[time-nuts] Ancient OCXO in scope calibrator. (William Rice)

brice at weaponeer.com brice at weaponeer.com
Sun Sep 7 15:56:24 EDT 2008


Grrrr. email failure, maybe a repeat:
I have one of those oscillators in a tek 184 that I do not use anymore. 
Those calibrators are really cool, I used one for a long time when I first started tinkering.
If you need it, you can have the oscillator. (brice at weaponeer.com)
Good luck!

Still needed HP 2509A digital clock manual, Help!!!

-----Original Message-----
From: time-nuts-request at febo.com [mailto:time-nuts-request at febo.com]
Sent: Sunday, September 7, 2008 11:00 AM
To: time-nuts at febo.com
Subject: time-nuts Digest, Vol 50, Issue 12

Send time-nuts mailing list submissions to	time-nuts at febo.comTo subscribe or unsubscribe via the World Wide Web, visit	https://www.febo.com/cgi-bin/mailman/listinfo/time-nutsor, via email, send a message with subject or body 'help' to	time-nuts-request at febo.comYou can reach the person managing the list at	time-nuts-owner at febo.comWhen replying, please edit your Subject line so it is more specificthan "Re: Contents of time-nuts digest..."Today's Topics: 1. Re: Help with HP 8640B generator (Richard (Rick)	Karlquist) (christopher hoover) 2. Re: Help with HP 8640B generator (Neon John) 3. Ancient OCXO in scope calibrator. (David C. Partridge) 4. Re: I want a good micro-controller (Bob Paddock) 5. Re: Ancient OCXO in scope calibrator. (David C. Partridge)----------------------------------------------------------------------Message: 1Date: Sat, 6 Sep 2008 16:06:10 -0700From: "christopher hoover" Subject: Re: [time-nuts] Help with HP 8640B generator (Richard (Rick)	Karlquist)To: Message-ID: <008a01c91075$27153890$753fa9b0$@com>Content-Type: text/plain;	charset="us-ascii""Richard (Rick) Karlquist" L:> Going back to Agilent's origins at HP, AFAIK, only Hewlett and Packard> ever had traditional "offices" with walls to the ceiling and doors.> Their offices are preserved in the condition they were in when> H & P left the company. Employees can visit these offices, which> are like a museum.Yep, they are still there, as is the old board room. My cubicle at HP Labs is about 25 yards away from them.The old board room is still use, mostly for customer visits to Labs.-ch------------------------------Message: 2Date: Sun, 07 Sep 2008 00:53:39 -0400From: Neon John Subject: Re: [time-nuts] Help with HP 8640B generatorTo: Discussion of precise time and frequency measurement	Message-ID: Content-Type: text/plain; charset=us-asciiOn Sat, 6 Sep 2008 07:09:33 -0400, "Bob Paddock" wrote:>> The cubicle?>>Anti-Productivity Pods: Cubicles as Dilbert so astutely noted.>>"For my money the most important work on software productivity in the>last 20 years> is DeMarco and Lister's Peopleware (1987 Dorset House Publishing, NY>NY). Peopleware became my management handbook. I can't tell you how many copiesI've purchased and handed out to clients.> Surprisingly, none of the factors you'd expect to matter correlated to the best> and worst performers. Even experience mattered little, as long as the>programmers> had been working for at least 6 months. They did find a very strong correlation> between the office environment and team performance. Needless>interruptions yielded> poor performance. The best teams had private (read "quiet") offices>and phones with> "off" switches. Their study suggests that quiet time saves vast>amounts of money.One of the most significant findings, one I took to heart in my shop, was thatit took about 30 minutes of recovery to get back to the state the person wasin when he was interrupted. "Interrupted" is anything that interrupts thetrain of thought, be it a phone, someone walking in or someone cutting upelsewhere in the cube farm.>> Think about this. The almost minor tweak of getting some quiet time can,> according to their data, multiply your productivity by 260%!> That's an astonishing result. For the same salary your boss pays you now,> he'd get essentially 2.6 of you." -- Jack Ganssle in The Embedded Muse #25.I found that book right after I hired on with Dunn & Bradstreet to managetheir new sales automation software development group. I implemented all therecommendations and then some. The door to our cube farm got a cipher lockand no one outside our group had the combo. That stopped the steady stream ofcompany salesmen and testing personnel who used to drift in any time theywanted.I had the PBX reprogrammed to give each person in my group an "off" buttonthat sent all calls either to reception or voice mail. I equipped eachcubicle with a dorm room refrigerator and small Mr. Coffee. I paid to havethem stocked out of my discretionary budget. I'd have put a head in each cubeif that had been possible. Walkmans and other headphone-based entertainment was encouraged but no devicesthat made noise were allowed. Not even speakers on the developers' PCs. Nomeetings were allowed in the cube farm and voices above a whisper were banned.The cube farm was ringed with small conference rooms where teams could go tomeet and coordinate. I had pink noise generators installed which masked thenormal noises such as chairs bumping into desks and file drawers opening andclosing.It took a few weeks for my group to come on board but then they loved it. Theywere self-policing. Anyone who made noise or otherwise disturbed theenvironment was quickly set upon by those disturbed.My group's productivity soared by all measures. My guys were happy campers.Turnover was nil. Yet for the 2 years that I stayed at the company, we wereunder constant assault from whiners and malingerers elsewhere in the companybecause we were getting "special treatment". After two years of fending offthat crap, I'd had enough. I took the best of my team and went back intoprivate practice.John--John De ArmondSee my website for my current email addresshttp://www.neon-john.comhttp://www.johndearmond.com <-- best little blog on the net!Tellico Plains, Occupied TNSome people are like a Slinky .. not really good for anything but you still smile when you shove them down the stairs.------------------------------Message: 3Date: Sun, 7 Sep 2008 14:56:25 +0100From: "David C. Partridge" Subject: [time-nuts] Ancient OCXO in scope calibrator.To: "'Discussion of precise time and frequency measurement'"	Message-ID: <57568D7DB5D04FB2989B00043F5AD06A at APOLLO>Content-Type: text/plain;	charset="US-ASCII"I'm having some problems with an ancient Bulova OCXO in a Tektronix 184'scope calibrator. This is an crystal mounted on an octal valve base with a heater windingwrapped round it, and a common or garden variety thermostat which issupposed to switch at 75 celsius. I've not measured the switchingtemperature, as I don't have the means but the outer case does get fairlywarm (40 plus degrees?). The oven is turning on and off.It is used in a circuit with a 7587 Nuvistor tetrode (yes it's a valve/tubecircuit). The crystal is connected cathode to G1 with a trimmer capacitorof 3-12pF. The signal at the cathode is supposed to be about 70V p-p.I'm measuring the frequency of the signal after the transformer stage whichcouples it to the first stage of a countdown board.For the first minute or so after turn on from cold, it sits below 10MHz andis fairly stable and climbing as the oven warms up, and I can adjust thefrequency up towards 10MHz with the capacitor (but not all the way), thensuddenly, at the stage where it is starting to look as if it will soonstabilise at about the right frequency, it jumps to way over 10MHz and thelowest I can get it down to with the capacitor is about 10.0003xxx MHz wherexxx is not very stable at all - in fact it can vary up to to 10.0005xxx anddown to 10.0002xxx.I've tried freeze spray on most of the components round there to no effect.If I try to probe the signal at the cathode of the nuvistor even with a highimpedance active probe with a P6201 with a 100x attenuator (about 1pFloading IIRC) the oscillation just drops dead.Now for calibrating 'scopes, it doesn't need to be any more accurate than itis (30ppm) - but ...Do any of the collected mavens have an explanation for the behaviour, andrecommendations for fixing things?CheersDave------------------------------Message: 4Date: Sun, 7 Sep 2008 09:57:37 -0400From: "Bob Paddock" Subject: Re: [time-nuts] I want a good micro-controllerTo: "Discussion of precise time and frequency measurement"	Message-ID:	Content-Type: text/plain; charset=ISO-8859-1> Beware, programmers have turned to screaming, blithering idiots with bits of their brains> oozing out all of their orifices just by glancing at that page.Worse than writing a Web Server in the language "BF"? The "B" standsfor Brain, and I'm not going to put the "F" on a family oriented list likethis one.The following program prints "Hello World!" and a newline to the screen,from the Wikipedia entry:++++++++++[ >+++++++>++++++++++>+++>+<<<<-] this loop sets the next four cells to 70/100/30/10>++. print 'H'>+. print 'e'+++++++. 'l'. 'l'+++. 'o'>++. space<<+++++++++++++++. 'W'>. 'o'+++. 'r'------. 'l'--------. 'd'>+. '!'>. newlineThat is not a badly formated message, that is what the cost is...At least it doesn't require a custom keyboard to code it.------------------------------Message: 5Date: Sun, 7 Sep 2008 15:00:53 +0100From: "David C. Partridge" Subject: Re: [time-nuts] Ancient OCXO in scope calibrator.To: "'Discussion of precise time and frequency measurement'"	Message-ID: <124F6752BF6B42F5BDF9F8F3D4035B96 at APOLLO>Content-Type: text/plain;	charset="US-ASCII"Oops I think its about 300ppm there...D. -----Original Message-----From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] OnBehalf Of David C. PartridgeSent: 07 September 2008 14:56To: 'Discussion of precise time and frequency measurement'Subject: [time-nuts] Ancient OCXO in scope calibrator.I'm having some problems with an ancient Bulova OCXO in a Tektronix 184'scope calibrator. This is an crystal mounted on an octal valve base with a heater windingwrapped round it, and a common or garden variety thermostat which issupposed to switch at 75 celsius. I've not measured the switchingtemperature, as I don't have the means but the outer case does get fairlywarm (40 plus degrees?). The oven is turning on and off.It is used in a circuit with a 7587 Nuvistor tetrode (yes it's a valve/tubecircuit). The crystal is connected cathode to G1 with a trimmer capacitorof 3-12pF. The signal at the cathode is supposed to be about 70V p-p.I'm measuring the frequency of the signal after the transformer stage whichcouples it to the first stage of a countdown board.For the first minute or so after turn on from cold, it sits below 10MHz andis fairly stable and climbing as the oven warms up, and I can adjust thefrequency up towards 10MHz with the capacitor (but not all the way), thensuddenly, at the stage where it is starting to look as if it will soonstabilise at about the right frequency, it jumps to way over 10MHz and thelowest I can get it down to with the capacitor is about 10.0003xxx MHz wherexxx is not very stable at all - in fact it can vary up to to 10.0005xxx anddown to 10.0002xxx.I've tried freeze spray on most of the components round there to no effect.If I try to probe the signal at the cathode of the nuvistor even with a highimpedance active probe with a P6201 with a 100x attenuator (about 1pFloading IIRC) the oscillation just drops dead.Now for calibrating 'scopes, it doesn't need to be any more accurate than itis (30ppm) - but ...Do any of the collected mavens have an explanation for the behaviour, andrecommendations for fixing things?CheersDave_______________________________________________time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go tohttps://www.febo.com/cgi-bin/mailman/listinfo/time-nutsand follow the instructions there.------------------------------_______________________________________________time-nuts mailing listtime-nuts at febo.comhttps://www.febo.com/cgi-bin/mailman/listinfo/time-nutsEnd of time-nuts Digest, Vol 50, Issue 12*****************************************


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