[time-nuts] time-nuts Geller 10 volt ref. modification.

Helge Kyndbo kyndbo at gmail.com
Sat Nov 29 09:46:36 UTC 2008


Geller 10 volt ref.

Hello WarrenS,
Is it possible to have some details of your 1 transistor 1st order
temperature modification,
on the Geller 10 volt ref. ?

Helge



2008/11/29 <time-nuts-request at febo.com>

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> Today's Topics:
>
>   1. Re: Calibration and temperature (Lux, James P)
>   2. Re: Voltage standards (Bruce Griffiths)
>   3. Re: Voltage standards (WarrenS)
>   4. Re: any way to bootstrap a frequency standard, into a,
>      voltage or resistance standard? (Ed Palmer)
>   5. Re: Cesium vs H Maser clocks (Tom Van Baak)
>   6. Re: Cesium vs H Maser clocks (Brian Kirby)
>   7. TBolt TC recs wanted (Richard Moore)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 28 Nov 2008 19:52:35 -0800
> From: "Lux, James P" <james.p.lux at jpl.nasa.gov>
> Subject: Re: [time-nuts] Calibration and temperature
> To: Discussion of precise time and frequency measurement
>        <time-nuts at febo.com>
> Message-ID: <C555FC83.2F5E%James.P.Lux at jpl.nasa.gov<C555FC83.2F5E%25James.P.Lux at jpl.nasa.gov>
> >
> Content-Type: text/plain; charset="iso-8859-1"
>
>
>
>
> On 11/28/08 11:27 AM, "Bill Hawkins" <bill at iaxs.net> wrote:
> >
> > Has any work been done on temperature compensation of quartz or other
> > oscillators to avoid the expense, space, and power of ovens? The
> > oscillating material must have a repeatable temperature curve, of
> > course.
> Look at MCXOs, a very clever technique using the different between third
> overtone and fundamental to measure the temperature of the rock.
>
>
> Jim Lux
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Sat, 29 Nov 2008 17:12:40 +1300
> From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
> Subject: Re: [time-nuts] Voltage standards
> To: Discussion of precise time and frequency measurement
>        <time-nuts at febo.com>
> Message-ID: <4930C138.3020105 at xtra.co.nz>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Richard Moore wrote:
> > What to do? Seems like a possible stable, yet low-cost source would
> > be to buy 10 or so LM399s and hook them up to a power supply to age
> > for 6 to 12 months, then use two or four in parallel (with suitable
> > resistor buffering) driving a chopper amp like the LT1050 to give
> > gain. Powered by a good, stiff regulated supply, and kept away from
> > stray air currents, this arrangement wouldn't cost as much as a
> > single LTZ1000A (which in singles is over $100 USD)
> LTZ1000A list price is about $54 (excluding freight and taxes) when
> ordering from Linear Technology.
> The LTC1050 is a bit marginal unless you bootstrap its power supply the
> LTC1151 is a better fit.
> >  and -- dang it,
> > there's always a catch -- after lab calibration, could be a source
> > that might need adjustment only once every few years to stay within 5
> > or 10ppm or so. Paralleling more LM399s would be better, and with an
> > initial purchase of 10, you could throw away the stinkers and
> > parallel all the rest. So, short of having a Fluke 732A or those
> > 8-1/2 digit meters, that's my recommendation for a low-cost V
> > standard. Unless you know someone, it'll cost less to build than to
> > calibrate...
> >
> > Dick Moore
> >
> >
> >
> Bruce
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Fri, 28 Nov 2008 20:51:12 -0800
> From: "WarrenS" <warrensjmail-one at yahoo.com>
> Subject: Re: [time-nuts] Voltage standards
> To: "Discussion of precise time and frequency measurement"
>        <time-nuts at febo.com>
> Message-ID: <029701c951de$1adadb70$6401a8c0 at WSOffice>
> Content-Type: text/plain;       charset="iso-8859-1"
>
>
> Just to add my experiences and throw in another two cents worth.
> I live in California,  and a few years back I did some experiments
> with Geller on the East coast shipping back and forth some of his 10V
> References in the regular mail that I had added a simple 1 transistor
> 1st order Temperature compensation circuit to some of his selected aged
> units and proved to my satisfaction that better than 2PPM transfer
> accuracy was obtained across the country. In house I can consistently
> get better than 1 PPM transfer with the same units. Of course there
> are more accurate ways, but for us cheap guys It sure beats the $500
> I heard Fluke charges to do their underlying Fluke 732B calibration.
>
> WarrenS
> *********************
>
> RE  Message 8 and a couple of earlier posts on standards
>
> > Date: Sat, 29 Nov 2008 10:38:53 +1300
> > From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
> > Subject: Re: [time-nuts] any way to bootstrap a frequency standard
> >  into  a, voltage or resistance standard?
> > To: Discussion of precise time and frequency measurement
> >  <time-nuts at febo.com>
> > Message-ID: <493064ED.1030501 at xtra.co.nz>
> > Content-Type: text/plain; charset=ISO-8859-1
> >
> > WB6BNQ wrote:
> >> Ed,
> >>
> >> No way in hell does that thing qualify as a voltage standard.  It
> >> barely qualifies as a VERY short term transfer device assuming the
> >> temperature does not change.
> >>
> >> If you want a real voltage reference then buy, from eBay, a Fluke
> >> 731B voltage standard.  You will still need to get it calibrated,
> >> but then it will hold under 10ppm for well over a year or
> >> more.  Actually, if they are adjusted correctly, you can get less
> >> than 5ppm and it will hold it at a given temperature.  These items
> >> are serious devices and their latest versions (very expensive)
> >> are better than a properly maintained and operated group of
> >> standard cells.
> >>
> > The latest Fluke voltage standards use a selected LTZ1000 plus a
> > precision resistor array.
> > The earlier versions used selected Motorola zener diode references.
> > The latest versions allow the LTZ1000 chip temperature to be cycled to
> > largely eliminate hysteresis which may occur when they lose power
> > during
> > shipment.
> >> Bill....WB6BNQ
> >
> > Bruce
>
> Since we've kinda strayed from the original topic, I'll throw in a
> couple of cents. The V references in these 6-1/2 and 7-1/2 digit DMMs
> (that I currently own at least one each of):  Keithley 196, HP 3456,
> 3457, and 34401, use selected -- some more than others -- National
> LM199/299/399 series references, which have their own heaters. The
> Datron 1080 series (that I own two of), as well as the 1070 series
> and 1060 series, use selected pairs of zeners connected in parallel,
> but not housed in ovens. The Fluke 8502/05/06 (and my Fluke 510A ACV
> std) use the aforementioned Motorola transistor+buried zener
> reference, also not in ovens.
>
> The HP 3458, as mentioned before, uses the Linear LTZ1000/1000A,
> which has its own heater. As to others, the old Fluke 895A, 887A, and
> 885A 6-digit analog Differential Meters (with K-V bridges for
> comparing the reference to the unknown in various ways), all use a
> pair of zeners in series, in an oven. A Fluke engineer told me years
> ago that those zeners were selected to have slightly different TC
> peaks so when one was falling in V the other was rising, so that they
> would spread the peak over a larger temperature range. They had a
> very elaborate automated system for testing the temp, voltage, and
> current values to do the pairing.
>
> My Fluke 732A DC reference standard, which uses the Motorola
> transistor+buried zener reference, housed in an oven together with
> all of the various fixed and variable resistors and the other active
> devices, has an extremely low drift rate -- unmeasurable over a month
> in any definitive way -- as measured with a rented HP 3458A. I have
> disabled the batteries because I discovered, thanks to the 3458A,
> that when turned off, cooled off, and turned back on, within a day,
> the output returned within 0.05ppm to it's cal'd value -- I know
> there can be hysteresis, I just couldn't see it.
>
> I have one of the little Geller 10V refs built around the AD587
> reference chips, and if you keep it enclosed and away from air
> currents, it's pretty stable, but would need to be in an oven to
> approach the performance of the LM199 series.
>
> All this is to say that if you can get a working HP 3458A or a Datron
> 1280 series (which is also the Fluke 8805), or a Datron 1270 series
> meter, all of which are self-calibrating in various ingenious ways,
> it will serve you well as a secondary standard for measurement on
> everything that  it can measure. I can't, or more properly, won't at
> the moment, spend the current freight of around $4,000 USD for a
> known good working 3458 or 1281.
>
> What to do? Seems like a possible stable, yet low-cost source would
> be to buy 10 or so LM399s and hook them up to a power supply to age
> for 6 to 12 months, then use two or four in parallel (with suitable
> resistor buffering) driving a chopper amp like the LT1050 to give
> gain. Powered by a good, stiff regulated supply, and kept away from
> stray air currents, this arrangement wouldn't cost as much as a
> single LTZ1000A (which in singles is over $100 USD) and -- dang it,
> there's always a catch -- after lab calibration, could be a source
> that might need adjustment only once every few years to stay within 5
> or 10ppm or so. Paralleling more LM399s would be better, and with an
> initial purchase of 10, you could throw away the stinkers and
> parallel all the rest. So, short of having a Fluke 732A or those
> 8-1/2 digit meters, that's my recommendation for a low-cost V
> standard. Unless you know someone, it'll cost less to build than to
> calibrate...
>
> Dick Moore
>
>
>
> ------------------------------
>
> Message: 4
> Date: Fri, 28 Nov 2008 23:18:39 -0600
> From: Ed Palmer <ed_palmer at sasktel.net>
> Subject: Re: [time-nuts] any way to bootstrap a frequency standard,
>        into a, voltage or resistance standard?
> To: time-nuts at febo.com
> Message-ID: <4930D0AF.9050708 at sasktel.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Bill,
>
> I agree with the comments made by you and everyone else.  That's why I said
> "..if it's good enough..".  But there's one thing that kind of slid by
> everyone.  All the other suggestions conclude with some variation of
> "..needs to be calibrated..".  Is there any other way to get a
> NIST-traceable voltage into your shop for $35?  (I'm not challenging you,
> I'd really like to know if there is another alternative)  Granted, it's only
> at the 10 uv level, but for many applications that *is* good enough.
>
> Let's be honest, as time-nuts we're spoiled rotten.  Almost all of us have
> got rubidium standards at 10E-11 per day or better and at a ridiculously low
> price.  Many have got cesium standards and a few have got hydrogen masers.
>  We can calibrate them against GPS or Loran-C to obsessive-compulsive
> levels.  So far, none of the other physical standards allow that level of
> independence for hobbyists.  So when dealing with other measurement units
> (e.g. volts, ohms, etc) we either have to ease the requirements by orders of
> magnitude or increase the budget by orders of magnitude!
>
> If you're doing this as part of your job and can justify the need and the
> expense - great!  I'm a hobbyist and I won't be spending $1843 any time soon
> to have NIST calibrate a DC solid-state voltage reference.  For my needs
> Geller Labs provides good value for the very nominal cost.
>
> And just to be clear, I have no relationship with Geller Labs.
>
> Ed
>
> WB6BNQ wrote:
>
> > No way in hell does that thing qualify as a voltage standard.  It barely
> qualifies as a VERY short term transfer device assuming the temperature does
> not change.
> >
> > If you want a real voltage reference then buy, from eBay, a Fluke 731B
> voltage standard.  You will still need to get it calibrated, but then it
> will hold under 10ppm for well over a year or
> > more.  Actually, if they are adjusted correctly, you can get less than
> 5ppm and it will hold it at a given temperature.  These items are serious
> devices and their latest versions (very expensive)
> > are better than a properly maintained and operated group of standard
> cells.
> >
> > I completely disagree with Brian about buying any standard cells.
>  Whatever voltage value they had is lost upon shipment.  Shaking the cells
> changes the value and it will not return to the
> > original value.  If you did have a set of cells, you would want at least
> 4 of them.  Then study statistical math all over again because you will need
> it to use the cells.
> >
> > As Brian does suggest, you would be much better off picking up a hp3456A,
> 3457A, 3458A or getting one of Fluke 8500 series if it has the Ohms and AC
> options included.  The basic Fluke 8500 series
> > is DC only mainframe.
> >
> > Measuring your resistors, using one of the above DVMs, in the 4-wire mode
> is about the best you could possibly do.  To do any better would require
> some very serious effort.
> >
> > By the way you could buy several of the latest and greatest Fluke super
> DVMs for the cost of what it would take to do a Josephson array and still
> have money left over to fund that divorce.
> >
> > Bill....WB6BNQ
> >
> >
> > Ed Palmer wrote:
> >
> >
> >> It's nowhere near the idea of a Josephson array, but if a NIST-traceable
> 10V +-10uV reference is good enough to satisfy your voltage-nut urges, you
> can buy it from www.gellerlabs.com for $35.
> >>
> >> I also have a few standard resistors (e.g. 1.000002 ohms) that I'd be
> interested in calibrating, but I can't seem to come up with a practical way
> of doing it.
> >>
> >> Frustrating, isn't it? :-)
> >>
> >> Ed
> >>
>
>
> ------------------------------
>
> Message: 5
> Date: Fri, 28 Nov 2008 22:30:33 -0800
> From: "Tom Van Baak" <tvb at LeapSecond.com>
> Subject: Re: [time-nuts] Cesium vs H Maser clocks
> To: "Discussion of precise time and frequency measurement"
>        <time-nuts at febo.com>
> Message-ID: <9FB14428535B4E0EAE3C34C33EE617F6 at pc52>
> Content-Type: text/plain; format=flowed; charset="Windows-1252";
>        reply-type=original
>
> > Isn't the temperature the _only_ thing to correct for?
>
> No, not at all. Read the links that I provided to see that a real
> cesium standard is not quite so simple, at least when you get
> down to the ten to the -13, -14, -15 levels. At that level there
> are all sorts of cool things that push or pull the frequency and
> need to be corrected for.
>
> > The definition of the second is "...the duration of 9 192 631 770
> > periods of the radiation corresponding to the transition between the
> > two hyperfine levels of the ground state of the cesium 133 atom." (and
> > affirmed by the CIPM in 1997 that this definition refers to a cesium
> > atom in its ground state at a temperature of 0 K)
>
> Right. But realize that most of the cesium standards that we use
> are not running at 0 Kelvin. So there is a correction for that.
>
> In order for cesium beam standards to even work, one must apply
> a slight magnetic field, the so-called C-field, which rather strongly
> distorts the shape of the resonance peak. The definition assumes
> zero magnetic field, so this too must be modeled and corrected for.
> That's why, for example, the hp 5062c runs at 9,192,631,774.3133 Hz,
> not the textbook 9,192,631,770 Hz. An internal synthesizer takes
> care of this correction.
>
> The NIST papers list a dozen or so of these corrections, each of
> which is a nice lesson in atomic physics by itself.
>
> Note also that clocks at NIST run about 1.8e-13 fast due to the high
> elevation of Boulder, CO (general relativity), which is yet another
> factor that has to be corrected for compared to the official sea-level
> definition of the second.
>
> > That other factors can change the relative frequency of different Cs
> > clocks is a problem with the definition, not an indication that any
> > particular one is better than another. If a magnetic field changes the
> > relative frequency, but that isn't reflected in the definition, is it
> > not the definition which is faulty, and not the timepiece? The second
> > is imprecise in this regard.
>
> The definition is fine -- it applies to the ideal conditions. But if you
> decide to build an apparatus to implement the definition, and if for
> whatever reason the ideal conditions can't be met in your apparatus,
> then is it up to you, the clock builder, to anticipate this and make
> corrections for it so that your clock still counts SI seconds at the
> output BNC connector.
>
> The other thing to note is that most cesium standards come with a
> specification, based on design. I don't have the exact numbers but
> a 5061A might be accurate out-of-the-box to 1e-11 while a 5071A
> might be accurate to 1e-13. This reflects the difference in design,
> manufacturing tolerances, and the number of internal frequency
> offsets that are controlled or compensated for in hardware or in
> firmware. So the definition of the SI second is fine; it's just that
> some clocks can get closer to realizing the definition than others.
>
> /tvb
>
>
>
>
> ------------------------------
>
> Message: 6
> Date: Sat, 29 Nov 2008 01:25:39 -0600
> From: Brian Kirby <kirbybq at bellsouth.net>
> Subject: Re: [time-nuts] Cesium vs H Maser clocks
> To: Tom Van Baak <tvb at leapsecond.com>,  Discussion of precise time and
>        frequency measurement <time-nuts at febo.com>
> Message-ID: <4930EE73.5080903 at bellsouth.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> The clocks (rubidium and cesium) in the GPS satellites are also run at a
> different frequency because of their altitudes....
>
> Also magnetic field are different on the earth and they sometimes adjust
> the "C" fields to correct for these differences.
>
> >> Isn't the temperature the _only_ thing to correct for?
> >
> > No, not at all. Read the links that I provided to see that a real
> > cesium standard is not quite so simple, at least when you get
> > down to the ten to the -13, -14, -15 levels. At that level there
> > are all sorts of cool things that push or pull the frequency and
> > need to be corrected for.
> >
> >> The definition of the second is "...the duration of 9 192 631 770
> >> periods of the radiation corresponding to the transition between the
> >> two hyperfine levels of the ground state of the cesium 133 atom." (and
> >> affirmed by the CIPM in 1997 that this definition refers to a cesium
> >> atom in its ground state at a temperature of 0 K)
>
>
>
> ------------------------------
>
> Message: 7
> Date: Sat, 29 Nov 2008 00:14:04 -0800
> From: Richard Moore <richiem at hughes.net>
> Subject: [time-nuts] TBolt TC recs wanted
> To: time-nuts at febo.com
> Message-ID: <604DA6FE-2511-4CBB-8D1B-2758A3FA5C58 at hughes.net>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
> Dear nuts -- What TBolt time constant setting have you found to work
> best for best frequency accuracy and-or stability?
>
> Dick Moore
>
>
>
> ------------------------------
>
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