Re: [time-nuts] Racal-Dana 1992 switches
Bruce Rex, You're both right. 1.25E-10 was for 40.000 000 005 GHz and 7.5E-11 is for 40.000 000 003 GHz. My bad, Good sleuthing. Tom Tom Duckworth 510-886-1396 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rex Sent: Wednesday, April 02, 2008 3:01 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal-Dana 1992 switches Bruce Griffiths wrote: Tom Duckworth wrote: Bill, I have attached a PDF of two methods we used at XL Microwave for adjusting the internal reference oscillators in our microwave counters. The second method (digital) was used to calibrate the internal reference time base of a 70 GHz microwave counter with an accuracy of parts in E-11. This digital method could be used to compare two GPSDOs, one to the other, and would probably yield greater resolution than trying to use a phase measurement on a counter due to jitter, internal noise, and stability issues in the count chain. This method proved to be fast, simple, stable, and superior to other methods we tried. Hope this helps. Tom Tom Duckworth 510-886-1396 Tom The first calculation at the bottom of the second page is incorrect the result should be: 1.25E-10 not 7.5E-11. Bruce The result was fine, but the measurement should have been 40.000 000 003 GHz. :-) -Rex ___ 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 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] Racal-Dana 1992 switches
Bruce Griffiths wrote: Tom Duckworth wrote: Bill, I have attached a PDF of two methods we used at XL Microwave for adjusting the internal reference oscillators in our microwave counters. The second method (digital) was used to calibrate the internal reference time base of a 70 GHz microwave counter with an accuracy of parts in E-11. This digital method could be used to compare two GPSDOs, one to the other, and would probably yield greater resolution than trying to use a phase measurement on a counter due to jitter, internal noise, and stability issues in the count chain. This method proved to be fast, simple, stable, and superior to other methods we tried. Hope this helps. Tom Tom Duckworth 510-886-1396 Tom The first calculation at the bottom of the second page is incorrect the result should be: 1.25E-10 not 7.5E-11. Bruce The result was fine, but the measurement should have been 40.000 000 003 GHz. :-) -Rex ___ 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] Racal-Dana 1992 switches
This topic has been addressed earlier; though with some debate. I have proposed a simple heterodyne scheme for beating 2 stable sources against each other observing a 1KHz difference frequency to resolve 1uHz deltas. This is NOT a state-of-the-art scheme, but it will provide better than 1E-12 resolution in less than 10s. This scheme does require some non-standard items. 1. You need a stable synthesizer with external clock capability to yield 10.001 Mhz, phase locked to one of your sources. The HP3336C or a PTS040 work fine. 2. You need a 1KHz zero crossing detector to drive your counter input with low jitter. The ZCD requires 2 opamps a few passive parts, including 2 inductors you'll need to wind by hand. 3. You need a level 7 double balanced mixer to heterodyne the second source the 10.001Mhz signal. Mixers optimized as phase detectors, like the mini-circuits SYPD-1 work well for this. You also need a diplexer on the mixer output to separate the 1KHz beat signal from the other mixer products. The diplexer is 6 passive parts. The results are stable provide counter readings of 9 significant digits down to 1uHz with the leading 4 digits of frequency assumed from the mixing process. The counter gate time setting provides useful often necessary averaging of the readings; so a variable gate time counter is handy. I've used a H-P 5335A, don't know much about the Racal 199x series, but I suspect they would do just fine. Pete Rawson ___ 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] Racal-Dana 1992 switches
How do you pick the optimal difference frequency? I see that 1kHz has a nice numerical property where you can read the frequency directly off the counter, you just need to mentally prepend the first 4 digits. With computers it's not that important, the difference can easily be a strange number if it optimizes performance. I'm wondering what difference frequency optimizes the performance of the mixer thing or if it really matters? Do you worry about the phase-noise contribution of the 10.001MHz source? As I do the math, it seems that the phase noise of the mixing signal is subtracted out after the mixing, so it shouldn't mater that the 10.001Mhz source comes from a frac-N synthesizer and has a few random spurs. You say this isn't state of the art. Why not? Can't you run the timing collection for longer runs and get higher resolution results? jeff Pete wrote: This topic has been addressed earlier; though with some debate. I have proposed a simple heterodyne scheme for beating 2 stable sources against each other observing a 1KHz difference frequency to resolve 1uHz deltas. This is NOT a state-of-the-art scheme, but it will provide better than 1E-12 resolution in less than 10s. This scheme does require some non-standard items. 1. You need a stable synthesizer with external clock capability to yield 10.001 Mhz, phase locked to one of your sources. The HP3336C or a PTS040 work fine. 2. You need a 1KHz zero crossing detector to drive your counter input with low jitter. The ZCD requires 2 opamps a few passive parts, including 2 inductors you'll need to wind by hand. 3. You need a level 7 double balanced mixer to heterodyne the second source the 10.001Mhz signal. Mixers optimized as phase detectors, like the mini-circuits SYPD-1 work well for this. You also need a diplexer on the mixer output to separate the 1KHz beat signal from the other mixer products. The diplexer is 6 passive parts. The results are stable provide counter readings of 9 significant digits down to 1uHz with the leading 4 digits of frequency assumed from the mixing process. The counter gate time setting provides useful often necessary averaging of the readings; so a variable gate time counter is handy. I've used a H-P 5335A, don't know much about the Racal 199x series, but I suspect they would do just fine. Pete Rawson ___ 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 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] Racal-Dana 1992 switches
Bill, I guess my reason for wanting to see beyond 0.001 Hz is the usual, I have reached a limit and wonder if the equipment I have is capable of more, if I just understood the more esoteric functions I seldom use. The Racal seems like my scientific calculator.. lots of shift functions that might be hiding some useful capabilities with a little coaching and study. Just saw Pete's answer, and I do have a PTS160 synthesizer. So the locked offset idea is do'able. Have mixers, phase detectors, but may need more info on the zero crossing detector opamp portion if you could point me in the right direction. From a GPS equipment standpoint more resolution might tell me if my GPS receivers are working good enough or marginally. I passive split the antenna line four ways. The Lucent units lock to it with about 34~45 C/N readings. But my Z3801A has some other issue now that I've replaced the UT+. It hasn't locked and gives recurring UTC receiver timeout messages on GPScon. The previous UT+ receiver was somewhat lightning damaged and would only lock to one or two satellites for a few hours a day, but at least it was communicating. It may just be a comm issue between the Z3801A motherboard and my present UT+, since the Z3801A motherboard does answer back with serial number etc to GPScon. So I know the baud rate at that level is communicating between PC and Z3801A. The UT+ is a used one from one of the Lucent RFTGm units. So maybe there's a difference in the way they were setup. The UT+'s are 2000 vintage Synergy R5122U1112 to Lucent with V2.2 firmware and no battery. I actually have collected enough damaged UT+ boards (from the lightning prone place I previously worked) that I should build up an NMEA test fixture to verify they work outside the systems they normally reside in, and that all the parameters are set correctly. Then I can try to resurrect a few. The M1501 LNA chips are usually what goes. And I have some ideas I want to try, to dead bug in a MMIC fix for that obsoleted LNA chip. Charles Osborne K4CSO, EM74wa Duluth, GA - Original Message - From: Bill Hawkins [EMAIL PROTECTED] To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Friday, March 28, 2008 9:09 PM Subject: Re: [time-nuts] Racal-Dana 1992 switches Charles S. Osborne said, in part, Now the real question is... is there a clever way to make the Racal 1992 readout the difference in µHz between two GPS disciplined oscillators? My only other counter, an HP5384A, is offscale at 10.000 000.000 MHz . I'm referencing the counter with one Lucent RFTG-m-XO and clocking a Lucent RFTGm-II-XO. Things are working well enough to be beyond my counter's ability to see any jitter. The Racal says nanosecond time interval counter, so I bet there's a way to subtract and increase the resolution similar to an HP53131? Haven't seen the answer on this list, so perhaps it occurred privately. The Racal 1992 is able to read the phase error between two 10 MHz signals (A and B) in degrees. I have done this with the outputs of two 3801s, which are the only pair of frequency sources that I have. This would be sub-nanosecond accuracy except that the display shows 3-10 degrees of jitter (difference between two successive readings). This, however, is only 10E-9. Most people on this list are investigating areas at least two orders of magnitude lower. I find that the phase method gives me comparative drift errors soon enough. An hour gets you near 10E-12. Others require measurement intervals much shorter than that, but the phase angle method is more than adequate for time errors that humans will notice. A drift of one second per year is on the order of 10E-8. It all depends on your reason for pursuing accurate time/frequency measurement. Bill Hawkins ___ 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 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] Racal-Dana 1992 switches
Jeff, There's nothing magic about 1KHz as the heterodyne frequency. I picked it to avoid power line pickup permit a tuned circuit to limit the noise bandwidth. But, any tuned circuit in the signal path will have temperature driven phase variations possibly signal level phase variations, as well. The opamps contribute some noise they also limit the output slew rate; yielding approx. 400ps rms jitter. Using rather stable L C components limits the total impact of these effects to less than +/-1E-9 @ 1KHz (equivalent to +/- 1E-13 @ 10MHz). These issues speak against extending this scheme to much longer times. The synthesizer PN does contribute to the counter measurements. But, even with 2s gate time you are averaging 1000 samples things quiet down nicely. Some synthesizers are better used at 9.999MHz as opposed to 10.001MHz, but I've no solid data on this. Either frequency is OK in this scheme. Pete Rawson ___ 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] Racal-Dana 1992 switches
Jeff Mock wrote: How do you pick the optimal difference frequency? I see that 1kHz has a nice numerical property where you can read the frequency directly off the counter, you just need to mentally prepend the first 4 digits. With computers it's not that important, the difference can easily be a strange number if it optimizes performance. I'm wondering what difference frequency optimizes the performance of the mixer thing or if it really matters? Do you worry about the phase-noise contribution of the 10.001MHz source? As I do the math, it seems that the phase noise of the mixing signal is subtracted out after the mixing, so it shouldn't mater that the 10.001Mhz source comes from a frac-N synthesizer and has a few random spurs. You say this isn't state of the art. Why not? Can't you run the timing collection for longer runs and get higher resolution results? jeff Jeff Whilst a naive analysis indicates that the phase noise of the offset oscillator isnt critical, in practice it is. The dependence on the offset oscillator phase arises because zero crossings of the 2 beat frequencies do not occur at the same time. The greater the time difference between the 2 zero crossings the more critical the phase noise of the offset oscillator becomes. Random spurs do matter, as JPL has found with their nominal 100Hz beat frequency system, performance is much better when the synthesizer is set for a 123Hz beat frequency. The optimum beat frequency is that which minimises the system noise. As the beat frequency is lowered the resolution, for a fixed accuracy in measuring the zero crossing times, increases. However as the beat frequency decreases the mixer output noise density increases. Thus a balance between increasing noise at low offset frequencies and increasing resolution at low offset frequencies has to be found. JPL currently uses 100MHz mixer input frequencies and a nominally 100Hz beat frequency. NIST have also moved from 10MHz mixer input frequencies with a 10Hz beat frequency to 100MHz mixer input frequencies and a 100Hz beat frequency. The system isnt state of the art because the zero crossing detector performance is far from state of the art. A diplexer isnt the optimum IF port termination for low noise at low ( 100kHz) beat frequencies. State of the art systems have a system noise level of around 1E-14/Tau or less. The use of tuned circuits in the zero crossing detector increases its phase shift tempco over that of a state of the art design. Thus as the averaging time increases ambient temperature variations will ultimately limit the system noise. In fact a similar performance to the proposed system is possible using an analog phase comparator if one takes a little care in the design. 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] Racal-Dana 1992 switches
Charles S. Osborne wrote: Now the real question is... is there a clever way to make the Racal 1992 readout the difference in µHz between two GPS disciplined oscillators? My only other counter, an HP5384A, is offscale at 10.000 000.000 MHz . I'm referencing the counter with one Lucent RFTG-m-XO and clocking a Lucent RFTGm-II-XO. Things are working well enough to be beyond my counter's ability to see any jitter. The Racal says nanosecond time interval counter, so I bet there's a way to subtract and increase the resolution similar to an HP53131? tnx, Charles K4CSO Duluth, GA Charles One way to achieve microHertz resolution at 10MHz is to use a dual mixer time difference system or a variant thereof. The output from each GPDSDO is mixed with the same low noise offset source. This produces a pair of beat frequencies (one from each mixer) outputs. The zero crossing from one beat frequency output is used connected start a time interval counter whilst the zero crossing of the other beat frequency output is used to stop the time interval counter. The trick is to amplify the low slew rate beat frequency signal in such a way that the time interval counter sees 2 high slew rate low jitter signals. Just connecting the low pass filtered beat frequency outputs to the counter inputs isnt effective as the measured timing jitter will inevitably be much greater than the actual zero crossing jitter in the beat frequency signal itself. A resolution approaching 1E-14/sec is possible with this technique. Another approach is to use a series of cascaded frequency difference multipliers, this is the approach used by Quartzlock in their precision frequency comparators. This approach can also have a resolution approaching 1E-14/sec. If you are willing to wait a little longer to see microHertz frequency differences then an analog phase comparator can be used. A resolution approaching 1E-11/sec is possible with this technique if a high resolution ADC (eg a high res DVM) is connected to the phase detector output. 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.
[time-nuts] Racal-Dana 1992 switches
Actually, after two days of studying catalogs and datasheets, I think I found a suitable replacement switch. The trick is to find the ones made for tape packaging, which only have 2 pins -- the others have 4. The Omron B3F-6050, available through Digikey as part no. SW798-ND is $0.28 each for 100 ($0.39 each for singles). It has nearly the same dimensions as the original Toko, except it is about 3mm shorter so it will need to either be shimmed up or left sitting up on its pins and the plunger is the standard 2.4mm square instead of the cross, so the keycaps will need some modification. I'll let you all know how they work out once I receive and install them. Chris ___ 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] Racal-Dana 1992 switches
Back to the switches... I found a Jameco bag for the ones I bought way back, which fitted pretty well and work. The part number was 115086, then quoted for KIE22, but not the same as the current ones with that number. Jameco might know who made the 115086, but there are no clues from the few remaining in the bag... Dan ___ 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] Racal-Dana 1992 switches
Charles S. Osborne said, in part, Now the real question is... is there a clever way to make the Racal 1992 readout the difference in µHz between two GPS disciplined oscillators? My only other counter, an HP5384A, is offscale at 10.000 000.000 MHz . I'm referencing the counter with one Lucent RFTG-m-XO and clocking a Lucent RFTGm-II-XO. Things are working well enough to be beyond my counter's ability to see any jitter. The Racal says nanosecond time interval counter, so I bet there's a way to subtract and increase the resolution similar to an HP53131? Haven't seen the answer on this list, so perhaps it occurred privately. The Racal 1992 is able to read the phase error between two 10 MHz signals (A and B) in degrees. I have done this with the outputs of two 3801s, which are the only pair of frequency sources that I have. This would be sub-nanosecond accuracy except that the display shows 3-10 degrees of jitter (difference between two successive readings). This, however, is only 10E-9. Most people on this list are investigating areas at least two orders of magnitude lower. I find that the phase method gives me comparative drift errors soon enough. An hour gets you near 10E-12. Others require measurement intervals much shorter than that, but the phase angle method is more than adequate for time errors that humans will notice. A drift of one second per year is on the order of 10E-8. It all depends on your reason for pursuing accurate time/frequency measurement. Bill Hawkins ___ 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] Racal-Dana 1992 switches
Matt, Not seeing a better alternative posted for the Racal 1992, and having dozens of similar bad Toko switches on some Pacific Measurements 1038-N10 Scalar Analyzers, I decided to buy a bunch of the Jameco ones and give it a try. Definitely not a form fit replacement. But if you're not too asthetically picky they do fit. The leads can be manually flattened with a pair of needle nose pliers and reformed to fit under and down to match the closer hole spacing. Also clip off the small plastic alignment pins to allow the switches to sit flush on the board. The process only takes a couple of seconds per switch. A lot quicker than removal of the original switches. The real catch is the hole size in the 1992 original switch layout is a couple of sizes smaller on one pin than the other. Using a #54 drill bit (no bigger) you can clean the hole out and enlarge it without taking the plated thru barrel out of the holes on that one side. All my switches are in and working. I didn't even put the keycaps back on as all the manual lead forming didn't necessarily center within the original panel cutouts and the plastic posts are adequate for use as switches. The numerical keys in center keypad may require Dan's epoxy trick. Haven't gotten to that yet. Now the real question is... is there a clever way to make the Racal 1992 readout the difference in µHz between two GPS disciplined oscillators? My only other counter, an HP5384A, is offscale at 10.000 000.000 MHz . I'm referencing the counter with one Lucent RFTG-m-XO and clocking a Lucent RFTGm-II-XO. Things are working well enough to be beyond my counter's ability to see any jitter. The Racal says nanosecond time interval counter, so I bet there's a way to subtract and increase the resolution similar to an HP53131? tnx, Charles K4CSO Duluth, GA - Original Message - From: Matt Ettus [EMAIL PROTECTED] To: [EMAIL PROTECTED]; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, March 24, 2008 1:46 PM Subject: Re: [time-nuts] Racal-Dana 1992 switches On Mon, Mar 10, 2008 at 8:47 AM, Dan Rae [EMAIL PROTECTED] wrote: David McGaw wrote: Does anyone know of a source of push-button switches for the Racal-Dana 1992? I have one that over half are bad. No luck from Racal-Dana or their service house. The original makers of that switch (Omron?) stopped making them years ago. I wonder why? The last time I did this I found a switch at Jameco that was a near exact replacement. The only difference was that the button was a little too loose a fit and needed a dab of epoxy inside to hold it firmly in place. These have been working in mine now for at least five years. The type I used was KIE22 (29 cents each in 100s), however the ones I got then with a cross section shape blue plunger do not look exactly the same as the ones pictured in the current on line catalog. Some further research is indicated obviously... Once they start to go they will all need to be replaced, I'm afraid. I bought the ones in the catalog, but they don't fit. The footprint is bigger, for one thing. Matt ___ 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 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] Racal-Dana 1992 switches
I fixed the switches on my Pacific Measurements 1038-N10 by adding a small coil spring to the insides of each switch. I don't remember it being very hard to do. There is even a place in the center of each switch that is perfect for putting the spring. The springs were something I had around in bulk, and were cut to length with a pair of dikes that I didn't care about. -Chuck Harris Charles S. Osborne wrote: Matt, Not seeing a better alternative posted for the Racal 1992, and having dozens of similar bad Toko switches on some Pacific Measurements 1038-N10 Scalar Analyzers, I decided to buy a bunch of the Jameco ones and give it a try. ___ 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] Racal-Dana 1992 switches
On Mon, Mar 10, 2008 at 8:47 AM, Dan Rae [EMAIL PROTECTED] wrote: David McGaw wrote: Does anyone know of a source of push-button switches for the Racal-Dana 1992? I have one that over half are bad. No luck from Racal-Dana or their service house. The original makers of that switch (Omron?) stopped making them years ago. I wonder why? The last time I did this I found a switch at Jameco that was a near exact replacement. The only difference was that the button was a little too loose a fit and needed a dab of epoxy inside to hold it firmly in place. These have been working in mine now for at least five years. The type I used was KIE22 (29 cents each in 100s), however the ones I got then with a cross section shape blue plunger do not look exactly the same as the ones pictured in the current on line catalog. Some further research is indicated obviously... Once they start to go they will all need to be replaced, I'm afraid. I bought the ones in the catalog, but they don't fit. The footprint is bigger, for one thing. Matt ___ 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] Racal-Dana 1992 switches
Matt Ettus wrote: On Mon, Mar 10, 2008 at 8:47 AM, Dan Rae [EMAIL PROTECTED] wrote: The last time I did this I found a switch at Jameco that was a near exact replacement. The only difference was that the button was a little too loose a fit and needed a dab of epoxy inside to hold it firmly in place. These have been working in mine now for at least five years. The type I used was KIE22 (29 cents each in 100s), however the ones I got then with a cross section shape blue plunger do not look exactly the same as the ones pictured in the current on line catalog. Some further research is indicated obviously... I bought the ones in the catalog, but they don't fit. The footprint is bigger, for one thing. Sorry Matt, but I did say they looked different now. At the time, and I'm talking about five years ago maybe, that was the closest one I could find, and they have worked well for me since. I just checked in my stash of racal bits and there are none left... The originals were apparently from Toko. No longer made. And judging from a couple of ebay postings recently, the problem still occurs. Maybe someone else has found a more recent replacement? Good luck! Dan ___ 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] Racal-Dana 1992 switches
Matt, as you are saying this I remember that i got my first set of replacement pushbuttons from a German TOKO distributor! If I memember right the name was TOKO 3D and not TOKO 30 As you I found out that they don't manufacture switches anymore. All my efforts to find a supplier have not been successful. Best regards Ulrich Bangert -Ursprungliche Nachricht- Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von Matt Ettus Gesendet: Sonntag, 16. Marz 2008 01:24 An: [EMAIL PROTECTED]; Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Racal-Dana 1992 switches On Tue, Mar 11, 2008 at 1:05 PM, Dan Rae [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: Are these switches the same as the ones in the 1996? Mine works perfectly now, but if the switches are a ticking time bomb, I'm going to move it to a area with better temperature control, and start looking for a donor unit just in case.They both used the same switches. However, not all batches of these seem to have suffered the problem. If any on a unit go they may well all die. Also it is possible that they may have been replaced at some time in the past, I knew a technician at the service dept here in California who did a lot of them way back, when they were still supported... It is hard to be more specific... From examination of the dead ones I remember it was a rubber insert that died. They start to feel a bit less springy than usual, then die. My 29 cent Jameco switches have worked for me for at least five years now. I don't think you would want to have paid racal's prices for them anyway :^) You guys are bad luck... My switches were all fine until you started talking about them dying... I desoldered one of them and it appears to be marked TOKO 30. I didn't know TOKO made switches, and none are listed on their web page. Would Racal still have them? Matt ___ 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 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] Racal-Dana 1992 switches
On Tue, Mar 11, 2008 at 1:05 PM, Dan Rae [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: Are these switches the same as the ones in the 1996? Mine works perfectly now, but if the switches are a ticking time bomb, I'm going to move it to a area with better temperature control, and start looking for a donor unit just in case. They both used the same switches. However, not all batches of these seem to have suffered the problem. If any on a unit go they may well all die. Also it is possible that they may have been replaced at some time in the past, I knew a technician at the service dept here in California who did a lot of them way back, when they were still supported... It is hard to be more specific... From examination of the dead ones I remember it was a rubber insert that died. They start to feel a bit less springy than usual, then die. My 29 cent Jameco switches have worked for me for at least five years now. I don't think you would want to have paid racal's prices for them anyway :^) You guys are bad luck... My switches were all fine until you started talking about them dying... I desoldered one of them and it appears to be marked TOKO 30. I didn't know TOKO made switches, and none are listed on their web page. Would Racal still have them? Matt ___ 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] Racal-Dana 1992 switches
Are these switches the same as the ones in the 1996? Mine works perfectly now, but if the switches are a ticking time bomb, I'm going to move it to a area with better temperature control, and start looking for a donor unit just in case. -Dave -- Original message -- From: [EMAIL PROTECTED] Had the same trouble!!! bought a junk racal unit (they have several models) for $10 stole the switches from it!!! Sad way to send a unit to the scrap BIN!!! The unit is EXCELLENT well worth the repair effort Norm David McGaw wrote: Does anyone know of a source of push-button switches for the Racal-Dana 1992? I have one that over half are bad. No luck from Racal-Dana or their service house. Thanks, David ___ 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 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 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] Racal-Dana 1992 switches
[EMAIL PROTECTED] wrote: Are these switches the same as the ones in the 1996? Mine works perfectly now, but if the switches are a ticking time bomb, I'm going to move it to a area with better temperature control, and start looking for a donor unit just in case. They both used the same switches. However, not all batches of these seem to have suffered the problem. If any on a unit go they may well all die. Also it is possible that they may have been replaced at some time in the past, I knew a technician at the service dept here in California who did a lot of them way back, when they were still supported... It is hard to be more specific... From examination of the dead ones I remember it was a rubber insert that died. They start to feel a bit less springy than usual, then die. My 29 cent Jameco switches have worked for me for at least five years now. I don't think you would want to have paid racal's prices for them anyway :^) dr ___ 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] Racal-Dana 1992 switches
David McGaw wrote: Does anyone know of a source of push-button switches for the Racal-Dana 1992? I have one that over half are bad. No luck from Racal-Dana or their service house. The original makers of that switch (Omron?) stopped making them years ago. I wonder why? The last time I did this I found a switch at Jameco that was a near exact replacement. The only difference was that the button was a little too loose a fit and needed a dab of epoxy inside to hold it firmly in place. These have been working in mine now for at least five years. The type I used was KIE22 (29 cents each in 100s), however the ones I got then with a cross section shape blue plunger do not look exactly the same as the ones pictured in the current on line catalog. Some further research is indicated obviously... Once they start to go they will all need to be replaced, I'm afraid. Good luck, Dan ___ 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] Racal-Dana 1992 switches
Does anyone know of a source of push-button switches for the Racal-Dana 1992? I have one that over half are bad. No luck from Racal-Dana or their service house. Thanks, David ___ 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] Racal-Dana 1992 switches
Had the same trouble!!! bought a junk racal unit (they have several models) for $10 stole the switches from it!!! Sad way to send a unit to the scrap BIN!!! The unit is EXCELLENT well worth the repair effort Norm David McGaw [EMAIL PROTECTED] wrote: Does anyone know of a source of push-button switches for the Racal-Dana 1992? I have one that over half are bad. No luck from Racal-Dana or their service house. Thanks, David ___ 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 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.
