[time-nuts] Fluke/Gigatronics 6060 series (6062A specifically) output amplitude cal constants
Does anyone know the procedure for resetting the output level constants in these generators? The manuals I’ve found are silent on this, but it was obviously done at the factory… Mine needs levelling. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Fluke 6061A Synth. RF Generator
Hi All -- Sorry if this is off-topic, but you all have a lot of experience with equipment. I just picked up a 6061A and I'm happy to say it mostly works. But... at frequencies below 250 MHz, as the frequency output is decreased, the level drops too, and starting from +12dBm (rated out, more-or-less), by 20MHz, the positive peak of the sine wave is flattening -- this progression of level drop and increasing distortion keeps on until the bottom at 10kHz, where the level is over 4dB low and distortion is fairly significant. I'm a complete novice to this instrument and to synthesizers in general. I can use some tips about what circuits or parts might be causing this, or where to look to start on a fix. I do have a manual with schematics. I seem to recal reading that there is a Low Band circuit that works at 245MHz and below, so it seems like that may be where to start looking. Any and all suggestions appreciated. I welcome off-list comments if that seems most appropriate. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Fluke 5440B Service Manual?
Hi, time-nuts. I know some of you are volt-nuts, too. I just got a Fluke 5440B DC Calibrator, which is a lovely instrument, and the service manual on the Fluke site has parts, layout and schematic pages out of order and/or completely missing (the operating manual seems to be OK). I know this because I forgot I had a guard lead hooked up to the scope and then I connected scope ground to the isolated chassis, causing a bad smell, a couple of blown fuses, and an unknown to me (so far) failure. In troubleshooting, I discovered the sad mess of the manual Fluke provides for free download. In one of the pages that is there, in BOLD CAPS it says not to do what I did I checked with all the usual suspects on-line and no pdf book that I know to be good is available. There is a hard copy original available for $175, but I think that's a bit much. If any of you have one or know of one I can copy, or one in pdf, I would be *most* glad to have it. Best, Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lady Heather Win port
John and Mark -- Thanks. I'm running it fine under XP sp3. I had to change my USB>serial port adapter's port number using the device manager in Windows. LH couldn't find port 1 unused (it wasn't - default allocated to comms), and would fail to boot. I couldn't figure out how to get into the shortcut's command line system to reconfig the port number. Once I got port 1 cleared, LH booted OK. The display is great looking. I booted it last night and went to bed; MS updated the system overnight and re-booted automatically, so I lost data. Am rerunning now. Good work! Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Bill Ezell's ftp
Mark (and Bill), I had to use my FTP client (Transmit) to get to anything. Using the browser did not work -- took me to an empty folder named "pub". Everything is there when I connect using Transmit on my iMac. Thanks Bill, for all the work! Greatly appreciated. Dick Moore On Feb 1, 2009, at 1:39 PM, time-nuts-requ...@febo.com wrote: > Message: 7 > Date: Sun, 01 Feb 2009 14:07:32 -0500 > From: wje > Subject: [time-nuts] Some pics of the Datron 491x DC reference cell > To: Discussion of precise time and frequency measurement > > Message-ID: <4985f2f4.8070...@quackers.net> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > I've uploaded some photos of the Datron 10 volt cell and reference > board, as requested by a few members. > I've kept them full-resolution so you can see fine detail. But, that > means they are about 3 mb each. > The schematics for the cell board I previously posted are also > still on > the FTP site. > > DatronCell.jpg is an image of the entire cell board. The reference > board > is piggybacked on it. Note the thermal shield around the LTZ1000, and > the completely shielded sections on the board. Those contain the > digital > circuitry. The cell board itself goes into a shielded enclosure along > with the other three cells and the output buffer amp. > > DatronLTZCloseup.jpg is exactly that, a closeup of the LTZ with > thermal > shield removed. The interesting detail here is the mounting. Note the > cutouts on the board to provide thermal isolation. This board is also > very thin; I didn't measure it, but it's on the order of 0.5 - 1 mm > thick. > > DatronRefCloseup.jpg is a closeup image of the rest of the > reference board. > > The ref board is permanently soldered in place on the cell board, so I > can't show the back of it. > > The ftp login is: > > ftp ftp.quackers.net > login: f...@quackers.net > password: (none required) > > Or, directly from a browser. I know this works for Firefox, I haven't > tried it with anything else: > > ftp://f...@quackers.net:f...@ftp.quackers.net/ > > Some of you are also waiting for the schematic for the LTZ board > itself; > I'm recreating it now (since I lost it) and will post when ready. > > -- > Bill Ezell > -- > They said 'Windows or better' > so I used Linux. > > > > > -- > > Message: 8 > Date: Sun, 1 Feb 2009 21:29:55 + > From: Mark Sims > Subject: [time-nuts] Some pics of the Datron 491x DC reference cell > To: > Message-ID: > Content-Type: text/plain; charset="Windows-1252" > > > I tried to access the photos... got to an empty pub directory... > > Cutouts in a circuit board around a reference chip are usually more > to relieve mechanical stress from the chip package caused by the PC > board expanding/contracting/warping. This stress can affect the > refereence voltage more than you might expect. Malone does this on > his little Xicor X6008C voltage reference boards. (BTW that chip > has been discontinued). That is why I prefer his boards over the > other one that is available on Ebay that does not cut out around > the ref chip. If you can live with that, you can get a packaged > 5V / 0.01% reference for $14.50 shipped... see Ebay item > 250366551770... the guy that builds them is closing them out... > and he ships worldwide. > _ > Windows Live? Hotmail??more than just e-mail. > http://windowslive.com/howitworks? > ocid=TXT_TAGLM_WL_t2_hm_justgotbetter_howitworks_012009 > > > -- > > Message: 9 > Date: Sun, 1 Feb 2009 16:39:47 -0500 (EST) > From: "Richard W. Solomon" > Subject: [time-nuts] Lady Heather Question > To: time-nuts@febo.com > Message-ID: > <29501338.1233524387396.javamail.r...@mswamui- > chipeau.atl.sa.earthlink.net> > > Content-Type: text/plain; charset=UTF-8 > > Having failed to get the program working properly on an old 486 > Laptop, > I installed it on a more modern machine running XP. When I try to open > the program I get an error message about Com Port Not Available ?? > > How does one select the COM Port ? > > Thanks, Dick, W1KSZ > > > > -- > > ___ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > End of time-nuts Digest, Vol 55, Issue 4 > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPSDO TC & Damping
On Jan 9, 2009, at 2:24 AM, time-nuts-requ...@febo.com wrote: > Message: 2 > Date: Fri, 09 Jan 2009 10:27:05 +0100 > From: Magnus Danielson > Subject: Re: [time-nuts] GPSDO TC & Damping > > Dick, > >> Well, like many here, I don't actually have the equipment, especially >> the reference std., to do these MDEV, ADEV and other analyses, so, >> since I use the GPSDO for a frequency standard and not for UTC, I >> thought I'd get the expert opinions. Magnus has several times >> indicated here that a TC laying somewhere in and around 100 to 1000 >> secs is probably optimum. > > I think you have misinterpreted my postings. I never claimed it was > optimum, or at least never intended to. I think 100 secs is good for > doing additional experiments with damping parameters. It would be > interesting to see just how low the bulb may go. This only since it is > obvious that it makes such a clear difference at 100 secs. It's a > choice > out of measurement and interpretation practicality, not optimum from a > use perspective. If you consider my postings you would see that I > rather > promote the concept of adjusting the time constant dynamically to > situations rather than say 1234.5678 seconds is the optimum. > > Cheers, > Magnus Sorry, Magnus, I didn't mean to put words in your mouth. I was remembering last Fall, when you suggested that people look at your ADEV plot and to be mindful of the of the bounding slopes of the curves. If I've mis-remembered the emphasis or the facts, I do apologize. I thought your argument then, as I remember it, was strong and valuable. Seems like it gave a good range of possible values to use for Tau in the measurements. I probably won't go far beyond the capabilities of the TBolt, such as implementing a PID controller with dynamic control of variables using a microcontroller and LPGAys and writing my own software, but I love it when you talk that way. Best, Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPSDO TC & Damping
On Jan 9, 2009, at 12:10 AM, time-nuts-requ...@febo.com wrote: > Message: 4 > Date: Fri, 09 Jan 2009 19:18:57 +1300 > From: Bruce Griffiths > Subject: Re: [time-nuts] GPSDO TC & Damping >> Well, like many here, I don't actually have the equipment, especially >> the reference std., to do these MDEV, ADEV and other analyses, so, >> since I use the GPSDO for a frequency standard and not for UTC, I >> thought I'd get the expert opinions. Magnus has several times >> indicated here that a TC laying somewhere in and around 100 to 1000 >> secs is probably optimum. When I enquired some time back about >> damping in the TBolt, the consensus seemed to be "leave it at 1.2". I >> have, but it just seems to me that won't be optimum for a fixed- >> position, lab-located frequency standard -- at the moment, I'm >> leaning toward the 0.7to 1.0 area. >> >> > Why, since it has been demonstrated that a damping factor of 1.2 is > better than one of 0.7 for a particular Thunderbolt this would tend to > indicate that adjusting the damping without good justification is > somewhat foolhardy. > If in fact the phase noise characteristics of your OCXO are similar > toi > the one in the Thunderbolt that Tom measured this would degrade the > performance. > > With no way of measuring the effect of such adjustments you are just > hoping that your particular Thunderbolt is similar to the one Tom > measured. > Thats not engineering its more like witchcraft. > >> Tom's recent chart was quite helpful, especially the 1000 sec curve. >> Now, I hope that Tom or someone else follows up on the suggestion to >> track performance vs. damping factor. I do understand that the >> results for any one GPSDO don't *necessarily* translate to other >> devices, but they don't necessarily don't, either. At least for the >> TBolts a lot of us are playing with, one good example (like Tom's) >> may well put mine in a better ballpark than the ballpark the factory >> wants it to play in, given the factors that you all have described. >> Thx everyone for the comments. Look forward to the next round! >> >> Dick Moore >> > The probability that you will improve the performance significantly > without a means of measuring the resultant performance is fairly low. > You will never know if either an improvement or a degradation in > performance has occurred. > The one saving grace being that the factory defaults can always be > restored. > > Bruce Bruce, thx for the reminder -- my friend and mentor Paul W. Klipsch was fond of saying that "You can't make what you can't measure 'cause you don't know when you've got it made!" At the same time, all sorts of wonderful things have come about thru just fooling around. Again, I remark that for all the reasons Tom enumerated -- er, listed -- the manufacturer's choice of settings may not be the best choice for a particular use. When in a strange country, local enquiry is usually recommended. For GPSDOs, a strange country to me, what better place to enquire than here? Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPSDO TC & Damping
On Jan 8, 2009, at 2:46 PM, time-nuts-requ...@febo.com wrote: > Message: 1 > Date: Fri, 09 Jan 2009 10:28:35 +1300 > From: Bruce Griffiths > Subject: Re: [time-nuts] GPSDO TC > To: Discussion of precise time and frequency measurement > > > Richard Moore wrote: >> On Jan 8, 2009, at 2:58 AM, time-nuts-requ...@febo.com wrote: >> >> >>> Message: 6 >>> Date: Thu, 08 Jan 2009 11:51:50 +0100 >>> From: Magnus Danielson >>> Subject: Re: [time-nuts] GPSDO time constant >>> To: Tom Van Baak , Discussion of precise >>> time and >>> frequency measurement >>> >>> For ThunderBolt owners it is pretty straightforward to adjust the >>> TC and >>> damping, which is very nice. Use this oppertunity! >>> >> >> So, Magnus (and Tom), what damping factor do you suggest for a TBolt? >> I'm running a verrry long TC now. If 1.2 is not actually critically >> damped, what value would be? Any guesses? BTW, I really like that >> plot of Tom's that tracks the oven and then gets better from the >> GPS... >> >> Dick Moore >> >> > Richard > > As always, the problem is how do you know that the time constant > you are > using is anywhere near optimum? > > > Bruce Well, like many here, I don't actually have the equipment, especially the reference std., to do these MDEV, ADEV and other analyses, so, since I use the GPSDO for a frequency standard and not for UTC, I thought I'd get the expert opinions. Magnus has several times indicated here that a TC laying somewhere in and around 100 to 1000 secs is probably optimum. When I enquired some time back about damping in the TBolt, the consensus seemed to be "leave it at 1.2". I have, but it just seems to me that won't be optimum for a fixed- position, lab-located frequency standard -- at the moment, I'm leaning toward the 0.7to 1.0 area. Tom's recent chart was quite helpful, especially the 1000 sec curve. Now, I hope that Tom or someone else follows up on the suggestion to track performance vs. damping factor. I do understand that the results for any one GPSDO don't *necessarily* translate to other devices, but they don't necessarily don't, either. At least for the TBolts a lot of us are playing with, one good example (like Tom's) may well put mine in a better ballpark than the ballpark the factory wants it to play in, given the factors that you all have described. Thx everyone for the comments. Look forward to the next round! Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPSDO TC
On Jan 8, 2009, at 2:58 AM, time-nuts-requ...@febo.com wrote: > Message: 6 > Date: Thu, 08 Jan 2009 11:51:50 +0100 > From: Magnus Danielson > Subject: Re: [time-nuts] GPSDO time constant > To: Tom Van Baak , Discussion of precise time and > frequency measurement > >>> > For ThunderBolt owners it is pretty straightforward to adjust the > TC and > damping, which is very nice. Use this oppertunity! So, Magnus (and Tom), what damping factor do you suggest for a TBolt? I'm running a verrry long TC now. If 1.2 is not actually critically damped, what value would be? Any guesses? BTW, I really like that plot of Tom's that tracks the oven and then gets better from the GPS... Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TBolt antenna
On Jan 7, 2009, at 2:43 PM, time-nuts-requ...@febo.com wrote: > > Message: 6 > Date: Wed, 7 Jan 2009 17:08:22 -0500 > From: "Ronald Held" > Subject: [time-nuts] TB PS/Antenna recommendations > To: time-nuts@febo.com > Message-ID: > <9a86fb0e0901071408r4a205518mc346d7694f9af...@mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > I have not following all of discussions for a while, so perhaps I > missed out on some of this. What do people suggest for a power supply > and from where? The harder request is for an indoor antenna probable > placed up against the window. Reliable dealers or stores would be very > helpful. > Ronald > I'm using a fairly crappy triple-output open-frame Autec supply from Marlin P. Jones that was $13. I'm not recommending it, but it works. My antenna is an active patch type by Hawk that runs off +5V from the TBolt. It has a magnetic base for top of vehicle use. I've got it feeding two GPSDOs thru a splitter and it's working great. I got it from Synergy for $35 if I remember correctly -- been a while. I've got it duct taped to a 2x4 sticking our from under the eave of my lab. Most any active antenna will likely work OK outdoors, but I don't know about indoors -- think you'll want some higher gain version. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] ESI 290A Z-bridge schematics needed
Hi, nuts: I have an operating manual for my ESI 290A impedance bridge, but I need the schematics. If any of you have them or know where I can get them, please drop me a line. Best, Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Solstice at Newgrange
> A visit to this site, which I make every day I can, and to this > particular page, will answer many questions and raise many more: http://antwrp.gsfc.nasa.gov/apod/ap081220.html Dick Moore > > > -- > > Message: 5 > Date: Mon, 22 Dec 2008 16:19:19 +1300 > From: "Steve Rooke" > Subject: Re: [time-nuts] Solstice question, about 5000 years ago > To: "Discussion of precise time and frequency measurement" > > Message-ID: > <1231b6a80812211919g36e5d363k90d8ad994d99e...@mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > Michael, > > 2008/12/22 Michael Sokolov : >> Bill Hawkins wrote: >> >>> The passage grave at New Grange, Ireland, is one of those >>> astronomical >>> wonders where the rising sun at winter solstice shines down a >>> relatively >>> long tunnel to shine on carved stone at the far wall of a chamber. >>> >>> We know that solstice has the shortest day and the longest night. >>> >>> How'd they know that? >> >> I'll abstain from answering the last question, but I'm more >> interested >> in a different question: from what I understand, the exact shape >> of the >> analemma depends on the misalignment between the line of apses >> (aphelion >> and perihelion of Earth's slightly eccentric orbit) and the solstices >> and equinoxes defined by Earth's obliquity. These things do >> change very >> slowly over the course of millennia, don't they? Isn't that change >> significant enough that the correct stone alignment would be >> different >> between today and 5000 y ago? If they got it right 5000 y ago for >> their >> epoch, why does it still work now? Hasn't the analemma shifted far >> enough to break the alignment? > > This is a very interesting point, of course, so this is my 2c worth:- > > 1) We talk about nano/pico/femto second differences here but I wonder > just how far the analema has shifted in the 5000 years and just how > much difference it would make physically to this location in Ireland. > I assume the slit of light that shines through the passage is not > microns wide and the target, similar. It may be that the change only > makes a small physical difference and is within the accuracy > percentage of the measuring instrument, being The Passage Grave. > > 2) Is it possible that any shift in the analema may be circular over > that time and has reverted to it's position of 5000 years ago. > > 3) Bill said that this alignment is noted at rising sun on the winter > solstice. Is it possible that originally the alignment was at a > different time of the day, say, mid-day which would seem to be a > better target to aim for. > > 4) Stonehenge dates from about the same time and there is a suggestion > that this has an astronomical connection. If that is the case, it > would also be affected by any shift in the analema but I wonder how > much physical difference that would make considering, what appears to > me, to be an instrument with quite a degree of accuracy latitude. > > 73, Steve - JAKDTTNW (yes, I got it right this time, said I was a > troglodyte :-) > -- > Steve Rooke - ZL3TUV & G8KVD > Omnium finis imminet > > -- > > Message: 8 > Date: Sun, 21 Dec 2008 19:38:11 -0800 > From: Brooke Clarke > Subject: Re: [time-nuts] Solstice question, about 5000 years ago > To: Discussion of precise time and frequency measurement > > Message-ID: <494f0ba3.9020...@pacific.net> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hi: > > Isn't it the case that if the tilt of the Earth's spin axis is the > same now as > it was 5,000 years ago that the Sun will shine through the tunnel > at the > Solstice independent of any time or calender changes between then > and now. > > If, the tilt axis has changed then all bets are off. > > > Have Fun, > > Brooke Clarke > http://www.prc68.com > > Steve Rooke wrote: >> Michael, >> >> 2008/12/22 Michael Sokolov : >>> Bill Hawkins wrote: >>> The passage grave at New Grange, Ireland, is one of those astronomical wonders where the rising sun at winter solstice shines down a relatively long tunnel to shine on carved stone at the far wall of a chamber. We know that solstice has the shortest day and the longest night. How'd they know that? >>> I'll abstain from answering the last question, but I'm more >>> interested >>> in a different question: from what I understand, the exact shape >>> of the >>> analemma depends on the misalignment between the line of apses >>> (aphelion >>> and perihelion of Earth's slightly eccentric orbit) and the >>> solstices >>> and equinoxes defined by Earth's obliquity. These things do >>> change very >>> slowly over the course of millennia, don't they? Isn't that change >>> significant enough that the correct stone alignment would be >>> different >>> between today and 5000 y ago? If they got it right 5000 y ago >>> for their >>> epoch, why does it sti
Re: [time-nuts] Speedometers -- bah, humbug
Shortly after I bought my '97 VW Eurovan Camper in late '97, I noticed that it was reading higher than I was going as timed by stopwatch and mile markers. I kept measuring from time to time to sort of average things out. I finally complained to the dealer that it was about 5% high. After a lot of incidental discussion about tire sizes, air pressure, etc. they called VWoA. The answer? The Feds then required the speedometer to read not less than 2% nor more than 8% high -- oddly enough, 5% is the mean of this variance. I don't know what's required now. My '02 Toyota Highlander reads a tad less than 1% high, based on readings from my Garmin eTrex. Dick Moore On Dec 21, 2008, at 9:34 AM, time-nuts-requ...@febo.com wrote: > Message: 3 > Date: Sun, 21 Dec 2008 15:23:13 +0100 > From: Predrag Dukic > Subject: Re: [time-nuts] How good is my T-bolt...?? > To: Discussion of precise time and frequency measurement > > Message-ID: <7.0.1.0.1.20081221151908.01e43...@tapko.de> > Content-Type: text/plain; charset="us-ascii"; format=flowed > > Mike, > Thunderbolt is going to bring You from NY to SF at exactly 55MPH > AVERAGE, down to the fraction of the INPH, and still there is a > possibility that You earn a speeding ticket or two (or more) on the > way. > > Predrag Dukic (also not an expert, but things are not that simple > as Your question) > > > -- > > Message: 9 > Date: Sun, 21 Dec 2008 10:34:49 -0700 > From: "Robert Darlington" > Subject: Re: [time-nuts] Thunderbolt Accuracy needs... > To: "Discussion of precise time and frequency measurement" > > Message-ID: > > Content-Type: text/plain; charset=ISO-8859-1 > > And faster speedometers make your warranty run out faster, which > nobody > except the car companies like. > > On Sun, Dec 21, 2008 at 10:21 AM, Magnus Danielson < > mag...@rubidium.dyndns.org> wrote: > >> Thomas A. Frank skrev: >>> On Dec 20, 2008, at 6:03 PM, Burt I. Weiner wrote: >>> I suppose a good comparison would be: How accurate does the speedometer in the car really need to be and why. >>> >>> Accurate enough so that if its reading matches the posted sign, you >>> don't receive a ticket? >> >> An engineer pointed out that due to the spreading of readings on >> various >> speedometers un-necessary take-overs where performed by those >> having a >> higher speed for the same reading than those having a lower speed for >> the same reading. Thus, the precaution is to some degree >> compromised by >> the lack of consistency in the degraded reading. This is further >> compromised by people knowing their speedometers is degraded, so they >> form their own rules of how to interprent them in a favorable >> fashion. >> The tires and air pressure in them comes in as things compromising >> the >> scale. My speedometer gives different readings on my summer-tires >> than >> my winter tires. >> >> I think I actually prefer more exact speedometer in all cars. Then >> there >> is less room for subjective judgements and less of a discussion >> altogether. >> >> I think we already did some work in a similar fields like weigth, >> lengths and time... >> >> I learned alot of what my speedometer told me when looking at my >> TomTom >> reading. >> >> Cheers, >> Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Manuals
On Dec 9, 2008, at 6:20 PM, Daun wrote: > -- > > Message: 5 > Date: Tue, 9 Dec 2008 20:43:10 -0500 > From: "Daun Yeagley" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Manuals > > Hi Dick > > You might try Dave at Artek Media http://www.artekmedia.com/ (or > email to > [EMAIL PROTECTED]). He's active on the > [EMAIL PROTECTED] list. I know he has literally > *tons* > of HP manuals, because he picked them up from my barn where I've been > storing them since saving them from the dumpster for the Dayton > Sales office > several years ago. (they were pitching the entire collection, and I > couldn't > bear the thought of loosing all those manuals). I think they've > now found a > good home with Dave, as he seems to really be in the spirit of > keeping the > older manuals available. His prices are pretty reasonable too! > > Daun Thanks, Daun -- I searched Dave's lists but didn't find it, but I have not asked him about it directly. It may be something he has but has not yet scanned, so I'll drop him a note. I've done a fair amount of business with Dave (just got a Fluke 853 book from him two days ago) and he's top-notch. I also looked at all of his competitors that I am aware of, and none of them had it either. I figure, if all else fails, go to time-nuts. Best, Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Manuals
Hi, tickers -- I recently picked up an HP 5353A plug-in for my HP 5345A. It's enroute now and is untested. I hate to pay twice as much for a manual as I did for the unit, and I really like having docs on stuff. I've visited all the usual suspects -- Didier, Boat-Anchor, TekNet, etc. -- and have found nothing. Anybody have one I can copy? Best, Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Ulrich, re PRS10
Ulrich, at the Stanford site, I found the manual for the PRS10 -- thanks for the link. The manual has very thorough descriptions of the circuits, but doesn't have schematics -- which I thought was kind of odd. Do you have schematics or does any one here? Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] DM5010
On Dec 2, 2008, at 1:01 PM, [EMAIL PROTECTED] wrote: > Message: 1 > Date: Tue, 02 Dec 2008 11:26:34 -0800 > From: "Burt I. Weiner" <[EMAIL PROTECTED]> > Subject: [time-nuts] Tektronix DC-5010 DVM... > > Since we're on the subject of Digital Voltmeters, accuracy and such, > I'm wondering if anyone in the group has an opinion regarding the > Tektronix DC-5010 DVM. I just want a good, reliable bench DVM and > would like to be able to stuff it in my TM-5006 frame. Any thoughts > or suggestions? > > Burt, K6OQK > > Burt I. Weiner Associates > Broadcast Technical Services > Glendale, California U.S.A. > [EMAIL PROTECTED] > K6OQK Burt, if you don't need autoranging, then I recommend a DM501A, readily available on fleaBay. 4-1/2 digits in a single-wide chassis, and easy to cal, too. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt settings
On Dec 2, 2008, at 1:59 AM, Ulrich wrote: > Message: 6 > Date: Tue, 2 Dec 2008 10:59:05 +0100 > From: "Ulrich Bangert" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Thunderbolt settings > > Dick, > to be honest, I did even some more things concerning the TBolt. Find > attached the results of an measurement where the oscillator > disciplining > has been disabled and the internal PPS comparison has been logged over > some time. So it is free running OCXO vs. GPS. The falling slope in > the > left is much due to GPS jitter averaging out with longer observation > times. The ascending slope is much due to the OCXO reacting to > environmental conditions. This measurement would indicate that > 1000-2000 > s is a good value for the time constant. However, I did not have the > heart yet to use such a big value. Neveretheless I use 1200 s TC in my > DIY GPSDO made from an M12+ and an FTS1200. > > I think that also an clarification is necessary what exactly different > manufactures mean by "time constant". I am using the term "time > constant" in the same sense as Stanford Research do in their PRS10 > manual, where they talk about the pll's "natural time constant". > When a > sudden step in OCXO frequency is noticed by the pll it will react > to it > by changing the EFC voltage. It is exactly the "natural time constant" > that the pll needs to bring the OCXO frequency to its original value. > The pll reaction as a whole lasts much longer since it wants to bring > the phase difference back to zero. > > Best regards > Ulrich Ulrich, thanks so much. I have upped the Loop TC using the TBolt monitor sw to 4000.0 secs, a bit over an hour. I really have no idea what that actually means, but the TBolt seems to be happy. I have no way that I know of to do an Allan Var measurement, so I don't know if this is a sweet spot or not. In the plot (thanks for that) can I assume that disciplining will keep the right end of the slope falling for a while? Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] V standards
On Dec 2, 2008, at 12:25 AM, Bruce and PHK wrote: >> >> There was a recent Design Idea in EDN or Electronic Design (don't >> remember >> which one) where someone claimed 32 bit resolution out of two 16 >> bit dacs. That >> claim is ridiculous of course due to noise and matching etc, but >> you can >> probably get 20 - 24 bits resolution and accuracy out of a >> cascaded system with >> some care. >> >> bye, >> Said >> > If you build this circuit using the values shown in the schematic you > won't actually achieve 20 bits performance. > One of the resistor values is incorrect. > The resistor matching requirements aren't anywhere near as > stringent as > one may think on first glance. > With some subtle alterations to the operating mode the resistor ratio > matching tolerances can be relaxed considerably. > In closed loop digital control systems the circuit noise should be at > least 1LSB or so to maximise performance. > The trick is to increase the DAC resolution until this condition is > achieved and not increase the noise to meet the condition. > 20 bit resolution performance is easy to achieve, 24 bit performance > requires 2 a little more work. > > Actually monotonicity to about 26 bits was claimed with noise a bit > below 1ppm. > However since the noise varies with the DAC output such claims are > perhaps a little too simplistic. > The noise can be reduced when required by using a better reference. > Any drift in DAC gain and offset could be compensated by a Kalman > filter > should they become significant. > > The major advantage of such a DAC is the inherent monotonicity which > cannot be achieved and maintained (around coarse DAC transitions) > without frequent calibration when the outputs of 2 16 bit DACs are > combined. > > Bruce Bruce, is there a way for non-subscribers to see this article? Dick Moore > -- > > Message: 8 > Date: Tue, 02 Dec 2008 08:25:00 + > From: "Poul-Henning Kamp" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] V standards > >> Coarsedac changes are an issue as you mentioned, but one can get >> around them >> by scaling the two dacs in a way to only use a couple of bits from >> the >> coarsedac, and operate most of the time using just the fine dac. > > If you are controlling this with a microcontroller, there is an > alternative > you should consider: > > Use only a single DAC and then PWM modulate its output, followed > by a low-pass filter. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > [EMAIL PROTECTED] | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by > incompetence. > Poul, how do I PWM a DAC that is itself a PWM device? This question is prompted by the DAC I'm using in Bert Zauhar's FLL GPSDO, which is a dithered 10-bit DAC in a PIC chip that results in 14-bit resolution. I'd like to have a simple way to get 2 to 4 extra bits of resolution out of this. Can you recommend some design resources to do this? Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 53, Issue 8
On Dec 1, 2008, at 2:33 PM, Stanley Reynolds wrote: > Message: 6 > Date: Mon, 1 Dec 2008 14:31:33 -0800 (PST) > From: Stanley Reynolds <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] DAC resolution in GPSDO > > The oscillator I think has a manual adjustment. You could be using > the 5 volt provided on board or the 8 volt provided by the OCXO for > the ECC op amp. Note the ECC voltage is dependent on the control > board regulation some what even using an external reference. You > may want to manually adjust the OCXO closer to zero and set the > upper limit lower as well. By?using a external voltage divider on > the ECC voltage or lowering the gain (R7 & R8). Nope, this Isotemp was made for OFC, labeled OSC092, or maybe OFC/ McCoy sold out to Isotemp. There's no external adjustment available. I used a 78L05 to make the +8V reference supply for the OCXO and it works quite well. I don't use the BertBoard's signal output chip at all, nor the RS-232 chip, so loading hasn't been a problem. Compared to my recently purchased Thunderbolt, running off the same antenna, the Zauhar GPSDO moves around by a few parts in 10E-10 to 10E-11. Using the +8V ref supply to make a larger range of DAC output makes the problem worse, not better. A 16-bit DAC would help, but this project has gotten more complicated than I wanted already -- see my webpage. The best solution now would be a good 10811A... Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] DAC resolution in GPSDO
On Dec 1, 2008, at 12:09 PM, Warren wrote: > Message: 4 > Date: Mon, 1 Dec 2008 11:22:42 -0800 > From: "WarrenS" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] V standards > > Concerning the Need for very high resolution Dacs in GPSDO. > >> Bruce said: "However there are low noise OCXOs with EFC adjustment >> ranges of 1E-6 or more, (that would benefit from >20 bit Dacs) >> Question: Is the Aging rate of these low noise OCXO units poor >> enough > that you could not use a couple of fixed precision resistor and/or > a pot > for course adjustment and reduce the EFC range of the DAC by say > 1/100 ?. > Are there low noise OCXO (that are being used in GPSDO) whose long > term > drift over say 6 months would need more than 1E-8 or so of > 'automatic' turning? I'm using an Isotemp 134 OCXO that has an EFC sensitivity of around 1.62E-6 Hz/V near the 10MHz point. It is very stable and also well- aged, and its non-adjustable EFC V for 10MHz is near 3.318V. I'm running it in Bert Zauhar's FLL GPSDO, which has a PWM DAC with 14- bit resolution and an output range of 0 to +5V. This DAC resolution is not enough for tight frequency control of the Isotemp, given its very coarse Hz/V sensitivity. Combined with the DAC resolution, the system granularity is roughly 4.9E-11 Re 10MHz for it's finest step. This just isn't quite enough. > And concerning the 10811A. Should one consider reducing its EFC > tuning range by say 2 to 20 to ease the requirements of the Dac? > Even if the EFC tuning range was reduced by just a factor of two, > It could then be done with just a standard 0 to 5 volt Dac > instead of the -5 to +5 that I saw suggested by its spec. > I would think that a well aged unit would be much better than its > worse case > spec of 1E-7 per year, And even if not, I'm guessing that many of > the time-nuts, > would be very welling to trade off it needing a have few extra > manual adjustments > in order to get better performance. > > WarrenS Warren, that's exactly what I'm doing with the Isotemp, aiming for a division of about 6-10x. It's no problem for folks like us to tweak stuff when needed, so that's an effective solution. I'd like to have a higher resolution DAC to preserve a large tuning range, but the whole idea of this GPSDO was a simple, inexpensive, yet effective DIY GPSDO. See www.moorepage.net/gps2.html Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt settings
On Dec 1, 2008, at 7:08 AM, Chuck and Ulrich wrote: > -- > > Message: 2 > Date: Mon, 01 Dec 2008 09:02:33 -0500 > From: Chuck Harris <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Thunderbolt settings -- one more time > > The T-Bolt is designed to be a turn key system, and is already > set up for the best operation the factory knew how to achieve. > I doubt that anyone has spent much time diddling the time constants. > > -Chuck Harris Thx, Chuck for your reply. > > -- > > Message: 3 > Date: Mon, 1 Dec 2008 16:08:44 +0100 > From: "Ulrich Bangert" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Thunderbolt settings -- one more time > > Chuck and Dick, > >> The T-Bolt is designed to be a turn key system, and is >> already set up for the best operation the factory knew how to >> achieve. > > Yes and no! Clearly the factory settings have to be so that a lock of > the pll is possible within a reasonable time, say minutes to hours or > so. With a freshly powered OCXO the initial aging effects can be that > large that really short time constants as the default 100 s of the > Thunderbolt are necessary. > > I attach a measurement that I made on a freshly powered up HP10811 > some > years ago. Note: This was by no means a new device but one that had > already thousands of hours lifetime. Clearly any regulation loop will > need short time constants to follow this initial aging. Note that the > aging effects are that big that frequency changes due to diurnal > temperature changes in my flat are not visible! Temperature has > otherwise the biggest impact of all environmental parameters on > oscillator stability. > > After some weeks of continuous (!) operation the time constant of the > Thunderbolt loop may be set to higher values. Mine currently runs at > 500.0 s. Some tests indicate that the time constant may even be set a > bit higher. I have made experiments on time constants with a number of > different gps receivers and different OCXOs (including RBs). As an > overall result it turned out that TCs > 1500 s are impraticcal in a > normal living environment. With some degrees Centigrade temperature > changes in a typical center European environment along the day that is > the maximum time that allows the loop to follow the temperature > changes. > This includes RBs which have an measurable coefficient of temperature > too. > > Best regards > Ulrich > >> >> Richard Moore wrote: >>> Dear nuts -- >>> >>> Let me see if I can ask this in a way that will prompt you to supply >>> some input: >>> >>> What is the maximum Loop time constant the TBolt (or perhaps the >>> TBolt monitor sw) will accept as input? >>> What TCs are you TBolt owners using? >>> >>> Thx, >>> Dick Moore >>> >>> -- next part -- > A non-text attachment was scrubbed... > Name: HP10811.pdf > Type: application/pdf > Size: 17055 bytes > Desc: not available > Url : http://www.febo.com/pipermail/time-nuts/attachments/20081201/ > f7077c5e/attachment.pdf > > -- Thanks Ulrich. The default TC on my used TBolt was 100.0s. I ran it for a couple of days and it was stable with a very low level of total DAC change -- about +10mV. After a few more days, and after looking a various ADEV plots, particularly yours, Ulrich, I set the TC to 1000.0 sec. It refuses to take 10,000 sec, but I haven't explored the limits of what it will accept, and was hoping, since Trimble won't tell me in the docs the acceptable ranges of anything you can adjust, that one of you would know. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Thunderbolt settings -- one more time
Dear nuts -- Let me see if I can ask this in a way that will prompt you to supply some input: What is the maximum Loop time constant the TBolt (or perhaps the TBolt monitor sw) will accept as input? What TCs are you TBolt owners using? Thx, Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] V refs -- Bruce
On Nov 30, 2008, at 3:39 PM, tBruce wrote: > Message: 6 > Date: Mon, 01 Dec 2008 11:53:32 +1300 > From: Bruce Griffiths <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] V refs > > The uA714 is claimed to be an OP07 equivalent. > A chopper stabilised amplifier would have lower drift and flicker > noise, > however the zener drift and flicker noise probably dominates. > > Stacking LTZ1000's in the same way is a little tricky. > The only satisfactory method I have devised so far uses a PJFET as a > voltage controlled resistor to sink the zener current whilst > allowing it > to be reused to bias lower LTZ1000s in the series stack. > > Bruce Bruce, The 714 opamp provides gain in the Datron 1082, and I would use one LTZ1000 (or two in parallel, rather than try to use them in series). A while back I tried using two LM399s in series in a Fluke 895, and really didn't like the results -- a single 399 with an amp was better in every way I could measure. As an alternative to a chopper like the 1151, I might consider an OPA27. I have used the now unobtainable OPA111 in the past, and that was a superb DC amp; they (TI) claim the OPA27 is as good. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] V refs -- Frank S and Bill E
Frank wrote: > The 5720A uses a stacked double Zener reference on a > proprietary hybrid > circuitry, giving 1-2 ppm/year stability, the 7001 and 732B use the > LTZ1000 (Zener above BE junction), as the 3458A, the 732A uses the > Motorola device (Zener below BE junction), and the elder 332D and 335D > use similar, but less longterm stable references. > -- My Fluke 332D uses the Motorola IC (zener below) in a small Klixon oven which seems to be an on-off type with relatively poor temp control. Of course none of the divider string resistors or other circuits are in a temp-controlled space. I've found it very hard to keep that box under 10ppm over even short periods. It mostly sits. Did I mention its very big and heavy? It does supply 50mA at 1100V though. Bill wrote: > These use a rather clever way of generating 1V and 1.18 volts without > significant division error. The 10V reference is sampled by a > pulse-width modulator whose duty cycle is crystal-controlled and > programmable. The result is then LP filtered using an active filter > and > tracks the primary reference to better than 1ppm. > > Bill Ezell > - All of the newer Fluke calibrators use the PWM/LP filter method to vary output, as does my Valhalla 2701C DC 6-1/2 digit, 100mV-1000V reference. The Valhalla has an LM299 for its reference, and given its generally good overall performance, would be a good candidate for an LTZ1000 transplant. Another project. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] V refs
On Nov 30, 2008, at 4:00 AM, Bruce wrote: > Message: 1 > Date: Sun, 30 Nov 2008 17:26:28 +1300 > From: Bruce Griffiths <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] V refs > > > Does the Datron use a series stack of zeners or does it use the once > popular ring of 2 reference circuit? > > Bruce Bruce, the 1082 uses two sets of two zeners in series. Each series set of zeners has its own current setting resistor set. The out put from each zener string is fed thru a 9.1k resistor into the + input of an opamp mixer which drives an emitter follower, and that drives the current setting resistors for the zeners, and, divided down, the ref. output for the meter. The system actually works very well, but given the ages of these meters, I suspect that the zero TC current point of the zeners might need tweaking. The opamp is a Fairchild uA714CH. I'm not familiar with its noise performance or, in this system, its input temp characteristics -- I'll bet this also would be a good spot for a chopper amp, if I switch to a LTZ1000 Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] V refs
RE comments from Bruce -- > Message: 1 > Date: Sun, 30 Nov 2008 10:33:36 +1300 > From: Bruce Griffiths <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] V standards > > Richard Moore wrote: >> Brooke, I read the patent with interest, and I cannot see how using >> the LM399 and AD587 together represents an improvement over just >> using a 399 and a chopper amp for the needed gain to get 10V (or >> whatever) out. Geller's external adjustment R chain will suffer >> tempco problems similar to a set of Rs used to gain-set the chopper, >> and making the chopper an integrator with a long TC should help with >> the 399's noise. > You need a low pass filter with a well defined dc gain not an > integrator. > You can also average the outputs of several 399s to reduce the noise. > However this requires a lot of 399s if one wants to reduce the > noise by > a large factor. > The LTZ1000 is significantly quieter than an LM399. > Its significantly cheaper to use a single LTZ1000 than an array of > 399s > with the same noise (using the same low pas filter). >> > Bruce > -- Bruce, thanks for the clarification, and also for your earlier suggestion on the chopper amp. I think I've got a couple of LT1150 or 1151s in a drawer. If I remember correctly, noise should improve roughly 3dB for every doubling of devices, which means that 8 399s should yield a 9dB improvement, which is nothing to sneeze at, and is still pretty cost-effective. Seems like using a chopper on each one and then paralleling those outputs into a chopper gain stage would make effective LP filtering relatively easy and would further average out noise and drift contributions from the various discrete parts, which means that using 1% MF resistors, for example, might be practical for sub-ppm results. I'm beginning to like this, and I can see replacing the dual zeners in one of my 7-1/2 digit Datron 1082s might be a lot of fun (the one with the bad VF display that's going to get 7-seg LEDs instead, 'cause I HATE LCD displays that aren't backlit -- no wonder HP went to VF in the 3458 -- they sure must have got tired of the complaints about the 3457). That 1082 shifts its reading of my Fluke 732A's 10V output about 8-10 ppm/year or a bit more, when I can get everything at the same temp for repeating the measuremement... Nevertheless, if I can get LTZ1000s for $60 a pop, that's a much simpler way to go mechanically and electrically. Are you sure that the price you stated is for singles? I wouldn't be averse to having a couple of them around. I appreciate very much the depth of both your theoretical and practical experience and the insight you bring to everything you comment on here. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] V standards
RE Brooke Clarke and Warren S posts: > Message: 6 > Date: Sat, 29 Nov 2008 08:24:43 -0800 > From: Brooke Clarke <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Voltage Standards > > Hi: > Geller's patent 7382179 Voltage reference with enhanced stability > explains how > he combines the AD587 voltage reference with the LM399 voltage > reference to > obtain improved temperature stability. The method can be used with > the LT1000. > http://www.google.com/patents?id=v0GqEBAJ&dq=7382179 > > Brooke Clarke > http://www.prc68.com > -- Brooke, I read the patent with interest, and I cannot see how using the LM399 and AD587 together represents an improvement over just using a 399 and a chopper amp for the needed gain to get 10V (or whatever) out. Geller's external adjustment R chain will suffer tempco problems similar to a set of Rs used to gain-set the chopper, and making the chopper an integrator with a long TC should help with the 399's noise. Can anyone see where a further tempco improvement from using the AD587might come from? > Message: 9 > Date: Sat, 29 Nov 2008 12:05:43 -0800 > From: "WarrenS" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Voltage standards > .clip > The TC correction circuit I use is just two standard parts. > A100K pot is placed between an added transistor's collector > and ground with the pot's wiper going to the transitor's base. > What that does when current is applied to the transistor is to make > the collector voltage vary with temperature by an adjustable amount. > This temperature sensitive voltage is then added with the trim voltage > to the reference's trim input to cancel the 1st order temperature > drift. > The results I got was a settable 4 degF wide ZERO TC, > turnover point at any desired room temperature. > The added parts fit on the small Geller's PCB. > ./clip > WarrenS > ** Thanks for the input Warren -- I think your mod explanation is pretty clear -- and nice. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Geller V std
> Message: 3 > Date: Fri, 28 Nov 2008 20:51:12 -0800 > From: "WarrenS" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Voltage standards > To: "Discussion of precise time and frequency measurement" > > Message-ID: <[EMAIL PROTECTED]> > 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 > * Warren, could you or would you share that little mod with us? Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] TBolt TC recs wanted
Dear nuts -- What TBolt time constant setting have you found to work best for best frequency accuracy and-or stability? Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Voltage standards
RE Message 8 and a couple of earlier posts on standards > Date: Sat, 29 Nov 2008 10:38:53 +1300 > From: Bruce Griffiths <[EMAIL PROTECTED]> > 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 > > Message-ID: <[EMAIL PROTECTED]> > 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. >> BillWB6BNQ > > 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 som
Re: [time-nuts] TBolt in the house -- MSFT mouse bug
On Nov 21, 2008, at 4:00 AM, [EMAIL PROTECTED] wrote: > Message: 2 > Date: Fri, 21 Nov 2008 01:25:38 -0500 > From: Norman J McSweyn <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] TBolt in the house! > To: Discussion of precise time and frequency measurement > > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Give this a try! > http://www.synergy-gps.com/images/stories/ShopTalk/disabling% > 20detection%20of%20microsoft%20ballpoint%20mouse.pdf > The serial mouse issue drove me nuts for a while. > Norm Norm, You Da Man!!! The regedit did the trick. Thanks also to Randy at Synergy, and Big Thanks to that unnamed customer who figured it out. Boy, was I tired of having to constantly disable that BallPoint driver. Just another reason to love time-nuts. Dick ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Wavetek 3010
On Nov 21, 2008, at 12:42 PM, [EMAIL PROTECTED] wrote: > Message: 2 > Date: Sat, 22 Nov 2008 01:21:16 +1300 > From: "Steve Rooke" <[EMAIL PROTECTED]> > Subject: [time-nuts] Off-Topic: On Wavetek 3010 lever thumbwheel > switchesand manual > To: "Discussion of precise time and frequency measurement" > > Message-ID: > <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1 > > snip > I've also trawled the Net to find a freely downloadable manual (user > and servicing) but to no avail. If anyone has a copy or could point me > in the right direction, I would be most grateful. > > 73, Steve > -- > Steve Rooke - ZL3TUV & G8KVD > Omnium finis imminet > Steve, I've got a Wavetek 3001/3002 manual that may get you near to where you need to go. Contact me at richiem at hughes.net, and let me know if that's something you can use. I'd be happy to loan it to you for copying. Best, Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TBolt in the house!
> Message: 2 > Date: Thu, 20 Nov 2008 15:36:48 -0800 > From: Brooke Clarke <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] TBolt in the house! > To: Discussion of precise time and frequency measurement > > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hi Dick: > > Did you set the COM port number? > Right click with the cursor on the window. > http://www.prc68.com/I/ThunderBolt.shtml#TBM > Yep, Brooke, I did. My ATEN 232>USB adapter looks like Com Port 6 to my windows box, which regularly thinks that it is a Microsoft Ball Point, whatever that is and it's a real pain to straighten that out. I'd like to get rid of the MS Ball Point driver completely if I could find it; any help with that appreciated. > Richard Moore wrote: >> Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in >> China. He nicely gave me the time-nuts discount, and also included a >> power connector with pigtail leads. Including shipping, it was $175 >> and it took 7 days to get here in W. Wash. You can find him and these >> units on eBay at: http://stores.ebay.com/High-precision-Osc-from- >> China >> >> It's date code is 3/19/05. >> The App Ver is 3.00 6/27/2. >> GPS Core is 10.02 11/14/1. >> ID is 96. >> s/n is 82331036 3/7/5. >> >> It's up and running in a top-of-bench way, and I have a few Qs: >> 1) What are good params to use for the loop to get best frequency >> acc'y and stability? >> 2) Is there a firmware upgrade you recommend? >> 3) What V/Hz figure do you all recommend? It's at what must be a >> default of -5... >> 4) DAC voltage is +0.0633... Is this a fairly normal value? >> 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB >> adapter, but DSPMon does not see the data at all -- no TX or RX. Does >> it not work with this vintage/version of TBolt? >> -- > Message: 3 > Date: Thu, 20 Nov 2008 15:44:49 -0800 > From: "John Miles" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] TBolt in the house! > To: "Discussion of precise time and frequency measurement" > > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset="us-ascii" > > Unless you are going to use a different OCXO, there is nothing to > do except > perhaps tell it to save the self-survey results and set your > "foilage mode" > if desired. They are plug and play. > > -5 V/Hz is the correct kvco parameter; any changes will either > degrade the > phase margin and give you a "hump" in your loop response, or > lengthen the > loop response. And it wouldn't be advisable to alter the loop-time > and > damping parameters without taking a series of ADEV plots under > various GPS > reception conditions to make sure you're actually improving things. John, thanks for the feedback. I'll leave the V/Hz alone, Any advice on loop time constant and damping? >> -Original Message- >> From: [EMAIL PROTECTED] [mailto:time-nuts- >> [EMAIL PROTECTED] >> Behalf Of Richard Moore >> Sent: Thursday, November 20, 2008 3:28 PM >> To: time-nuts@febo.com >> Subject: [time-nuts] TBolt in the house! >> >> >> Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in >> China. He nicely gave me the time-nuts discount, and also included a >> power connector with pigtail leads. Including shipping, it was $175 >> and it took 7 days to get here in W. Wash. You can find him and these >> units on eBay at: http://stores.ebay.com/High-precision-Osc-from- >> China >> >> It's date code is 3/19/05. >> The App Ver is 3.00 6/27/2. >> GPS Core is 10.02 11/14/1. >> ID is 96. >> s/n is 82331036 3/7/5. >> >> It's up and running in a top-of-bench way, and I have a few Qs: >> 1) What are good params to use for the loop to get best frequency >> acc'y and stability? >> 2) Is there a firmware upgrade you recommend? >> 3) What V/Hz figure do you all recommend? It's at what must be a >> default of -5... >> 4) DAC voltage is +0.0633... Is this a fairly normal value? >> 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB >> adapter, but DSPMon does not see the data at all -- no TX or RX. Does >> it not work with this vintage/version of TBolt? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] TBolt in the house!
Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in China. He nicely gave me the time-nuts discount, and also included a power connector with pigtail leads. Including shipping, it was $175 and it took 7 days to get here in W. Wash. You can find him and these units on eBay at: http://stores.ebay.com/High-precision-Osc-from-China It's date code is 3/19/05. The App Ver is 3.00 6/27/2. GPS Core is 10.02 11/14/1. ID is 96. s/n is 82331036 3/7/5. It's up and running in a top-of-bench way, and I have a few Qs: 1) What are good params to use for the loop to get best frequency acc'y and stability? 2) Is there a firmware upgrade you recommend? 3) What V/Hz figure do you all recommend? It's at what must be a default of -5... 4) DAC voltage is +0.0633... Is this a fairly normal value? 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB adapter, but DSPMon does not see the data at all -- no TX or RX. Does it not work with this vintage/version of TBolt? Best, Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Z3801 outer oven temp?
Hi folks, wondering if any of you can tell me the outer oven temperature of the Z3801. Since the 10811As run in the range of 80-85 deg C, I'm guessing it might be something like 40 deg C? Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tek 602
Magnus, what everyone else said, plus, I have seen a few older Tek scopes with bad focus and/or intensity controls as well as HV divider resistors for the screens. If the HVs at the anode cap and cathode are good, then I would look there. The heater is, of course, at high voltage to prevent arcing to the cathode and it is run off a winding of the HV transformer. HV could be as much as 10kV, so be careful. > > Message: 8 > Date: Sat, 08 Nov 2008 01:30:17 +0100 > From: Magnus Danielson <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Tek 602, no trace > To: Discussion of precise time and frequency measurement > > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Richard Moore skrev: >> >> Magnus, a few thoughts that have most likely already occurred to >> you -- >> 1) HV supply failure -- I think it will be around 2 or 3kV if >> working. > > It's 3,9 kV. There is a test point, but I need to dig up a very old HV > probe lying around somewhere in the junk. Finally I get some use for > it... maybe > >> 2) X or Y deflection amp has failed, moving the trace offscreen. > > The X deflection amp seems to work at least. > >> 3) CRT heater dead. > > No, I have a very faint ligthening up on the screen which the > horizontal > control can move on or off screen. I need to shield the screen from > light to see it. It's so out of focus that it hits the full screen. > Could be an HV issue, but I am not sure at this moment. > >> Either 1 or 2 should be easy to detect. Having the manual will >> certainly help with repair. 3, however, is really discouraging. > > Certainly. I have enought of large scopes at a friends place to be > able > to salvage tubes before being tossed. I even think he still has the > spare tube NOS. :) > > Cheers, > Magnus > > End of time-nuts Digest, Vol 52, Issue 19 > * ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tek 602, no trace
> Magnus, a few thoughts that have most likely already occurred to you -- 1) HV supply failure -- I think it will be around 2 or 3kV if working. 2) X or Y deflection amp has failed, moving the trace offscreen. 3) CRT heater dead. Either 1 or 2 should be easy to detect. Having the manual will certainly help with repair. 3, however, is really discouraging. Dick Moore > However, currently I am lacking the dot on the screen to begin > with. Power > lines seems OKish but could be trimmed. > > Cheers, > Magnus > > End of time-nuts Digest, Vol 52, Issue 18 > * ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Isotemp 134-10 & Fury
The Isotemp 134-10 *may* have a screw in the side of the case that gives access to a trimmer for the frequency. You can set your Fury to an EFC output of 2.5V and try adjusting the trimmer for 10MHz or as close as you can get it. This will optimize your control range from the Fury, with the proviso that the Isotemp's control slope is not linear. My OFC version does not have the access port, but it it a much earlier model than the Isotemp 134. The Isotemp has a positive control slope -- increasing EFC increases frequency. Mine has an EFC sensitivity of about 2E-7 per Volt. Dick Moore > From: Matt Osborn <[EMAIL PROTECTED] > (mailto:[EMAIL PROTECTED]) > > Date: November 1, 2008 23:28:34 PDT > To: time-nuts <[EMAIL PROTECTED] (mailto:time-nuts@febo.com) > > Subject: [time-nuts] Jackson Labs Fury & Isotemp OCXO134-10 > Reply-To: Discussion of precise time and frequency measurement > <[EMAIL PROTECTED] (mailto:time-nuts@febo.com) > > > I think that I've managed to keep a low profile here, trusting that I > would learn more if I refrained from random interjections of > ill-informed thoughts. However, there comes a point in every man's > life... > > A year or two ago, I took advantage of Said's offer and purchased one > of the Jackson Labs OEM external OCXO Fury units and am > attempting to > put it to work. I've decided to use an Isotemp OCXO134-10 oscillator > and have several decisions which I would like to vet with those of > you > that have been down this road before. > > The Isotemp unit has an EFC range of 0 to 8 Volts; the Fury has an > EFC > range of 0 to 5 volts. Using my HP 53131A, I'm able to adjust the > Isotemp to 10 MHz +- 5 mHz with an EFC voltage of 4.64 volts. > That is > within the adjustment range of the Fury, but I'm not sure of the > accuracy of the HP53131A. Should I construct a resistive network ala > Brooks Shera to 'boost' the EFC range just in case or would I be > better off just using the Fury 'as is'? > > Secondly, the Jackson Labs advises that since the Fury uses the > external oscillator as its clock, that the oscillator should be > powered up before the Fury itself. I was hoping that I would be able > to use a single power switch to power both the oscillator and the > Fury > simultaneously, but now I'm not so sure. > > Finally, are there any of you that have used the Isotemp OXCO134-10 > with the Fury? Have any of you worked out the various SERVO settings > that the Fury makes available? I'm interested in the DAC gain, EFC > scale, EFC dampening and Phase compensation. > > Any and all advice will be gratefully accepted. > > -- kc0ukk at msosborn dot com > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LP filter on EFC line
Bruce, thanks for the tip on the anti-charge injection LP filter. Actually, early on, I put a 0.1uF cap across the EFC line on the osc, support board, so there is some LP filtering working there. But my old Tektronix "prayer wheel" Circuit Computer says that's only a 5ms TC -- prolly need quite a bit more or else buffer the EFC line from the DPM. Best, Dick Moore On Oct 31, 2008, at 5:56 PM, [EMAIL PROTECTED] wrote: > -- > > Message: 6 > Date: Sat, 01 Nov 2008 11:00:59 +1300 > From: Bruce Griffiths <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] OFC OCXO > To: Discussion of precise time and frequency measurement > > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1 > > Richard Moore wrote: >> Hi Ernie -- thx for the feedback. I have had all of those effects and >> more with an HP10811A and an EG&G Cinox version of the 10811A, so I >> won't be surprised to see such things with this one either. I'm going >> to try it with Bert Zauhar's FLL controller to see how it runs. You >> can visit my experience to date at: >> www.moorepage.net/gps2.html >> >> I'll update the site again after I run the OFC for a while. >> >> Best, >> Dick Moore >> > Dick > > The usual way of reducing charge injection transients from a DVM into > the circuit being measured is to use an RC low pass filter between the > circuit and THE DVM. > Charge injection can be somewhat larger for those autozeroing DVMs > that > do not use a precharge amplifier to reduce the effect. > panel mount DVMs do not usually have a precharge amplifier. > > With a low pass filter it may be possible to reduce the value of > the 50K > isolation resistor that you used. > The value is relatively high because it relies on the DVM and wiring > capacitance as the capacitive part of the RC low pass filter. > > Bruce > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OFC OCXO
Hi Ernie -- thx for the feedback. I have had all of those effects and more with an HP10811A and an EG&G Cinox version of the 10811A, so I won't be surprised to see such things with this one either. I'm going to try it with Bert Zauhar's FLL controller to see how it runs. You can visit my experience to date at: www.moorepage.net/gps2.html I'll update the site again after I run the OFC for a while. Best, Dick Moore Original message Message: 9 Date: Fri, 31 Oct 2008 07:52:28 -0400 From: [EMAIL PROTECTED] Subject: Re: [time-nuts] OFC (McCoy?)(Isotemp?) OCXO To: time-nuts@febo.com Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="us-ascii"; format=flowed Hi Dick, I also have the same OCXO OFC and tried in a Brook Shera circuit but I was not satisfied on the long run I could notice the day and night temp difference on the EFC scale and the phase plot also show similar deviation... Rgds Ernie. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] OFC (McCoy?)(Isotemp?) OCXO
Just received this OCXO from mr. fluke in China. Took exactly 14 days from time of order to get here to W. Washington. Hooked it up like the Isotemp 134 diagram. He said it would work, and it works perfectly. The Isotemp spec EFC voltage range (positive slope) is 0 to the ref. voltage, in my set-up, +8.0V. On this OFC unit, I found no change in frequency until the EFC gets to about 1.28V. It reached 10 MHz, to within 1E-9, at about 3.33V, with a total frequency span (1.28V to 7.9V) of 10.6E-7, or very roughly 1.6E-7/V. Unlike the Isotemp 134, this one has no trimming adjustment, so the only freq. control is via the EFC line, whose slope seems quite non-linear. Output is a very clean sine wave, about 2.8Vp-p unloaded and 1.8Vp-p into 50 ohms. This thing reaches temp fast and seems to be quite stable, but I won't have any reliable data until it is used in a more permanent way with stable supply voltages. Seems like a very nice unit. Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] McCoy OCXO pin outs
On Oct 27, 2008, at 2:59 PM, [EMAIL PROTECTED] wrote: > I have acquired a nice 10 MHz oscillator, but have absolutely no data. > Model is marked as a McCoy OSC92-100B, it is rectangular 3"x2"x1.5" > with six > leads out one side. Does anyone have the pinout, operating > voltage, EFC > voltage for this unit? Thanks in advance, as always. > > Regards, > Skip Withrow Google isotemp 134 and the first listing will likely be a pdf link for the specs and pin-outs. Best, Dick Moore ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
