. However, if the figures you've shown represent the resolution limit of your counter then you may want to consider a counter with better resolution, still using the Thunderbolt as a reference of course, but just watch your balance as the downward slide continues:-) regards Nigel GM8PZR From dave.g0dja at tiscali.co.uk Tue Jul 22 19:42:46 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Wed, 23 Jul 2008 00:42:46 +0100 Subject: [time-nuts] Thunderbolt SV and AMU Signal levels In-Reply-To: <91981b3e0807221625o27df7417m9ebe98322a8a2c09@mail.gmail.com> References: <0K4F007DFF1SV0A0@msgmmp-1.gci.net> <4886585D.9010001@tiscali.co.uk> <488669E1.4040704@tiscali.co.uk> <91981b3e0807221625o27df7417m9ebe98322a8a2c09@mail.gmail.com> Message-ID: <48867076.2020308@tiscali.co.uk> Chris Kuethe wrote: >> What do the values under SV and AMU mean? > > SV = space vehicle. mostly irrelevant, unless you care about the > serial number of the bit of metal up there. Usually people mean to say > PRN, or Pseudo-Random Noise code number - one of the 32 codes > transmitted by the satellite. > > AMU is Amplitude Measurement Unit. Trimble's signal strength measurement. Thanks Chris, I'll watch that value instead. >> I'm sure it all means that they are to the north, south, east or west of >> here and to do with signal strength to my location or how good, or bad, >> the lock to the satellites is.. But, nothing that I can remember, to be >> honest... > > You're thinking of azimuth and elevation. You are probably correct, some other software probably did that for me. Not that it helped me much, to be honest. Dave (G0DJA) From mikes at flatsurface.com Tue Jul 22 19:58:38 2008 From: mikes at flatsurface.com (Mike S) Date: Tue, 22 Jul 2008 19:58:38 -0400 Subject: [time-nuts] Thunderbolt SV and AMU Signal levels In-Reply-To: <488669E1.4040704@tiscali.co.uk> References: <0K4F007DFF1SV0A0@msgmmp-1.gci.net> <4886585D.9010001@tiscali.co.uk> <488669E1.4040704@tiscali.co.uk> Message-ID: <20080722235843.F1C281165C3@hamburg.alientech.net> At 07:14 PM 7/22/2008, David Ackrill wrote... >So, my guess is that my poor old counter is +/- 10Hz out, but that may > >be due to the age and non-calibration of my frequency counter over the > >years. > >Or... The Thunderbolt 10MHz output is moving up and down by 0.00001 >MHz >within a 10MHz band. That would be extremely unlikely. Your counter timebase is changing, probably temperature related. Oh, SV is "Space Vehicle," and is probably being used incorrectly - the Thunderbolt is likely reporting the PRN (Pseudo Random Noise) number for each of the signals received. For the first GPS satellites, SV typically equalled the PRN, but that is not required to be the case, and it isn't always. For example, in 1993, SV-32's PRN number was changed from PRN#32 to PRN#01, due to poor programming in some GPS receivers. AMU are "amplitude measurement units," (aka "arbitrary mystery units") and are used to report S/N of received signals. From jmfranke at cox.net Tue Jul 22 20:28:11 2008 From: jmfranke at cox.net (John Franke) Date: Tue, 22 Jul 2008 20:28:11 -0400 Subject: [time-nuts] Thunderbolt SV and AMU Signal levels References: <0K4F007DFF1SV0A0@msgmmp-1.gci.net><4886585D.9010001@tiscali.co.uk> <488669E1.4040704@tiscali.co.uk> Message-ID: <013501c8ec5a$fd98f210$1e89a662@youre7075dc078> Variation of +/- one count in the last digit is normal for any counter. It is caused by a slight shift between the counter gate and the input signal. The longer the time between digit changes, the more stable the phase between the unknown and the counter gate. John WA4WDL ----- Original Message ----- From: "David Ackrill" To: "Discussion of precise time and frequency measurement" Sent: Tuesday, July 22, 2008 7:14 PM Subject: [time-nuts] Thunderbolt SV and AMU Signal levels > Sorry to be a bore, but like any kid with a new toy I'm facinated by the > changing values on the display... > > What do the values under SV and AMU mean? > > Maybe I should recognise them from other GPS satellite days, but they > don't seem to be values that I remember. > > I'm sure it all means that they are to the north, south, east or west of > here and to do with signal strength to my location or how good, or bad, > the lock to the satellites is.. But, nothing that I can remember, to be > honest... > > The 10MHz output seems, as far as my old Multifunction Counter is > concerned, to be to 10.00000MHz within +/-0.00001 MHz. > > The display showing 10.00003 to 10.00004 MHz all evening. > > So, my guess is that my poor old counter is +/- 10Hz out, but that may > be due to the age and non-calibration of my frequency counter over the > years. > > Or... The Thunderbolt 10MHz output is moving up and down by 0.00001 MHz > within a 10MHz band. > > This is where I start to get to grips with the spectrum analyser that a > friend of mine lent to me. I hope... > > Dave (G0DJA) > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From didier at cox.net Wed Jul 23 00:47:32 2008 From: didier at cox.net (Didier Juges) Date: Tue, 22 Jul 2008 23:47:32 -0500 Subject: [time-nuts] Thunderbolt Lives In-Reply-To: <48860F05.1060509@tiscali.co.uk> References: <4885AD39.8080304@tiscali.co.uk> <20080722131003.E7F471165C3@hamburg.alientech.net> <4885ECB1.2060303@tiscali.co.uk> <4885FC95.60300@ieee.org><4886082F.2070702@tiscali.co.uk> <48860F05.1060509@tiscali.co.uk> Message-ID: <005401c8ec7f$38e40b10$0a01a8c0@didierhp> http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:store_position_on _trimble_thunderbolt Thank to John Miles for that one... Didier KO4BB > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of David Ackrill > Sent: Tuesday, July 22, 2008 11:47 AM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] Thunderbolt Lives > > Well, setting up the Trimble software was quite straight > forward, and I've got nearly all Green on the alarms. > > The only two yellowed are "Self Survey Activity" and "Stored > Possition". > ... > > Dave (G0DJA) > From df6jb at ulrich-bangert.de Wed Jul 23 02:48:52 2008 From: df6jb at ulrich-bangert.de (Ulrich Bangert) Date: Wed, 23 Jul 2008 08:48:52 +0200 Subject: [time-nuts] Thunderbolt SV and AMU Signal levels In-Reply-To: <013501c8ec5a$fd98f210$1e89a662@youre7075dc078> Message-ID: <9835219326F6421AB4A20EA07D3471FD@athlon> Gents, just in order to prevent anybody into believing that > Variation of +/- one count in the last digit is normal for > any counter. It > is caused by a slight shift between the counter gate and the > input signal. > The longer the time between digit changes, the more stable > the phase between > the unknown and the counter gate. were some kind of universal truth: This resembles the counter technology of some 30-40 years ago and you will not find any counter model of any serious manufacturer that uses "gate times" (if this term should be allowed at all today) which are uncorrelated to the input signal. I am well aware of the fact that the existence of easy programmable microcontrollers and cheap high frequency dividers have encouraged zillions of amateur developers to publish mcu based "frequency counters" that work the way as described above. Nevertheless this is by far not of the technology of today. Best regards Ulrich Bangert > -----Ursprungliche Nachricht----- > Von: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] Im Auftrag von John Franke > Gesendet: Mittwoch, 23. Juli 2008 02:28 > An: Discussion of precise time and frequency measurement > Betreff: Re: [time-nuts] Thunderbolt SV and AMU Signal levels > > > Variation of +/- one count in the last digit is normal for > any counter. It > is caused by a slight shift between the counter gate and the > input signal. > The longer the time between digit changes, the more stable > the phase between > the unknown and the counter gate. > > John WA4WDL > > ----- Original Message ----- > From: "David Ackrill" > To: "Discussion of precise time and frequency measurement" > > Sent: Tuesday, July 22, 2008 7:14 PM > Subject: [time-nuts] Thunderbolt SV and AMU Signal levels > > > > Sorry to be a bore, but like any kid with a new toy I'm > facinated by > > the changing values on the display... > > > > What do the values under SV and AMU mean? > > > > Maybe I should recognise them from other GPS satellite > days, but they > > don't seem to be values that I remember. > > > > I'm sure it all means that they are to the north, south, > east or west > > of here and to do with signal strength to my location or > how good, or > > bad, the lock to the satellites is.. But, nothing that I can > > remember, to be honest... > > > > The 10MHz output seems, as far as my old Multifunction Counter is > > concerned, to be to 10.00000MHz within +/-0.00001 MHz. > > > > The display showing 10.00003 to 10.00004 MHz all evening. > > > > So, my guess is that my poor old counter is +/- 10Hz out, > but that may > > be due to the age and non-calibration of my frequency > counter over the > > years. > > > > Or... The Thunderbolt 10MHz output is moving up and down by 0.00001 > > MHz within a 10MHz band. > > > > This is where I start to get to grips with the spectrum > analyser that > > a friend of mine lent to me. I hope... > > > > Dave (G0DJA) > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts at febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts > and > follow the instructions there. > From GandalfG8 at aol.com Wed Jul 23 06:06:20 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Wed, 23 Jul 2008 06:06:20 EDT Subject: [time-nuts] Thunderbolt SV and AMU Signal levels Message-ID: In a message dated 23/07/2008 00:42:47 GMT Daylight Time, GandalfG8 at aol.com writes: It turned out that the basic reference as fitted to the 3132A was fine to demonstrate that the counter was working, but that was it. -------------- Please excuse late night brain misfunction..... 3132A should read 53132A regards Nigel GM8PZR From mskop at bigpond.net.au Wed Jul 23 10:09:29 2008 From: mskop at bigpond.net.au (Max Skop) Date: Thu, 24 Jul 2008 00:09:29 +1000 Subject: [time-nuts] How to get 32.768KHz from 10MHz. Message-ID: <00b901c8eccd$b95782b0$7300a8c0@p4253> How does one get a 32.768KHz signal from our 10MHz reference. There does not appear to be a nice divide ratio to do this. With a locked 32.768KHz signal one could lock the oscillator of any of the cheap (low cost) LCD clocks that are available with nice big digits, temperature sensors and calendars, etc. Any suggestions on how to do it?? Regards Max ps. I got sucked in good. Six months ago all I had was an HP 10811 and now I have another crystal oscillator, two rubidiums and a Trimble GPS. From newell at cei.net Wed Jul 23 10:18:39 2008 From: newell at cei.net (Scott Newell) Date: Wed, 23 Jul 2008 09:18:39 -0500 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <00b901c8eccd$b95782b0$7300a8c0@p4253> Message-ID: <200807231418.m6NEIeAY019070@mail963c35.nsolutionszone.com> At 09:09 AM 7/23/2008 , Max Skop wrote: >How does one get a 32.768KHz signal from our 10MHz reference. >There does not appear to be a nice divide ratio to do this. >With a locked 32.768KHz signal one could lock the oscillator of any of the cheap (low cost) LCD clocks that are available with nice big digits, temperature sensors and calendars, etc. >Any suggestions on how to do it?? DDS? From mikes at flatsurface.com Wed Jul 23 10:32:34 2008 From: mikes at flatsurface.com (Mike S) Date: Wed, 23 Jul 2008 10:32:34 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <00b901c8eccd$b95782b0$7300a8c0@p4253> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> Message-ID: <20080723143304.18A811165C3@hamburg.alientech.net> At 10:09 AM 7/23/2008, Max Skop wrote... >How does one get a 32.768KHz signal from our 10MHz reference. >There does not appear to be a nice divide ratio to do this. I've thought about this too. It seems the simple way would be to clock a PIC with the 10 MHz, then use loops to produce the 32768 Hz. It's easier than it seems once you realize that phase noise doesn't really matter in this application - duty cycles don't need to be exactly 50%, etc. From jmfranke at cox.net Wed Jul 23 11:11:39 2008 From: jmfranke at cox.net (John Franke) Date: Wed, 23 Jul 2008 11:11:39 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. References: <00b901c8eccd$b95782b0$7300a8c0@p4253> Message-ID: <008401c8ecd6$680ba810$1e89a662@youre7075dc078> The only thing that comes to mind is to divide the 10 MHz by 2500000 (5x5x100000) and then use a phase locked loop to multiply by 8192. Of course the PLL would best control a varactor with a clock crystal vice controlling an RC oscillator. Other divisor multiplier pairs are: 1250000/4096, 625000/2048, 312500/1024, 156250/512, and 78125/256. John WA4WDL ----- Original Message ----- From: "Max Skop" To: Sent: Wednesday, July 23, 2008 10:09 AM Subject: [time-nuts] How to get 32.768KHz from 10MHz. > How does one get a 32.768KHz signal from our 10MHz reference. > There does not appear to be a nice divide ratio to do this. > With a locked 32.768KHz signal one could lock the oscillator of any of > the cheap (low cost) LCD clocks that are available with nice big digits, > temperature sensors and calendars, etc. > Any suggestions on how to do it?? > > Regards > Max > > ps. I got sucked in good. Six months ago all I had was an HP 10811 and now > I have another crystal oscillator, two rubidiums and a Trimble GPS. > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From wje at quackers.net Wed Jul 23 11:30:16 2008 From: wje at quackers.net (wje) Date: Wed, 23 Jul 2008 11:30:16 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <008401c8ecd6$680ba810$1e89a662@youre7075dc078> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <008401c8ecd6$680ba810$1e89a662@youre7075dc078> Message-ID: <48874E88.2070101@quackers.net> I was faced with this problem a few years ago, too. I essentially followed John's solution, but used the 1pps GPS pulse as the PLL reference. I then used the 32.768K vco output to injection-lock the 32.768K crystal on the LCD clock. Much to my surprise, it worked quite well. And, as pointed out already, jitter isn't an issue for this application. Bill Ezell ---------- They said 'Windows or better' so I used Linux. John Franke wrote: The only thing that comes to mind is to divide the 10 MHz by 2500000 (5x5x100000) and then use a phase locked loop to multiply by 8192. Of course the PLL would best control a varactor with a clock crystal vice controlling an RC oscillator. Other divisor multiplier pairs are: 1250000/4096, 625000/2048, 312500/1024, 156250/512, and 78125/256. John WA4WDL ----- Original Message ----- From: "Max Skop" [1] To: [2] Sent: Wednesday, July 23, 2008 10:09 AM Subject: [time-nuts] How to get 32.768KHz from 10MHz. How does one get a 32.768KHz signal from our 10MHz reference. There does not appear to be a nice divide ratio to do this. With a locked 32.768KHz signal one could lock the oscillator of any of the cheap (low cost) LCD clocks that are available with nice big digits, temperature sensors and calendars, etc. Any suggestions on how to do it?? Regards Max ps. I got sucked in good. Six months ago all I had was an HP 10811 and now I have another crystal oscillator, two rubidiums and a Trimble GPS. _______________________________________________ time-nuts mailing list -- [3]time-nuts at febo.com To unsubscribe, go to [4]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [5]time-nuts at febo.com To unsubscribe, go to [6]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:mskop at bigpond.net.au 2. mailto:time-nuts at febo.com 3. mailto:time-nuts at febo.com 4. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 5. mailto:time-nuts at febo.com 6. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts From James.P.Lux at jpl.nasa.gov Wed Jul 23 11:55:00 2008 From: James.P.Lux at jpl.nasa.gov (Jim Lux) Date: Wed, 23 Jul 2008 08:55:00 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <00b901c8eccd$b95782b0$7300a8c0@p4253> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> Message-ID: <6.2.5.6.2.20080723085020.02d54a40@jpl.nasa.gov> At 07:09 AM 7/23/2008, Max Skop wrote: >How does one get a 32.768KHz signal from our 10MHz reference. >There does not appear to be a nice divide ratio to do this. >With a locked 32.768KHz signal one could lock the oscillator of any >of the cheap (low cost) LCD clocks that are available with nice big >digits, temperature sensors and calendars, etc. >Any suggestions on how to do it?? > >Regards >Max > >ps. I got sucked in good. Six months ago all I had was an HP 10811 >and now I have another crystal oscillator, two rubidiums and a >Trimble GPS. >____ There's two approaches to your high level problem (driving a clock)... one is to make 32.768 kHz, the other is to directly drive the 1pps. Obviously, dividing down 10M to get to 1Hz is easy. But, for the other, you don't need to have a perfect symmetrical sine wave. All you need to do is make sure that there are 32,768 transitions in a second, so any sort of rough and ready divider scheme will work. Now.. in the lab what I did is use a HP3325B to make clocks run on Mars time See: http://www.techbriefs.com/content/view/2299/34/ Since the 3325 was locked to the lab's maser, it's probably the most accurate Mars clock around (bearing in mind that Mars's rotation isn't nearly as stable as the maser, so it's superfluous accuracy) You can do other nifty things, by the way... you can make a clock that displays solar elevation ("sundial time") because the rate can be changed systematically. I never did get around to programming a PIC to do some of this stuff, but it would be quite straightforward. Jim Lux From tvb at LeapSecond.com Wed Jul 23 11:55:34 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Wed, 23 Jul 2008 08:55:34 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz. References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> Message-ID: <002301c8ecdc$8ee4aad0$0900a8c0@pc52> Since synchronization is more important than jitter in this application it's easy to generate 32 kHz from 10 MHz. A 10 MHz clock into a PIC gives a 400 ns/instruction time. To produce 32.768 kHz you flip an output pin put every 38 instructions, except that 9632 times per second you make it 39 instructions instead. The result is 65536 bit flips per second (giving a frequency of exactly 32768 Hz) consuming 2 500 000 instructions per second. The output accuracy equals the input accuracy. The output jitter is as most 400 ns. /tvb From didier at cox.net Wed Jul 23 11:56:04 2008 From: didier at cox.net (Didier Juges) Date: Wed, 23 Jul 2008 11:56:04 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <20080723143304.18A811165C3@hamburg.alientech.net> Message-ID: <20080723115604.G9SDY.207613.imail@eastrmwml14.mgt.cox.net> Problem is one period of 32768 is not a multiple of 100nS (one period of 10 MHz) so that won't work. Maybe there is a common denominator and it may be possible to generate an average 32768 periods over one second, even though all periods may not be equal. Didier KO4BB ---- Mike S wrote: > At 10:09 AM 7/23/2008, Max Skop wrote... > >How does one get a 32.768KHz signal from our 10MHz reference. > >There does not appear to be a nice divide ratio to do this. > > I've thought about this too. It seems the simple way would be to clock > a PIC with the 10 MHz, then use loops to produce the 32768 Hz. It's > easier than it seems once you realize that phase noise doesn't really > matter in this application - duty cycles don't need to be exactly 50%, > etc. > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From dave.g0dja at tiscali.co.uk Wed Jul 23 12:28:49 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Wed, 23 Jul 2008 17:28:49 +0100 Subject: [time-nuts] Thunderbolt SV and AMU Signal levels In-Reply-To: References: Message-ID: <48875C41.3000900@tiscali.co.uk> GandalfG8 at aol.com wrote: > If your counter will accept an external reference I'd suggest using the > Thunderbolt for that and just trusting the results. > However, if the figures you've shown represent the resolution limit of your > counter then you may want to consider a counter with better resolution, still > using the Thunderbolt as a reference of course, but just watch your balance > as the downward slide continues:-) Thanks Nigel, Yes, I suspected the counter, rather than the Thunderbolt. After all, as I said before, the counter is over 20 years old and probably wasn't a cutting edge design even then. It was bought from Maplins in Erdington, Birmingham, just a year after I got my old G6 callsign. The thing with precision and accuracy is that it's all relative to whatever standard you have to measure the readings you get against. This frequency counter of mine has never been checked against any form of standard since I bought it anyway. In my case, as long as the 10MHz output keeps the frequency of the 10GHz transceiver (when I save enough to get one) in one place long enough for another station to find it, whatever the nth decimal place might be, so that we can make a contact, that will be fine by me. I've had the Thunderbolt and the counter running for over 24 hours now, and the 5th decimal figure, for a 1 second gate time, seems to have settled down a bit. Now, that could be the counter , or the thunderbolt, or both. Who can tell? :-) The next arguement usually goes along the lines that, according to what I hear from some physicists, the very act of measuring something changes it... Dave (G0DJA) From GandalfG8 at aol.com Wed Jul 23 12:44:47 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Wed, 23 Jul 2008 12:44:47 EDT Subject: [time-nuts] Thunderbolt SV and AMU Signal levels Message-ID: In a message dated 23/07/2008 17:31:28 GMT Daylight Time, dave.g0dja at tiscali.co.uk writes: I've had the Thunderbolt and the counter running for over 24 hours now, and the 5th decimal figure, for a 1 second gate time, seems to have settled down a bit. Now, that could be the counter , or the thunderbolt, or both. Who can tell? :-) --------------- Well, you better just hope it's the counter, if it's the Thunderbolt you really do have a problem:-) regards Nigel GM8PZR From dave.g0dja at tiscali.co.uk Wed Jul 23 12:59:33 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Wed, 23 Jul 2008 17:59:33 +0100 Subject: [time-nuts] Thunderbolt SV and AMU Signal levels In-Reply-To: <9835219326F6421AB4A20EA07D3471FD@athlon> References: <9835219326F6421AB4A20EA07D3471FD@athlon> Message-ID: <48876375.5060200@tiscali.co.uk> Ulrich Bangert wrote: > just in order to prevent anybody into believing that > >> Variation of +/- one count in the last digit is normal for >> any counter. It >> is caused by a slight shift between the counter gate and the >> input signal. >> The longer the time between digit changes, the more stable >> the phase between >> the unknown and the counter gate. > > were some kind of universal truth: This resembles the counter technology > of some 30-40 years ago and you will not find any counter model of any > serious manufacturer that uses "gate times" (if this term should be > allowed at all today) which are uncorrelated to the input signal. Remember that I am using a counter that is probably of that sort of vintage... It would not have been 'cutting edge' even when I bourght it over 20 years ago, and it does have diferent gate setting times of 0.01, 0.1 and 1 second. As a general purpose counter, it works OK. At least, for the majority of Amateur Radio use where precision and accuracy are not necessarily required to really close limits anyway. Dave (G0DJA) From mikes at flatsurface.com Wed Jul 23 12:59:28 2008 From: mikes at flatsurface.com (Mike S) Date: Wed, 23 Jul 2008 12:59:28 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <20080723115604.G9SDY.207613.imail@eastrmwml14.mgt.cox.net> References: <20080723143304.18A811165C3@hamburg.alientech.net> <20080723115604.G9SDY.207613.imail@eastrmwml14.mgt.cox.net> Message-ID: <20080723165936.B9DB71165C3@hamburg.alientech.net> At 11:56 AM 7/23/2008, Didier Juges wrote... >Problem is one period of 32768 is not a multiple of 100nS (one period >of 10 MHz) so that won't work. As long as both periods are rational numbers, it doesn't matter, and it can work. For this purpose (display for humans), it doesn't matter if some seconds have 32768.xxx cycles and some have 32767.yyy, as long as they average to exactly 32768. Being off by a whole lot less than the time it takes an LCD segment to change contrast won't hurt anything. From stijena at tapko.de Wed Jul 23 13:17:27 2008 From: stijena at tapko.de (Predrag Dukic) Date: Wed, 23 Jul 2008 19:17:27 +0200 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <00b901c8eccd$b95782b0$7300a8c0@p4253> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> Message-ID: <7.0.1.0.1.20080723191431.01d45bf8@tapko.de> Max, You are a mild case.... I also got bitten by the bug: Now I have 4 HP10811, two rubidiums, two cesiums, T-Bolt and I am seriously considering making my own Cesium. A visit to Las Vegas could turn to be cheaper fun than this...... Predrag At 16:09 23.7.2008, you wrote: >How does one get a 32.768KHz signal from our 10MHz reference. >There does not appear to be a nice divide ratio to do this. >With a locked 32.768KHz signal one could lock the oscillator of any >of the cheap (low cost) LCD clocks that are available with nice big >digits, temperature sensors and calendars, etc. >Any suggestions on how to do it?? > >Regards >Max > >ps. I got sucked in good. Six months ago all I had was an HP 10811 >and now I have another crystal oscillator, two rubidiums and a >Trimble GPS. >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From k1ggi at arrl.net Wed Jul 23 13:22:58 2008 From: k1ggi at arrl.net (Ed, k1ggi) Date: Wed, 23 Jul 2008 13:22:58 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <00b901c8eccd$b95782b0$7300a8c0@p4253> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> Message-ID: <008801c8ece8$c0faaa40$0a01a8c0@ATHLONXP1700> I see I'm coming to the party late, on the heels of Mike and Tom, but here's some additional from playing with the numbers during lunch. A mix of 30.4 us and 31.2 us periods (76 and 78 pic instr loops) in the ratio of 1747 to 301 does it -- 32768Hz with a few percent fm-ing. With just the two outer loops, abt 200usec of lag accumulates (after 53 msec) before it gets pulled back. Some nesting can easily cut that excursion down some. Ed (just posted this from the wrong account, hope it doesn't dupe). From david at endor.com Wed Jul 23 13:27:29 2008 From: david at endor.com (David McGaw) Date: Wed, 23 Jul 2008 13:27:29 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <48874E88.2070101@quackers.net> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <008401c8ecd6$680ba810$1e89a662@youre7075dc078> <48874E88.2070101@quackers.net> Message-ID: <200807231727.m6NHRSVU025904@mailhub2.dartmouth.edu> Divide 10 MHz by 250 to get 40 kHz, to be within range of the clock's logic, then use a presettable counter loaded by the 1 PPS to count off 32768 clocks per second. David McGaw At 11:30 AM 7/23/2008, you wrote: > I was faced with this problem a few years ago, too. > I essentially followed John's solution, but used the 1pps GPS pulse as > the PLL reference. > I then used the 32.768K vco output to injection-lock the 32.768K > crystal on the LCD clock. > Much to my surprise, it worked quite well. And, as pointed out already, > jitter isn't an issue for this application. >Bill Ezell >---------- >They said 'Windows or better' >so I used Linux. > > John Franke wrote: > >The only thing that comes to mind is to divide the 10 MHz by 2500000 >(5x5x100000) and then use a phase locked loop to multiply by 8192. Of >course the PLL would best control a varactor with a clock crystal vice >controlling an RC oscillator. Other divisor multiplier pairs are: >1250000/4096, 625000/2048, 312500/1024, 156250/512, and 78125/256. > >John WA4WDL > >----- Original Message ----- >From: "Max Skop" [1] >To: [2] >Sent: Wednesday, July 23, 2008 10:09 AM >Subject: [time-nuts] How to get 32.768KHz from 10MHz. > > > >How does one get a 32.768KHz signal from our 10MHz reference. >There does not appear to be a nice divide ratio to do this. >With a locked 32.768KHz signal one could lock the oscillator of any of >the cheap (low cost) LCD clocks that are available with nice big digits, >temperature sensors and calendars, etc. >Any suggestions on how to do it?? > >Regards >Max > >ps. I got sucked in good. Six months ago all I had was an HP 10811 and now >I have another crystal oscillator, two rubidiums and a Trimble GPS. >_______________________________________________ >time-nuts mailing list -- [3]time-nuts at febo.com >To unsubscribe, go to >[4]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > > > >_______________________________________________ >time-nuts mailing list -- [5]time-nuts at febo.com >To unsubscribe, go to >[6]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > >References > > 1. mailto:mskop at bigpond.net.au > 2. mailto:time-nuts at febo.com > 3. mailto:time-nuts at febo.com > 4. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > 5. mailto:time-nuts at febo.com > 6. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From k1ggi at arrl.net Wed Jul 23 13:43:37 2008 From: k1ggi at arrl.net (Ed, k1ggi) Date: Wed, 23 Jul 2008 13:43:37 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <008801c8ece8$c0faaa40$0a01a8c0@ATHLONXP1700> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <008801c8ece8$c0faaa40$0a01a8c0@ATHLONXP1700> Message-ID: <00ae01c8eceb$a3475590$0a01a8c0@ATHLONXP1700> Correction - freq is high (*lead* builds up) for 53msec. Ed abt 200usec of lag accumulates From Murray.Greenman at rakon.com Wed Jul 23 14:35:24 2008 From: Murray.Greenman at rakon.com (Murray Greenman) Date: Thu, 24 Jul 2008 06:35:24 +1200 Subject: [time-nuts] 32768Hz from 10MHz In-Reply-To: References: Message-ID: There is no easy way to divide directly from 10MHz to 32768Hz. On my web site at www.qsl.net/zl1bpu/MICRO there are several signal generator projects which would do the job of generating 32768Hz from 10MHz for you. With any of these (single chip micro approach, using 24-bit Direct Digital Synthesis) the closest you'd get would be to load 078CBC into the DDS. The result would be 32767.9846Hz, an error of 0.47ppm (14 sec/year). By extending the algorithm to 32 bit, as I did in my LF Exciter, the step resolution improves to 0.23mHz, and by loading 8637BD0 you'd generate 32767.999917 Hz, or an error of 2.5ppb. To put it into perspective, that's an error of 8 seconds in 100 years! Similar maths would apply to any micro-based DDS. I suggest adapting my design purely because it's simple, and a chip like the ATTiny2313 is well suited to the job. Regards, Murray ZL1BPU From richard at karlquist.com Wed Jul 23 15:08:37 2008 From: richard at karlquist.com (Rick Karlquist) Date: Wed, 23 Jul 2008 12:08:37 -0700 (PDT) Subject: [time-nuts] 32768Hz from 10MHz In-Reply-To: References: Message-ID: <14166.192.25.142.225.1216840117.squirrel@webmail.sonic.net> These limitations only apply because you have chosen an accumulator size that is a binary power (ie 2^N). If the accumulator is modulo 78,125 (ie 5^7), and you load the value 256 (ie 2^8) every 100 nsec, the accumulator will overflow at the rate of 32768 Hz, on the average. And it will be exact, on the average. There is an easy way to implement this. Make the accumulator, say, 131,072 (ie 2^17). Each time it overflows, add an extra 52,947 to it (ie 131,072 - 78125). This will make it look like it has the size of 78,125. I'm sure you can figure this out. You can still use a binary word size for the DAC data. Rick Karlquist N6RK Murray Greenman wrote: > There is no easy way to divide directly from 10MHz to 32768Hz. > > On my web site at www.qsl.net/zl1bpu/MICRO there are several signal > generator projects which would do the job of generating 32768Hz from > 10MHz for you. > > With any of these (single chip micro approach, using 24-bit Direct > Digital Synthesis) the closest you'd get would be to load 078CBC into > the DDS. The result would be 32767.9846Hz, an error of 0.47ppm (14 > sec/year). > > By extending the algorithm to 32 bit, as I did in my LF Exciter, the > step resolution improves to 0.23mHz, and by loading 8637BD0 you'd > generate 32767.999917 Hz, or an error of 2.5ppb. To put it into > perspective, that's an error of 8 seconds in 100 years! > > Similar maths would apply to any micro-based DDS. I suggest adapting my > design purely because it's simple, and a chip like the ATTiny2313 is > well suited to the job. > > Regards, > Murray ZL1BPU > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From tvb at LeapSecond.com Wed Jul 23 16:17:08 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Wed, 23 Jul 2008 13:17:08 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz. References: <00b901c8eccd$b95782b0$7300a8c0@p4253><20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> Message-ID: <001801c8ed01$1a7c19b0$0900a8c0@pc52> > Since synchronization is more important than jitter in this > application it's easy to generate 32 kHz from 10 MHz. > > A 10 MHz clock into a PIC gives a 400 ns/instruction time. > > To produce 32.768 kHz you flip an output pin put every 38 > instructions, except that 9632 times per second you make > it 39 instructions instead. > > The result is 65536 bit flips per second (giving a frequency > of exactly 32768 Hz) consuming 2 500 000 instructions per > second. The output accuracy equals the input accuracy. > The output jitter is as most 400 ns. > > /tvb I just prototyped this PIC algorithm and it works perfectly: Exactly 10 MHz in gives exactly 32.768 kHz out. There are several ways to manage the variable 38 vs. 39 instruction cycle duration of the output waveform. The crude way, for every 65536 half-cycles, is to generate the first 9632 using 39 instructions and the remaining 55904 using 38 instructions. This uses a total of (9632*39) + (55904*38) = 2500000 instructions (10 MHz) to generate a 32768 Hz output clock. But if you note that 2500000 / 65536 = 38.14697265625 and think about leap years, there are cute ways to distribute these "leap cycles" more evenly throughout successive one second periods, if that is desired. /tvb From Murray.Greenman at rakon.com Wed Jul 23 16:27:13 2008 From: Murray.Greenman at rakon.com (Murray Greenman) Date: Thu, 24 Jul 2008 08:27:13 +1200 Subject: [time-nuts] 32768Hz using DDS In-Reply-To: References: Message-ID: What Rick says is completely correct. I took the general approach (so you can generate any frequency) and by using a binary counting scheme, the number of clock cycles required is reduced to 9 (for 24-bit) or 10 (for 32-bit), provided you use an AVR processor. The advantage then is that you have a high sample rate (1.111MHz or 1MHz with a 10MHz clock) and can generate frequencies up to about 300kHz from 10MHz. The difficulty with adding a preset value at overflow is that first you have to test for overflow, and second that the time around the loop is changed by the instructions involved in loading. It's no problem at all in this particular application, but in the general case as a high frequency signal generator this introduces undesirable jitter. You could of course run the whole shebang in an interrupt and thus avoid the jitter, replacing it instead with interrupt latency jitter. This you can avoid by putting the micro to sleep after each interrupt, so the interrupt routine always starts the same way. There's an even better really simple trick. If you use a GPSDO as the source of 10MHz, use a simple 24-bit binary DDS to generate close to 32768Hz, and then use the 1pps output from the GPSDO to drive an interrupt to reset the phase. You need only do it every few hundred seconds, easy to set up in the micro. I use this technique to generate GPS synchronous radio transmissions on LF. 73, Murray From wb6bnq at cox.net Wed Jul 23 16:34:16 2008 From: wb6bnq at cox.net (WB6BNQ) Date: Wed, 23 Jul 2008 13:34:16 -0700 Subject: [time-nuts] 32.768KHz from a DDS References: <00b901c8eccd$b95782b0$7300a8c0@p4253> Message-ID: <488795C8.3DF3186B@cox.net> If you use a DDS then it pays to use the Analog Devices design tool. It is at this URL [1]http://designtools.analog.com/dtDDSWeb/dtDDSMain.aspx You can open multiple instances in different browser windows. Also, there is an area under the graphs called DISPLAY which allows for some selections. One of them is for a filter. If you click on the blue configure to the right of the filter selection it allows you to set the parameters for the filter. It is interesting to note just how imprecise these DDS devices really are ! For instance, the tendency to use the house standard (i.e., 10 MHz) as the DDS source clock produces the following values for 32 KHz clock. 1. AD9850 DDS {32 bit tuning/10 bit output} with 10 MHz clock produces: 32768.00038293 Hz 2. AD9956 DDS {48 bit tuning/14 bit output} with 10 MHz clock produces: 32767.999999983 Hz You would think scaling the clock by [sub] multiples would make no difference. However, this is not true. You would think using a clock that was a binary multiple, just like the 32 KHz number, would make it come out precisely. As well, this was not the case ! Experiment with the better 48 bit DDS and varying the clock from 10 MHz down with the following results: * CLOCK FREQUENCY * * 0.01 MHz 32768.0000000000 Hz perfect but no output ! See Mr. Nyquest. * * 0.1 MHz 32768.0000000001 Hz * * 0.2 MHz 32768.0000000001 Hz * * 0.3 MHz 32768.0000000004 Hz * * 0.4 MHz 32768.0000000001 Hz * * 0.5 MHz 32768.0000000008 Hz * * 0.6 MHz 32767.9999999994 Hz * * 0.7 MHz 32767.9999999990 Hz * * 0.8 MHz 32767.9999999987 Hz * * 0.9 MHz 32768.0000000004 Hz * * 1 MHz 32768.0000000008 Hz * * 2 MHz 32767.9999999972 Hz * * 3 MHz 32767.9999999972 Hz * * 4 MHz 32768.0000000044 Hz * * 5 MHz 32768.0000000008 Hz * * 6 MHz 32767.9999999972 Hz * * 7 MHz 32768.0000000115 Hz * * 8 MHz 32768.0000000044 Hz * * 9 MHz 32767.9999999972 Hz * * 10 MHz 32767.9999999830 Hz What is interesting is there were few repetitive values. Also surprising is the lower the clock the closer to the correct output. BUT BIG SURPRISE ! Dont forget Mr. Nyquest. To get a reasonable wave form you really need to have the clock 3 times the highest output. So that leaves us with 100 KHz as the minimum practical clock frequency. The error at 100 KHz is quite small and essentially beyond the range of the DDSs 48 bit tuning word. Of course one should be mindful of the spurious responses out of the DDS. The 200 KHz selection { an easy sub of 10 MHz} would be better based on the Analog Devices program after setting the filter factors. I certainly am no expert but the Elliptical filter, which I have some small familiarity with, seemed to be the best choice for the frequency range. Bill....WB6BNQ References 1. http://designtools.analog.com/dtDDSWeb/dtDDSMain.aspx From mikes at flatsurface.com Wed Jul 23 16:58:07 2008 From: mikes at flatsurface.com (Mike S) Date: Wed, 23 Jul 2008 16:58:07 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <001801c8ed01$1a7c19b0$0900a8c0@pc52> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> Message-ID: <20080723210020.67E951165C3@hamburg.alientech.net> At 04:17 PM 7/23/2008, Tom Van Baak wrote... >I just prototyped this PIC algorithm and it works perfectly: >Exactly 10 MHz in gives exactly 32.768 kHz out. TPIWWSC. (This Post Is Worthless Without Source Code) :-) From didier at cox.net Wed Jul 23 17:24:17 2008 From: didier at cox.net (Didier Juges) Date: Wed, 23 Jul 2008 17:24:17 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <20080723210020.67E951165C3@hamburg.alientech.net> Message-ID: <20080723172417.83CVK.213078.imail@eastrmwml14.mgt.cox.net> Start: NOP NOP NOP ... NOP flip_bit NOP NOP NOP ... flip_bit JUMP Start (details omitted for clarity) :-) Didier KO4BB ---- Mike S wrote: > At 04:17 PM 7/23/2008, Tom Van Baak wrote... > >I just prototyped this PIC algorithm and it works perfectly: > >Exactly 10 MHz in gives exactly 32.768 kHz out. > > TPIWWSC. > > (This Post Is Worthless Without Source Code) > > :-) > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. From bruce.griffiths at xtra.co.nz Wed Jul 23 17:42:21 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Thu, 24 Jul 2008 09:42:21 +1200 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <20080723210020.67E951165C3@hamburg.alientech.net> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> Message-ID: <4887A5BD.3040208@xtra.co.nz> Another approach is to divide the 10MHz by 5^7 (78125) and then use an injection locked multiplier chain to generate 32768 Hz from the resultant 128Hz output. It may even be possible to do the 256x multiplication using a single injection locked 32768Hz injection locked multiplier. When designed correctly the close in phase noise of an injection locked oscillator is determined by that of the injection source whereas the phase noise floor is determined by that of the oscillator being locked. To optimise the performance the oscillator to be injection locked should be designed to facilitate injection locking. Bruce From mikes at flatsurface.com Wed Jul 23 18:01:37 2008 From: mikes at flatsurface.com (Mike S) Date: Wed, 23 Jul 2008 18:01:37 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <4887A5BD.3040208@xtra.co.nz> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> Message-ID: <20080723220139.8796B1165C3@hamburg.alientech.net> At 05:42 PM 7/23/2008, Bruce Griffiths wrote... >Another approach is to divide the 10MHz by 5^7 (78125) and then use an > >injection locked multiplier chain to generate 32768 Hz from the >resultant 128Hz output. >It may even be possible to do the 256x multiplication using a single >injection locked 32768Hz injection locked multiplier. You're missing the point. The application is to drive a common, readily available consumer clock. Simple and cheap. It can be done with a single $1 PIC. You could spend $20 or $100 and not get better results for the application. If you can describe a way of doing it for $0.50, please do. From James.P.Lux at jpl.nasa.gov Wed Jul 23 18:22:08 2008 From: James.P.Lux at jpl.nasa.gov (Jim Lux) Date: Wed, 23 Jul 2008 15:22:08 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <20080723220139.8796B1165C3@hamburg.alientech.net> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> <20080723220139.8796B1165C3@hamburg.alientech.net> Message-ID: <6.2.5.6.2.20080723151808.02d4dcf0@jpl.nasa.gov> At 03:01 PM 7/23/2008, Mike S wrote: >At 05:42 PM 7/23/2008, Bruce Griffiths wrote... > >Another approach is to divide the 10MHz by 5^7 (78125) and then use an > > > >injection locked multiplier chain to generate 32768 Hz from the > >resultant 128Hz output. > >It may even be possible to do the 256x multiplication using a single > >injection locked 32768Hz injection locked multiplier. > >You're missing the point. The application is to drive a common, readily >available consumer clock. Simple and cheap. It can be done with a >single $1 PIC. You could spend $20 or $100 and not get better results >for the application. If you can describe a way of doing it for $0.50, >please do. But this is time-nuts... Any approach that doesn't have the performance of a hydrogen maser or cryogenic sapphire resonator just isn't good enough. Why, we haven't even started on how to build a radial ruling engine to make sure the clock face is precisely divided into 60 segments to ppb accuracy. Based on the clocks I've taken apart, dividing the 10MHz down to 1 Hz is probably your best bet, rather than trying to hit 32768. However, I don't know of a non-programmable single chip solution that will do a divide by 1E7. If you want programmable chips, there's countless ways, some more elegant than others. From wb6bnq at cox.net Wed Jul 23 18:28:43 2008 From: wb6bnq at cox.net (WB6BNQ) Date: Wed, 23 Jul 2008 15:28:43 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz. References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> <20080723220139.8796B1165C3@hamburg.alientech.net> Message-ID: <4887B09B.AFDDFCFC@cox.net> Mike S, I think you missed the point ! One does not ask the question "How does one get a 32.768KHz signal from our 10MHz reference ?" and not expect it to cost both in terms of money and effort. There was no statement of doing it cheap, re-read the original Email. Bill....WB6BNQ Mike S wrote: At 05:42 PM 7/23/2008, Bruce Griffiths wrote... >Another approach is to divide the 10MHz by 5^7 (78125) and then use an > >injection locked multiplier chain to generate 32768 Hz from the >resultant 128Hz output. >It may even be possible to do the 256x multiplication using a single >injection locked 32768Hz injection locked multiplier. You're missing the point. The application is to drive a common, readily available consumer clock. Simple and cheap. It can be done with a single $1 PIC. You could spend $20 or $100 and not get better results for the application. If you can describe a way of doing it for $0.50, please do. _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to [1]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts From richard at karlquist.com Wed Jul 23 19:07:04 2008 From: richard at karlquist.com (Rick Karlquist) Date: Wed, 23 Jul 2008 16:07:04 -0700 (PDT) Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <4887A5BD.3040208@xtra.co.nz> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> Message-ID: <18191.192.25.142.225.1216854424.squirrel@webmail.sonic.net> A more practical offshoot of this concept is to subsample the 32 kHz oscillator at 128 Hz (ie a sampling phase detector) and use a slow loop to tune the 32768 kHz oscillator. The biggest problem here is that you have to have a tunable oscillator. Attempting to get around this by injection locking a non-tunable oscillator is probably not going to work very well, since the frequency tolerance is likely to be larger than the small amount of frequency pulling you can get with injection locking. Basically, if the oscillator tolerance is 0.01%, and it has a Q of >>10,000, it will be hit or miss depending on luck. Rick N6RK Bruce Griffiths wrote: > Another approach is to divide the 10MHz by 5^7 (78125) and then use an > injection locked multiplier chain to generate 32768 Hz from the > resultant 128Hz output. > It may even be possible to do the 256x multiplication using a single > injection locked 32768Hz injection locked multiplier. > When designed correctly the close in phase noise of an injection locked > oscillator is determined by that of the injection source whereas the > phase noise floor is determined by that of the oscillator being locked. > To optimise the performance the oscillator to be injection locked should > be designed to facilitate injection locking. > > Bruce > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From bruce.griffiths at xtra.co.nz Wed Jul 23 19:19:50 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Thu, 24 Jul 2008 11:19:50 +1200 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <20080723172417.83CVK.213078.imail@eastrmwml14.mgt.cox.net> References: <20080723172417.83CVK.213078.imail@eastrmwml14.mgt.cox.net> Message-ID: <4887BC96.3010100@xtra.co.nz> An oscillator can be injection locked to at frequency that is a rational number (M/N where M, N are integers ) multiplier of the injection frequency. Thus, in principle, a 32768Hz oscillator can be injection locked directly to a 10MHz signal (32768Hz = (256/78125)*10MHz) without requiring any external dividers or multipliers. In practice this will only be practical with a 32768Hz crystal oscillator whose frequency determining crystal is tuned sufficiently closely to 32768Hz. Note this is not quite the same as tuning the free running oscillator frequency. The sensitivity to the injected signal can be optimised if the 32768Hz oscillator is suitably designed. The 32768Hz injection locked oscillator output can be used to injection lock another 32768Hz crystal oscillator whose design cannot be optimised for direct injection locking to a 10MHz signal. Bruce From bruce.griffiths at xtra.co.nz Wed Jul 23 19:31:16 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Thu, 24 Jul 2008 11:31:16 +1200 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <18191.192.25.142.225.1216854424.squirrel@webmail.sonic.net> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> <18191.192.25.142.225.1216854424.squirrel@webmail.sonic.net> Message-ID: <4887BF44.2010301@xtra.co.nz> Rick Karlquist wrote: > A more practical offshoot of this concept is to subsample the > 32 kHz oscillator at 128 Hz (ie a sampling phase detector) and use a slow > loop to tune the 32768 kHz oscillator. The biggest problem here is that > you have to have a tunable oscillator. Attempting to get around > this by injection locking a non-tunable oscillator is probably not > going to work very well, since the frequency tolerance is likely > to be larger than the small amount of frequency pulling you can > get with injection locking. Basically, if the oscillator tolerance > is 0.01%, and it has a Q of >>10,000, it will be hit or miss depending > on luck. > > Rick N6RK > The drawback of all injection locked oscillator schemes is that the injection locked oscillator needs to be tunable. However a simple trimmer cap may suffice if the temperature excursion of the oscillator isnt too large and the occasional readjustment to compensate for aging is acceptable. Bruce From bruce.griffiths at xtra.co.nz Wed Jul 23 20:37:11 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Thu, 24 Jul 2008 12:37:11 +1200 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <4887BC96.3010100@xtra.co.nz> References: <20080723172417.83CVK.213078.imail@eastrmwml14.mgt.cox.net> <4887BC96.3010100@xtra.co.nz> Message-ID: <4887CEB7.5060909@xtra.co.nz> Bruce Griffiths wrote: > An oscillator can be injection locked to at frequency that is a rational > number (M/N where M, N are integers ) multiplier of the injection frequency. > Thus, in principle, a 32768Hz oscillator can be injection locked > directly to a 10MHz signal (32768Hz = (256/78125)*10MHz) without > requiring any external dividers or multipliers. > In practice this will only be practical with a 32768Hz crystal > oscillator whose frequency determining crystal is tuned sufficiently > closely to 32768Hz. > Note this is not quite the same as tuning the free running oscillator > frequency. > The sensitivity to the injected signal can be optimised if the 32768Hz > oscillator is suitably designed. > > The 32768Hz injection locked oscillator output can be used to injection > lock another 32768Hz crystal oscillator whose design cannot be optimised > for direct injection locking to a 10MHz signal. > > Bruce > > The major problem with this approach is the extremely small (<<1ppm) locking range achievable. Thus it isnt likely to be practical with standard 32768Hz crystals, as even a relatively small temperature change will perturb the tuning sufficiently to make locking to the desired frequency impossible. Bruce From tvb at LeapSecond.com Wed Jul 23 21:27:30 2008 From: tvb at LeapSecond.com (Tom Van Baak) Date: Wed, 23 Jul 2008 18:27:30 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz. References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> Message-ID: <004e01c8ed2c$7432f660$0900a8c0@pc52> > At 04:17 PM 7/23/2008, Tom Van Baak wrote... >>I just prototyped this PIC algorithm and it works perfectly: >>Exactly 10 MHz in gives exactly 32.768 kHz out. > > TPIWWSC. > > (This Post Is Worthless Without Source Code) > > :-) Hi Mike, Yeah, I thought I provided enough information in that posting so that anyone that's programmed a uC before, or has seen the free source code to the 1PPS PIC divider would get the idea. By the way it's almost the 10th anniversary of that PIC divider: http://www.leapsecond.com/pages/ppsdiv/ OK, you asked about the prototype for the 32 kHz algorithm. See: http://www.leapsecond.com/tools/10m32k.c The basic idea is as I described a few hours ago; with a correct combination of 38 and 39 cycle instruction code paths, you get a 32 kHz output that has some jitter in phase but has perfect frequency accuracy from one second to infinity. This is similar to the case of the special 100 kHz output of the PPS divider. The cute algorithm that I prototyped is one that is inspired by the way we handle leap years. The result is that all the "leap cycles" are as evenly spaced throughout the second as possible, both minimizing jitter to the extent possible with a 400 ns PIC cycle time, and maintaining an absolute division of the 10 MHz to 32.768 kHz, as averaged over any multiple of 1 second. There are comments in the C code. Note this is not PIC code; it is simply my proof-of-concept (compiles under windows or unix) for isochronous PIC assembler code that can (will?) be written. If I know you PIC'ers with spare time out there (not me right now) it will be done by tonight. It should be end up on the order of 40 lines of careful isochronous assembler code. I assume the AVR would work too. The result will be a $1, 8-pin, single-chip, 10 MHz to 32 kHz, low (not zero) jitter frequency divider, suitable for driving cheap digital or analog clock and watch movements from a 10 MHz source. Extra credit for the 5 MHz version. /tvb From jim77742 at gmail.com Thu Jul 24 00:11:32 2008 From: jim77742 at gmail.com (Jim Palfreyman) Date: Thu, 24 Jul 2008 14:11:32 +1000 Subject: [time-nuts] How to get 32.768KHz from 10MHz Message-ID: In response to Jim Lux's email I checked out the NASA tech brief. According to them to run a sidereal clock you should set the frequency to 32,859.27577 Hz. Now the length of the sidereal day is 23:56:4.091 seconds. This is 23.934469722 hours. That is, the sidereal clock must cover 24 "hours" on the clock in 23.934469722 real hours. That is, it must run 24/23.934469722 times as fast. Hence it's crystal needs to be at 32768*1.002737904=32,857.71563469 Hz not the 32,859.27577 as stated. Interestingly if you multiply 32767*1.002737904 you get the above result. I think they have made a mistake. My guess is the author is very computer literate and typed in 32767 without thinking! That sidereal clock would be out by a few seconds per day. We cannot have that! Jim There's two approaches to your high level problem (driving a clock)... one is to make 32.768 kHz, the other is to directly drive the 1pps. Obviously, dividing down 10M to get to 1Hz is easy. But, for the other, you don't need to have a perfect symmetrical sine wave. All you need to do is make sure that there are 32,768 transitions in a second, so any sort of rough and ready divider scheme will work. Now.. in the lab what I did is use a HP3325B to make clocks run on Mars time See: http://www.techbriefs.com/content/view/2299/34/ Since the 3325 was locked to the lab's maser, it's probably the most accurate Mars clock around (bearing in mind that Mars's rotation isn't nearly as stable as the maser, so it's superfluous accuracy) You can do other nifty things, by the way... you can make a clock that displays solar elevation ("sundial time") because the rate can be changed systematically. I never did get around to programming a PIC to do some of this stuff, but it would be quite straightforward. Jim Lux From james.p.lux at jpl.nasa.gov Thu Jul 24 00:58:42 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Wed, 23 Jul 2008 21:58:42 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <004e01c8ed2c$7432f660$0900a8c0@pc52> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <004e01c8ed2c$7432f660$0900a8c0@pc52> Message-ID: <20080723215842.3phbzaddswskkkg8@webmail.jpl.nasa.gov> Quoting Tom Van Baak , on Wed 23 Jul 2008 06:27:30 PM PDT: > The result will be a $1, 8-pin, single-chip, 10 MHz to 32 kHz, low > (not zero) jitter frequency divider, suitable for driving cheap digital > or analog clock and watch movements from a 10 MHz source. > Extra credit for the 5 MHz version. > Or, with a bit of work, you could make a sidereal clock (handy for astronomers) or a Mars clock (handy for a very small set of people who want to keep Mars time). One might also be able to do a tide clock of some sort too, but it would probably require a variable speed. Jim From james.p.lux at jpl.nasa.gov Thu Jul 24 01:03:57 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Wed, 23 Jul 2008 22:03:57 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz In-Reply-To: References: Message-ID: <20080723220357.x3yiws6egoo4s4oo@webmail.jpl.nasa.gov> Quoting Jim Palfreyman , on Wed 23 Jul 2008 09:11:32 PM PDT: > In response to Jim Lux's email I checked out the NASA tech brief. > > According to them to run a sidereal clock you should set the frequency to > 32,859.27577 Hz. > > Now the length of the sidereal day is 23:56:4.091 seconds. This is > 23.934469722 hours. That is, the sidereal clock must cover 24 "hours" on the > clock in 23.934469722 real hours. That is, it must run 24/23.934469722 times > as fast. Hence it's crystal needs to be at 32768*1.002737904=32,857.71563469 > Hz not the 32,859.27577 as stated. > > Interestingly if you multiply 32767*1.002737904 you get the above result. > > I think they have made a mistake. My guess is the author is very computer > literate and typed in 32767 without thinking! That author being me, you're probably right. I remember checking the Mars clock time against a variety of other sources over a few weeks, but I don't recall checking the sidereal time. Jim From chris.cheney at tesco.net Thu Jul 24 04:36:07 2008 From: chris.cheney at tesco.net (Chris Cheney) Date: Thu, 24 Jul 2008 09:36:07 +0100 Subject: [time-nuts] 32768Hz using DDS In-Reply-To: References: , Message-ID: <48884D07.28339.47A53F@chris.cheney.tesco.net> On 24 Jul 2008 at 8:27, Murray Greenman wrote: > and second that the time around the loop is > changed by the instructions involved in loading. Well, the timing can be kept constant by always adding in a value. For the AVR, using a branch to test for overflow is not necessary: ROL followed by ANDI will get carry (instead of overflow as we are performing unsigned arithmetic) into the bottom bit of a register from where it can be used to index for the appropriate value (0 or 52,947) to be added. So the relevant calculation can be done with straight-through code, without any branches, giving a constant instruction count. Regards from Cambridge Chris G3RSE From stork3264 at comcast.net Thu Jul 24 11:04:26 2008 From: stork3264 at comcast.net (stork3264 at comcast.net) Date: Thu, 24 Jul 2008 15:04:26 +0000 Subject: [time-nuts] Watkins Johnson Info Message-ID: <072420081504.15918.488899FA0009FEDF00003E2E2200750744CBC0CDCC059D019B9C@comcast.net> Watkins Johnson produced some excellent microwave oscillators, but their microwave division was sold and resold about a decade ago. Product information is difficult to find. I need pin out, product data and/or a link for two of their oscillators. WJ-5133-3 WJ-5908-79 Thanks, Stork From jmfranke at cox.net Thu Jul 24 11:29:35 2008 From: jmfranke at cox.net (John Franke) Date: Thu, 24 Jul 2008 11:29:35 -0400 Subject: [time-nuts] Watkins Johnson Info References: <072420081504.15918.488899FA0009FEDF00003E2E2200750744CBC0CDCC059D019B9C@comcast.net> Message-ID: <001401c8eda2$140bed70$1e89a662@youre7075dc078> The 5133 is a YIG Tuned Harmonic Generator designed for an input frequency of 500 MHz and an output frequency range of 1.0-12.5 GHz. Nominal drive is 1 Watt. Nominal output power is -13 dbm min. Tuning coil data: 20 MHz/mA, 10 Ohms, 100 mH. Heater:28V, 1A surge, 250mA max steady state. An external bias supply of 0-3V at 300mA max can be used for leveling output power from multi-octave units. Pin-out is unknown. John WA4WDL ----- Original Message ----- From: To: Sent: Thursday, July 24, 2008 11:04 AM Subject: [time-nuts] Watkins Johnson Info > Watkins Johnson produced some excellent microwave oscillators, but their > microwave division was sold and resold about a decade ago. Product > information is difficult to find. > > I need pin out, product data and/or a link for two of their oscillators. > > WJ-5133-3 > > WJ-5908-79 > > Thanks, > > Stork > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From GandalfG8 at aol.com Thu Jul 24 13:12:02 2008 From: GandalfG8 at aol.com (GandalfG8 at aol.com) Date: Thu, 24 Jul 2008 13:12:02 EDT Subject: [time-nuts] Anti-Static conductive foam warning Message-ID: Apologies to those who might see this on more than one group or list and apologies again if it's old news to everyone but me, but I did think it important enough to share. I've just retrieved a pair of ICs that have been dry stored as spares in a component storage rack since 1979, a long time I know but probably not unusual for those of us using and maintaining older equipment. These, as I thought anyway, were correctly stored with the pins pressed into black anti-static foam, the usual stuff that's been used for this purpose for years. Unfortunately the foam has broken down into a sticky crumble and the plating on the IC pins is quite badly corroded, probably to the point where they won't take solder. A metal canned crystal lying against the foam has also corroded at the pont of contact. I've seen this stuff turn into a gooey mess inside some instrument cases but hadn't previously even thought about the same thing happening where it's used used for component storage. I've checked other trays and whilst not too many used this stuff but where they did there's evidence of similar problems. I've even got a later large component rack, all ok so far but for how long?, where it was fitted from new to every drawer:-( That's all, just offered as a word of warning to anyone else with components similarly stored. regards Nigel GM8PZR From daun at yeagley.net Thu Jul 24 13:38:45 2008 From: daun at yeagley.net (Daun Yeagley) Date: Thu, 24 Jul 2008 13:38:45 -0400 Subject: [time-nuts] Anti-Static conductive foam warning In-Reply-To: References: Message-ID: <005101c8edb4$20027fb0$0c00a8c0@daundell> Hi Nigel I've seen this happen in some other circumstances too, and one of the worst ones was for VNA Cal kits. It really makes a mess, and it's pretty hard to clean up. I'm wondering if anyone else who's seen this problem has some advice on a good way to restore the items. It does seem that there are several types of foam (and rubber for that matter) Daun -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of GandalfG8 at aol.com Sent: Thursday, July 24, 2008 1:12 PM To: time-nuts at febo.com Subject: [time-nuts] Anti-Static conductive foam warning Apologies to those who might see this on more than one group or list and apologies again if it's old news to everyone but me, but I did think it important enough to share. I've just retrieved a pair of ICs that have been dry stored as spares in a component storage rack since 1979, a long time I know but probably not unusual for those of us using and maintaining older equipment. These, as I thought anyway, were correctly stored with the pins pressed into black anti-static foam, the usual stuff that's been used for this purpose for years. Unfortunately the foam has broken down into a sticky crumble and the plating on the IC pins is quite badly corroded, probably to the point where they won't take solder. A metal canned crystal lying against the foam has also corroded at the pont of contact. I've seen this stuff turn into a gooey mess inside some instrument cases but hadn't previously even thought about the same thing happening where it's used used for component storage. I've checked other trays and whilst not too many used this stuff but where they did there's evidence of similar problems. I've even got a later large component rack, all ok so far but for how long?, where it was fitted from new to every drawer:-( That's all, just offered as a word of warning to anyone else with components similarly stored. regards Nigel GM8PZR _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From gwinn at raytheon.com Thu Jul 24 14:43:28 2008 From: gwinn at raytheon.com (Joseph M Gwinn) Date: Thu, 24 Jul 2008 14:43:28 -0400 Subject: [time-nuts] Anti-Static conductive foam warning In-Reply-To: <005101c8edb4$20027fb0$0c00a8c0@daundell> Message-ID: The turning into goo is called "reversion", and is a property of some kinds of polyurethane. There is a good explanation in US patent 4040991, and in www.wolaa.org/files/Spring_2007_OHS_-_WOL_In-house_Expertise.pdf . It can be difficult to find a solvent for the goo. As for corrosion causing unsolderability, there is a draconian solution. It was a classic story from the 1970s. We were getting a demo ready for a show, and it turned out that the leads on the Nixie tubes had corroded enough that they would not take solder. This is Sunday afternoon. What to do? I dipped them in dilute sulfuric acid (battery acid cut 3:1), rinsed them off in hot water, and then had no problem soldering. The acid dip did not cause subsequent problems, although one could have also used dilute bicarbonate of soda to neutralize any traces of acid that survived the hot rinse. Joe Gwinn time-nuts-bounces at febo.com wrote on 07/24/2008 01:38:45 PM: > Hi Nigel > > I've seen this happen in some other circumstances too, and one of the worst > ones was for VNA Cal kits. It really makes a mess, and it's > pretty hard to clean up. > I'm wondering if anyone else who's seen this problem has some advice on a > good way to restore the items. > It does seem that there are several types of foam (and rubber for that > matter) > > Daun > > > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On > Behalf Of GandalfG8 at aol.com > Sent: Thursday, July 24, 2008 1:12 PM > To: time-nuts at febo.com > Subject: [time-nuts] Anti-Static conductive foam warning > > Apologies to those who might see this on more than one group or list and > apologies again if it's old news to everyone but me, but I did think it > important enough to share. > > I've just retrieved a pair of ICs that have been dry stored as > spares in a > component storage rack since 1979, a long time I know but probably not > unusual for those of us using and maintaining older equipment. > > These, as I thought anyway, were correctly stored with the pins pressed > into black anti-static foam, the usual stuff that's been used for this > purpose for years. > Unfortunately the foam has broken down into a sticky crumble and the > plating on the IC pins is quite badly corroded, probably to the > point where > they won't take solder. A metal canned crystal lying against the foam has > also corroded at the pont of contact. > I've seen this stuff turn into a gooey mess inside some instrument cases > but hadn't previously even thought about the same thing happening where > it's used used for component storage. > > I've checked other trays and whilst not too many used this > stuff but where > they did there's evidence of similar problems. > I've even got a later large component rack, all ok so far but for how > long?, where it was fitted from new to every drawer:-( > > That's all, just offered as a word of warning to anyone else with > components similarly stored. > > regards > > Nigel > GM8PZR > > > > > > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi- > bin/mailman/listinfo/time-nuts > and follow the instructions there. From david.partridge at dsl.pipex.com Thu Jul 24 14:43:23 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Thu, 24 Jul 2008 19:43:23 +0100 Subject: [time-nuts] PCB for frequency dividers Message-ID: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> I'm going to place an order for the PCB for my frequency divider in the next few days. If I can get a batch of ten ordered the cost will be about USD60 each plus postage to wherever you are. PCB is four layer, 5" by 3.5", pads will be electrolytic Ni/Au (this house doesn't charge extra for that). The price goes down as the numbers go up of course. If anyone thinks they can better this price, I'm happy to ship the gerbers and NC drill files. I never did hear back from Magnus about the circuit driving the selectors on the '4051, so that stays as it is. I have one firm request from Norman J McSweyn. If anyone else would like to order a PCB please could you email me directly (rather than on list) at david dot partridge at dsl dot pipex dot com I also have a few spare of the '4017 dividers and lots of BAV99 which I'm happy to pass on at cost to me. Cheers Dave From gbusg at comcast.net Thu Jul 24 14:57:32 2008 From: gbusg at comcast.net (Greg Burnett) Date: Thu, 24 Jul 2008 12:57:32 -0600 Subject: [time-nuts] Anti-Static conductive foam warning References: <005101c8edb4$20027fb0$0c00a8c0@daundell> Message-ID: <000301c8edbf$211d1670$6501a8c0@gb02> Hi Daun & Nigel, I've experienced the same problem, for example with sliding loads, cal kits and other accessories. The trick is to remove all the foam *before* the damage is done. Once the deteriorating foam turns to "sticky crumble" and reacts with the precision plated metal surfaces in these kits, the surfaces can actually become physically pitted and discolored. I could kick myself for not staying on top of this and removing the foam sooner in some instances. Next question: Are the manufacturers listening? Or are they still using the same foam (that will de-compose in 15 or 20 years). Greg ---------------- Daun wrote: --clip-- I'm wondering if anyone else who's seen this problem has some advice on a good way to restore the items. --clip-- From g4hup at btinternet.com Thu Jul 24 15:18:58 2008 From: g4hup at btinternet.com (dave powis) Date: Thu, 24 Jul 2008 19:18:58 +0000 (GMT) Subject: [time-nuts] PCB for frequency dividers Message-ID: <653277.35636.qm@web86302.mail.ird.yahoo.com> David, Have you had a look at http://www.top-tec-pcb.com/eng/index_.html? I use them for my boards, and running a quick estimate using the details you've published. They aren't quite at the price you've indicated, but for a slightly higher number they do get significantly cheaper. There are some items which could affect the price that you haven't quoted, such the number of buried vias, but you can input all that in their on-line calculator - use the Power-Pool quote system, not the prototype quote link. Regards, Dave, G4HUP http://g4hup.com ----- Original Message ---- From: David C. Partridge To: Discussion of precise time and frequency measurement Sent: Thursday, 24 July, 2008 7:43:23 PM Subject: [time-nuts] PCB for frequency dividers I'm going to place an order for the PCB for my frequency divider in the next few days. If I can get a batch of ten ordered the cost will be about USD60 each plus postage to wherever you are. PCB is four layer, 5" by 3.5", pads will be electrolytic Ni/Au (this house doesn't charge extra for that). The price goes down as the numbers go up of course. If anyone thinks they can better this price, I'm happy to ship the gerbers and NC drill files. I never did hear back from Magnus about the circuit driving the selectors on the '4051, so that stays as it is. I have one firm request from Norman J McSweyn. If anyone else would like to order a PCB please could you email me directly (rather than on list) at david dot partridge at dsl dot pipex dot com I also have a few spare of the '4017 dividers and lots of BAV99 which I'm happy to pass on at cost to me. Cheers Dave _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From gbusg at comcast.net Thu Jul 24 15:59:56 2008 From: gbusg at comcast.net (Greg Burnett) Date: Thu, 24 Jul 2008 13:59:56 -0600 Subject: [time-nuts] Thunderbolt Free-running Freq. Offset References: Message-ID: <001b01c8edc7$d8c6ef50$6501a8c0@gb02> Has anyone established a recommended adjustment window for the Thunderbolt's 10MHz oscillator free-running frequency? Put another way, does anybody have a feel for how far from "nominal 10 MHz" the free-running frequency can be before it in some way (if at all) degrades "locked" performance? I'm assuming that, after power-down, the box looses its 'holdover' memory and, upon re-power, reverts to zero hold-over correction? Or does the box remember its last hold-over offset correction despite a power loss? Cheers, Greg From bruce.griffiths at xtra.co.nz Thu Jul 24 17:50:37 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 25 Jul 2008 09:50:37 +1200 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> Message-ID: <4888F92D.6070206@xtra.co.nz> David C. Partridge wrote: > I'm going to place an order for the PCB for my frequency divider in the next > few days. If I can get a batch of ten ordered the cost will be about USD60 > each plus postage to wherever you are. PCB is four layer, 5" by 3.5", pads > will be electrolytic Ni/Au (this house doesn't charge extra for that). > > Au plating leaves the solder joints vulnerable to the formation of the AuSn intermetallic compound which will lead to joint failure. You may need to remove the Au before soldering. > The price goes down as the numbers go up of course. If anyone thinks they > can better this price, I'm happy to ship the gerbers and NC drill files. > > I never did hear back from Magnus about the circuit driving the selectors on > the '4051, so that stays as it is. > > I have one firm request from Norman J McSweyn. > > If anyone else would like to order a PCB please could you email me directly > (rather than on list) at > > david dot partridge at dsl dot pipex dot com > > I also have a few spare of the '4017 dividers and lots of BAV99 which I'm > happy to pass on at cost to me. > > Cheers > Dave > > > Bruce From bruce.griffiths at xtra.co.nz Thu Jul 24 17:55:45 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 25 Jul 2008 09:55:45 +1200 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> Message-ID: <4888FA61.3040405@xtra.co.nz> For some some images illustrating the intermetallic problem at the microscopic level see: http://journals.cambridge.org/download.php?file=%2FMAM%2FMAM11_S02%2FS1431927605504483a.pdf&code=bdfd9822c124e17308c095f29250a990 Bruce From daun at yeagley.net Thu Jul 24 18:01:27 2008 From: daun at yeagley.net (Daun Yeagley) Date: Thu, 24 Jul 2008 18:01:27 -0400 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <4888FA61.3040405@xtra.co.nz> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> <4888FA61.3040405@xtra.co.nz> Message-ID: <008301c8edd8$d39a1af0$0c00a8c0@daundell> I get the following error: File not available. [S1431927605504483a.pdf]. Daun -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Bruce Griffiths Sent: Thursday, July 24, 2008 5:56 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] PCB for frequency dividers For some some images illustrating the intermetallic problem at the microscopic level see: http://journals.cambridge.org/download.php?file=%2FMAM%2FMAM11_S02%2FS143192 7605504483a.pdf&code=bdfd9822c124e17308c095f29250a990 Bruce _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From had at to-way.com Thu Jul 24 18:04:55 2008 From: had at to-way.com (Had) Date: Thu, 24 Jul 2008 15:04:55 -0700 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <008301c8edd8$d39a1af0$0c00a8c0@daundell> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> <4888FA61.3040405@xtra.co.nz> <008301c8edd8$d39a1af0$0c00a8c0@daundell> Message-ID: <20080724220514.B2914164822@mail-in05.adhost.com> Yup, same error I got. Had, K7MLR At 03:01 PM 7/24/2008, you wrote: >I get the following error: >File not available. [S1431927605504483a.pdf]. > >Daun > >-----Original Message----- >From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On >Behalf Of Bruce Griffiths >Sent: Thursday, July 24, 2008 5:56 PM >To: Discussion of precise time and frequency measurement >Subject: Re: [time-nuts] PCB for frequency dividers > >For some some images illustrating the intermetallic problem at the >microscopic level see: >http://journals.cambridge.org/download.php?file=%2FMAM%2FMAM11_S02%2FS143192 >7605504483a.pdf&code=bdfd9822c124e17308c095f29250a990 >27605504483a.pdf&code=bdfd9822c124e17308c095f29250a990> > > >Bruce > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > > > > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From bruce.griffiths at xtra.co.nz Thu Jul 24 18:08:10 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 25 Jul 2008 10:08:10 +1200 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <008301c8edd8$d39a1af0$0c00a8c0@daundell> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> <4888FA61.3040405@xtra.co.nz> <008301c8edd8$d39a1af0$0c00a8c0@daundell> Message-ID: <4888FD4A.1020506@xtra.co.nz> Daun Yeagley wrote: > I get the following error: > File not available. [S1431927605504483a.pdf]. > > Daun > > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On > Behalf Of Bruce Griffiths > Sent: Thursday, July 24, 2008 5:56 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] PCB for frequency dividers > > For some some images illustrating the intermetallic problem at the > microscopic level see: > http://journals.cambridge.org/download.php?file=%2FMAM%2FMAM11_S02%2FS143192 > 7605504483a.pdf&code=bdfd9822c124e17308c095f29250a990 > 27605504483a.pdf&code=bdfd9822c124e17308c095f29250a990> > > > Bruce > > > Try this link: http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=326392 Bruce From bruce.griffiths at xtra.co.nz Thu Jul 24 18:09:18 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 25 Jul 2008 10:09:18 +1200 Subject: [time-nuts] [Fwd: Re: PCB for frequency dividers] Message-ID: <4888FD8E.3080106@xtra.co.nz> -------------- next part -------------- An embedded message was scrubbed... From: Bruce Griffiths Subject: Re: [time-nuts] PCB for frequency dividers Date: Fri, 25 Jul 2008 10:08:10 +1200 Size: 1627 Url: http://www.febo.com/pipermail/time-nuts/attachments/20080725/fc8b2630/attachment.eml From bruce.griffiths at xtra.co.nz Thu Jul 24 18:24:01 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 25 Jul 2008 10:24:01 +1200 Subject: [time-nuts] [Fwd: Re: PCB for frequency dividers] In-Reply-To: <4888FD8E.3080106@xtra.co.nz> References: <4888FD8E.3080106@xtra.co.nz> Message-ID: <48890101.1020505@xtra.co.nz> Additional link on soldering of Au plated Ni surfaces: http://www.tkb-4u.com/articles/soldering/sgons/sgons.php Includes some info on problems in soldering Nickel. Bruce From holrum at hotmail.com Thu Jul 24 18:34:19 2008 From: holrum at hotmail.com (Mark Sims) Date: Thu, 24 Jul 2008 22:34:19 +0000 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: References: Message-ID: Check out MYLYDIA.COM ... for around $720 ($320 setup plus $0.20 / sq in x 2000 sq in minimum) you can get 115 circuit boards with solder mask and silk screen ($6.30 per board if you can sell them all). Even if you sell a dozen of them, it's cheaper than what you are considering... ---------------------------------------- _________________________________________________________________ Keep your kids safer online with Windows Live Family Safety. http://www.windowslive.com/family_safety/overview.html?ocid=TXT_TAGLM_WL_family_safety_072008 From johnday at wordsnimages.com Thu Jul 24 21:14:03 2008 From: johnday at wordsnimages.com (John Day) Date: Thu, 24 Jul 2008 21:14:03 -0400 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: References: Message-ID: At 06:34 PM 7/24/2008, you wrote: Yikes, those are both expensive. http://myropcb.com/ Online quote system is very accurate. I have used them for 12x13inch 6 layer, very reasonable and plenty of smaller 2 and 4 layer PCB's. They are reliable, speedy and accurate. John Try these people: S1D13513 >Check out MYLYDIA.COM ... for around $720 ($320 setup plus $0.20 / >sq in x 2000 sq in minimum) you can get 115 circuit boards with >solder mask and silk screen ($6.30 per board if you can sell them >all). Even if you sell a dozen of them, it's cheaper than what >you are considering... >---------------------------------------- > >_________________________________________________________________ >Keep your kids safer online with Windows Live Family Safety. >http://www.windowslive.com/family_safety/overview.html?ocid=TXT_TAGLM_WL_family_safety_072008 >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > > >-- >No virus found in this incoming message. >Checked by AVG. >Version: 7.5.524 / Virus Database: 270.5.5/1571 - Release Date: >7/24/2008 5:42 PM From johnday at wordsnimages.com Thu Jul 24 21:26:29 2008 From: johnday at wordsnimages.com (John Day) Date: Thu, 24 Jul 2008 21:26:29 -0400 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: References: Message-ID: Oops! Left out the link: http://www.myropcb.com At 09:14 PM 7/24/2008, you wrote: >At 06:34 PM 7/24/2008, you wrote: > >Yikes, those are both expensive. http://myropcb.com/ > >Online quote system is very accurate. I have used them for 12x13inch >6 layer, very reasonable and plenty of smaller 2 and 4 layer PCB's. >They are reliable, speedy and accurate. > >John > >Try these people: S1D13513 > > >Check out MYLYDIA.COM ... for around $720 ($320 setup plus $0.20 / > >sq in x 2000 sq in minimum) you can get 115 circuit boards with > >solder mask and silk screen ($6.30 per board if you can sell them > >all). Even if you sell a dozen of them, it's cheaper than what > >you are considering... > >---------------------------------------- > > > >_________________________________________________________________ > >Keep your kids safer online with Windows Live Family Safety. > >http://www.windowslive.com/family_safety/overview.html?ocid=TXT_TAG > LM_WL_family_safety_072008 > >_______________________________________________ > >time-nuts mailing list -- time-nuts at febo.com > >To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >and follow the instructions there. > > > > > >-- > >No virus found in this incoming message. > >Checked by AVG. > >Version: 7.5.524 / Virus Database: 270.5.5/1571 - Release Date: > >7/24/2008 5:42 PM > > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > > >-- >No virus found in this incoming message. >Checked by AVG. >Version: 7.5.524 / Virus Database: 270.5.5/1571 - Release Date: >7/24/2008 5:42 PM From david.partridge at dsl.pipex.com Fri Jul 25 01:28:37 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Fri, 25 Jul 2008 06:28:37 +0100 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <4888F92D.6070206@xtra.co.nz> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> <4888F92D.6070206@xtra.co.nz> Message-ID: <7E06A7A651B94C8AAD35C0F1F3164FD2@APOLLO> So if Au isn't the thing, what's the better answer? HASL Sn is the other common option and I can smell tin whiskers as the counter argument to that. Electroless Ag? Don't even think of suggesting regular HASL Sn/Pb - none of the PCB shops will do that here (RoHS). Dave -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Bruce Griffiths Sent: 24 July 2008 22:51 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] PCB for frequency dividers Au plating leaves the solder joints vulnerable to the formation of the AuSn intermetallic compound which will lead to joint failure. You may need to remove the Au before soldering. From don at k7tsv.com Fri Jul 25 11:00:18 2008 From: don at k7tsv.com (Don Garlick) Date: Fri, 25 Jul 2008 08:00:18 -0700 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> Message-ID: <00d201c8ee67$27fe2b70$77fa8250$@com> It can be about matched at www.sunstone.com Current Quote for 4-Layer Quickturn Boards http://www.sunstone.com/images/Question.gif Upload Files | Print this Quote Print this Quote Build Time: 3 days Unit Price: $60.30 Quantity: 10 Total Price: $603.00 Part Number: Revision No: Email this Quote to Someone Save this Quote Email Address: Receive Email Pricing Matrix Select an alternative quantity or build time from below to change your quote. Change To Lot Pricing Quantity 3 days 4 days 5 days 2 $216.00$432.00 4 $123.00$492.00 6 $89.00$534.00 8 $71.25$570.00 10 $60.30$603.00 15 $42.20$633.00 20 $33.00$660.00 25 $30.56$764.00 30 $28.53$856.00 50 $26.82$1,341.00 75 $24.15$1,811.00 100 $19.62$1,962.00 Quantity: 10 Build Time: 3 days Layers: 4 _____ Board Size: 5 X 3.5 (in.) Thickness: .062 in. Finished Copper: 1.0 oz. _____ Surface Mount: 1-2 sds Solder Mask: 2 Side Green Silkscreen: 1 Side White _____ Min Trace Space: .006 in. Finished Holes Predefined 24 Number Of Holes: 35/sqin _____ Routing: Individual Surface Finish: Tin Lead Slots/Cutouts: 0 (qty/board) _____ Gold Fingers: 0 (in.) UL Certification: No Lot Code: No _____ Date Code: No Silkscreen Clip: Yes Smallest Hole: _____ File Conversion: No Electrical Test: No -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of David C. Partridge Sent: Thursday, July 24, 2008 11:43 AM To: 'Discussion of precise time and frequency measurement' Subject: [time-nuts] PCB for frequency dividers I'm going to place an order for the PCB for my frequency divider in the next few days. If I can get a batch of ten ordered the cost will be about USD60 each plus postage to wherever you are. PCB is four layer, 5" by 3.5", pads will be electrolytic Ni/Au (this house doesn't charge extra for that). The price goes down as the numbers go up of course. If anyone thinks they can better this price, I'm happy to ship the gerbers and NC drill files. I never did hear back from Magnus about the circuit driving the selectors on the '4051, so that stays as it is. I have one firm request from Norman J McSweyn. If anyone else would like to order a PCB please could you email me directly (rather than on list) at david dot partridge at dsl dot pipex dot com I also have a few spare of the '4017 dividers and lots of BAV99 which I'm happy to pass on at cost to me. Cheers Dave _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.138 / Virus Database: 270.5.5/1570 - Release Date: 7/24/2008 6:59 AM -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 1013 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080725/4fd2bd66/attachment-0002.gif -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 712 bytes Desc: not available Url : http://www.febo.com/pipermail/time-nuts/attachments/20080725/4fd2bd66/attachment-0003.gif From david.partridge at dsl.pipex.com Fri Jul 25 12:17:56 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Fri, 25 Jul 2008 17:17:56 +0100 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <00d201c8ee67$27fe2b70$77fa8250$@com> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> <00d201c8ee67$27fe2b70$77fa8250$@com> Message-ID: Currently I have requests for 5 boards. The pricing I gave earlier (based on an order qty of ten) didn't include the tax I have to pay or the shipping to me. Pricing will be about USD70 each plus shipping if I get no further requests. The more interest the lower the price of course. If I can buy 'em cheaper you will get 'em cheaper. In the unlikely event that there are requests for 50 units, the price will be somewhere around USD20 each (or less). I'll hold off placing the order until after the weekend to see if there are any more takers. BTW Someone suggested that this might be relevant to TAPR. I'm very happy to grant TAPR the free (no charge) use of the design, conditional only on my retaining copyright. If Didier is happy to host the files, I'm also very happy to make the gerbers and other stuff available on his website. The gerbers are of course already packaged up ready to ship to the PCB mfr. Oh yes, a question - is it normal for solder mask gerbers to show where the solder mask WON'T be (that is on the pads)? I've looked at the other PCB houses folks have suggested, but most are US/Canada based, and by the time I've paid shipping to the UK, import duty, handling charges, and taxes any small saving in the per board cost is totally wiped out. The crazy thing is that the UK house I'm proposing to use actually gets their stuff fabbed in China, shipped half way round the world, and still end up charging a very small fraction of the cost of using local PCB manufacturers. Dave From jra at febo.com Fri Jul 25 13:18:12 2008 From: jra at febo.com (John Ackermann N8UR) Date: Fri, 25 Jul 2008 13:18:12 -0400 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> <00d201c8ee67$27fe2b70$77fa8250$@com> Message-ID: <488A0AD4.4000707@febo.com> David C. Partridge said the following on 07/25/2008 12:17 PM: > BTW Someone suggested that this might be relevant to TAPR. I'm very happy > to grant TAPR the free (no charge) use of the design, conditional only on my > retaining copyright. TAPR's Time and Frequency Design Team (i.e., me) is definitely interested in a divider design, though what I had in mind is slightly different than your design, David, perhaps because of a slightly different idea of functionality, as well as matching the footprint of the existing TADD-1 and TADD-3 boards. I've been a bit out of the loop lately because of some medical problems, but would love to talk with you about this. But more generally, and why I'm sending this to the list, I'd encourage hardware designers to look at the TAPR Open Hardware License (http://www.tapr.org/OHL) for their projects. It's available for use by anyone, whether or not connected with TAPR. John From wje at quackers.net Fri Jul 25 13:28:19 2008 From: wje at quackers.net (wje) Date: Fri, 25 Jul 2008 13:28:19 -0400 Subject: [time-nuts] 5061A S/N ratio, EM voltage questions Message-ID: <488A0D33.4080105@quackers.net> Can someone provide a sanity check on my S/N and FOM measurements? I've used the procedure in my manual, but there is one rather vague calculation involving 2.3 e 13 x V403b. I assume this is actually 2.3 e -13 x (noise voltage in mv), because otherwise the other calculations result in absurd values. I have a high-output tube and got the following measurements: Vpeak -278 mv Vvalley -81 mv Vbase -65 mv which gives a 'flop' of 3.03. Using the more advanced measurements for the high-output tube, I get: Isig 1.97 e -9 Inoise 6.44 e-13 (assuming my comment abut the V403b calculation is correct; I measured a noise voltage of 2.8 mv rms). which gives an S/N ratio of 3059 (!) and a FOM of 7.89. This is all from a 25-year-old CBT, so I'm a bit suspicious. It does lock and stay locked, even in low-flux mode, though. As for the EM voltage, I measured a peak beam current of 3.6 e -9 amps; HP says the acceptable low bound is 8 e -9. This current makes sense, since the tube is so old. So, would it be useful to increase the EM voltage from 1700 (as marked on the CBT and verified) to increase the beam current? I assume doing so would accelerate the deterioration of the EM, though, so maybe I should leave well enough alone. BTW, I had to make up a precision 100 meg probe to do the Vp, Vv, and Vb measurements; my voltmeter has a 1 e 13 ohm input resistance, which makes the technique in the manual useless. (a Solartron 7081 8.5 digit beauty) -- Bill Ezell ---------- They said 'Windows or better' so I used Linux. From david.partridge at dsl.pipex.com Fri Jul 25 16:47:39 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Fri, 25 Jul 2008 21:47:39 +0100 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <488A0AD4.4000707@febo.com> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO> <00d201c8ee67$27fe2b70$77fa8250$@com> <488A0AD4.4000707@febo.com> Message-ID: John, Read the license - seems appropriate to me. Happy to talk further, let's take this off list. Please use my email david dot partridge at dsl dot pipex dot com I'll be away over the w/e so don't expect a prompt reply ... Cheers Dave -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of John Ackermann N8UR Sent: 25 July 2008 18:18 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] PCB for frequency dividers David C. Partridge said the following on 07/25/2008 12:17 PM: > BTW Someone suggested that this might be relevant to TAPR. I'm very happy > to grant TAPR the free (no charge) use of the design, conditional only > on my retaining copyright. TAPR's Time and Frequency Design Team (i.e., me) is definitely interested in a divider design, though what I had in mind is slightly different than your design, David, perhaps because of a slightly different idea of functionality, as well as matching the footprint of the existing TADD-1 and TADD-3 boards. I've been a bit out of the loop lately because of some medical problems, but would love to talk with you about this. But more generally, and why I'm sending this to the list, I'd encourage hardware designers to look at the TAPR Open Hardware License (http://www.tapr.org/OHL) for their projects. It's available for use by anyone, whether or not connected with TAPR. John _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From j-shank at comcast.net Fri Jul 25 18:51:54 2008 From: j-shank at comcast.net (jshank) Date: Fri, 25 Jul 2008 18:51:54 -0400 Subject: [time-nuts] LPRO 101 ADJUSTMENT References: <9835219326F6421AB4A20EA07D3471FD@athlon> <48876375.5060200@tiscali.co.uk> Message-ID: <05B23324048C4866A8B94C37A6E6BDD1@DESKTOP> Hi, I recently acquired a LPRO 101 Rubidium Oscillator. After reading the manual I see that there are two ways to adjust the frequency 1) using and adjusting screw on the unit and 2) using the External C-field control signal at pin J1-7. Has anyone experimented with either method and if so what method was preferred? Jeff From namichie at gmail.com Fri Jul 25 19:08:49 2008 From: namichie at gmail.com (Neville Michie) Date: Sat, 26 Jul 2008 09:08:49 +1000 Subject: [time-nuts] LPRO 101 ADJUSTMENT In-Reply-To: <05B23324048C4866A8B94C37A6E6BDD1@DESKTOP> References: <9835219326F6421AB4A20EA07D3471FD@athlon> <48876375.5060200@tiscali.co.uk> <05B23324048C4866A8B94C37A6E6BDD1@DESKTOP> Message-ID: <44B13E79-A106-4BA5-A48D-E6FBDB9C6280@gmail.com> Hi Jeff, if you read the manual you will see (there is a partial circuit diagram) that the external voltage trim is added to the voltage on the internal trim-pot, so both adjustments have the same effect. I was thinking of using an 8bit DAC to put a very small correcting voltage on the electrical input while I use the internal pot to adjust it centre scale or if it runs off scale. That way I can get microhertz steps of adjustment from an external circuit without an extreme stability DAC. cheers, Neville Michie On 26/07/2008, at 8:51 AM, jshank wrote: > Hi, > > I recently acquired a LPRO 101 Rubidium Oscillator. After reading the > manual I see that there are two ways to adjust the frequency 1) > using and > adjusting screw on the unit and 2) using the External C-field > control signal > at pin J1-7. Has anyone experimented with either method and if so > what > method was preferred? > > Jeff > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. From smace at intt.net Fri Jul 25 19:15:06 2008 From: smace at intt.net (Scott Mace) Date: Fri, 25 Jul 2008 18:15:06 -0500 Subject: [time-nuts] LPRO 101 ADJUSTMENT In-Reply-To: <05B23324048C4866A8B94C37A6E6BDD1@DESKTOP> References: <9835219326F6421AB4A20EA07D3471FD@athlon> <48876375.5060200@tiscali.co.uk> <05B23324048C4866A8B94C37A6E6BDD1@DESKTOP> Message-ID: <488A5E7A.6060602@intt.net> Both methods work well. Be sure the unit is mounted to some sort of heatsink,chassis, etc. I'm using a Fury GPS receiver to drive the EFC on an LPRO-101. You won't get much range out of either adjustment. Leave it powered on for a couple of hours before trying to adjust it. I usually set the trim pot in the middle of it's range and use the EFC pin. I think it's a 28 or 30 turn pot. EFC is 0-5v. The unit will self-bias to around 2.5v if the EFC pin is open. Scott jshank wrote: > Hi, > > I recently acquired a LPRO 101 Rubidium Oscillator. After reading the > manual I see that there are two ways to adjust the frequency 1) using and > adjusting screw on the unit and 2) using the External C-field control signal > at pin J1-7. Has anyone experimented with either method and if so what > method was preferred? > > Jeff > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From j-shank at comcast.net Fri Jul 25 20:33:26 2008 From: j-shank at comcast.net (jshank) Date: Fri, 25 Jul 2008 20:33:26 -0400 Subject: [time-nuts] LPRO 101 ADJUSTMENT References: <9835219326F6421AB4A20EA07D3471FD@athlon> <48876375.5060200@tiscali.co.uk> <05B23324048C4866A8B94C37A6E6BDD1@DESKTOP> <488A5E7A.6060602@intt.net> Message-ID: <1AC9FBE457064A31938866B12D0E56F8@DESKTOP> If I choose to control the frequency via External C-field control I guess it would take a very precise and stable voltage source. Any thoughts or suggestions? ----- Original Message ----- From: "Scott Mace" To: "jshank" ; "Discussion of precise time and frequency measurement" Sent: Friday, July 25, 2008 7:15 PM Subject: Re: [time-nuts] LPRO 101 ADJUSTMENT > Both methods work well. Be sure the unit is mounted to some sort of > heatsink,chassis, etc. > I'm using a Fury GPS receiver to drive the EFC on an LPRO-101. > You won't get much range out of either adjustment. Leave it powered > on for a couple of hours before trying to adjust it. I usually set the > trim pot in the > middle of it's range and use the EFC pin. I think it's a 28 or 30 turn > pot. EFC > is 0-5v. The unit will self-bias to around 2.5v if the EFC pin is open. > > Scott > > jshank wrote: >> Hi, >> >> I recently acquired a LPRO 101 Rubidium Oscillator. After reading the >> manual I see that there are two ways to adjust the frequency 1) using and >> adjusting screw on the unit and 2) using the External C-field control >> signal at pin J1-7. Has anyone experimented with either method and if so >> what method was preferred? >> >> Jeff >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts at febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> From bruce.griffiths at xtra.co.nz Fri Jul 25 20:43:20 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 26 Jul 2008 12:43:20 +1200 Subject: [time-nuts] LPRO 101 ADJUSTMENT In-Reply-To: <1AC9FBE457064A31938866B12D0E56F8@DESKTOP> References: <9835219326F6421AB4A20EA07D3471FD@athlon> <48876375.5060200@tiscali.co.uk> <05B23324048C4866A8B94C37A6E6BDD1@DESKTOP> <488A5E7A.6060602@intt.net> <1AC9FBE457064A31938866B12D0E56F8@DESKTOP> Message-ID: <488A7328.5070601@xtra.co.nz> jshank wrote: > If I choose to control the frequency via External C-field control I guess it > would take a very precise and stable voltage source. Any thoughts or > suggestions? > 1) Quantify quiet and stable. Otherwise you'll either get suggestions that are inexpensive with inadequate stability or suggestions that are expensive and have more stability and lower noise than is actually required. One method is to use a stable quiet and slow ADC to measure the output of a DAC system that is sufficiently quiet with good short term stability and adjust the DAC output to the desired value using the ADC to detect when this is achieved. Bruce From smace at intt.net Fri Jul 25 21:49:59 2008 From: smace at intt.net (Scott Mace) Date: Fri, 25 Jul 2008 20:49:59 -0500 Subject: [time-nuts] LPRO 101 ADJUSTMENT In-Reply-To: <1AC9FBE457064A31938866B12D0E56F8@DESKTOP> References: <9835219326F6421AB4A20EA07D3471FD@athlon> <48876375.5060200@tiscali.co.uk> <05B23324048C4866A8B94C37A6E6BDD1@DESKTOP> <488A5E7A.6060602@intt.net> <1AC9FBE457064A31938866B12D0E56F8@DESKTOP> Message-ID: <488A82C7.1010009@intt.net> Here's an idea of what the DAC on my system is doing: timestamp freq_err time_int efc_voltage 54672 85907.015 2.18e-12 -5.00e-10 1.976955 54672 85917.015 1.87e-12 -4.10e-10 1.976116 54672 85927.015 1.96e-12 -3.00e-10 1.975772 54672 85937.016 1.49e-12 -1.90e-10 1.975664 54672 85947.017 1.52e-12 -1.50e-10 1.975790 54672 85957.017 8.29e-13 -1.60e-10 1.976403 54672 85967.018 8.95e-13 -9.10e-11 1.976403 54672 85977.009 2.52e-14 -9.20e-11 1.976634 54672 85987.009 -1.16e-13 -2.30e-10 1.977615 54672 85997.010 -5.73e-13 -2.30e-10 1.977615 54672 86007.011 -6.71e-13 -3.40e-10 1.977129 54672 86017.011 -1.10e-12 -4.70e-10 1.977208 54672 86027.013 -1.31e-12 -6.70e-10 1.977122 54672 86037.013 -1.79e-12 -9.90e-10 1.977883 54672 86047.013 -2.16e-12 -1.40e-09 1.978333 54672 86057.015 -2.59e-12 -1.70e-09 1.978397 54672 86067.015 -2.94e-12 -2.10e-09 1.978397 54672 86077.015 -3.12e-12 -2.50e-09 1.978521 54672 86087.017 -3.36e-12 -2.80e-09 1.978479 54672 86097.010 -3.20e-12 -3.00e-09 1.978253 54672 86107.018 -3.33e-12 -3.20e-09 1.977620 54672 86117.018 -3.05e-12 -3.30e-09 1.977035 54672 86127.010 -3.09e-12 -3.40e-09 1.976963 54672 86137.010 -2.83e-12 -3.30e-09 1.976998 54672 86147.011 -2.68e-12 -3.20e-09 1.976998 54672 86157.010 -2.20e-12 -3.00e-09 1.976787 54672 86167.010 -1.93e-12 -2.70e-09 1.976953 54672 86177.012 -1.81e-12 -2.50e-09 1.977248 54672 86187.014 -1.51e-12 -2.20e-09 1.977218 54672 86197.015 -1.52e-12 -2.00e-09 1.976899 54672 86207.015 -1.27e-12 -1.80e-09 1.976659 54672 86217.017 -1.09e-12 -1.60e-09 1.976506 54672 86227.016 -8.53e-13 -1.40e-09 1.976144 54672 86237.017 -7.64e-13 -1.20e-09 1.976058 54672 86247.018 -6.27e-13 -1.10e-09 1.976518 54672 86257.018 -8.53e-13 -9.90e-10 1.976634 54672 86267.010 -8.15e-13 -9.60e-10 1.977167 54672 86277.010 -1.24e-12 -1.00e-09 1.978143 54672 86287.010 -1.27e-12 -1.00e-09 1.977806 54672 86297.012 -1.72e-12 -1.10e-09 1.977363 54672 86307.010 -1.79e-12 -1.20e-09 1.977358 54672 86317.009 -2.10e-12 -1.30e-09 1.977070 54672 86327.013 -2.27e-12 -1.50e-09 1.977347 54672 86337.014 -2.35e-12 -1.80e-09 1.978016 54672 86347.014 -2.63e-12 -2.10e-09 1.978357 54672 86357.016 -2.57e-12 -2.40e-09 1.978433 54672 86367.010 -2.87e-12 -2.70e-09 1.978821 54672 86377.014 -2.50e-12 -2.90e-09 1.978657 54672 86387.013 -2.64e-12 -3.00e-09 1.978657 54672 86397.010 -2.00e-12 -3.10e-09 1.977049 Scott jshank wrote: > If I choose to control the frequency via External C-field control I guess it > would take a very precise and stable voltage source. Any thoughts or > suggestions? > > ----- Original Message ----- > From: "Scott Mace" > To: "jshank" ; "Discussion of precise time and > frequency measurement" > Sent: Friday, July 25, 2008 7:15 PM > Subject: Re: [time-nuts] LPRO 101 ADJUSTMENT > > >> Both methods work well. Be sure the unit is mounted to some sort of >> heatsink,chassis, etc. >> I'm using a Fury GPS receiver to drive the EFC on an LPRO-101. >> You won't get much range out of either adjustment. Leave it powered >> on for a couple of hours before trying to adjust it. I usually set the >> trim pot in the >> middle of it's range and use the EFC pin. I think it's a 28 or 30 turn >> pot. EFC >> is 0-5v. The unit will self-bias to around 2.5v if the EFC pin is open. >> >> Scott >> >> jshank wrote: >>> Hi, >>> >>> I recently acquired a LPRO 101 Rubidium Oscillator. After reading the >>> manual I see that there are two ways to adjust the frequency 1) using and >>> adjusting screw on the unit and 2) using the External C-field control >>> signal at pin J1-7. Has anyone experimented with either method and if so >>> what method was preferred? >>> >>> Jeff >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts at febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From bruce.griffiths at xtra.co.nz Fri Jul 25 23:32:28 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sat, 26 Jul 2008 15:32:28 +1200 Subject: [time-nuts] LPRO 101 ADJUSTMENT In-Reply-To: <1AC9FBE457064A31938866B12D0E56F8@DESKTOP> References: <9835219326F6421AB4A20EA07D3471FD@athlon> <48876375.5060200@tiscali.co.uk> <05B23324048C4866A8B94C37A6E6BDD1@DESKTOP> <488A5E7A.6060602@intt.net> <1AC9FBE457064A31938866B12D0E56F8@DESKTOP> Message-ID: <488A9ACC.9040100@xtra.co.nz> jshank wrote: > If I choose to control the frequency via External C-field control I guess it > would take a very precise and stable voltage source. Any thoughts or > suggestions? > The range of adjustment for a typical Datum/Efratom rubidium standard is only a few parts in1E9. Thus to achieve a resolution of 1E-13( overkill??) a DAC with ENOB= 16 bits should suffice. If the DAC is part of a servo loop it only has to be quiet, have a monotonic transfer function and not drift too rapidly. Thus a string DAC or KV style DAC (eg AD569) are ideally suited. Sigma delta DACs are also suitable. PWM DACs are less useful. The DAC response time need not be particularly fast if the loop time constant is several seconds or more. Slow drifts in the DAC gain and offset will be corrected by the servo loop. Bruce From w.knowles at xtra.co.nz Sat Jul 26 23:29:33 2008 From: w.knowles at xtra.co.nz (Wayne Knowles) Date: Sun, 27 Jul 2008 15:29:33 +1200 Subject: [time-nuts] Firefox/IE7 plugin for searching mail archives Message-ID: <200807271529.33434.w.knowles@xtra.co.nz> Several people have recently asked how to search the mail archives. Recently I got tired of using Google and specifying the site: prefix, so I have built a configuration that allows me to search the Time-Nuts mail archives directly from the Firefox search bar as I do for other sites (eBay, Wikipedia etc). It also works for me under IE7 (for reasons known only to Microsoft it would not install under Vista, but works fine under XP) The plugin is available for download from: http://mycroft.mozdev.org/search-engines.html?name=timenuts Note that Google is used as the back end. Enjoy! -- Wayne From rk at timing-consultants.com Sun Jul 27 03:28:14 2008 From: rk at timing-consultants.com (Rob Kimberley) Date: Sun, 27 Jul 2008 08:28:14 +0100 Subject: [time-nuts] Firefox/IE7 plugin for searching mail archives In-Reply-To: <200807271529.33434.w.knowles@xtra.co.nz> References: <200807271529.33434.w.knowles@xtra.co.nz> Message-ID: <295306FD5D6C40ECBB587CBB9EDB1B09@Robin> Hi Wayne, Just installed it and works fine. Thanks. Rob Kimberley -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Wayne Knowles Sent: 27 July 2008 04:30 To: time-nuts at febo.com Subject: [time-nuts] Firefox/IE7 plugin for searching mail archives Several people have recently asked how to search the mail archives. Recently I got tired of using Google and specifying the site: prefix, so I have built a configuration that allows me to search the Time-Nuts mail archives directly from the Firefox search bar as I do for other sites (eBay, Wikipedia etc). It also works for me under IE7 (for reasons known only to Microsoft it would not install under Vista, but works fine under XP) The plugin is available for download from: http://mycroft.mozdev.org/search-engines.html?name=timenuts Note that Google is used as the back end. Enjoy! -- Wayne _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From bruce.griffiths at xtra.co.nz Sun Jul 27 03:44:47 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Sun, 27 Jul 2008 19:44:47 +1200 Subject: [time-nuts] Firefox/IE7 plugin for searching mail archives In-Reply-To: <295306FD5D6C40ECBB587CBB9EDB1B09@Robin> References: <200807271529.33434.w.knowles@xtra.co.nz> <295306FD5D6C40ECBB587CBB9EDB1B09@Robin> Message-ID: <488C276F.5060604@xtra.co.nz> Rob Kimberley wrote: > Hi Wayne, > > Just installed it and works fine. > > Thanks. > > Rob Kimberley > > -----Original Message----- > From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On > Behalf Of Wayne Knowles > Sent: 27 July 2008 04:30 > To: time-nuts at febo.com > Subject: [time-nuts] Firefox/IE7 plugin for searching mail archives > > Several people have recently asked how to search the mail archives. > > Recently I got tired of using Google and specifying the site: prefix, so I > have built a configuration that allows me to search the Time-Nuts mail > archives directly from the Firefox search bar as I do for other sites (eBay, > > Wikipedia etc). > It also works for me under IE7 (for reasons known only to Microsoft it would > not install under Vista, but works fine under XP) > > The plugin is available for download from: > > http://mycroft.mozdev.org/search-engines.html?name=timenuts > > Note that Google is used as the back end. > > Enjoy! > -- > Wayne > > Also works for Linux. Thanks. Bruce From d.seiter at comcast.net Sun Jul 27 04:54:11 2008 From: d.seiter at comcast.net (d.seiter at comcast.net) Date: Sun, 27 Jul 2008 08:54:11 +0000 Subject: [time-nuts] Grounding a Z3801A Message-ID: <072720080854.24502.488C37B300029B1100005FB622058891169D0A9B070A9CD20B@comcast.net> I'm finally getting around to reinstalling my Z3801A after frying and then fixing the on-board power supply, but I'm really paranoid about doing it again (I had forgotten that the unit has a positive ground). The external supply had floating outputs, the AC input was grounded to the chassis and the case of the Z3801A was grounded. I also realized that the external clock display board was grounded to both the chassis and the internal ground of the Z3801A, which is probably where the short came from. In this next attempt, the external PS AC input ground will be eliminated and it's case will be isolated from the chassis. The Z3801A will also be isolated from the chassis, as will the display assembly. That leaves the RS232 cable, which is grounded as it passes through the front of the chassis, and the signal outputs. Should I isolate the rs-232 as well? What about a double dc block on the output signals? I realize this all sounds a bit extreme... -Dave. From dibene at usa.net Sun Jul 27 10:16:58 2008 From: dibene at usa.net (Alberto di Bene) Date: Sun, 27 Jul 2008 16:16:58 +0200 Subject: [time-nuts] Grounding a Z3801A In-Reply-To: <072720080854.24502.488C37B300029B1100005FB622058891169D0A9B070A9CD20B@comcast.net> References: <072720080854.24502.488C37B300029B1100005FB622058891169D0A9B070A9CD20B@comcast.net> Message-ID: <488C835A.6010800@usa.net> Talking of the Z3801A, has anybody added a small fan to it ? Mine is very hot inside, especially the large VLSI chips on the upper board. I contemplated adding a couple of small DC fans, to push out the hot air, but first would like to know your opinions and your experiences, if any, about that. Thanks Alberto I2PHD From buehl at superlink.net Sun Jul 27 10:23:29 2008 From: buehl at superlink.net (buehl) Date: Sun, 27 Jul 2008 10:23:29 -0400 Subject: [time-nuts] Grounding a Z3801A In-Reply-To: <072720080854.24502.488C37B300029B1100005FB622058891169D0A9 B070A9CD20B@comcast.net> References: <072720080854.24502.488C37B300029B1100005FB622058891169D0A9B070A9CD20B@comcast.net> Message-ID: Dave: Keep in mind that you can do grounding of the noise/ RF using a capacitor; not risking any potential shorts. Of course, all cousions about 'ground loops' still apply. Tom At 08:54 AM 7/27/2008 +0000, you wrote: >I'm finally getting around to reinstalling my Z3801A after frying >and then fixing the on-board power supply, but I'm really paranoid >about doing it again (I had forgotten that the unit has a positive >ground). The external supply had floating outputs, the AC input was >grounded to the chassis and the case of the Z3801A was grounded. I >also realized that the external clock display board was grounded to >both the chassis and the internal ground of the Z3801A, which is >probably where the short came from. > >In this next attempt, the external PS AC input ground will be >eliminated and it's case will be isolated from the chassis. The >Z3801A will also be isolated from the chassis, as will the display >assembly. That leaves the RS232 cable, which is grounded as it >passes through the front of the chassis, and the signal outputs. > >Should I isolate the rs-232 as well? What about a double dc block >on the output signals? I realize this all sounds a bit extreme... > >-Dave. > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From Murray.Greenman at rakon.com Sun Jul 27 14:56:55 2008 From: Murray.Greenman at rakon.com (Murray Greenman) Date: Mon, 28 Jul 2008 06:56:55 +1200 Subject: [time-nuts] A fan for the Z3801A In-Reply-To: References: Message-ID: Alberto, I'm not much in favour of the idea of adding a fan (to any GPSDO, not just the Z3801A). While I've not tried it, there would be a risk of upsetting the stability of the unit, especially if the fan speed varied or the air flow changed for some other reason. If you could be sure that the airflow was steady and was not directed at the OCXO, it might be OK, but test it out. In my experience with the Z3815A I noticed a marked change in frequency (it returned and settled after a while) when I turned the unit gently upside down, i.e. reversed the direction of convection. It would be preferable, in my opinion, to simply improve the convection paths in your present setup. As an aside, it is interesting to note the steady-state power consumption of the various units. The Z3801A is spec'd at 25W, the Z3815A (with hockey-puck oscillator) 35W, and at the other extreme, the Trimble NTGS50AA only 5W! 73, Murray ZL1BPU From SAIDJACK at aol.com Sun Jul 27 15:30:14 2008 From: SAIDJACK at aol.com (SAIDJACK at aol.com) Date: Sun, 27 Jul 2008 15:30:14 EDT Subject: [time-nuts] A fan for the Z3801A Message-ID: Hello Murray, moving air also affects the DAC and voltage reference, so while your OCXO may perform flawlessly, the EFC voltage can vary. For example capacitors have a thermal voltage on them, Elkos more so than Tantalum, etc all the way down to COG. Thus filter capacitors can affect EFC voltage when you point moving air on them. Then there are all the thermocouples in the solder junctions and cabling, and the other parts.. BTW: the lowest power GPSDO is not the Trimble unit you mentioned - as far as I know it is our FireFly GPSDO which only consumes a meager 1.35W at room temperature, and it also uses an OCXO. Bye, Said In a message dated 7/27/2008 11:56:04 Pacific Daylight Time, Murray.Greenman at rakon.com writes: As an aside, it is interesting to note the steady-state power consumption of the various units. The Z3801A is spec'd at 25W, the Z3815A (with hockey-puck oscillator) 35W, and at the other extreme, the Trimble NTGS50AA only 5W! 73, Murray ZL1BPU **************Get fantasy football with free live scoring. Sign up for FanHouse Fantasy Football today. (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020) From dibene at usa.net Mon Jul 28 09:40:40 2008 From: dibene at usa.net (Alberto di Bene) Date: Mon, 28 Jul 2008 15:40:40 +0200 Subject: [time-nuts] A fan for the Z3801A In-Reply-To: References: Message-ID: <488DCC58.6000802@usa.net> Murray, thanks for the advice. Well, my intention was, as suggested by a private message, to use a 12V fan powered at 5V, so that it runs slowly and silently, not blowing external air into the unit, but just extracting the hot air from the inside. And given that the unit is placed in the basement of the house, with a change in temperature between the day and the night of no more than 1 Celsius, may be the use of the fan should not disturb the thermal regulation of the OCXO and the other temperature-sensitive devices, while at the same time lowering the working temperature of those hot ICs, thus prolonging (maybe) their life. Anyway I am open to comments and suggestions. Thanks 73 Alberto I2PHD ------------------------------------------ Murray Greenman wrote: > Alberto, > > I'm not much in favour of the idea of adding a fan (to any GPSDO, not > just the Z3801A). While I've not tried it, there would be a risk of > upsetting the stability of the unit, especially if the fan speed varied > or the air flow changed for some other reason. If you could be sure that > the airflow was steady and was not directed at the OCXO, it might be OK, > but test it out. > > In my experience with the Z3815A I noticed a marked change in frequency > (it returned and settled after a while) when I turned the unit gently > upside down, i.e. reversed the direction of convection. > > It would be preferable, in my opinion, to simply improve the convection > paths in your present setup. > > As an aside, it is interesting to note the steady-state power > consumption of the various units. The Z3801A is spec'd at 25W, the > Z3815A (with hockey-puck oscillator) 35W, and at the other extreme, the > Trimble NTGS50AA only 5W! > > 73, > Murray ZL1BPU From gbusg at comcast.net Mon Jul 28 13:11:01 2008 From: gbusg at comcast.net (Greg Burnett) Date: Mon, 28 Jul 2008 11:11:01 -0600 Subject: [time-nuts] A fan for the Z3801A References: Message-ID: <003101c8f0d4$e93f4570$6501a8c0@gb02> Another thing to consider: Depending on how well you shock-mount the fan, what if its vibration translates to sideband spurs or noise? -Greg ---------------------- Alberto wrote: Talking of the Z3801A, has anybody added a small fan to it ? Mine is very hot inside, especially the large VLSI chips on the upper board. I contemplated adding a couple of small DC fans, to push out the hot air, but first would like to know your opinions and your experiences, if any, about that. Thanks Alberto I2PHD From SAIDJACK at aol.com Mon Jul 28 17:04:03 2008 From: SAIDJACK at aol.com (SAIDJACK at aol.com) Date: Mon, 28 Jul 2008 17:04:03 EDT Subject: [time-nuts] Low power GPSDO Message-ID: Hello Murray, no problem :) just wanted to make sure folks know that there are options below 5W out there. I am impressed with your 50mW TCXO unit. We've been thinking about offering DIP14 TCXO's as well on the FireFly. That would allow for true battery operation. We are also testing extremely low power (~120mW) OCXO's, with the heating elements integrated into the Crystal Blank itself, but I am not happy with the stability of these just yet. We also have a Fury GPSDO wired up to the Agilent E1938A - while it's the best Fury I have it's a real power hog. In fact I am having a hard time finding a power supply capable of delivering sufficient warmup current to that box.. bye, Said In a message dated 7/28/2008 11:33:44 Pacific Daylight Time, Murray.Greenman at rakon.com writes: Jack, I didn't claim that the Trimble NTGS50AA was the "lowest power GPSDO". Those are your words. I simply said it was "at the other extreme", meaning (although not said) at the other extreme of my limited experience of about 10 different models. I own only five commercial GPSDOs (HP Z3801A; Symmetricom Z3815A with MTI 260 OCXO; CIC GPSR-A and Samsung GCRU-D with Rakon CFPO-2 OCXO; and the Trimble NTGS50AA), plus a working relationship with the Datum and Symmetricom units at work and a previously owned HP Z3815A with E1938A OCXO. I've also built a few, but not in the class of the commercial units. My lowest power one is battery operated (uses a V-TCXO) and has a power consumption of 50mW (with display backlight off!), but is more affected by sun load than is desirable. Another uses the HP 10811A OCXO, and can hardly be classed as low power. I have a professional interest in achieving low power in the GPSDO, as the company I work for are part of the Femtocell working group. I am certainly impressed that the Firefly is down at 1.35W. Regards, Murray Greenman **************Get fantasy football with free live scoring. Sign up for FanHouse Fantasy Football today. (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020) From kScally at BYTECAN.com.au Mon Jul 28 18:56:24 2008 From: kScally at BYTECAN.com.au (Kit Scally) Date: Tue, 29 Jul 2008 08:56:24 +1000 Subject: [time-nuts] time-nuts Digest, Vol 48, Issue 75 In-Reply-To: References: Message-ID: <281090D5003763419A5AC496FF087B2A3B81D8@msg01nsw.BYTECAN.com.au> Alberto, In the commercial world that the Z3815A's (and quite possibly the Z3801 etc) were used in, they were installed "vertically" at the bottom of a large equipment cabinet that had convection air channels running within it. A bank of 12-16 fans towards the top of the cabinet sucked up ambient air and forced it past the PA heatsinks. The hot air was vented out the PA modules & cabinet top. Ambient air temp was controlled at 20-25 deg C. The GPSDO pcb (and associated electronics) was cooled with incoming ambient air with the pcb and IC temperatures settling at some value. The critical point here is that the whole cabinet was operating 24x365 and for years on end. While semiconductor life is inversely proportional (?) to Tamb and cooling the electronics may seem a logical approach to prolonging life, I would suggest that , this is a second-order effect. The killer is thermal cycling which can induce premature failure in any electronic assembly - passive or active - with everything else being equal. Most (if not all) of these commerciall modules were designed with very high MTBF's in mind when used "au natural". I would leave well alone and look into providing "standby power" to your Z3801. Regards, Kit VK2LL ************* Message: 3 Date: Mon, 28 Jul 2008 15:40:40 +0200 From: Alberto di Bene Subject: Re: [time-nuts] A fan for the Z3801A To: Discussion of precise time and frequency measurement Message-ID: <488DCC58.6000802 at usa.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Murray, thanks for the advice. Well, my intention was, as suggested by a private message, to use a 12V fan powered at 5V, so that it runs slowly and silently, not blowing external air into the unit, but just extracting the hot air from the inside. And given that the unit is placed in the basement of the house, with a change in temperature between the day and the night of no more than 1 Celsius, may be the use of the fan should not disturb the thermal regulation of the OCXO and the other temperature-sensitive devices, while at the same time lowering the working temperature of those hot ICs, thus prolonging (maybe) their life. Anyway I am open to comments and suggestions. Thanks 73 Alberto I2PHD -- From jgd at johngsbbq.com Mon Jul 28 19:22:37 2008 From: jgd at johngsbbq.com (Neon John) Date: Mon, 28 Jul 2008 19:22:37 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <6.2.5.6.2.20080723151808.02d4dcf0@jpl.nasa.gov> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> <20080723220139.8796B1165C3@hamburg.alientech.net> <6.2.5.6.2.20080723151808.02d4dcf0@jpl.nasa.gov> Message-ID: On Wed, 23 Jul 2008 15:22:08 -0700, Jim Lux wrote: >At 03:01 PM 7/23/2008, Mike S wrote: >>You're missing the point. The application is to drive a common, readily >>available consumer clock. Simple and cheap. It can be done with a >>single $1 PIC. You could spend $20 or $100 and not get better results >>for the application. If you can describe a way of doing it for $0.50, >>please do. > > >But this is time-nuts... Any approach that doesn't have the >performance of a hydrogen maser or cryogenic sapphire resonator just >isn't good enough. Why, we haven't even started on how to build a >radial ruling engine to make sure the clock face is precisely divided >into 60 segments to ppb accuracy. Yep. There's turd polishing and then there is time nuts turd polishing. Going for the angstrom finish on the turd. The latter sometimes makes me grit my teeth.... > >Based on the clocks I've taken apart, dividing the 10MHz down to 1 Hz >is probably your best bet, rather than trying to hit 32768. However, >I don't know of a non-programmable single chip solution that will do >a divide by 1E7. If you want programmable chips, there's countless >ways, some more elegant than others. Seems to me that all the solutions proposed so far are a bit complex, trying to go for the 32khz frequency when that's not necessary. The quartz analog clockworks has a one or two winding stepper motor. The SIMPLEST solution is to drive those coils directly with the PIC output and scrap the rest of the circuitry. With some clever fiddling, one could use one of the 8 pin PICs and that WOULD get the solution cost down to around 50 cents :-) John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com <-- best little blog on the net! Tellico Plains, Occupied TN Save the whales, collect the whole set! From James.P.Lux at jpl.nasa.gov Mon Jul 28 19:35:53 2008 From: James.P.Lux at jpl.nasa.gov (Jim Lux) Date: Mon, 28 Jul 2008 16:35:53 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> <20080723220139.8796B1165C3@hamburg.alientech.net> <6.2.5.6.2.20080723151808.02d4dcf0@jpl.nasa.gov> Message-ID: <6.2.5.6.2.20080728163240.02dd5ed0@jpl.nasa.gov> At 04:22 PM 7/28/2008, you wrote: >On Wed, 23 Jul 2008 15:22:08 -0700, Jim Lux wrote: > > > > > >Based on the clocks I've taken apart, dividing the 10MHz down to 1 Hz > >is probably your best bet, rather than trying to hit 32768. However, > >I don't know of a non-programmable single chip solution that will do > >a divide by 1E7. If you want programmable chips, there's countless > >ways, some more elegant than others. > >Seems to me that all the solutions proposed so far are a bit complex, trying >to go for the 32khz frequency when that's not necessary. The quartz analog >clockworks has a one or two winding stepper motor. The SIMPLEST solution is >to drive those coils directly with the PIC output and scrap the rest of the >circuitry. Actually, it's not even that complex... it's often an electromagnet/solenoid driving a conventional escapement type clock mechanism. Why use 2 coils when you don't ever need to go backwards? One advantage of generating 32kHz (averaged over 1 second) is that you don't have to build the power driver stage to actuate that electromagnet.. (since it's built into the single dirt-cheap chip in the clock in the first place) >With some clever fiddling, one could use one of the 8 pin PICs and that WOULD >get the solution cost down to around 50 cents :-) And, one could probably figure out a way to use the original 32kHz crystal AND run at different speeds.. From holrum at hotmail.com Mon Jul 28 20:01:24 2008 From: holrum at hotmail.com (Mark Sims) Date: Tue, 29 Jul 2008 00:01:24 +0000 Subject: [time-nuts] Leap Second Pending In-Reply-To: References: Message-ID: My Thunderbolts have just raised the "Leapsecond Pending" minor alarm... six months seems a bit early for such a warning... ---------------------------------------- _________________________________________________________________ Stay in touch when you're away with Windows Live Messenger. http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_messenger2_072008 From namichie at gmail.com Mon Jul 28 20:04:46 2008 From: namichie at gmail.com (Neville Michie) Date: Tue, 29 Jul 2008 10:04:46 +1000 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <6.2.5.6.2.20080728163240.02dd5ed0@jpl.nasa.gov> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> <20080723220139.8796B1165C3@hamburg.alientech.net> <6.2.5.6.2.20080723151808.02d4dcf0@jpl.nasa.gov> <6.2.5.6.2.20080728163240.02dd5ed0@jpl.nasa.gov> Message-ID: FYI, Quartz analogue clocks almost universally use a bipolar motor, a two pole magnetic circuit with the minimum reluctance axis displaced from the direction of the energised field. When activated the 2 pole magnetic rotor aligns with the magnetic field, when the field collapses, the magnetic rotor moves a little towards the position of greater self attraction, so that it is set up for a move in the right direction when the reverse field is applied. To drive these motors as clock displays you either replicate the alternate 1.5 volt 20mS pulses, or connect a capacitor, about 10 - 100 mfd in series and drive them with a 0.5 hertz square wave of about 1.5 volt amplitude. The drive voltage and pulse duration should be adjusted for each type of motor, or else the voltage and capacitor size so that reliable stepping occurs. Overdrive can stop some types as the rotor "poles". just in case you were interested, cheers, Neville Michie On 29/07/2008, at 9:35 AM, Jim Lux wrote: > At 04:22 PM 7/28/2008, you wrote: >> On Wed, 23 Jul 2008 15:22:08 -0700, Jim Lux >> wrote: >> >> >>> >>> Based on the clocks I've taken apart, dividing the 10MHz down to >>> 1 Hz >>> is probably your best bet, rather than trying to hit 32768. However, >>> I don't know of a non-programmable single chip solution that will do >>> a divide by 1E7. If you want programmable chips, there's countless >>> ways, some more elegant than others. >> >> Seems to me that all the solutions proposed so far are a bit >> complex, trying >> to go for the 32khz frequency when that's not necessary. The >> quartz analog >> clockworks has a one or two winding stepper motor. The SIMPLEST >> solution is >> to drive those coils directly with the PIC output and scrap the >> rest of the >> circuitry. > Actually, it's not even that complex... it's often an > electromagnet/solenoid driving a conventional escapement type clock > mechanism. Why use 2 coils when you don't ever need to go backwards? > > One advantage of generating 32kHz (averaged over 1 second) is that > you don't have to build the power driver stage to actuate that > electromagnet.. (since it's built into the single dirt-cheap chip in > the clock in the first place) > > >> With some clever fiddling, one could use one of the 8 pin PICs and >> that WOULD >> get the solution cost down to around 50 cents :-) > > > And, one could probably figure out a way to use the original 32kHz > crystal AND run at different speeds.. > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. From wa2lbi at frontiernet.net Mon Jul 28 20:05:25 2008 From: wa2lbi at frontiernet.net (Ken Winterling) Date: Mon, 28 Jul 2008 20:05:25 -0400 Subject: [time-nuts] Leap Second Pending In-Reply-To: References: Message-ID: <608ed23c0807281705r2dc48576ob804dd9189b036a3@mail.gmail.com> So has mine. Ken, WA2LBI On Mon, Jul 28, 2008 at 8:01 PM, Mark Sims wrote: > > My Thunderbolts have just raised the "Leapsecond Pending" minor alarm... > six months seems a bit early for such a warning... > ---------------------------------------- > From jgd at johngsbbq.com Mon Jul 28 20:08:58 2008 From: jgd at johngsbbq.com (Neon John) Date: Mon, 28 Jul 2008 20:08:58 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: <6.2.5.6.2.20080728163240.02dd5ed0@jpl.nasa.gov> References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> <20080723220139.8796B1165C3@hamburg.alientech.net> <6.2.5.6.2.20080723151808.02d4dcf0@jpl.nasa.gov> <6.2.5.6.2.20080728163240.02dd5ed0@jpl.nasa.gov> Message-ID: On Mon, 28 Jul 2008 16:35:53 -0700, Jim Lux wrote: >>Seems to me that all the solutions proposed so far are a bit complex, trying >>to go for the 32khz frequency when that's not necessary. The quartz analog >>clockworks has a one or two winding stepper motor. The SIMPLEST solution is >>to drive those coils directly with the PIC output and scrap the rest of the >>circuitry. > >Actually, it's not even that complex... it's often an >electromagnet/solenoid driving a conventional escapement type clock >mechanism. Why use 2 coils when you don't ever need to go backwards? The clockworks that I've taken apart almost all have 2 coils. One brand has one. They all drive a permanent magnet rotor that turns 90 degrees on each tick. I'm not sure what the single coil design does to make sure the rotor always turns the right direction. Or maybe it doesn't matter if the rotor turns a cam and ratchet mechanism. I've never taken one apart far enough to know. > >One advantage of generating 32kHz (averaged over 1 second) is that >you don't have to build the power driver stage to actuate that >electromagnet.. (since it's built into the single dirt-cheap chip in >the clock in the first place) No driver needed. Each coil has about a bazillion (bazillion.000000 for time nuts) turns of wire so fine I can't see it without my 7x OptiVisor. I've never bothered to measure but the resistance has to be in the hundreds of ohms or more. It has to be that high to get over a year's operation from an AA battery. Duck soup for a PIC output pin driver. Funny how this works. I've been thinking about this same type problem for a few days independent of reading this list. I'm old-fashioned and like analog clocks much better than digital. I also like the precision of radio-controlled clocks. I've bought several different WWVB analog clocks, all of which seem to use the same cheap ChiCom movement. They uniformly suck (to use a technical term) at receiving WWVB where I live. The digital versions have no problem receiving but I don't like the looks. What I've been thinking about is a modern version of the Simplex master/slave clock system. A GPS disciplined master clock sending out operating pulses to slave clocks around my house and shop. I thought about wireless, including synthesizing my own WWVB signal but I know that I'll not get enough round tuits to do that. What I'm working toward is just about what I described above, except that the master clock will drive 4 conductor telephone station wire and the slave clocks will contain no electronics. Only the clockwork and the coils. All the clocks will be wired in parallel. This is an open-loop system that assumes all the clocks are in the same mechanical position when the master is activated. Perfectly acceptable, given the relatively few number of clocks and the small area involved. This architecture should give me what I want - REALLY simple, no electronics in the individual clocks, "atomic" accuracy, automatic DST correction and perfect synchronism. Comments? John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com <-- best little blog on the net! Tellico Plains, Occupied TN No one can be right all of the time, but it helps to be right most of the time. -Robert Half From had at to-way.com Mon Jul 28 20:18:14 2008 From: had at to-way.com (Had) Date: Mon, 28 Jul 2008 17:18:14 -0700 Subject: [time-nuts] Leap Second Pending In-Reply-To: <608ed23c0807281705r2dc48576ob804dd9189b036a3@mail.gmail.co m> References: <608ed23c0807281705r2dc48576ob804dd9189b036a3@mail.gmail.com> Message-ID: <20080729001818.A06FC164821@mail-in06.adhost.com> Same here, both T-Bolts have Leap Second Flags=Yellow Had, K7MLR At 05:05 PM 7/28/2008, you wrote: >So has mine. > >Ken, WA2LBI > >On Mon, Jul 28, 2008 at 8:01 PM, Mark Sims wrote: > > > > > My Thunderbolts have just raised the "Leapsecond Pending" minor alarm... > > six months seems a bit early for such a warning... > > ---------------------------------------- > > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From James.P.Lux at jpl.nasa.gov Mon Jul 28 20:19:32 2008 From: James.P.Lux at jpl.nasa.gov (Jim Lux) Date: Mon, 28 Jul 2008 17:19:32 -0700 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> <20080723220139.8796B1165C3@hamburg.alientech.net> <6.2.5.6.2.20080723151808.02d4dcf0@jpl.nasa.gov> <6.2.5.6.2.20080728163240.02dd5ed0@jpl.nasa.gov> Message-ID: <6.2.5.6.2.20080728171533.02ce0ef8@jpl.nasa.gov> At 05:04 PM 7/28/2008, you wrote: >FYI, >Quartz analogue clocks almost universally use a bipolar motor, a two >pole >magnetic circuit with the minimum reluctance axis displaced from the >direction >of the energised field. >When activated the 2 pole magnetic rotor aligns with the magnetic >field, when the field collapses, >the magnetic rotor moves a little towards the position of greater >self attraction, so that it is >set up for a move in the right direction when the reverse field is >applied. >To drive these motors as clock displays you either replicate the >alternate 1.5 volt 20mS pulses, or connect a capacitor, >about 10 - 100 mfd in series and drive them with a 0.5 hertz square >wave of about 1.5 volt amplitude. >The drive voltage and pulse duration should be adjusted for each type >of motor, or else >the voltage and capacitor size so that reliable stepping occurs. >Overdrive can stop some types as the rotor "poles". >just in case you were interested, >cheers, Neville Michie The ones I have here have a single solenoid with a sort of wishbone shaped thing around it. A curved metal rod with a thicker center portion is connected between the arms of the wishbone. The rod goes through the center of the solenoid, and it looks like when the current pulse is applied to the solenoid, the armature is pulled through. Imagine a sort of pendulum with the solenoid at the bottom. In any case, faking the 32.768 is going to be easiest, because the clock mfr has already fooled with figuring out the right voltages, currents, and pulse widths. From phk at phk.freebsd.dk Mon Jul 28 20:32:05 2008 From: phk at phk.freebsd.dk (Poul-Henning Kamp) Date: Tue, 29 Jul 2008 00:32:05 +0000 Subject: [time-nuts] Leap Second Pending In-Reply-To: Your message of "Tue, 29 Jul 2008 00:01:24 GMT." Message-ID: <93931.1217291525@critter.freebsd.dk> In message , Mark Sims writes: >My Thunderbolts have just raised the "Leapsecond Pending" minor >alarm... six months seems a bit early for such a warning... Yup, got it on my oncore as well: NTPns > show oncore 0 serial port = /dev/cuad5 state = 12 visible/track/lock = 11/8/0 dop = 0.0 [m] 2008-07-29 00:31:29.000744307 Leap second info: 2009-01-01 00:00:00 INSERT 13476511 seconds (155 days) from now [...] -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk at FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. From jltran at worldnet.att.net Mon Jul 28 21:48:52 2008 From: jltran at worldnet.att.net (J. L. Trantham) Date: Mon, 28 Jul 2008 20:48:52 -0500 Subject: [time-nuts] Leap Second Pending In-Reply-To: <20080729001818.A06FC164821@mail-in06.adhost.com> Message-ID: <6CDCD7EFEEB54CC092AC4D746C7597B8@S0028384766> Same here. Joe -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Had Sent: Monday, July 28, 2008 7:18 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Leap Second Pending Same here, both T-Bolts have Leap Second Flags=Yellow Had, K7MLR At 05:05 PM 7/28/2008, you wrote: >So has mine. > >Ken, WA2LBI > >On Mon, Jul 28, 2008 at 8:01 PM, Mark Sims wrote: > > > > > My Thunderbolts have just raised the "Leapsecond Pending" minor alarm... > > six months seems a bit early for such a warning... > > ---------------------------------------- > > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From ddabney01 at yahoo.com Mon Jul 28 23:09:02 2008 From: ddabney01 at yahoo.com (Richard Dabney) Date: Mon, 28 Jul 2008 20:09:02 -0700 (PDT) Subject: [time-nuts] time-nuts Digest, Vol 48, Issue 76 In-Reply-To: Message-ID: <54344.32503.qm@web62507.mail.re1.yahoo.com> Reply to message 6:.............?????????????? .7300 de Dick W5UFZ How are leap seconds declared? The International Earth Rotation and Reference System Service (IERS) observes the Earth's rotation and nearly 6 months in advance (January and July) a "Bulletin C" message is sent out, which reports whether or not to add a leap second in the end of June and December. --- On Mon, 7/28/08, time-nuts-request at febo.com wrote: From: time-nuts-request at febo.com Subject: time-nuts Digest, Vol 48, Issue 76 To: time-nuts at febo.com Date: Monday, July 28, 2008, 5:09 PM Send time-nuts mailing list submissions to time-nuts at febo.com To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts or, via email, send a message with subject or body 'help' to time-nuts-request at febo.com You can reach the person managing the list at time-nuts-owner at febo.com When replying, please edit your Subject line so it is more specific than "Re: Contents of time-nuts digest..." Today's Topics: 1. Re: A fan for the Z3801A (Greg Burnett) 2. Low power GPSDO (SAIDJACK at aol.com) 3. Re: time-nuts Digest, Vol 48, Issue 75 (Kit Scally) 4. Re: How to get 32.768KHz from 10MHz. (Neon John) 5. Re: How to get 32.768KHz from 10MHz. (Jim Lux) 6. Leap Second Pending (Mark Sims) 7. Re: How to get 32.768KHz from 10MHz. (Neville Michie) 8. Re: Leap Second Pending (Ken Winterling) 9. Re: How to get 32.768KHz from 10MHz. (Neon John) ---------------------------------------------------------------------- Message: 1 Date: Mon, 28 Jul 2008 11:11:01 -0600 From: "Greg Burnett" Subject: Re: [time-nuts] A fan for the Z3801A To: "Discussion of precise time and frequency measurement" Message-ID: <003101c8f0d4$e93f4570$6501a8c0 at gb02> Content-Type: text/plain; charset="iso-8859-1" Another thing to consider: Depending on how well you shock-mount the fan, what if its vibration translates to sideband spurs or noise? -Greg ---------------------- Alberto wrote: Talking of the Z3801A, has anybody added a small fan to it ? Mine is very hot inside, especially the large VLSI chips on the upper board. I contemplated adding a couple of small DC fans, to push out the hot air, but first would like to know your opinions and your experiences, if any, about that. Thanks Alberto I2PHD ------------------------------ Message: 2 Date: Mon, 28 Jul 2008 17:04:03 EDT From: SAIDJACK at aol.com Subject: [time-nuts] Low power GPSDO To: Murray.Greenman at rakon.com, time-nuts at febo.com Message-ID: Content-Type: text/plain; charset="US-ASCII" Hello Murray, no problem :) just wanted to make sure folks know that there are options below 5W out there. I am impressed with your 50mW TCXO unit. We've been thinking about offering DIP14 TCXO's as well on the FireFly. That would allow for true battery operation. We are also testing extremely low power (~120mW) OCXO's, with the heating elements integrated into the Crystal Blank itself, but I am not happy with the stability of these just yet. We also have a Fury GPSDO wired up to the Agilent E1938A - while it's the best Fury I have it's a real power hog. In fact I am having a hard time finding a power supply capable of delivering sufficient warmup current to that box.. bye, Said In a message dated 7/28/2008 11:33:44 Pacific Daylight Time, Murray.Greenman at rakon.com writes: Jack, I didn't claim that the Trimble NTGS50AA was the "lowest power GPSDO". Those are your words. I simply said it was "at the other extreme", meaning (although not said) at the other extreme of my limited experience of about 10 different models. I own only five commercial GPSDOs (HP Z3801A; Symmetricom Z3815A with MTI 260 OCXO; CIC GPSR-A and Samsung GCRU-D with Rakon CFPO-2 OCXO; and the Trimble NTGS50AA), plus a working relationship with the Datum and Symmetricom units at work and a previously owned HP Z3815A with E1938A OCXO. I've also built a few, but not in the class of the commercial units. My lowest power one is battery operated (uses a V-TCXO) and has a power consumption of 50mW (with display backlight off!), but is more affected by sun load than is desirable. Another uses the HP 10811A OCXO, and can hardly be classed as low power. I have a professional interest in achieving low power in the GPSDO, as the company I work for are part of the Femtocell working group. I am certainly impressed that the Firefly is down at 1.35W. Regards, Murray Greenman **************Get fantasy football with free live scoring. Sign up for FanHouse Fantasy Football today. (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020) ------------------------------ Message: 3 Date: Tue, 29 Jul 2008 08:56:24 +1000 From: "Kit Scally" Subject: Re: [time-nuts] time-nuts Digest, Vol 48, Issue 75 To: Message-ID: <281090D5003763419A5AC496FF087B2A3B81D8 at msg01nsw.BYTECAN.com.au> Content-Type: text/plain; charset="us-ascii" Alberto, In the commercial world that the Z3815A's (and quite possibly the Z3801 etc) were used in, they were installed "vertically" at the bottom of a large equipment cabinet that had convection air channels running within it. A bank of 12-16 fans towards the top of the cabinet sucked up ambient air and forced it past the PA heatsinks. The hot air was vented out the PA modules & cabinet top. Ambient air temp was controlled at 20-25 deg C. The GPSDO pcb (and associated electronics) was cooled with incoming ambient air with the pcb and IC temperatures settling at some value. The critical point here is that the whole cabinet was operating 24x365 and for years on end. While semiconductor life is inversely proportional (?) to Tamb and cooling the electronics may seem a logical approach to prolonging life, I would suggest that , this is a second-order effect. The killer is thermal cycling which can induce premature failure in any electronic assembly - passive or active - with everything else being equal. Most (if not all) of these commerciall modules were designed with very high MTBF's in mind when used "au natural". I would leave well alone and look into providing "standby power" to your Z3801. Regards, Kit VK2LL ************* Message: 3 Date: Mon, 28 Jul 2008 15:40:40 +0200 From: Alberto di Bene Subject: Re: [time-nuts] A fan for the Z3801A To: Discussion of precise time and frequency measurement Message-ID: <488DCC58.6000802 at usa.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Murray, thanks for the advice. Well, my intention was, as suggested by a private message, to use a 12V fan powered at 5V, so that it runs slowly and silently, not blowing external air into the unit, but just extracting the hot air from the inside. And given that the unit is placed in the basement of the house, with a change in temperature between the day and the night of no more than 1 Celsius, may be the use of the fan should not disturb the thermal regulation of the OCXO and the other temperature-sensitive devices, while at the same time lowering the working temperature of those hot ICs, thus prolonging (maybe) their life. Anyway I am open to comments and suggestions. Thanks 73 Alberto I2PHD -- ------------------------------ Message: 4 Date: Mon, 28 Jul 2008 19:22:37 -0400 From: Neon John Subject: Re: [time-nuts] How to get 32.768KHz from 10MHz. To: Discussion of precise time and frequency measurement Message-ID: Content-Type: text/plain; charset=us-ascii On Wed, 23 Jul 2008 15:22:08 -0700, Jim Lux wrote: >At 03:01 PM 7/23/2008, Mike S wrote: >>You're missing the point. The application is to drive a common, readily >>available consumer clock. Simple and cheap. It can be done with a >>single $1 PIC. You could spend $20 or $100 and not get better results >>for the application. If you can describe a way of doing it for $0.50, >>please do. > > >But this is time-nuts... Any approach that doesn't have the >performance of a hydrogen maser or cryogenic sapphire resonator just >isn't good enough. Why, we haven't even started on how to build a >radial ruling engine to make sure the clock face is precisely divided >into 60 segments to ppb accuracy. Yep. There's turd polishing and then there is time nuts turd polishing. Going for the angstrom finish on the turd. The latter sometimes makes me grit my teeth.... > >Based on the clocks I've taken apart, dividing the 10MHz down to 1 Hz >is probably your best bet, rather than trying to hit 32768. However, >I don't know of a non-programmable single chip solution that will do >a divide by 1E7. If you want programmable chips, there's countless >ways, some more elegant than others. Seems to me that all the solutions proposed so far are a bit complex, trying to go for the 32khz frequency when that's not necessary. The quartz analog clockworks has a one or two winding stepper motor. The SIMPLEST solution is to drive those coils directly with the PIC output and scrap the rest of the circuitry. With some clever fiddling, one could use one of the 8 pin PICs and that WOULD get the solution cost down to around 50 cents :-) John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com <-- best little blog on the net! Tellico Plains, Occupied TN Save the whales, collect the whole set! ------------------------------ Message: 5 Date: Mon, 28 Jul 2008 16:35:53 -0700 From: Jim Lux Subject: Re: [time-nuts] How to get 32.768KHz from 10MHz. To: Discussion of precise time and frequency measurement Message-ID: <6.2.5.6.2.20080728163240.02dd5ed0 at jpl.nasa.gov> Content-Type: text/plain; charset="us-ascii"; format=flowed At 04:22 PM 7/28/2008, you wrote: >On Wed, 23 Jul 2008 15:22:08 -0700, Jim Lux wrote: > > > > > >Based on the clocks I've taken apart, dividing the 10MHz down to 1 Hz > >is probably your best bet, rather than trying to hit 32768. However, > >I don't know of a non-programmable single chip solution that will do > >a divide by 1E7. If you want programmable chips, there's countless > >ways, some more elegant than others. > >Seems to me that all the solutions proposed so far are a bit complex, trying >to go for the 32khz frequency when that's not necessary. The quartz analog >clockworks has a one or two winding stepper motor. The SIMPLEST solution is >to drive those coils directly with the PIC output and scrap the rest of the >circuitry. Actually, it's not even that complex... it's often an electromagnet/solenoid driving a conventional escapement type clock mechanism. Why use 2 coils when you don't ever need to go backwards? One advantage of generating 32kHz (averaged over 1 second) is that you don't have to build the power driver stage to actuate that electromagnet.. (since it's built into the single dirt-cheap chip in the clock in the first place) >With some clever fiddling, one could use one of the 8 pin PICs and that WOULD >get the solution cost down to around 50 cents :-) And, one could probably figure out a way to use the original 32kHz crystal AND run at different speeds.. ------------------------------ Message: 6 Date: Tue, 29 Jul 2008 00:01:24 +0000 From: Mark Sims Subject: [time-nuts] Leap Second Pending To: Message-ID: Content-Type: text/plain; charset="iso-8859-1" My Thunderbolts have just raised the "Leapsecond Pending" minor alarm... six months seems a bit early for such a warning... ---------------------------------------- _________________________________________________________________ Stay in touch when you're away with Windows Live Messenger. http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_messenger2_072008 ------------------------------ Message: 7 Date: Tue, 29 Jul 2008 10:04:46 +1000 From: Neville Michie Subject: Re: [time-nuts] How to get 32.768KHz from 10MHz. To: Discussion of precise time and frequency measurement Message-ID: Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed FYI, Quartz analogue clocks almost universally use a bipolar motor, a two pole magnetic circuit with the minimum reluctance axis displaced from the direction of the energised field. When activated the 2 pole magnetic rotor aligns with the magnetic field, when the field collapses, the magnetic rotor moves a little towards the position of greater self attraction, so that it is set up for a move in the right direction when the reverse field is applied. To drive these motors as clock displays you either replicate the alternate 1.5 volt 20mS pulses, or connect a capacitor, about 10 - 100 mfd in series and drive them with a 0.5 hertz square wave of about 1.5 volt amplitude. The drive voltage and pulse duration should be adjusted for each type of motor, or else the voltage and capacitor size so that reliable stepping occurs. Overdrive can stop some types as the rotor "poles". just in case you were interested, cheers, Neville Michie On 29/07/2008, at 9:35 AM, Jim Lux wrote: > At 04:22 PM 7/28/2008, you wrote: >> On Wed, 23 Jul 2008 15:22:08 -0700, Jim Lux >> wrote: >> >> >>> >>> Based on the clocks I've taken apart, dividing the 10MHz down to >>> 1 Hz >>> is probably your best bet, rather than trying to hit 32768. However, >>> I don't know of a non-programmable single chip solution that will do >>> a divide by 1E7. If you want programmable chips, there's countless >>> ways, some more elegant than others. >> >> Seems to me that all the solutions proposed so far are a bit >> complex, trying >> to go for the 32khz frequency when that's not necessary. The >> quartz analog >> clockworks has a one or two winding stepper motor. The SIMPLEST >> solution is >> to drive those coils directly with the PIC output and scrap the >> rest of the >> circuitry. > Actually, it's not even that complex... it's often an > electromagnet/solenoid driving a conventional escapement type clock > mechanism. Why use 2 coils when you don't ever need to go backwards? > > One advantage of generating 32kHz (averaged over 1 second) is that > you don't have to build the power driver stage to actuate that > electromagnet.. (since it's built into the single dirt-cheap chip in > the clock in the first place) > > >> With some clever fiddling, one could use one of the 8 pin PICs and >> that WOULD >> get the solution cost down to around 50 cents :-) > > > And, one could probably figure out a way to use the original 32kHz > crystal AND run at different speeds.. > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. ------------------------------ Message: 8 Date: Mon, 28 Jul 2008 20:05:25 -0400 From: "Ken Winterling" Subject: Re: [time-nuts] Leap Second Pending To: "Discussion of precise time and frequency measurement" Message-ID: <608ed23c0807281705r2dc48576ob804dd9189b036a3 at mail.gmail.com> Content-Type: text/plain; charset=UTF-8 So has mine. Ken, WA2LBI On Mon, Jul 28, 2008 at 8:01 PM, Mark Sims wrote: > > My Thunderbolts have just raised the "Leapsecond Pending" minor alarm... > six months seems a bit early for such a warning... > ---------------------------------------- > ------------------------------ Message: 9 Date: Mon, 28 Jul 2008 20:08:58 -0400 From: Neon John Subject: Re: [time-nuts] How to get 32.768KHz from 10MHz. To: Discussion of precise time and frequency measurement Message-ID: Content-Type: text/plain; charset=us-ascii On Mon, 28 Jul 2008 16:35:53 -0700, Jim Lux wrote: >>Seems to me that all the solutions proposed so far are a bit complex, trying >>to go for the 32khz frequency when that's not necessary. The quartz analog >>clockworks has a one or two winding stepper motor. The SIMPLEST solution is >>to drive those coils directly with the PIC output and scrap the rest of the >>circuitry. > >Actually, it's not even that complex... it's often an >electromagnet/solenoid driving a conventional escapement type clock >mechanism. Why use 2 coils when you don't ever need to go backwards? The clockworks that I've taken apart almost all have 2 coils. One brand has one. They all drive a permanent magnet rotor that turns 90 degrees on each tick. I'm not sure what the single coil design does to make sure the rotor always turns the right direction. Or maybe it doesn't matter if the rotor turns a cam and ratchet mechanism. I've never taken one apart far enough to know. > >One advantage of generating 32kHz (averaged over 1 second) is that >you don't have to build the power driver stage to actuate that >electromagnet.. (since it's built into the single dirt-cheap chip in >the clock in the first place) No driver needed. Each coil has about a bazillion (bazillion.000000 for time nuts) turns of wire so fine I can't see it without my 7x OptiVisor. I've never bothered to measure but the resistance has to be in the hundreds of ohms or more. It has to be that high to get over a year's operation from an AA battery. Duck soup for a PIC output pin driver. Funny how this works. I've been thinking about this same type problem for a few days independent of reading this list. I'm old-fashioned and like analog clocks much better than digital. I also like the precision of radio-controlled clocks. I've bought several different WWVB analog clocks, all of which seem to use the same cheap ChiCom movement. They uniformly suck (to use a technical term) at receiving WWVB where I live. The digital versions have no problem receiving but I don't like the looks. What I've been thinking about is a modern version of the Simplex master/slave clock system. A GPS disciplined master clock sending out operating pulses to slave clocks around my house and shop. I thought about wireless, including synthesizing my own WWVB signal but I know that I'll not get enough round tuits to do that. What I'm working toward is just about what I described above, except that the master clock will drive 4 conductor telephone station wire and the slave clocks will contain no electronics. Only the clockwork and the coils. All the clocks will be wired in parallel. This is an open-loop system that assumes all the clocks are in the same mechanical position when the master is activated. Perfectly acceptable, given the relatively few number of clocks and the small area involved. This architecture should give me what I want - REALLY simple, no electronics in the individual clocks, "atomic" accuracy, automatic DST correction and perfect synchronism. Comments? John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com <-- best little blog on the net! Tellico Plains, Occupied TN No one can be right all of the time, but it helps to be right most of the time. -Robert Half ------------------------------ _______________________________________________ time-nuts mailing list time-nuts at febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts End of time-nuts Digest, Vol 48, Issue 76 ***************************************** From didier at cox.net Mon Jul 28 23:24:42 2008 From: didier at cox.net (Didier Juges) Date: Mon, 28 Jul 2008 22:24:42 -0500 Subject: [time-nuts] time-nuts Digest, Vol 48, Issue 76 In-Reply-To: <54344.32503.qm@web62507.mail.re1.yahoo.com> References: <54344.32503.qm@web62507.mail.re1.yahoo.com> Message-ID: <00af01c8f12a$a4dc2370$0a01a8c0@didierhp> > Reply to message 6:.............?????????????? .7300 de Dick > W5UFZ How are leap seconds declared? > When tvb tells them to :-) Didier KO4BB From ddabney01 at yahoo.com Mon Jul 28 23:42:17 2008 From: ddabney01 at yahoo.com (Richard Dabney) Date: Mon, 28 Jul 2008 20:42:17 -0700 (PDT) Subject: [time-nuts] Fw: GPS, UTC, and TAI Clocks Message-ID: <41660.96924.qm@web62515.mail.re1.yahoo.com> A fun site............. --- On Mon, 7/28/08, Richard Dabney wrote: From: Richard Dabney Subject: GPS, UTC, and TAI Clocks To: "Richard Dabney" Date: Monday, July 28, 2008, 8:38 PM http://leapsecond.com/java/gpsclock.htm From had at to-way.com Tue Jul 29 00:22:33 2008 From: had at to-way.com (Had) Date: Mon, 28 Jul 2008 21:22:33 -0700 Subject: [time-nuts] time-nuts Digest, Vol 48, Issue 76 In-Reply-To: <00af01c8f12a$a4dc2370$0a01a8c0@didierhp> References: <54344.32503.qm@web62507.mail.re1.yahoo.com> <00af01c8f12a$a4dc2370$0a01a8c0@didierhp> Message-ID: <20080729042236.3922436F2A3@mail-in01.adhost.com> Didier, That was a good one. I LIKE IT! 73 Had, K7MLR At 08:24 PM 7/28/2008, you wrote: > > Reply to message 6:............. .7300 de Dick > > W5UFZ How are leap seconds declared? > > > >When tvb tells them to :-) > >Didier KO4BB > > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From dave.g0dja at tiscali.co.uk Tue Jul 29 05:23:00 2008 From: dave.g0dja at tiscali.co.uk (David Ackrill) Date: Tue, 29 Jul 2008 10:23:00 +0100 Subject: [time-nuts] Leap Second Pending In-Reply-To: <6CDCD7EFEEB54CC092AC4D746C7597B8@S0028384766> References: <6CDCD7EFEEB54CC092AC4D746C7597B8@S0028384766> Message-ID: <488EE174.2070803@tiscali.co.uk> J. L. Trantham wrote: > Same here. Yes, seems that it's pending in the UK as well. ;-) Dave (G0DJA) From ka2cdk at cox.net Tue Jul 29 08:34:56 2008 From: ka2cdk at cox.net (Thomas A. Frank) Date: Tue, 29 Jul 2008 08:34:56 -0400 Subject: [time-nuts] How to get 32.768KHz from 10MHz. In-Reply-To: References: <00b901c8eccd$b95782b0$7300a8c0@p4253> <20080723143304.18A811165C3@hamburg.alientech.net> <002301c8ecdc$8ee4aad0$0900a8c0@pc52> <001801c8ed01$1a7c19b0$0900a8c0@pc52> <20080723210020.67E951165C3@hamburg.alientech.net> <4887A5BD.3040208@xtra.co.nz> <20080723220139.8796B1165C3@hamburg.alientech.net> <6.2.5.6.2.20080723151808.02d4dcf0@jpl.nasa.gov> <6.2.5.6.2.20080728163240.02dd5ed0@jpl.nasa.gov> Message-ID: <76FC13E2-FA0D-4551-9DE4-4E1E4609F2B6@cox.net> > Only the clockwork and the coils. All the clocks will be wired > in parallel. Traditionally, such systems had all the slave coils in series. I suspect you will find that the better way; less room for weirdness. Otherwise, I like it! Tom Frank From randy at geodetics.com Tue Jul 29 11:58:11 2008 From: randy at geodetics.com (randy warner) Date: Tue, 29 Jul 2008 08:58:11 -0700 Subject: [time-nuts] Leap Second Pending In-Reply-To: <488EE174.2070803@tiscali.co.uk> Message-ID: Guys, This is typical. The Air Force inserts this flag into the almanac well before the actual event (normally about 6 months) to allow users to prepare for it. Randy Warner -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of David Ackrill Sent: Tuesday, July 29, 2008 2:23 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Leap Second Pending J. L. Trantham wrote: > Same here. Yes, seems that it's pending in the UK as well. ;-) Dave (G0DJA) _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From david.partridge at dsl.pipex.com Tue Jul 29 12:12:12 2008 From: david.partridge at dsl.pipex.com (David C. Partridge) Date: Tue, 29 Jul 2008 17:12:12 +0100 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO><00d201c8ee67$27fe2b70$77fa8250$@com> Message-ID: <8332BE8EF8F0471AB44BDC2E950330F7@APOLLO> I've taken a bit of a risk and ordered 20 boards. Rash in extreme or what! What does this mean? It means that I can sell the boards at a price of GBP20 each (about USD40). I will not request $$$ or ship any boards until I have made up my own first to confirm everything is OK. This won't be until end August as some parts are on back-order with Mouser. Please email me direct if you would like to pre-order any. If you would like a copy of the circuit diagram, or the BOM (.xls file) just shout (it's complete bar the thumbwheel switch, and wire). Dave From imp at bsdimp.com Tue Jul 29 12:13:20 2008 From: imp at bsdimp.com (M. Warner Losh) Date: Tue, 29 Jul 2008 10:13:20 -0600 (MDT) Subject: [time-nuts] Leap Second Pending In-Reply-To: References: <488EE174.2070803@tiscali.co.uk> Message-ID: <20080729.101320.-1625879287.imp@bsdimp.com> In message: "randy warner" writes: : This is typical. The Air Force inserts this flag into the almanac well : before the actual event (normally about 6 months) to allow users to prepare : for it. Yes. All the old clocks that stuttered and did the leap second at the 'alternative date' have updated their firmware to not do that anymore... Although the standard says any month, it also says that June/December are primary, with March/September being secondary. I believe it was the Oscilloquartz GPS disciplined clock that did this for sure, and has been reported here. It would be nice if there were more than 6 months of notice for these things, but I don't want to get into that whole debate again here... Warner From holrum at hotmail.com Tue Jul 29 17:28:41 2008 From: holrum at hotmail.com (Mark Sims) Date: Tue, 29 Jul 2008 21:28:41 +0000 Subject: [time-nuts] Leap Second Pending In-Reply-To: References: Message-ID: And my clepsydra is now indicating "Leak Second Pending"... ---------------------------------------- _________________________________________________________________ With Windows Live for mobile, your contacts travel with you. http://www.windowslive.com/mobile/overview.html?ocid=TXT_TAGLM_WL_mobile_072008 From mark.amos at toast.net Tue Jul 29 20:32:10 2008 From: mark.amos at toast.net (Mark Amos) Date: Tue, 29 Jul 2008 20:32:10 -0400 Subject: [time-nuts] driving cheap clock motors Message-ID: Neon John, I did something similar to what you're talking about. I wanted an analog output for a GPSDO/clock (originally based on a Brooks Shera design, but recently upgraded to a Thunderbolt.) I use the 1PPS GPSDO output to drive a CD4093 Schmidt trigger, which clocks a D flip flop. I use the outputs of the flip flop to drive the coil that I disconnected from the cheap on-board crystal driven clock circuit. This one (like most of the cheap plastic movements) uses one coil - it's input reverses polarity each second. I used an inexpensive "open frame" clock movement with all the gears exposed to add some aesthetic interest. It's also an "open loop" design - I set the time according to WWV and plug in the BNC connector between the 1 second ticks. The Schmidt trigger and flip flop are wired up on a little perfboard powered from a wall wart. I'm way overdriving the motor coil, but other than maybe make it a little louder, doesn't seem to be a problem. I've mounted the movement in a cheap lacquered box. It looks pretty nice. (I don't claim that it's the cheapest, best, neatest, coolest or anything elsest. But it was fun and quick to put together, it works and it met my budgetary constraints...) It's on one side of my office on a shelf. On the opposite wall is a La Crosse "atomic" radio. People are amazed when they hear the two of them ticking in synchrony. Then I turn on WWV and they're even more amazed. Of course, when I tell them how it all works, they look at me like I'm Doc Brown explaining a the quantum chromodynamics of a flux capacitor... Of course, when I tell them about some of the stuff the serious time-nuts use for time keeping they start to get that glazed look... Mark ------------------------------ Message: 9 Date: Mon, 28 Jul 2008 20:08:58 -0400 From: Neon John Subject: Re: [time-nuts] How to get 32.768KHz from 10MHz. To: Discussion of precise time and frequency measurement Message-ID: Content-Type: text/plain; charset=us-ascii On Mon, 28 Jul 2008 16:35:53 -0700, Jim Lux wrote: >>Seems to me that all the solutions proposed so far are a bit complex, trying >>to go for the 32khz frequency when that's not necessary. The quartz analog >>clockworks has a one or two winding stepper motor. The SIMPLEST >>solution is >>to drive those coils directly with the PIC output and scrap the rest >>of the >>circuitry. > >Actually, it's not even that complex... it's often an >electromagnet/solenoid driving a conventional escapement type clock >mechanism. Why use 2 coils when you don't ever need to go backwards? The clockworks that I've taken apart almost all have 2 coils. One brand has one. They all drive a permanent magnet rotor that turns 90 degrees on each tick. I'm not sure what the single coil design does to make sure the rotor always turns the right direction. Or maybe it doesn't matter if the rotor turns a cam and ratchet mechanism. I've never taken one apart far enough to know. > >One advantage of generating 32kHz (averaged over 1 second) is that you >don't have to build the power driver stage to actuate that >electromagnet.. (since it's built into the single dirt-cheap chip in >the clock in the first place) No driver needed. Each coil has about a bazillion (bazillion.000000 for time nuts) turns of wire so fine I can't see it without my 7x OptiVisor. I've never bothered to measure but the resistance has to be in the hundreds of ohms or more. It has to be that high to get over a year's operation from an AA battery. Duck soup for a PIC output pin driver. Funny how this works. I've been thinking about this same type problem for a few days independent of reading this list. I'm old-fashioned and like analog clocks much better than digital. I also like the precision of radio-controlled clocks. I've bought several different WWVB analog clocks, all of which seem to use the same cheap ChiCom movement. They uniformly suck (to use a technical term) at receiving WWVB where I live. The digital versions have no problem receiving but I don't like the looks. What I've been thinking about is a modern version of the Simplex master/slave clock system. A GPS disciplined master clock sending out operating pulses to slave clocks around my house and shop. I thought about wireless, including synthesizing my own WWVB signal but I know that I'll not get enough round tuits to do that. What I'm working toward is just about what I described above, except that the master clock will drive 4 conductor telephone station wire and the slave clocks will contain no electronics. Only the clockwork and the coils. All the clocks will be wired in parallel. This is an open-loop system that assumes all the clocks are in the same mechanical position when the master is activated. Perfectly acceptable, given the relatively few number of clocks and the small area involved. This architecture should give me what I want - REALLY simple, no electronics in the individual clocks, "atomic" accuracy, automatic DST correction and perfect synchronism. Comments? John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com <-- best little blog on the net! Tellico Plains, Occupied TN No one can be right all of the time, but it helps to be right most of the time. -Robert Half From rexa at sonic.net Tue Jul 29 21:48:00 2008 From: rexa at sonic.net (Rex) Date: Tue, 29 Jul 2008 18:48:00 -0700 Subject: [time-nuts] Leap Second Pending In-Reply-To: References: Message-ID: <488FC850.5060805@sonic.net> Mark Sims wrote: > And my clepsydra is now indicating "Leak Second Pending"... > ---------------------------------------- > > > Did you make a typo... or is clepsydra a real word? :-) (just joking) From cfharris at erols.com Tue Jul 29 22:05:10 2008 From: cfharris at erols.com (Chuck Harris) Date: Tue, 29 Jul 2008 22:05:10 -0400 Subject: [time-nuts] Leap Second Pending In-Reply-To: <488FC850.5060805@sonic.net> References: <488FC850.5060805@sonic.net> Message-ID: <488FCC56.7060906@erols.com> According to Donald DeCarle's Watch and Clock Encyclopedia: Clepsydra- Water Clock. There are various types of water clocks, from the plain vessel with an orifice at its base through which water percolates and, by the lowering of the surface of the water the passage of time is denoted, to the water clock with a mechanical device to cause a hand to rotate. The mechanical clepsydra shown overleaf is simple in operation. The cylindrical vessel is slowly filled with water and a float with a stem and rack engages the wheel to which the hour hand is attached. As the vessel fills so the float rises and the hour hand is made to rotate. When the vessel is full it is emtied (sic) and the process starts over again. While this type of clock is spectacular and one would like to think it is of ancient origin, it has to be recorded that no ancient example has been handed down to us. On the other hand, Egyptian water clocks, as illustrated, have been found and date from about 1400B.C. Primitive water clocks of Saxon times have been found in the British Isles. They are of the "sinking bowl" type, where a bronze bowl with a hole in the bottom was placed upon the surface of the water, water percolated through the hole and eventually it sank which denoted a period of time. It is interesting to note that this system is still used in Algeria for timing periods of the supply of water for irrigation purposes. -Chuck Harris Rex wrote: > Mark Sims wrote: >> And my clepsydra is now indicating "Leak Second Pending"... >> ---------------------------------------- >> >> >> > > Did you make a typo... or is clepsydra a real word? > > > :-) (just joking) > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From rexa at sonic.net Tue Jul 29 22:11:50 2008 From: rexa at sonic.net (Rex) Date: Tue, 29 Jul 2008 19:11:50 -0700 Subject: [time-nuts] Leap Second Pending In-Reply-To: <488FCC56.7060906@erols.com> References: <488FC850.5060805@sonic.net> <488FCC56.7060906@erols.com> Message-ID: <488FCDE6.5090708@sonic.net> Oh. I see! It was already a joke that I didn't get. Thanks. Chuck Harris wrote: > According to Donald DeCarle's Watch and Clock Encyclopedia: > > Clepsydra- Water Clock. There are various types of water > clocks, from the plain vessel with an orifice at its base through > which water percolates and, by the lowering of the surface > of the water the passage of time is denoted, to the water clock > with a mechanical device to cause a hand to rotate. The mechanical > clepsydra shown overleaf is simple in operation. The cylindrical > vessel is slowly filled with water and a float with a stem and rack > engages the wheel to which the hour hand is attached. As the vessel > fills so the float rises and the hour hand is made to rotate. When > the vessel is full it is emtied (sic) and the process starts over > again. While this type of clock is spectacular and one would like > to think it is of ancient origin, it has to be recorded that no > ancient example has been handed down to us. On the other hand, > Egyptian water clocks, as illustrated, have been found and date from > about 1400B.C. Primitive water clocks of Saxon times have been > found in the British Isles. They are of the "sinking bowl" type, > where a bronze bowl with a hole in the bottom was placed upon the > surface of the water, water percolated through the hole and > eventually it sank which denoted a period of time. It is > interesting to note that this system is still used in Algeria for > timing periods of the supply of water for irrigation purposes. > > -Chuck Harris > > Rex wrote: > >> Mark Sims wrote: >> >>> And my clepsydra is now indicating "Leak Second Pending"... >>> ---------------------------------------- >>> >>> >>> >>> >> Did you make a typo... or is clepsydra a real word? >> >> >> :-) (just joking) >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts at febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > From holrum at hotmail.com Tue Jul 29 23:07:34 2008 From: holrum at hotmail.com (Mark Sims) Date: Wed, 30 Jul 2008 03:07:34 +0000 Subject: [time-nuts] Clepsydra In-Reply-To: References: Message-ID: I have actually built two different GPS disciplined clepsydra... The first one used six precision syringe pumps (basically syringes with the plungers hooked to lead screws/stepper motors). They were set up to draw colored fluid up into the syringes (HH MM SS). When the seconds syringe filled, it was dumped and the minutes syringe drew up an increment of fluid, etc. Worked very well. Certain people were rather peeved that I used several thousand dollars of their product for such a frivolity. The company president and board of directors wanted their own (but they did not get the GPS version). The second one was an hour clock. It had four 1 liter separation funnels at the bottom, each with a different colored fluid. Every 15 minutes one funnel would be pumped into an upper funnel where its contents would be dispensed in 1 CC pulses each second by a very precision (and hideously expensive) flow meter valve into spiral tubes leading back to the original funnel. Each pulse of fluid would wind its way down the tube. After a week or so you got enough mixing of the fluids that you would have to change them to keep the colors fresh. Great fun... totally useless... I liked it... certain people did not... those that mattered did. ---------------------------------------- _________________________________________________________________ Time for vacation? WIN what you need- enter now! http://www.gowindowslive.com/summergiveaway/?ocid=tag_jlyhm From james.p.lux at jpl.nasa.gov Tue Jul 29 23:16:29 2008 From: james.p.lux at jpl.nasa.gov (Jim Lux) Date: Tue, 29 Jul 2008 20:16:29 -0700 Subject: [time-nuts] Leap Second Pending In-Reply-To: <488FCC56.7060906@erols.com> References: <488FC850.5060805@sonic.net> <488FCC56.7060906@erols.com> Message-ID: <20080729201629.4pfejfrf480s8cc4@webmail.jpl.nasa.gov> Quoting Chuck Harris , on Tue 29 Jul 2008 07:05:10 PM PDT: > According to Donald DeCarle's Watch and Clock Encyclopedia: > > Clepsydra- Water Clock. There are various types of water > I should note that because the flow is a function of the viscosity of the working fluid, the clepsydra has a very nonlinear temperature coefficient (with a saturation at around 0C and another saturation at around 100C, if the working fluid is water, depending on the atmospheric pressure) although this can be compensated to a certain extent by changing fluids.. Is a clepsydra using, say, alcohol or fluorinert(tm) still a clepsydra? I wonder if one could make a temperature compensated one (where the orifice size changes with temperature.. much like building a temperature compensated pendulum using metals with two different CTE) There are various forms with tipping bucket (like rain gages) that one might be able to make a calendar with (raising the prospect of actually having a leak second) From didier at cox.net Wed Jul 30 01:19:40 2008 From: didier at cox.net (Didier Juges) Date: Wed, 30 Jul 2008 00:19:40 -0500 Subject: [time-nuts] Leap Second Pending In-Reply-To: References: <488EE174.2070803@tiscali.co.uk> Message-ID: <010801c8f203$df0d8cd0$0a01a8c0@didierhp> Very interesting thread. I have been following half distractedly the thread on leap second, while working on the firmware for my GPS Monitor. I am at version 0.1.2, and the second line of the display is now used to display RX Mode, Disciplining Mode, Temperature or DAC Voltage in succession, by pressing a push button. I am using my second prototype for that, the first prototype is still connected to the other TB. This is working, then I glanced at the first prototype, running firmware 0.0.9, and it was alternating between "Normal" and "Leap Second Pending" . V0.0.9 is designed to alternate between the mode and warning flags when any is present. I had not been able to test that feature, because my Thunderbolts are all stabilized, surveyed and so forth. Well, I know now that works too :-) Unfortunately, v0.1.2 at the moment does not display flags at all :-( I have to decide what to do with the flags, I don't want to be displaying "Leap Second Pending" for 6 months, yet other flags may be important to display (like antenna disconnected or shorted). Didier KO4BB From J.Bastemeijer at TUDelft.nl Wed Jul 30 02:53:06 2008 From: J.Bastemeijer at TUDelft.nl (Jeroen Bastemeijer) Date: Wed, 30 Jul 2008 08:53:06 +0200 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <8332BE8EF8F0471AB44BDC2E950330F7@APOLLO> References: <5399C239FEF14EAF9C04F4AC39BBF5A8@APOLLO><00d201c8ee67$27fe2b70$77fa8250$@com> <8332BE8EF8F0471AB44BDC2E950330F7@APOLLO> Message-ID: <48900FD2.4030906@TUDelft.nl> Dear Dave, If there is one board left, I would like to buy and try one. Shipping will be to the Netherlands, so that won't be a problem. Could you send met the BOM and the circuit diagram? Thank you, Best regards, Jeroen David C. Partridge schreef: > I've taken a bit of a risk and ordered 20 boards. Rash in extreme or what! > > What does this mean? It means that I can sell the boards at a price of > GBP20 each (about USD40). > > I will not request $$$ or ship any boards until I have made up my own first > to confirm everything is OK. > > This won't be until end August as some parts are on back-order with Mouser. > > Please email me direct if you would like to pre-order any. > > If you would like a copy of the circuit diagram, or the BOM (.xls file) just > shout (it's complete bar the thumbwheel switch, and wire). > > Dave > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > -- Ing. Jeroen Bastemeijer Delft University of Technology Department of Electrical Engineering Electronic Instrumentation Laboratory Mekelweg 4, Room 13.090 2628 CD Delft The Netherlands Phone: +31.15.27.86542 Fax: +31.15.27.85755 E-mail: J.Bastemeijer at TUDelft.nl GPS: Lat N52.00002 Lon E4.37157 Alt 46.2m From jltran at worldnet.att.net Wed Jul 30 08:56:09 2008 From: jltran at worldnet.att.net (J. L. Trantham) Date: Wed, 30 Jul 2008 07:56:09 -0500 Subject: [time-nuts] PCB for frequency dividers In-Reply-To: <8332BE8EF8F0471AB44BDC2E950330F7@APOLLO> Message-ID: David, I am interested in your PCB and frequency divider project. How can I contact you directly? Joe (jltran at worldnet.att.net) -----Original Message----- From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of David C. Partridge Sent: Tuesday, July 29, 2008 11:12 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] PCB for frequency dividers I've taken a bit of a risk and ordered 20 boards. Rash in extreme or what! What does this mean? It means that I can sell the boards at a price of GBP20 each (about USD40). I will not request $$$ or ship any boards until I have made up my own first to confirm everything is OK. This won't be until end August as some parts are on back-order with Mouser. Please email me direct if you would like to pre-order any. If you would like a copy of the circuit diagram, or the BOM (.xls file) just shout (it's complete bar the thumbwheel switch, and wire). Dave _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. From d.seiter at comcast.net Wed Jul 30 15:50:25 2008 From: d.seiter at comcast.net (d.seiter at comcast.net) Date: Wed, 30 Jul 2008 19:50:25 +0000 Subject: [time-nuts] Leap Second Pending Message-ID: <073020081950.9436.4890C601000D245B000024DC22058891169D0A9B070A9CD20B@comcast.net> The mechanical > clepsydra shown overleaf is simple in operation. The cylindrical > vessel is slowly filled with water and a float with a stem and rack > engages the wheel to which the hour hand is attached. As the vessel > fills so the float rises and the hour hand is made to rotate. When > the vessel is full it is emtied (sic) and the process starts over > again. While this type of clock is spectacular and one would like > to think it is of ancient origin, it has to be recorded that no > ancient example has been handed down to us. Actually, if I'm visualizing this correctly, a similar design was built by the ancient Greeks. I recall a article in National Geographic about the "Tower of the Winds" (or similar). The source of the water stream was a tank that constantly overflowed, maintaining constant water pressure. There was little to go on as far as actual physical evidence, so maybe it was wishful thinking and has been debunked since? -Dave From bob.paddock at gmail.com Wed Jul 30 20:34:34 2008 From: bob.paddock at gmail.com (Bob Paddock) Date: Wed, 30 Jul 2008 20:34:34 -0400 Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? Message-ID: <200807302034.34650.bob.paddock@gmail.com> Can you point me to a Time-Nut grade Zero Crossing circuit that I can feed a Actel Igloo FPGA (It doesn't like sine waves)? For the sake of discussion the source signal is a ThunderBolt at 10 MHz. The FPGA is rated to 350 MHz, so no need to have a 5.0000000000000000 GHz Zero Crossing circuit. ;-) The FPGA has several interface styles, so we are not limited to just TTL or CMOS. Suggestions? From cfharris at erols.com Wed Jul 30 21:44:39 2008 From: cfharris at erols.com (Chuck Harris) Date: Wed, 30 Jul 2008 21:44:39 -0400 Subject: [time-nuts] Leap Second Pending In-Reply-To: <073020081950.9436.4890C601000D245B000024DC22058891169D0A9B070A9CD20B@comcast.net> References: <073020081950.9436.4890C601000D245B000024DC22058891169D0A9B070A9CD20B@comcast.net> Message-ID: <48911907.6020605@erols.com> d.seiter at comcast.net wrote: > The mechanical >> clepsydra shown overleaf is simple in operation. The cylindrical vessel is slowly filled with water and a float >> with a stem and rack engages the wheel to which the hour hand is attached. As the vessel fills so the float rises >> and the hour hand is made to rotate. When the vessel is full it is emtied (sic) and the process starts over again. >> While this type of clock is spectacular and one would like to think it is of ancient origin, it has to be recorded >> that no ancient example has been handed down to us. > > Actually, if I'm visualizing this correctly, a similar design was built by the ancient Greeks. I recall a article in > National Geographic about the "Tower of the Winds" (or similar). The source of the water stream was a tank that > constantly overflowed, maintaining constant water pressure. There was little to go on as far as actual physical > evidence, so maybe it was wishful thinking and has been debunked since? DeCarle was an old guy in the 1960's. What he is referring to is a picture in the encyclopedia of a clock that has a float attached to a rack that drives a pinion attached to an hour hand. The water is directed into the tank, and as the tank fills, the hour hand rotates indicating the time. When the tank is full, a valve is tripped letting the water out of the tank, and the cycle repeats. He acknowledges that there were clepsydra's used in ancient cultures, just not one as cool as the one shown in the picture. > > -Dave _______________________________________________ time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go > to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. > From SAIDJACK at aol.com Wed Jul 30 21:57:39 2008 From: SAIDJACK at aol.com (SAIDJACK at aol.com) Date: Wed, 30 Jul 2008 21:57:39 EDT Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? Message-ID: Hi Bob, since the sine wave is symmetric, you can use a simple LVC type CMOS inverter with 1M Ohm resistor from input to output, and a 100nF cap (or the largest COG cap you can find) from the input of the inverter to the sine wave output. You may also want to load the sine wave output with 50 Ohms, as required by the source. This works very well. Don't use a schmitt trigger inverter though. bye, Said In a message dated 7/30/2008 17:35:46 Pacific Daylight Time, bob.paddock at gmail.com writes: Can you point me to a Time-Nut grade Zero Crossing circuit that I can feed a Actel Igloo FPGA (It doesn't like sine waves)? For the sake of discussion the source signal is a ThunderBolt at 10 MHz. The FPGA is rated to 350 MHz, so no need to have a 5.0000000000000000 GHz Zero Crossing circuit. ;-) The FPGA has several interface styles, so we are not limited to just TTL or CMOS. Suggestions? **************Get fantasy football with free live scoring. Sign up for FanHouse Fantasy Football today. (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020) From ch at murgatroid.com Wed Jul 30 22:54:11 2008 From: ch at murgatroid.com (christopher hoover) Date: Wed, 30 Jul 2008 19:54:11 -0700 Subject: [time-nuts] Complete Lucent RFTG setup on eBay Message-ID: <001801c8f2b8$b59eda10$20dc8e30$@com> There have been lots of messages about how the Lucent RFTG disciplined oscillator bits work in a system. This, from its appearance, is the entire set up with all necessary cables and proper connections: 1 - Lucent RFTGm-II-Rb 15MHz Frequency Reference with 10MHz output 1 - Lucent RFTGm-II-XO 15MHz GPS Disciplined Frequency Reference Interconnection cable set and mounting frame eBay item # 300244547378 (This is not my auction; I have no relation to the seller.) The (quite detailed) pictures alone are worth a look if you are interested in this gear. -ch From bruce.griffiths at xtra.co.nz Wed Jul 30 23:05:04 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Thu, 31 Jul 2008 15:05:04 +1200 Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: References: Message-ID: <48912BE0.7090009@xtra.co.nz> SAIDJACK at aol.com wrote: > Hi Bob, > > since the sine wave is symmetric, you can use a simple LVC type CMOS > inverter with 1M Ohm resistor from input to output, and a 100nF cap (or the largest > COG cap you can find) from the input of the inverter to the sine wave output. > > You may also want to load the sine wave output with 50 Ohms, as required by > the source. > > This works very well. Don't use a schmitt trigger inverter though. > > bye, > Said > > > Said Noise is lower if you use a pair of resistor to bias the inverter input at the threshold rather than the feedback resistor. A feedback circuit can be added to stabilise the output duty cycle. If you want subpicosecond jitter you need to use a different device/logic family. Bruce From had at to-way.com Thu Jul 31 00:01:28 2008 From: had at to-way.com (Had) Date: Wed, 30 Jul 2008 21:01:28 -0700 Subject: [time-nuts] Complete Lucent RFTG setup on eBay In-Reply-To: <001801c8f2b8$b59eda10$20dc8e30$@com> References: <001801c8f2b8$b59eda10$20dc8e30$@com> Message-ID: <20080731040133.3755F16482B@mail-in06.adhost.com> I have no connection with this seller, but have done business, several times in the past, and consider them to be very reputable. Had, K7MLR ------------------------------------------------------------------------------------------------------------------------------------------------------------------- At 07:54 PM 7/30/2008, you wrote: >There have been lots of messages about how the Lucent RFTG disciplined >oscillator bits work in a system. > > > >This, from its appearance, is the entire set up with all necessary cables >and proper connections: > > > >1 - Lucent RFTGm-II-Rb 15MHz Frequency Reference with 10MHz output >1 - Lucent RFTGm-II-XO 15MHz GPS Disciplined Frequency Reference >Interconnection cable set and mounting frame > > > >eBay item # 300244547378 > > > >(This is not my auction; I have no relation to the seller.) > > > >The (quite detailed) pictures alone are worth a look if you are interested >in this gear. > > > >-ch > > > >_______________________________________________ >time-nuts mailing list -- time-nuts at febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. From SAIDJACK at aol.com Thu Jul 31 03:19:57 2008 From: SAIDJACK at aol.com (SAIDJACK at aol.com) Date: Thu, 31 Jul 2008 03:19:57 EDT Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? Message-ID: Hi Bruce, that would work too. We get <330fs jitter rms with this circuit using the Fairchild UHS LVC family, that's pretty much the noise floor of the OCXO :) If you use a bias network, you won't get 50% symmetry since it will never perfectly match the inverter's inflection point (which changes with temp etc), and you may insert noise from the power supply. With the feedback resistor it will operation at the inversion point without adding power supply noise. bye, Said In a message dated 7/30/2008 20:06:12 Pacific Daylight Time, bruce.griffiths at xtra.co.nz writes: > Said Noise is lower if you use a pair of resistor to bias the inverter input at the threshold rather than the feedback resistor. A feedback circuit can be added to stabilise the output duty cycle. If you want subpicosecond jitter you need to use a different device/logic family. Bruce **************Get fantasy football with free live scoring. Sign up for FanHouse Fantasy Football today. (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020) From bruce.griffiths at xtra.co.nz Thu Jul 31 04:58:16 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Thu, 31 Jul 2008 20:58:16 +1200 Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: References: Message-ID: <48917EA8.2060101@xtra.co.nz> SAIDJACK at aol.com wrote: > Hi Bruce, > > that would work too. We get <330fs jitter rms with this circuit using the > Fairchild UHS LVC family, that's pretty much the noise floor of the OCXO :) > > If you use a bias network, you won't get 50% symmetry since it will never > perfectly match the inverter's inflection point (which changes with temp etc), > and you may insert noise from the power supply. With the feedback resistor it > will operation at the inversion point without adding power supply noise. > > bye, > Said > > > Yes, however it is quieter and adding duty cycle stabilisation feedback fixes that problem. For even lower noise, bandpass filter the OCXO output (a crystal filter is particularly effective). Its not too difficult to drop the noise floor to a few tens of femtosec. The drawbacks being the cost, and the need to regulate the bandpass filter temperature to minimise phase shift variations with ambient temperature. You would also need to use a quieter clock driver. It may even be necessary to use a well designed bandpass limiter to increase the signal zero crossing slew rate before using a 6GHz bandwidth clock driver. However the cost and complexity probably isnt justified when driving an FPGA which may have tens of picoseconds of jitter. Bruce From SAIDJACK at aol.com Thu Jul 31 12:02:15 2008 From: SAIDJACK at aol.com (SAIDJACK at aol.com) Date: Thu, 31 Jul 2008 12:02:15 EDT Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? Message-ID: Hello Bruce, I believe a driver for an FPGA running at 350MHz was the initial query, 6GHz BW and crystal filters are probably overkill. bye, Said In a message dated 7/31/2008 01:59:34 Pacific Daylight Time, bruce.griffiths at xtra.co.nz writes: Yes, however it is quieter and adding duty cycle stabilisation feedback fixes that problem. For even lower noise, bandpass filter the OCXO output (a crystal filter is particularly effective). Its not too difficult to drop the noise floor to a few tens of femtosec. The drawbacks being the cost, and the need to regulate the bandpass filter temperature to minimise phase shift variations with ambient temperature. You would also need to use a quieter clock driver. It may even be necessary to use a well designed bandpass limiter to increase the signal zero crossing slew rate before using a 6GHz bandwidth clock driver. However the cost and complexity probably isnt justified when driving an FPGA which may have tens of picoseconds of jitter. Bruce **************Get fantasy football with free live scoring. Sign up for FanHouse Fantasy Football today. (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020) From richard at karlquist.com Thu Jul 31 16:13:34 2008 From: richard at karlquist.com (Rick Karlquist) Date: Thu, 31 Jul 2008 13:13:34 -0700 (PDT) Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: <200807302034.34650.bob.paddock@gmail.com> References: <200807302034.34650.bob.paddock@gmail.com> Message-ID: <22887.192.25.142.225.1217535214.squirrel@webmail.sonic.net> Two things NOT to do: 1. Do NOT use ECL. CMOS is much lower jitter. 2. Do NOT use a comparator to square up the sine wave. Especially don't use a ultrafast ECL based comparator. ------------------------------------------- Some things that you should do: Make all circuitry differential if possible. Make your 10 MHz source differential by putting a transformer on the output. Band pass filter your 10 MHz source with an LC filter. I recommend Coilcraft Unicoils or Maxicoils. Rick Karlquist N6RK Bob Paddock wrote: > > Can you point me to a Time-Nut grade Zero Crossing > circuit that I can feed a Actel Igloo FPGA (It doesn't > like sine waves)? > > For the sake of discussion the source signal > is a ThunderBolt at 10 MHz. > > The FPGA is rated to 350 MHz, so no need to have > a 5.0000000000000000 GHz Zero Crossing circuit. ;-) > > The FPGA has several interface styles, > so we are not limited to just TTL or CMOS. > > Suggestions? > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > From didier at cox.net Thu Jul 31 16:25:33 2008 From: didier at cox.net (Didier Juges) Date: Thu, 31 Jul 2008 15:25:33 -0500 Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: <22887.192.25.142.225.1217535214.squirrel@webmail.sonic.net> References: <200807302034.34650.bob.paddock@gmail.com> <22887.192.25.142.225.1217535214.squirrel@webmail.sonic.net> Message-ID: <019501c8f34b$9608b930$0a01a8c0@didierhp> Rick, Can you explain #2? I understand ECL has more jitter, so I understand excluding ECL based comparators, but why excluding ALL comparators? It seems to me the comparators allow tighter control of the threshold, so it sounds as if it would help at very low frequencies, unless the higher 1/f noise of the compartor dominates other factors. How does the 1/f noise of a CMOS gate compare to an analog comparator? Didier KO4BB > -----Original Message----- > From: time-nuts-bounces at febo.com > [mailto:time-nuts-bounces at febo.com] On Behalf Of Rick Karlquist > Sent: Thursday, July 31, 2008 3:14 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] What is a Time-Nut grade Zero > Crossing Circuit? > > Two things NOT to do: > > 1. Do NOT use ECL. CMOS is much lower jitter. > > 2. Do NOT use a comparator to square up the sine wave. > Especially don't use a ultrafast ECL based comparator. > From richard at karlquist.com Thu Jul 31 16:47:33 2008 From: richard at karlquist.com (Rick Karlquist) Date: Thu, 31 Jul 2008 13:47:33 -0700 (PDT) Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: <019501c8f34b$9608b930$0a01a8c0@didierhp> References: <200807302034.34650.bob.paddock@gmail.com> <22887.192.25.142.225.1217535214.squirrel@webmail.sonic.net> <019501c8f34b$9608b930$0a01a8c0@didierhp> Message-ID: <22931.192.25.142.225.1217537253.squirrel@webmail.sonic.net> Comparators have very wideband, high gain inputs with typically high noise figures. The effective input noise is determined by the noise figure and the comparator bandwidth and the fact the the comparator only utilizes a few mV of the input signal. If you are trying to square up a 10 MHz signal, and noise from DC-1000 MHz is affecting the comparator switching time, you have unnecessarily added a bunch of noise above 10 MHz. You can't filter this noise back out after the comparator output. That's the theory of it. 1/f noise is not the issue. CMOS gates have lower input noise IN RELATION TO THE SIGNAL LEVEL involved. Comparators only use a few mV of your signal. That's why the high gain is bad. The ideal circuit is a bandpass linear amplifier that makes a large filtered 10 MHz sine wave, which is then passively clipped with diodes at the logic levels you need. This is based on the paradigm described by John Dick (of JPL) in his 1990 PTTI paper on zero crossing detectors (someone posted that paper I think; anyone know the URL?). It is clear IMHO that a comparator is just about exactly the opposite of what Dr. Dick prescribed. In any event, if you actually test real comparators, you will find them to be universally lousy. I will be happy to be proven wrong if someone is aware of a good comparator. It's just that I have never met I comparator I liked :-) Rick Karlquist N6RK Didier Juges wrote: > Rick, > > Can you explain #2? > > I understand ECL has more jitter, so I understand excluding ECL based > comparators, but why excluding ALL comparators? It seems to me the > comparators allow tighter control of the threshold, so it sounds as if it > would help at very low frequencies, unless the higher 1/f noise of the > compartor dominates other factors. > > How does the 1/f noise of a CMOS gate compare to an analog comparator? > > Didier KO4BB > >> -----Original Message----- >> From: time-nuts-bounces at febo.com >> [mailto:time-nuts-bounces at febo.com] On Behalf Of Rick Karlquist >> Sent: Thursday, July 31, 2008 3:14 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] What is a Time-Nut grade Zero >> Crossing Circuit? >> >> Two things NOT to do: >> >> 1. Do NOT use ECL. CMOS is much lower jitter. >> >> 2. Do NOT use a comparator to square up the sine wave. >> Especially don't use a ultrafast ECL based comparator. >> > > From cupido at mail.ua.pt Thu Jul 31 17:11:50 2008 From: cupido at mail.ua.pt (Luis Cupido) Date: Thu, 31 Jul 2008 22:11:50 +0100 Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: <22931.192.25.142.225.1217537253.squirrel@webmail.sonic.net> References: <200807302034.34650.bob.paddock@gmail.com> <22887.192.25.142.225.1217535214.squirrel@webmail.sonic.net> <019501c8f34b$9608b930$0a01a8c0@didierhp> <22931.192.25.142.225.1217537253.squirrel@webmail.sonic.net> Message-ID: <48922A96.3010807@mail.ua.pt> I do agree with Richard, comparators are quite bad... Having played with interfacing signals to FPGA 'ad nausea' I found that the only simple scheme that works better than biased (or feedback) cmos gates and of course much better than ECL line receivers or comparators (even cmos gates biased sometimes exhibit some strange issues specially when no signal is present)... As I was saying the best I could find was a differential pair of fets set to not too high gain. Signal is not step-square to the ps but the outcome on jitter viewed from inside the FPGA is the best of all many combinations I've tried, imediately followed by a differential pair of microwave bipolar transistors which preform excellent also... (note gains about 5 only, resistors set to naturally clip the signal to 0 - 2.5V (FPGA friendly) by the nature of the differential pair behaviour). (PFET or PNP) All the rest is crap compared to this... At least in my experiments. discrete but simple... sometimes super-duper ic's are not the best option. Luis Cupido. ct1dmk. p.s. my interest was wide band so filtering amplifying and clipping (by far the best solution) was not an option for me. Rick Karlquist wrote: > Comparators have very wideband, high gain inputs with typically > high noise figures. The effective input noise is determined by > the noise figure and the comparator bandwidth and the fact > the the comparator only utilizes a few mV of the input signal. If you are > trying to square up a 10 MHz signal, and noise from DC-1000 MHz > is affecting the comparator switching time, you have unnecessarily > added a bunch of noise above 10 MHz. You can't filter this noise > back out after the comparator output. That's the theory of it. > > 1/f noise is not the issue. CMOS gates have lower input noise > IN RELATION TO THE SIGNAL LEVEL involved. Comparators only use > a few mV of your signal. That's why the high gain is bad. > > The ideal circuit is a bandpass linear amplifier that makes a > large filtered 10 MHz sine wave, which is then passively clipped with > diodes at the logic levels you need. This is based on the paradigm > described by John Dick (of JPL) in his 1990 PTTI paper on zero > crossing detectors (someone posted that paper I think; anyone know > the URL?). It is clear IMHO that a comparator is just about exactly > the opposite of what Dr. Dick prescribed. > > In any event, if you actually test real comparators, you will > find them to be universally lousy. I will be happy to be proven > wrong if someone is aware of a good comparator. It's just that > I have never met I comparator I liked :-) > > Rick Karlquist N6RK > > > Didier Juges wrote: >> Rick, >> >> Can you explain #2? >> >> I understand ECL has more jitter, so I understand excluding ECL based >> comparators, but why excluding ALL comparators? It seems to me the >> comparators allow tighter control of the threshold, so it sounds as if it >> would help at very low frequencies, unless the higher 1/f noise of the >> compartor dominates other factors. >> >> How does the 1/f noise of a CMOS gate compare to an analog comparator? >> >> Didier KO4BB >> >>> -----Original Message----- >>> From: time-nuts-bounces at febo.com >>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Rick Karlquist >>> Sent: Thursday, July 31, 2008 3:14 PM >>> To: Discussion of precise time and frequency measurement >>> Subject: Re: [time-nuts] What is a Time-Nut grade Zero >>> Crossing Circuit? >>> >>> Two things NOT to do: >>> >>> 1. Do NOT use ECL. CMOS is much lower jitter. >>> >>> 2. Do NOT use a comparator to square up the sine wave. >>> Especially don't use a ultrafast ECL based comparator. >>> >> > > > > _______________________________________________ > time-nuts mailing list -- time-nuts at febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > From peterawson at earthlink.net Thu Jul 31 17:24:31 2008 From: peterawson at earthlink.net (Pete) Date: Thu, 31 Jul 2008 15:24:31 -0600 Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? References: <200807302034.34650.bob.paddock@gmail.com><22887.192.25.142.225.1217535214.squirrel@webmail.sonic.net><019501c8f34b$9608b930$0a01a8c0@didierhp> <22931.192.25.142.225.1217537253.squirrel@webmail.sonic.net> Message-ID: <000c01c8f353$f611b590$0200a8c0@BASE1> The JPL paper is here: http://tycho.usno.navy.mil/ptti/1990/Vol%2022_20.pdf Pete Rawson From jmiles at pop.net Thu Jul 31 17:22:23 2008 From: jmiles at pop.net (John Miles) Date: Thu, 31 Jul 2008 14:22:23 -0700 Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: <22931.192.25.142.225.1217537253.squirrel@webmail.sonic.net> Message-ID: > In any event, if you actually test real comparators, you will > find them to be universally lousy. I will be happy to be proven > wrong if someone is aware of a good comparator. It's just that > I have never met I comparator I liked :-) I think you're right about that. About the best thing you can say for using a comparator is that it can still be better than feeding a CMOS input that has insufficient gain by itself. You definitely get better inband phase noise from the output of an Analog Devices ADF-series or NatSemi LMX-series synthesizer if you feed its reference input through an external comparator such as an LT1016. Is that the best part for the job? No, but it still offers an improvement. Something I've wanted to do for a long time now, but haven't had enough spare time to, is to document the additive noise of a large list of sine->square converters. There is an extensive table in the manual for the Lucent rubidium oscillator that was just mentioned on eBay ( http://www.symmetricom.com/media/pdf/manuals/man-lpro.pdf ), but it has several limitations. It doesn't cover single-ended versus differential variations, it only considers 10 MHz inputs, it's not clear how they controlled for amplitude levels and source impedance, and their LT1016 test circuit is just embarassing. It's an interesting topic, especially when you're not trying to go for absolute optimal performance but just want to choose a quick/simple hack that won't degrade whatever you're driving. The literature is biased (no pun intended) toward more complex circuits that are quieter than most signal sources and destinations are likely to need. That's what would be nice about the Lucent app note, if only it were better realized. -- john, KE5FX From jmiles at pop.net Thu Jul 31 17:27:53 2008 From: jmiles at pop.net (John Miles) Date: Thu, 31 Jul 2008 14:27:53 -0700 Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: <48922A96.3010807@mail.ua.pt> Message-ID: > > I do agree with Richard, comparators are quite bad... > > Having played with interfacing signals to FPGA 'ad nausea' > I found that the only simple scheme that works > better than biased (or feedback) cmos gates and of > course much better than ECL line receivers or comparators > (even cmos gates biased sometimes exhibit some strange issues > specially when no signal is present)... Modern ECL parts aren't necessarily that bad compared to the old MECL stuff. For some reason, though, the one circuit I measured (MC100EL16 line receiver, driven single-ended) was much quieter at 100 MHz (-150 dBc/Hz floor) than at 10 MHz (-140 dBc/Hz floor). I need to look into that a bit further. Point being, benchmarks taken at the usual 10 MHz may not be helpful if you are actually going to work at higher frequencies. If the additive jitter remains constant, the additive phase noise should get worse at higher carrier frequencies, not better... but that doesn't always seem to be what happens. -- john, KE5FX From bruce.griffiths at xtra.co.nz Thu Jul 31 17:58:48 2008 From: bruce.griffiths at xtra.co.nz (Bruce Griffiths) Date: Fri, 01 Aug 2008 09:58:48 +1200 Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: <000c01c8f353$f611b590$0200a8c0@BASE1> References: <200807302034.34650.bob.paddock@gmail.com><22887.192.25.142.225.1217535214.squirrel@webmail.sonic.net><019501c8f34b$9608b930$0a01a8c0@didierhp> <22931.192.25.142.225.1217537253.squirrel@webmail.sonic.net> <000c01c8f353$f611b590$0200a8c0@BASE1> Message-ID: <48923598.3030800@xtra.co.nz> Pete wrote: > The JPL paper is here: http://tycho.usno.navy.mil/ptti/1990/Vol%2022_20.pdf > > Pete Rawson > Pete You can usually do much better than that. The Collins paper indicates how. http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?isnumber=10665&arnumber=494304&type=ref (I know you have to purchase it or perhaps photocopy it. - but its well worth the effort) I have extended the theory to include the case where the input noise spectral density is not the same for all finite gain limiter stages. I also have a few spreadsheets which can be used to calculte the optimum gain distribution and corresponding filter bandwidths etc both for the restricted case that Collins analyses and the more general case. The Collin's paper indicates how much better one can do with an optimised cascade of finite gain filtered limiter stages as opposed to the relatively conventional design in the Dick paper. With high frequency signals one can use a bandpass filter at least for the first couple of low gain limiter stages. Bruce From richard at karlquist.com Thu Jul 31 20:59:11 2008 From: richard at karlquist.com (Rick Karlquist) Date: Thu, 31 Jul 2008 17:59:11 -0700 (PDT) Subject: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit? In-Reply-To: References: Message-ID: <22592.192.25.142.225.1217552351.squirrel@webmail.sonic.net> John Miles wrote: > Modern ECL parts aren't necessarily that bad compared to the old MECL > stuff. My experience goes all the way back to the MECL 1000 series that was discontinued 30 years ago. I designed many synthesizers around them for Zeta Labs. Every newer family of ECL line receivers has been faster and had worse phase noise, in my experience. > For some reason, though, the one circuit I measured (MC100EL16 line > receiver, driven single-ended) was much quieter at 100 MHz (-150 dBc/Hz > floor) than at 10 MHz (-140 dBc/Hz floor). I need to look into that a > bit > further. This is a very tricky topic. When measuring the phase noise of a non sine wave, there are dependencies on how the measurement is done. What is the measurement bandwidth? Etc. In some cases, the noise is mostly common mode, and therefore will depend on the common mode rejection ratio (if any) of your measurement circuit. Rick Karlquist N6RK Rick Karlquist N6RK