Re: [time-nuts] Surge Arresters
On 26 November 2012 15:44, Peter G. Viscarola pete...@osr.com wrote: Hi TimeNuts, What are people using for surge arresters between your GPS receiver and the antenna, at the entrance to your house? Several years ago there was lightning near my house, which I think went on the telephone lines, as it destroyed the ADSL modem, and destroyed the ethernet ports on everything connected to it. Luckily my instance company paid for this, although it was a battle with their computer experts, who clearly got very lost when coming to Sun workstations, despite me warning the insurers before that these were not ordinary computers. I once worked for a defunt company Belling Lee Intec who built Electromagnetic Pulse (EMP) protection systems for customers. 95% were military, but the BBC were also a big customer. These systems used to consist of 3 components. 1) Spark gap 2) Voltage dependant resistor 3) Low pass filter. You could take a similar approach, but with a band-pass filter. A VDR is not going to be any use at 1.6 GHz, so you could forget that part. But that method is not going to be foolproof, as a direct hit would destroy the capacitors in your BPF. If I was reallly concerned, then I'd look at using an optical interace. Use a battery to power the GPS antenna, modulate a laser and detect the RF on a photodiode connected by a metre of so of optical fibre. Whilst nothing can be considered 100% relieble, an optical interface is probably the best you can do. One might consider this OTT, but I don't see any other method can be very certain to work. Having had the problem with the ADSL modem on the telphone line, I did promise myself I'd build such an optical interface, which is much easy at ADSL frequencies. But I never did! Dave ___ 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] Surge Arresters
On 27 November 2012 09:15, David Kirkby david.kir...@onetel.net wrote: If I was reallly concerned, then I'd look at using an optical interace. Use a battery to power the GPS antenna, modulate a laser and detect the RF on a photodiode connected by a metre of so of optical fibre. Of course, I mean detect the RF modulated light on a photodiode. An optical interface is I believe the best you can do. I would certainly not trust surge protectors on this sort of thing. But a band-pass filter would do a pretty decent job, as there will be very little RF at those frequencies from lightning. I did once used to know the frequency range of EMP and ligthning, and whilst I can't remember them now, it is well below 1.6 GHz where there is significant energy. Dave ___ 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] Best phase detector / mixer for 100MHz?
Demian Martin wrote: I asked Wenzel about mixers for phase noise measurement and they directed me to Marki Microwave as what they use: http://www.markimicrowave.com/2770/Mixers.aspx I have not obtained or tested any myself but it's a pretty solid recommendation I think. I got this guy to add cross correlation to his FFT software suite: http://www.hpw-works.com/ however I have not built hardware to try it. He has a 30 day trial and its not expensive for what it is, $300. There's no evidence of a cross power spectrum function in this suite. One needs to be able to average at least 10,000 cross power spectra for some applications. 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] Best phase detector / mixer for 100MHz?
Bruce Griffiths schrieb: Richard (Rick) Karlquist wrote: On 11/23/2012 9:38 AM, Bruce Griffiths wrote: NIST have shown (at least at 10MHz) that the high level mixers they tested are noisier than the ZRPD1. Bruce Do you have a citation to where they said that? What you quoted doesn't make sense, at least, out of context. We need to clarify phase detector sensitivity specs. For conventional (IE 50 ohm) phase detectors, it is apples vs apples to just go by the volts per radian number. However, mixers like the ZRPD1 artificially triple the voltage sensitivity by operating at 500 ohms, and using transformers to connect to 50 ohm equipment. Doing this doesn't increase the possible signal to noise ratio. Consider this thought experiment. Build your best 500 ohm phase detector and postamp. Now replace with a 50 ohm phase detector and connect 3 postamps in parallel. It is a wash. Of course, you don't have to actually do this. You can simply use an op amp like the LT1028 with very low noise voltage. To actually put a 500 ohm detector on a par with a 50 ohm detector, the 500 ohm detector would need to use 3 diodes in series compared to one in the 50 ohm case. With only one diode per arm, the maximum drive power utilization is considerably lower. Rick Karlquist N6RK http://tf.boulder.nist.gov/general/pdf/2556.pdf Where all the high level mixers measured have a higher phase noise than lower level mixers/phase detectors like the ZRPD1. Bruce I can't confirm their results, at least not when plugged into a HP 11848A which loads the PD with 50 Ohms. Too bad they are unclear about the applied power. (1) Is it 'LO Power = maximum mixer power = 11 dBm', that is +11 dBm into both ports? (2) Is it +17 dBm due to 'mixers with a nominal LO rating of +7 dBm and maximum rating of +17 dBm'? Or, is it 50 mW as specified by Minicircuits, which would be the maximum mixer power as by (1)? With +16...+17 dBm signals I'm getting a noise floor of -175 dBc/Hz which is quite poor but understandable as in order to drive it at nominal input power, I have to put 6 dB attenuators between the oscillators and the phase detector. With only 3 dB attenuation, I'm getting -178 dBc/Hz. I wasn't sure if the 50 mW spec refers to the total RF power into the ZRPD-1 or if that is the max. power into each input, so I didn't try +17 dBm. I would have expected to see -180...-181 dBc/Hz. At that input level the 11848A internal PD gets me -179 dBc/Hz (no attenuators required). A WJ M9GC was 1 dB worse than the internal PD (also w/o attenuators). Surprisingly I've got the best results (-181) with a +23 dBm mixer (w/o attenuators of course). I did not have +23 dBm signals at hands, but I don't see that the ZRPD-1 can compete with the 11848A PD or an external +23 dBm mixer at input levels of +17 dBm and above. Adrian ___ 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] Best phase detector / mixer for 100MHz?
Bruce Griffiths schrieb: Demian Martin wrote: I asked Wenzel about mixers for phase noise measurement and they directed me to Marki Microwave as what they use: http://www.markimicrowave.com/2770/Mixers.aspx I have not obtained or tested any myself but it's a pretty solid recommendation I think. I got this guy to add cross correlation to his FFT software suite: http://www.hpw-works.com/ however I have not built hardware to try it. He has a 30 day trial and its not expensive for what it is, $300. There's no evidence of a cross power spectrum function in this suite. One needs to be able to average at least 10,000 cross power spectra for some applications. Bruce Here is one that does cross spectrum and more: http://www.sigview.com/ A while ago I tried it with a Xonar Essence XT sound card and the results looked quite promising. Then I got a 3562A to get to 100 kHz (don't follow me there! These can be challenging to fix if not impossible. PAL's and other unobtainable 'field programmables' appear to die faster than anything else in that boxes. Finally, I needed three of them to get one working unit...) Adrian ___ 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] Best phase detector / mixer for 100MHz?
Adrian wrote: Bruce Griffiths schrieb: Demian Martin wrote: I asked Wenzel about mixers for phase noise measurement and they directed me to Marki Microwave as what they use: http://www.markimicrowave.com/2770/Mixers.aspx I have not obtained or tested any myself but it's a pretty solid recommendation I think. I got this guy to add cross correlation to his FFT software suite: http://www.hpw-works.com/ however I have not built hardware to try it. He has a 30 day trial and its not expensive for what it is, $300. There's no evidence of a cross power spectrum function in this suite. One needs to be able to average at least 10,000 cross power spectra for some applications. Bruce Here is one that does cross spectrum and more: http://www.sigview.com/ A while ago I tried it with a Xonar Essence XT sound card and the results looked quite promising. Then I got a 3562A to get to 100 kHz (don't follow me there! These can be challenging to fix if not impossible. PAL's and other unobtainable 'field programmables' appear to die faster than anything else in that boxes. Finally, I needed three of them to get one working unit...) Adrian Tried that as well, how does one get a log y scale on the cross spectrum plot? 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] Best phase detector / mixer for 100MHz?
Bruce Griffiths schrieb: Adrian wrote: Bruce Griffiths schrieb: Demian Martin wrote: I asked Wenzel about mixers for phase noise measurement and they directed me to Marki Microwave as what they use: http://www.markimicrowave.com/2770/Mixers.aspx I have not obtained or tested any myself but it's a pretty solid recommendation I think. I got this guy to add cross correlation to his FFT software suite: http://www.hpw-works.com/ however I have not built hardware to try it. He has a 30 day trial and its not expensive for what it is, $300. There's no evidence of a cross power spectrum function in this suite. One needs to be able to average at least 10,000 cross power spectra for some applications. Bruce Here is one that does cross spectrum and more: http://www.sigview.com/ A while ago I tried it with a Xonar Essence XT sound card and the results looked quite promising. Then I got a 3562A to get to 100 kHz (don't follow me there! These can be challenging to fix if not impossible. PAL's and other unobtainable 'field programmables' appear to die faster than anything else in that boxes. Finally, I needed three of them to get one working unit...) Adrian Tried that as well, how does one get a log y scale on the cross spectrum plot? Bruce With Sigview? I'm sorry my trial version has long expired and even after installing the latest version it's now requiring a license key... Adrian ___ 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] Best phase detector / mixer for 100MHz?
Bruce, There's no evidence of a cross power spectrum function in this suite. One needs to be able to average at least 10,000 cross power spectra for some applications. In the PSD (power density) PSP (power spectrum) there are cross power and cross power complex average implemented (selectable using the spectrum channel mixer)! Additional to this you may apply / add averaging of the resulting spectrum or use additional peak hold. Average of 10'000 cross points is a large count and often seen on 1-4k sample size. Better in my opinion is to use a higher sample size 32k-64k and then less averaging is required. Just download the evaluation version with fully feature set. HpW ___ 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] Best phase detector / mixer for 100MHz?
Adrian wrote: Bruce Griffiths schrieb: Adrian wrote: Bruce Griffiths schrieb: Demian Martin wrote: I asked Wenzel about mixers for phase noise measurement and they directed me to Marki Microwave as what they use: http://www.markimicrowave.com/2770/Mixers.aspx I have not obtained or tested any myself but it's a pretty solid recommendation I think. I got this guy to add cross correlation to his FFT software suite: http://www.hpw-works.com/ however I have not built hardware to try it. He has a 30 day trial and its not expensive for what it is, $300. There's no evidence of a cross power spectrum function in this suite. One needs to be able to average at least 10,000 cross power spectra for some applications. Bruce Here is one that does cross spectrum and more: http://www.sigview.com/ A while ago I tried it with a Xonar Essence XT sound card and the results looked quite promising. Then I got a 3562A to get to 100 kHz (don't follow me there! These can be challenging to fix if not impossible. PAL's and other unobtainable 'field programmables' appear to die faster than anything else in that boxes. Finally, I needed three of them to get one working unit...) Adrian Tried that as well, how does one get a log y scale on the cross spectrum plot? Bruce With Sigview? I'm sorry my trial version has long expired and even after installing the latest version it's now requiring a license key... Adrian The help file states that the cross power spectrum is the product of the individual spectra - this is only correct if the individual spectra are real. 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] Best phase detector / mixer for 100MHz?
Support HpW-Works.com wrote: Bruce, There's no evidence of a cross power spectrum function in this suite. One needs to be able to average at least 10,000 cross power spectra for some applications. In the PSD (power density) PSP (power spectrum) there are cross power and cross power complex average implemented (selectable using the spectrum channel mixer)! Additional to this you may apply / add averaging of the resulting spectrum or use additional peak hold. Average of 10'000 cross points is a large count and often seen on 1-4k sample size. Better in my opinion is to use a higher sample size 32k-64k and then less averaging is required. The equivalent phase noise (measured in dBc/Hz) is essentially independent of the sample size. So increasing the sample size isnt particularly useful for reducing the phase noise floor. The increased frequency resolution achieved by increasing the sample size is only useful for measuring spurs. In the direct digital method of measuring phase noise a few terasamples (a few gigasamples at baseband) need to be processed to achieve a sufficiently low instrument noise floor. However with a sound card plus a mixer a somewhat lower number of samples should suffice since there is no carrier. Just download the evaluation version with fully feature set. HpW 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] Best phase detector / mixer for 100MHz?
Bruce Griffiths schrieb: Support HpW-Works.com wrote: Bruce, There's no evidence of a cross power spectrum function in this suite. One needs to be able to average at least 10,000 cross power spectra for some applications. In the PSD (power density) PSP (power spectrum) there are cross power and cross power complex average implemented (selectable using the spectrum channel mixer)! Additional to this you may apply / add averaging of the resulting spectrum or use additional peak hold. Average of 10'000 cross points is a large count and often seen on 1-4k sample size. Better in my opinion is to use a higher sample size 32k-64k and then less averaging is required. The equivalent phase noise (measured in dBc/Hz) is essentially independent of the sample size. So increasing the sample size isnt particularly useful for reducing the phase noise floor. The increased frequency resolution achieved by increasing the sample size is only useful for measuring spurs. In the direct digital method of measuring phase noise a few terasamples (a few gigasamples at baseband) need to be processed to achieve a sufficiently low instrument noise floor. However with a sound card plus a mixer a somewhat lower number of samples should suffice since there is no carrier. Just download the evaluation version with fully feature set. HpW Bruce A HP/Agilent VEE based solution would be much more flexible. There is a sound card driver available. I just didn't get deep enough into digital signal processing before the 3562A came... Adrian ___ 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] EIP545A 18GHz counter query
27/11/2012 14:18 I bought a 18GHz EIP545A counter which the vendor said was working fine the day before and when on overnight soak test, and also when last used some months agao. But when he checked it on the morning of my coming over to see it he found it had developed a fault... I bought it off him cheaply, as seen, hoping it might be fixable. Here's the basic tale: It was acquired displaying just dashes. I checked the PSU voltages and found the PSU section outputting well away from the manual figures. I corrected these and checked supplies for ripple and they were all good. I then decided to remove any board that was not essential to operation. It came with a GPIB option board, so I pulled it. Luckily this did some good and a working display appeared. There were three tantalum caps on this board, as a matter of interest I pulled a leg on each and tested them, all were OK. Refitting it killed the display back to dashes again, so I set it aside as having an unknown fault, and continued. I can get it to accurately display up to EXACTLY 188. MHz. Inputting 190. MHz gives zeros. It has three frequency bands. Band one works perfectly right up and well beyond its 10Hz to 100MHz range. Band two often doesn't work at all, and just diplays zeros, it's a 50 ohm input, compared to the 1meg 20pF Band 1 input. Sometimes by ramping the frequency up slowly from 100 MHz I can get a seemingly random reading. Band 3, the GHz range, doesn't work at all. Again, only zeros are displayed. The machine has quite a good range of self diagnosis tests. Tests are via the key pad. The first test checks the VCO and other stuff, and should display an accurate 200. MHz. It displays well over, always in the range 253.5 and the display isn't stable, it hovers over several KHz. There's a tree menu to see where this issue could lie. One limb suggests using a known good counter on the output of the VCO. I did this and the output is miles high in frequency, about double, and unstable. The tree menus goes on to suggest a phase lock circuitry fault. Further tests seem to depend in part upon using something called a Signature Analyser, which I have never even heard of They suggest an HP5004A, which is apparently pretty ancient. Is there a cheap way of acquiring something to do this sort of testing? I believe given a few pointers my scope, multi meter, sig gen and my other (working) Racal counter could take me further. It's a nice old thing, and I would quite like a means of counting into the higher frequencies it offers, but don't want to spend too much time or money on it. It works a damned sight more than when it first landed, which has kind of given me incentive to push a bit further, given I have a .pdf copy of the repair manual. Here's the page of the schematic I think is relevant, if it is a phase locked loop problem. This morning I realised there's a chip missing from a socket on the board in question. It's U6, a flip flop, part of the pre scaler I think? I assumed it was for some option, not fitted, but I am not so sure now. A Chinese Ebay seller is breaking one of these machines and he lists all the boards seperately, with decent photos. His board has this socket populated, and looking at the schematic, (linked at the bottom of this post), I think it's probably a vital component? I am sure the seller must have known about this, but who knows... I have ordered a new chip and will fit it whwen it arrives tomorrow. Now, assuming I ever get this thing up and running fully, is there a quick and dirty way of producing a test signal in the upper limits of its range to check it out, given my Marconi sig gen stops at 1040 MHz? Perhaps using a diode to give some harmonics? Diagram of the board I believe is faulty and missing the chip is at: http://www.gatesgarth.com/phaselockloop.jpg The text for this section, from the manual is at: http://www.gatesgarth.com/phaselocklooptext1.jpg and at http://www.gatesgarth.com/phaselocklooptext2.jpg Thanks for looking! -- Best Regards, Chris Wilson. mailto: ch...@chriswilson.tv ___ 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] pulse height
Said, I agree with all you say. My web page does not intend to show what is best, simply what is. Many people are puzzled by the issues of line impedance. Best practices have been discussed at length on this list, but always theoretically. I thought a few scope pictures and explanations would be useful. I did not think it would raise such an issue. Didier Sent from my Droid Razr 4G LTE wireless tracker. -Original Message- From: saidj...@aol.com To: time-nuts@febo.com Sent: Mon, 26 Nov 2012 4:01 PM Subject: Re: [time-nuts] pulse height Hi Didier, yes, if you put a 50 Ohm termination at the far end all looks good, but you are still driving a 91mA DC current through the cable during the high times, and that will have rippling effects on the driver board by loading the 5V power supply down with a 1Hz period. And if you forget to switch on the 50 Ohms end-termination, you get ~10V as shown in your plots, and you might just blow up your expensive instrument :) One reason I don't like fast edges being driven by 50 Ohms series resistance. Also, if you use 50 Ohms series termination, AND 50 Ohms end-termination, you still get a 2.5V pulse, enough voltage to cleanly switch most of today's logic inputs (either TTL or 3.3V LVCMOS). There are just so many things wrong with the 5 Ohms termination, for example what happens if you short that output to ground? What happens if you feed a parasitic pulse into the line, say from a nearby lightning strike or EMI or ESD event etc? With proper 50 Ohms series termination the pulse should simply be absorbed if it is not unreasonably high and the resistor is large enough. With 5 Ohms, the driver will likely fly off the PCB.. In terms of the incident wave switching issue that Hal mentioned, the wave will stay at about 2.5V for a while, then go to 5V, - again enough voltage to switch TTL and LVCMOS logic inputs cleanly. But then again it is never a good idea to daisy-chain inputs via BNC-T's anyway's. bye, Said In a message dated 11/26/2012 13:11:21 Pacific Standard Time, shali...@gmail.com writes: Said, I agree. I intended to complete the page by doing more tests, but the interesting point of the demonstration is that it is sufficient to match the cable at the far end, and in doing so, you preserve the full amplitude of the pulse. If you put 45 ohms in series and terminate in 50 ohms at the other end, you end up with half the signal. However you do not need to do that. That was the reason why I wrote the page in the first place. I will try to clarify that when I get a chance. Didier ___ 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] EIP545A 18GHz counter query
The first thing to do with any EIP counter is to remove and reseat all the PCBs. The card sockets they use are sometimes flaky. Simply doing this fixed most of the counters. This is especially true if they have been storfed for a while. YMMV, -John === 27/11/2012 14:18 I bought a 18GHz EIP545A counter which the vendor said was working fine the day before and when on overnight soak test, and also when last used some months agao. But when he checked it on the morning of my coming over to see it he found it had developed a fault... I bought it off him cheaply, as seen, hoping it might be fixable. Here's the basic tale: It was acquired displaying just dashes. I checked the PSU voltages and found the PSU section outputting well away from the manual figures. I corrected these and checked supplies for ripple and they were all good. I then decided to remove any board that was not essential to operation. It came with a GPIB option board, so I pulled it. Luckily this did some good and a working display appeared. There were three tantalum caps on this board, as a matter of interest I pulled a leg on each and tested them, all were OK. Refitting it killed the display back to dashes again, so I set it aside as having an unknown fault, and continued. I can get it to accurately display up to EXACTLY 188. MHz. Inputting 190. MHz gives zeros. It has three frequency bands. Band one works perfectly right up and well beyond its 10Hz to 100MHz range. Band two often doesn't work at all, and just diplays zeros, it's a 50 ohm input, compared to the 1meg 20pF Band 1 input. Sometimes by ramping the frequency up slowly from 100 MHz I can get a seemingly random reading. Band 3, the GHz range, doesn't work at all. Again, only zeros are displayed. The machine has quite a good range of self diagnosis tests. Tests are via the key pad. The first test checks the VCO and other stuff, and should display an accurate 200. MHz. It displays well over, always in the range 253.5 and the display isn't stable, it hovers over several KHz. There's a tree menu to see where this issue could lie. One limb suggests using a known good counter on the output of the VCO. I did this and the output is miles high in frequency, about double, and unstable. The tree menus goes on to suggest a phase lock circuitry fault. Further tests seem to depend in part upon using something called a Signature Analyser, which I have never even heard of They suggest an HP5004A, which is apparently pretty ancient. Is there a cheap way of acquiring something to do this sort of testing? I believe given a few pointers my scope, multi meter, sig gen and my other (working) Racal counter could take me further. It's a nice old thing, and I would quite like a means of counting into the higher frequencies it offers, but don't want to spend too much time or money on it. It works a damned sight more than when it first landed, which has kind of given me incentive to push a bit further, given I have a .pdf copy of the repair manual. Here's the page of the schematic I think is relevant, if it is a phase locked loop problem. This morning I realised there's a chip missing from a socket on the board in question. It's U6, a flip flop, part of the pre scaler I think? I assumed it was for some option, not fitted, but I am not so sure now. A Chinese Ebay seller is breaking one of these machines and he lists all the boards seperately, with decent photos. His board has this socket populated, and looking at the schematic, (linked at the bottom of this post), I think it's probably a vital component? I am sure the seller must have known about this, but who knows... I have ordered a new chip and will fit it whwen it arrives tomorrow. Now, assuming I ever get this thing up and running fully, is there a quick and dirty way of producing a test signal in the upper limits of its range to check it out, given my Marconi sig gen stops at 1040 MHz? Perhaps using a diode to give some harmonics? Diagram of the board I believe is faulty and missing the chip is at: http://www.gatesgarth.com/phaselockloop.jpg The text for this section, from the manual is at: http://www.gatesgarth.com/phaselocklooptext1.jpg and at http://www.gatesgarth.com/phaselocklooptext2.jpg Thanks for looking! -- Best Regards, Chris Wilson. mailto: ch...@chriswilson.tv ___ 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] EIP545A 18GHz counter query
This one is usually an easy fix. The EPROMS on the controller card are using tin plated sockets, and they become tin-whisker cities. The counter will usually have enough oomph to blow any transient whiskers away if it is left running, but if it sits the whiskers will grow quickly and prevent the CPU from passing its power on self-test, and you get the -- display. Take a high pressure air gun and blow under, around and through the EPROM sockets from all directions and angles. When you plug the board back in, it should start to work again... for a while. A more permanent fix involves removing the sockets and replacing them with gold plated sockets with machined pins. Also, on many of the 545A counters there is a design mistake on the power supply board where the wire tie that holds an electrolytic capacitor passes through the board. The holes the wire tie passes through are plated, and come through alongside of the +9V unregulated traces... bringing ground and +9V together. Drill or file the plating out of the holes to prevent spurious blowing of the mains fuse. -Chuck Harris Chris Wilson wrote: 27/11/2012 14:18 I bought a 18GHz EIP545A counter which the vendor said was working fine the day before and when on overnight soak test, and also when last used some months agao. But when he checked it on the morning of my coming over to see it he found it had developed a fault... I bought it off him cheaply, as seen, hoping it might be fixable. Here's the basic tale: It was acquired displaying just dashes. I checked the PSU voltages and found the PSU section outputting well away from the manual figures. I corrected these and checked supplies for ripple and they were all good. I then decided to remove any board that was not essential to operation. It came with a GPIB option board, so I pulled it. Luckily this did some good and a working display appeared. There were three tantalum caps on this board, as a matter of interest I pulled a leg on each and tested them, all were OK. Refitting it killed the display back to dashes again, so I set it aside as having an unknown fault, and continued. I can get it to accurately display up to EXACTLY 188. MHz. Inputting 190. MHz gives zeros. It has three frequency bands. Band one works perfectly right up and well beyond its 10Hz to 100MHz range. Band two often doesn't work at all, and just diplays zeros, it's a 50 ohm input, compared to the 1meg 20pF Band 1 input. Sometimes by ramping the frequency up slowly from 100 MHz I can get a seemingly random reading. Band 3, the GHz range, doesn't work at all. Again, only zeros are displayed. The machine has quite a good range of self diagnosis tests. Tests are via the key pad. The first test checks the VCO and other stuff, and should display an accurate 200. MHz. It displays well over, always in the range 253.5 and the display isn't stable, it hovers over several KHz. There's a tree menu to see where this issue could lie. One limb suggests using a known good counter on the output of the VCO. I did this and the output is miles high in frequency, about double, and unstable. The tree menus goes on to suggest a phase lock circuitry fault. Further tests seem to depend in part upon using something called a Signature Analyser, which I have never even heard of They suggest an HP5004A, which is apparently pretty ancient. Is there a cheap way of acquiring something to do this sort of testing? I believe given a few pointers my scope, multi meter, sig gen and my other (working) Racal counter could take me further. It's a nice old thing, and I would quite like a means of counting into the higher frequencies it offers, but don't want to spend too much time or money on it. It works a damned sight more than when it first landed, which has kind of given me incentive to push a bit further, given I have a .pdf copy of the repair manual. Here's the page of the schematic I think is relevant, if it is a phase locked loop problem. This morning I realised there's a chip missing from a socket on the board in question. It's U6, a flip flop, part of the pre scaler I think? I assumed it was for some option, not fitted, but I am not so sure now. A Chinese Ebay seller is breaking one of these machines and he lists all the boards seperately, with decent photos. His board has this socket populated, and looking at the schematic, (linked at the bottom of this post), I think it's probably a vital component? I am sure the seller must have known about this, but who knows... I have ordered a new chip and will fit it whwen it arrives tomorrow. Now, assuming I ever get this thing up and running fully, is there a quick and dirty way of producing a test signal in the upper limits of its range to check it out, given my Marconi sig gen stops at 1040 MHz? Perhaps using a diode to give some harmonics? Diagram of the board I believe is faulty and missing the chip is at: http://www.gatesgarth.com/phaselockloop.jpg The text for this
Re: [time-nuts] EIP545A 18GHz counter query
Not that it's likely to help you, but a signature analyzer uses a shift register with feedback to generate a 4 hex character signature from a serial data stream. It would only help if the troubleshooting tree includes a list a bad signatures for specific failures. http://www.prc68.com/I/HP5004.shtml Bob -Original Message- From: Chuck Harris Sent: Tuesday, November 27, 2012 7:45 AM To: Chris Wilson ; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] EIP545A 18GHz counter query This one is usually an easy fix. The EPROMS on the controller card are using tin plated sockets, and they become tin-whisker cities. The counter will usually have enough oomph to blow any transient whiskers away if it is left running, but if it sits the whiskers will grow quickly and prevent the CPU from passing its power on self-test, and you get the -- display. Take a high pressure air gun and blow under, around and through the EPROM sockets from all directions and angles. When you plug the board back in, it should start to work again... for a while. A more permanent fix involves removing the sockets and replacing them with gold plated sockets with machined pins. Also, on many of the 545A counters there is a design mistake on the power supply board where the wire tie that holds an electrolytic capacitor passes through the board. The holes the wire tie passes through are plated, and come through alongside of the +9V unregulated traces... bringing ground and +9V together. Drill or file the plating out of the holes to prevent spurious blowing of the mains fuse. -Chuck Harris Chris Wilson wrote: 27/11/2012 14:18 I bought a 18GHz EIP545A counter which the vendor said was working fine the day before and when on overnight soak test, and also when last used some months agao. But when he checked it on the morning of my coming over to see it he found it had developed a fault... I bought it off him cheaply, as seen, hoping it might be fixable. Here's the basic tale: It was acquired displaying just dashes. I checked the PSU voltages and found the PSU section outputting well away from the manual figures. I corrected these and checked supplies for ripple and they were all good. I then decided to remove any board that was not essential to operation. It came with a GPIB option board, so I pulled it. Luckily this did some good and a working display appeared. There were three tantalum caps on this board, as a matter of interest I pulled a leg on each and tested them, all were OK. Refitting it killed the display back to dashes again, so I set it aside as having an unknown fault, and continued. I can get it to accurately display up to EXACTLY 188. MHz. Inputting 190. MHz gives zeros. It has three frequency bands. Band one works perfectly right up and well beyond its 10Hz to 100MHz range. Band two often doesn't work at all, and just diplays zeros, it's a 50 ohm input, compared to the 1meg 20pF Band 1 input. Sometimes by ramping the frequency up slowly from 100 MHz I can get a seemingly random reading. Band 3, the GHz range, doesn't work at all. Again, only zeros are displayed. The machine has quite a good range of self diagnosis tests. Tests are via the key pad. The first test checks the VCO and other stuff, and should display an accurate 200. MHz. It displays well over, always in the range 253.5 and the display isn't stable, it hovers over several KHz. There's a tree menu to see where this issue could lie. One limb suggests using a known good counter on the output of the VCO. I did this and the output is miles high in frequency, about double, and unstable. The tree menus goes on to suggest a phase lock circuitry fault. Further tests seem to depend in part upon using something called a Signature Analyser, which I have never even heard of They suggest an HP5004A, which is apparently pretty ancient. Is there a cheap way of acquiring something to do this sort of testing? I believe given a few pointers my scope, multi meter, sig gen and my other (working) Racal counter could take me further. It's a nice old thing, and I would quite like a means of counting into the higher frequencies it offers, but don't want to spend too much time or money on it. It works a damned sight more than when it first landed, which has kind of given me incentive to push a bit further, given I have a .pdf copy of the repair manual. Here's the page of the schematic I think is relevant, if it is a phase locked loop problem. This morning I realised there's a chip missing from a socket on the board in question. It's U6, a flip flop, part of the pre scaler I think? I assumed it was for some option, not fitted, but I am not so sure now. A Chinese Ebay seller is breaking one of these machines and he lists all the boards seperately, with decent photos. His board has this socket populated, and looking at the schematic, (linked at the bottom of this post), I think it's probably a vital component? I am
Re: [time-nuts] EIP545A 18GHz counter query
It is also used to check ROMs and RAMs for good data. The service manual will often contain 'signatures' for each pinout of a device, as it runs through a set, respective routine. Specific start, stop, and clock signals are defined in the service manual. A very valuable tool. I have a 5005A. Also comes equipped with a voltmeter, ohmmeter and counter. Nothing a nice logic analyzer can't do, ...just simpler and quicker. -Don -- From: Bob Quenelle bobqh...@live.com Sent: Tuesday, November 27, 2012 10:05 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] EIP545A 18GHz counter query Not that it's likely to help you, but a signature analyzer uses a shift register with feedback to generate a 4 hex character signature from a serial data stream. It would only help if the troubleshooting tree includes a list a bad signatures for specific failures. http://www.prc68.com/I/HP5004.shtml Bob -Original Message- From: Chuck Harris Sent: Tuesday, November 27, 2012 7:45 AM To: Chris Wilson ; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] EIP545A 18GHz counter query This one is usually an easy fix. The EPROMS on the controller card are using tin plated sockets, and they become tin-whisker cities. The counter will usually have enough oomph to blow any transient whiskers away if it is left running, but if it sits the whiskers will grow quickly and prevent the CPU from passing its power on self-test, and you get the -- display. Take a high pressure air gun and blow under, around and through the EPROM sockets from all directions and angles. When you plug the board back in, it should start to work again... for a while. A more permanent fix involves removing the sockets and replacing them with gold plated sockets with machined pins. Also, on many of the 545A counters there is a design mistake on the power supply board where the wire tie that holds an electrolytic capacitor passes through the board. The holes the wire tie passes through are plated, and come through alongside of the +9V unregulated traces... bringing ground and +9V together. Drill or file the plating out of the holes to prevent spurious blowing of the mains fuse. -Chuck Harris Chris Wilson wrote: 27/11/2012 14:18 I bought a 18GHz EIP545A counter which the vendor said was working fine the day before and when on overnight soak test, and also when last used some months ago. But when he checked it on the morning of my coming over to see it he found it had developed a fault... I bought it off him cheaply, as seen, hoping it might be fixable. Here's the basic tale: It was acquired displaying just dashes. I checked the PSU voltages and found the PSU section outputting well away from the manual figures. I corrected these and checked supplies for ripple and they were all good. I then decided to remove any board that was not essential to operation. It came with a GPIB option board, so I pulled it. Luckily this did some good and a working display appeared. There were three tantalum caps on this board, as a matter of interest I pulled a leg on each and tested them, all were OK. Refitting it killed the display back to dashes again, so I set it aside as having an unknown fault, and continued. I can get it to accurately display up to EXACTLY 188. MHz Inputting 190. MHz gives zeros. It has three frequency bands. Band one works perfectly right up and well beyond its 10 Hz to 100 MHz range. Band two often doesn't work at all, and just displays zeros, it's a 50 ohm input, compared to the 1meg 20pF Band 1 input. Sometimes by ramping the frequency up slowly from 100 MHz I can get a seemingly random reading. Band 3, the GHz range, doesn't work at all. Again, only zeros are displayed. The machine has quite a good range of self diagnosis tests. Tests are via the key pad. The first test checks the VCO and other stuff, and should display an accurate 200. MHz It displays well over, always in the range 253.5 and the display isn't stable, it hovers over several KHz. There's a tree menu to see where this issue could lie. One limb suggests using a known good counter on the output of the VCO. I did this and the output is miles high in frequency, about double, and unstable. The tree menus goes on to suggest a phase lock circuitry fault. Further tests seem to depend in part upon using something called a Signature Analyzer, which I have never even heard of They suggest an HP5004A, which is apparently pretty ancient. Is there a cheap way of acquiring something to do this sort of testing? I believe given a few pointers my scope, multi meter, sig gen and my other (working) Racal counter could take me further. It's a nice old thing, and I would quite like a means of counting into the higher frequencies it offers, but
Re: [time-nuts] EIP545A 18GHz counter query
EIP was like many smaller TM companies, they by virtue of the size of lack of the desire to research component, manufacturing, life cycle testing, TQM, etc, etc. produced great instruments the day they were made. After that things went down hill. BTW, the big boys would forget all the above from time to time as well. What's that about history and repeating ? Having said that Chucks recommendation covers a lot of the issues, I've have over the year a dozen EIP and the socket/tin issue was one of the top 5 or so issues. Another is the power supplies specially around the pass transistors/regulators. A bit more air flow would have been suggested. But that's not just EIP. A couple other steps on the whisker issue, get a good stiff brush go over the whole board. If you don't own an air compressor get a cheap OIL LESS one. Remember the words OIL LESS. IF not invest in a OIL separator. Dont only blow around the connectors and under them. Once you worked around all the suspect parts, wash over the board with the compressed air starting at one corner and ending up at its opposing end. If you don't you run the chance of depositing the 'short' to a different place. BTW did i mention OIL LESS ? .. I've serviced quite a few instruments that when I got them had a nice ultra thin layer of sticky all over them. Sorry for the rant, all memories of TM repair were not the best :-) -pete On Tue, Nov 27, 2012 at 7:45 AM, Chuck Harris cfhar...@erols.com wrote: This one is usually an easy fix. The EPROMS on the controller card are using tin plated sockets, and they become tin-whisker cities. The counter will usually have enough oomph to blow any transient whiskers away if it is left running, but if it sits the whiskers will grow quickly and prevent the CPU from passing its power on self-test, and you get the -- display. Take a high pressure air gun and blow under, around and through the EPROM sockets from all directions and angles. When you plug the board back in, it should start to work again... for a while. A more permanent fix involves removing the sockets and replacing them with gold plated sockets with machined pins. Also, on many of the 545A counters there is a design mistake on the power supply board where the wire tie that holds an electrolytic capacitor passes through the board. The holes the wire tie passes through are plated, and come through alongside of the +9V unregulated traces... bringing ground and +9V together. Drill or file the plating out of the holes to prevent spurious blowing of the mains fuse. -Chuck Harris Chris Wilson wrote: 27/11/2012 14:18 I bought a 18GHz EIP545A counter which the vendor said was working fine the day before and when on overnight soak test, and also when last used some months agao. But when he checked it on the morning of my coming over to see it he found it had developed a fault... I bought it off him cheaply, as seen, hoping it might be fixable. Here's the basic tale: It was acquired displaying just dashes. I checked the PSU voltages and found the PSU section outputting well away from the manual figures. I corrected these and checked supplies for ripple and they were all good. I then decided to remove any board that was not essential to operation. It came with a GPIB option board, so I pulled it. Luckily this did some good and a working display appeared. There were three tantalum caps on this board, as a matter of interest I pulled a leg on each and tested them, all were OK. Refitting it killed the display back to dashes again, so I set it aside as having an unknown fault, and continued. I can get it to accurately display up to EXACTLY 188. MHz. Inputting 190. MHz gives zeros. It has three frequency bands. Band one works perfectly right up and well beyond its 10Hz to 100MHz range. Band two often doesn't work at all, and just diplays zeros, it's a 50 ohm input, compared to the 1meg 20pF Band 1 input. Sometimes by ramping the frequency up slowly from 100 MHz I can get a seemingly random reading. Band 3, the GHz range, doesn't work at all. Again, only zeros are displayed. The machine has quite a good range of self diagnosis tests. Tests are via the key pad. The first test checks the VCO and other stuff, and should display an accurate 200. MHz. It displays well over, always in the range 253.5 and the display isn't stable, it hovers over several KHz. There's a tree menu to see where this issue could lie. One limb suggests using a known good counter on the output of the VCO. I did this and the output is miles high in frequency, about double, and unstable. The tree menus goes on to suggest a phase lock circuitry fault. Further tests seem to depend in part upon using something called a Signature Analyser, which I have never even heard of They suggest an HP5004A, which is apparently pretty ancient. Is there a cheap way of acquiring something to do this sort of testing? I believe given
Re: [time-nuts] GPS antenna in attic?
While NPT (US) and BSPT (UK) are different, 1/2 and 3/4 variants are both 14 threads per inch and are similar enough to intermate, but are unlikely to seal. Since sealing is not a requirement here it ought to be good enough. Failing that, maybe one of our members on the continent would send you a short piece for a nominal fee. As I understand it, all continental European plumbing that is not hard metric is BSPT, and most is not hard metric so it's a hardware store item. Rich On 11/26/2012 8:28 PM, Peter Gottlieb wrote: Unfortunately not, it's part of the molded bottom piece of the antenna casing. On 11/26/2012 9:24 PM, Chris Albertson wrote: On Mon, Nov 26, 2012 at 5:51 PM, Peter Gottlieb n...@verizon.net mailto:n...@verizon.net wrote: The antenna I got fron Nichegeek on ebay uses British Pipe Threads! Just can't get anything here that matches it. Perhaps I should just get a unit with regular NPT size threads? Can anyone recommend a specific model which works well with the Thunderbolt and has such a threaded bottom? The typical antenna has a flat bottom that is bolted to some kind of mounting adaptor. Perhaps the thing with the British treads will un-bolt. THen you can buy a pipe flange at any hardware store. -- Chris Albertson Redondo Beach, California No virus found in this message. Checked by AVG - www.avg.com http://www.avg.com Version: 10.0.1427 / Virus Database: 2629/5420 - Release Date: 11/26/12 ___ 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. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] Surge Arresters
You really can't protect yourself from a direct strike. But that is rare. More common is a close strike. You first line of defense is to ground the metal mast (pipe). Place a ground clamp on the pipe and run a large ground write by the most direct route to a ground rod driven into the soil. This rod needs to be tied into the the building ground. You must use mechanical clamp type connections at each end.This ground system is direct almost all the energy away. If the coax wire is inside the mast it will be well protected. I owned a sail boat for years. On the ocean my 65 foot aluminum mast was the tallest conductor for many miles. But it was securely conected to a 8,000 pound lead keel that was in saltwater. Any lightening strike the energy would go mostly to the water. Then inside the atto you have a lighten/surge protector mounted on some kind of metal bulkhead. (A common electrical box works for this and is cheap. As long as you don't like in Orlando FL you should be fine -- Chris Albertson Redondo Beach, California ___ 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] EIP545A 18GHz counter query
Hi Chris, The first thing you should do is join the EIP_Microwave group at yahoo: http://tech.groups.yahoo.com/group/EIP_Microwave There's lots of info and help there for EIP counters. Don't worry about the signature analyzer for now. It would normally be used if the processor was dead. The fact that Band 1 works means that the processor/memory is okay. If the processor / memory / display related diagnostics like 02, 03, 04, 05 also pass, then signature analysis is unlikely to tell you anything more. The first thing you have to do is replace that missing chip. Bands 2 and 3 require the VCO and phase-lock circuitry to be working. As far as I can see, U6 is not optional. Until the 200 MHz test passes, you can't get any further. Be sure to check for obvious problems. I bought a 545A parts unit that wouldn't pass the 200 MHz test. It turned out that some of the board-to-board cables were plugged into the wrong connectors! I'm in the same position as you regarding testing at high frequencies. You might be able to get a signal at the second or third harmonic of your generator by cranking the level to the maximum and then using the counter's Band 3 frequency limits feature to only look at that frequency. My HP 8647A only goes to 1 GHz, but I can see harmonics up to 3 GHz. I've also picked up a few cheap YIG oscillators that have allowed me to test in the 1-10 GHz range. Watch out for the signal levels. YIG oscillators have lots of output! By the way, I'd be reluctant to purchase anything else from that vendor. Chips don't evaporate overnight. Mind you, I guess chips have fallen out of sockets. Any strange rattling noises when you shake it? :-) Ed On 11/27/2012 8:37 AM, Chris Wilson wrote: 27/11/2012 14:18 I bought a 18GHz EIP545A counter which the vendor said was working fine the day before and when on overnight soak test, and also when last used some months agao. But when he checked it on the morning of my coming over to see it he found it had developed a fault... I bought it off him cheaply, as seen, hoping it might be fixable. Here's the basic tale: It was acquired displaying just dashes. I checked the PSU voltages and found the PSU section outputting well away from the manual figures. I corrected these and checked supplies for ripple and they were all good. I then decided to remove any board that was not essential to operation. It came with a GPIB option board, so I pulled it. Luckily this did some good and a working display appeared. There were three tantalum caps on this board, as a matter of interest I pulled a leg on each and tested them, all were OK. Refitting it killed the display back to dashes again, so I set it aside as having an unknown fault, and continued. I can get it to accurately display up to EXACTLY 188. MHz. Inputting 190. MHz gives zeros. It has three frequency bands. Band one works perfectly right up and well beyond its 10Hz to 100MHz range. Band two often doesn't work at all, and just diplays zeros, it's a 50 ohm input, compared to the 1meg 20pF Band 1 input. Sometimes by ramping the frequency up slowly from 100 MHz I can get a seemingly random reading. Band 3, the GHz range, doesn't work at all. Again, only zeros are displayed. The machine has quite a good range of self diagnosis tests. Tests are via the key pad. The first test checks the VCO and other stuff, and should display an accurate 200. MHz. It displays well over, always in the range 253.5 and the display isn't stable, it hovers over several KHz. There's a tree menu to see where this issue could lie. One limb suggests using a known good counter on the output of the VCO. I did this and the output is miles high in frequency, about double, and unstable. The tree menus goes on to suggest a phase lock circuitry fault. Further tests seem to depend in part upon using something called a Signature Analyser, which I have never even heard of They suggest an HP5004A, which is apparently pretty ancient. Is there a cheap way of acquiring something to do this sort of testing? I believe given a few pointers my scope, multi meter, sig gen and my other (working) Racal counter could take me further. It's a nice old thing, and I would quite like a means of counting into the higher frequencies it offers, but don't want to spend too much time or money on it. It works a damned sight more than when it first landed, which has kind of given me incentive to push a bit further, given I have a .pdf copy of the repair manual. Here's the page of the schematic I think is relevant, if it is a phase locked loop problem. This morning I realised there's a chip missing from a socket on the board in question. It's U6, a flip flop, part of the pre scaler I think? I assumed it was for some option, not fitted, but I am not so sure now. A Chinese Ebay seller is breaking one of these machines and he lists all the boards seperately, with decent photos. His board has this socket populated, and
Re: [time-nuts] Z3805 two frequency maxima
I followed your argument and tried to synthesize such a signal. I built a simple power combiner (3 times 18 ohms resistors) and combined the 10 MHz reference output of my signal generator with a 5 MHz signal from the same generators regular output at the same amplitude. My oscilloscope showed the locked phase of the two signals. I applied this combo signal to the SR620 and observed a wonderful two-maxima histogram. When reducing the amplitude of the 5 MHz signal (while keeping the 10 MHz amplitude) the peaks distance decreased linearly with the voltage reduction, until the peaks melted togehter at about -20dBc. On the one hand it was a success, but why only 20dBc? My experiences with the Z3805 showed a 5 MHz subharmonic at 62dBc and the peaks spaced at 60 ps. So I startet to add phase delay to the 5 MHz signal by looping-in some meters of coax cable. When coming to a delay time of 66 ns I could distinguish the two peaks at a spacing of 240 ps down to an amplitude ratio of about 1000, that is, 60dB. Volker Am 18.11.2012 03:36, schrieb Bob Camp: Hi Just good old Fourier series. Bob On Nov 17, 2012, at 9:12 PM, Volker Esperail...@t-online.de wrote: I'm impressed - but what law is behind this? Am 17.11.2012 21:26, schrieb Bob Camp: Hi 60 db isn't to bad a number. More or less: 100 ns - 100 ps is 1000:1. 20 log of that is 60 db. 100 ps to 60 ps is about 4.4 db. That would sum up to -64.4 dbc. The main gotcha is that you *might* also have some 15 MHz (and higher) energy in the signal as well. Also phase gets into the calculation. Still, pretty close. Bob On Nov 17, 2012, at 12:50 PM, Volker Esperail...@t-online.de wrote: So let's have a look into the machine... and what do we see? There's a nice little Symmetrcom oven, with the sign reading 5.000 MHz - bingo! May be there's a time saving way to determine the energie of the sub harmonic: using my spectrum analyzer. It tells me, that there's a 5 MHz subharmonic at the level of -62dBc. How would you have calculated the energy? What would be your ansatz? Thanks so far Volker Am 17.11.2012 17:55, schrieb Bob Camp: Hi That's what you get if you have sub harmonic energy in the output of your OCXO. I'd bet you a warm glass of beer that you have a 5 MHz / doubled to 10 MHz MTI OCXO in your Z3805. If you have a lot of time on your hands, you can calculate the likely level of the energy from the amount of jitter (spacing between the two peaks) you get. Bob On Nov 17, 2012, at 11:41 AM, Volker Esperail...@t-online.dewrote: Hi, while playing with my recently aquired TIC (SR620) and measuring the period time of some oscillators I discovered something I hadn't expect at all: The output of my GPSDO (Z3805) writes two maxima in the period histogram (at a spacing of 60ps). I didn't believe that result and assumed an inherent error in my measuring setup or the counter itself. So I plugged another oscillator, the reference TCXO of my signal generator (RS SMX), and that result made me happy and uneasy at once: The TCXO hat only one maximum. I havn't calculated the ADEV curve, yet. See pictures. Why does my GPSDO produce such a weird result? Cheers Volker - DF9PL DSCF1437_bbb.jpgDSCF1439_bbb.jpg___ 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. ___ 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. ___ 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] EIP545A 18GHz counter query
snip I'm in the same position as you regarding testing at high frequencies. You might be able to get a signal at the second or third harmonic of your generator by cranking the level to the maximum and then using the counter's Band 3 frequency limits feature to only look at that frequency. snip You can also get a step recovery diode and generate a bunch of harmonics... DonL -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.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] Z3805 two frequency maxima
Hi Phase does indeed matter, it just messes up the math. Most multiplier / filter combinations have significant phase shift between the sub-harmonic and the carrier. You rarely know what the phase shift is, but you can read the sub-harmonic. The simple db to jitter ratio gets you close enough to make rational decisions on how much filtering you need. You could play with filter phase but I've never seen that done in practice. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Volker Esper Sent: Tuesday, November 27, 2012 2:34 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3805 two frequency maxima I followed your argument and tried to synthesize such a signal. I built a simple power combiner (3 times 18 ohms resistors) and combined the 10 MHz reference output of my signal generator with a 5 MHz signal from the same generators regular output at the same amplitude. My oscilloscope showed the locked phase of the two signals. I applied this combo signal to the SR620 and observed a wonderful two-maxima histogram. When reducing the amplitude of the 5 MHz signal (while keeping the 10 MHz amplitude) the peaks distance decreased linearly with the voltage reduction, until the peaks melted togehter at about -20dBc. On the one hand it was a success, but why only 20dBc? My experiences with the Z3805 showed a 5 MHz subharmonic at 62dBc and the peaks spaced at 60 ps. So I startet to add phase delay to the 5 MHz signal by looping-in some meters of coax cable. When coming to a delay time of 66 ns I could distinguish the two peaks at a spacing of 240 ps down to an amplitude ratio of about 1000, that is, 60dB. Volker Am 18.11.2012 03:36, schrieb Bob Camp: Hi Just good old Fourier series. Bob On Nov 17, 2012, at 9:12 PM, Volker Esperail...@t-online.de wrote: I'm impressed - but what law is behind this? Am 17.11.2012 21:26, schrieb Bob Camp: Hi 60 db isn't to bad a number. More or less: 100 ns - 100 ps is 1000:1. 20 log of that is 60 db. 100 ps to 60 ps is about 4.4 db. That would sum up to -64.4 dbc. The main gotcha is that you *might* also have some 15 MHz (and higher) energy in the signal as well. Also phase gets into the calculation. Still, pretty close. Bob On Nov 17, 2012, at 12:50 PM, Volker Esperail...@t-online.de wrote: So let's have a look into the machine... and what do we see? There's a nice little Symmetrcom oven, with the sign reading 5.000 MHz - bingo! May be there's a time saving way to determine the energie of the sub harmonic: using my spectrum analyzer. It tells me, that there's a 5 MHz subharmonic at the level of -62dBc. How would you have calculated the energy? What would be your ansatz? Thanks so far Volker Am 17.11.2012 17:55, schrieb Bob Camp: Hi That's what you get if you have sub harmonic energy in the output of your OCXO. I'd bet you a warm glass of beer that you have a 5 MHz / doubled to 10 MHz MTI OCXO in your Z3805. If you have a lot of time on your hands, you can calculate the likely level of the energy from the amount of jitter (spacing between the two peaks) you get. Bob On Nov 17, 2012, at 11:41 AM, Volker Esperail...@t-online.de wrote: Hi, while playing with my recently aquired TIC (SR620) and measuring the period time of some oscillators I discovered something I hadn't expect at all: The output of my GPSDO (Z3805) writes two maxima in the period histogram (at a spacing of 60ps). I didn't believe that result and assumed an inherent error in my measuring setup or the counter itself. So I plugged another oscillator, the reference TCXO of my signal generator (RS SMX), and that result made me happy and uneasy at once: The TCXO hat only one maximum. I havn't calculated the ADEV curve, yet. See pictures. Why does my GPSDO produce such a weird result? Cheers Volker - DF9PL DSCF1437_bbb.jpgDSCF1439_bbb.jpg ___ 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. ___ 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
Re: [time-nuts] EIP545A 18GHz counter query
Hi Don, Yes, I've heard of SRDs. I think every Rb standard uses them. I recently purchased a YIG Multiplier that includes an SRD followed by a YIG filter. But, from my reading, there are some significant issues that you run into when driving an SRD. I'm still playing with mine. Ed On 11/27/2012 2:15 PM, Don Latham wrote: snip I'm in the same position as you regarding testing at high frequencies. You might be able to get a signal at the second or third harmonic of your generator by cranking the level to the maximum and then using the counter's Band 3 frequency limits feature to only look at that frequency. snip You can also get a step recovery diode and generate a bunch of harmonics... DonL ___ 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] EIP545A 18GHz counter query
You can also overdrive a mmic and get good results. That is what I'm using as the oscillator for my 1.296 GHz beacon. Bob On Nov 27, 2012, at 15:45, Ed Palmer ed_pal...@sasktel.net wrote: Hi Don, Yes, I've heard of SRDs. I think every Rb standard uses them. I recently purchased a YIG Multiplier that includes an SRD followed by a YIG filter. But, from my reading, there are some significant issues that you run into when driving an SRD. I'm still playing with mine. Ed On 11/27/2012 2:15 PM, Don Latham wrote: snip I'm in the same position as you regarding testing at high frequencies. You might be able to get a signal at the second or third harmonic of your generator by cranking the level to the maximum and then using the counter's Band 3 frequency limits feature to only look at that frequency. snip You can also get a step recovery diode and generate a bunch of harmonics... DonL ___ 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] EIP545A 18GHz counter query
Hi Ed: I have one of these too; it takes in about 200 MHz, output 0.4-1.8 GHz. ten ohm coil, also a heater at 28 v. I also have a filter that uses about the same voltage/current. I did find an LED/battery charger module from China, pretty cheap, that purports to be pwm adjustable; we'll see. I'll try driving it with an Arduino. Don Ed Palmer Hi Don, Yes, I've heard of SRDs. I think every Rb standard uses them. I recently purchased a YIG Multiplier that includes an SRD followed by a YIG filter. But, from my reading, there are some significant issues that you run into when driving an SRD. I'm still playing with mine. Ed On 11/27/2012 2:15 PM, Don Latham wrote: snip I'm in the same position as you regarding testing at high frequencies. You might be able to get a signal at the second or third harmonic of your generator by cranking the level to the maximum and then using the counter's Band 3 frequency limits feature to only look at that frequency. snip You can also get a step recovery diode and generate a bunch of harmonics... DonL ___ 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.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] EIP545A 18GHz counter query
Hi Chris, The first thing you should do is join the EIP_Microwave group at yahoo: http://tech.groups.yahoo.com/group/EIP_Microwave There's lots of info and help there for EIP counters. Don't worry about the signature analyzer for now. It would normally be used if the processor was dead. The fact that Band 1 works means that the processor/memory is okay. If the processor / memory / display related diagnostics like 02, 03, 04, 05 also pass, then signature analysis is unlikely to tell you anything more. The first thing you have to do is replace that missing chip. Bands 2 and 3 require the VCO and phase-lock circuitry to be working. As far as I can see, U6 is not optional. Until the 200 MHz test passes, you can't get any further. Be sure to check for obvious problems. I bought a 545A parts unit that wouldn't pass the 200 MHz test. It turned out that some of the board-to-board cables were plugged into the wrong connectors! I'm in the same position as you regarding testing at high frequencies. You might be able to get a signal at the second or third harmonic of your generator by cranking the level to the maximum and then using the counter's Band 3 frequency limits feature to only look at that frequency. My HP 8647A only goes to 1 GHz, but I can see harmonics up to 3 GHz. I've also picked up a few cheap YIG oscillators that have allowed me to test in the 1-10 GHz range. Watch out for the signal levels. YIG oscillators have lots of output! By the way, I'd be reluctant to purchase anything else from that vendor. Chips don't evaporate overnight. Mind you, I guess chips have fallen out of sockets. Any strange rattling noises when you shake it? :-) Ed 27/11/2012 22:08 Thanks Ed, someone else kindly e-mailed me and told me of the existence of the Yahoo reflector for EIP equipment. Sadly U6 is definitely not rattling about in the case :( Happily I didn't pay a lot for this thing :) I have had all the boards out and double checked all the cables are correctly connected. The only issue apart from the missing chip is that installing the GPIB board kills the thing completely. I am not sure why, but I can live without that. It seems it may the power meter and DAC options, at least the buttons are present, but pressing them gives Error 13. Are the buttons present on all the front panels? The processor, memory and display tests pass AOK. If I get it running further I may try and boorow a friends microwave sig gen, rather than try getting clever and break it agin with too high an input signal. Thanks very much for the tips Ed, much appreciated. -- Best Regards, Chris Wilson. ___ 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] Z3805 two frequency maxima
Very interesting indeed. Two questions: after adding the 66nS phase shift, were the two peaks at 66nS when at the same amplitude? Then, while reducing the amplitude of the 5MHz, were they getting closer (until the 240pS)? On Tue, Nov 27, 2012 at 9:21 PM, Bob Camp li...@rtty.us wrote: Hi Phase does indeed matter, it just messes up the math. Most multiplier / filter combinations have significant phase shift between the sub-harmonic and the carrier. You rarely know what the phase shift is, but you can read the sub-harmonic. The simple db to jitter ratio gets you close enough to make rational decisions on how much filtering you need. You could play with filter phase but I've never seen that done in practice. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Volker Esper Sent: Tuesday, November 27, 2012 2:34 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3805 two frequency maxima I followed your argument and tried to synthesize such a signal. I built a simple power combiner (3 times 18 ohms resistors) and combined the 10 MHz reference output of my signal generator with a 5 MHz signal from the same generators regular output at the same amplitude. My oscilloscope showed the locked phase of the two signals. I applied this combo signal to the SR620 and observed a wonderful two-maxima histogram. When reducing the amplitude of the 5 MHz signal (while keeping the 10 MHz amplitude) the peaks distance decreased linearly with the voltage reduction, until the peaks melted togehter at about -20dBc. On the one hand it was a success, but why only 20dBc? My experiences with the Z3805 showed a 5 MHz subharmonic at 62dBc and the peaks spaced at 60 ps. So I startet to add phase delay to the 5 MHz signal by looping-in some meters of coax cable. When coming to a delay time of 66 ns I could distinguish the two peaks at a spacing of 240 ps down to an amplitude ratio of about 1000, that is, 60dB. Volker Am 18.11.2012 03:36, schrieb Bob Camp: Hi Just good old Fourier series. Bob On Nov 17, 2012, at 9:12 PM, Volker Esperail...@t-online.de wrote: I'm impressed - but what law is behind this? Am 17.11.2012 21:26, schrieb Bob Camp: Hi 60 db isn't to bad a number. More or less: 100 ns - 100 ps is 1000:1. 20 log of that is 60 db. 100 ps to 60 ps is about 4.4 db. That would sum up to -64.4 dbc. The main gotcha is that you *might* also have some 15 MHz (and higher) energy in the signal as well. Also phase gets into the calculation. Still, pretty close. Bob On Nov 17, 2012, at 12:50 PM, Volker Esperail...@t-online.de wrote: So let's have a look into the machine... and what do we see? There's a nice little Symmetrcom oven, with the sign reading 5.000 MHz - bingo! May be there's a time saving way to determine the energie of the sub harmonic: using my spectrum analyzer. It tells me, that there's a 5 MHz subharmonic at the level of -62dBc. How would you have calculated the energy? What would be your ansatz? Thanks so far Volker Am 17.11.2012 17:55, schrieb Bob Camp: Hi That's what you get if you have sub harmonic energy in the output of your OCXO. I'd bet you a warm glass of beer that you have a 5 MHz / doubled to 10 MHz MTI OCXO in your Z3805. If you have a lot of time on your hands, you can calculate the likely level of the energy from the amount of jitter (spacing between the two peaks) you get. Bob On Nov 17, 2012, at 11:41 AM, Volker Esperail...@t-online.de wrote: Hi, while playing with my recently aquired TIC (SR620) and measuring the period time of some oscillators I discovered something I hadn't expect at all: The output of my GPSDO (Z3805) writes two maxima in the period histogram (at a spacing of 60ps). I didn't believe that result and assumed an inherent error in my measuring setup or the counter itself. So I plugged another oscillator, the reference TCXO of my signal generator (RS SMX), and that result made me happy and uneasy at once: The TCXO hat only one maximum. I havn't calculated the ADEV curve, yet. See pictures. Why does my GPSDO produce such a weird result? Cheers Volker - DF9PL DSCF1437_bbb.jpgDSCF1439_bbb.jpg ___ 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
Re: [time-nuts] Z3805 two frequency maxima
Now, that you ask: the measurements are in that range, yes, though it's not exactly the values. time shift 12ns - spacing 10ns 28ns35ns 66ns55ns 0ns 8ns and yes, the peaks get closer while reducing the amplitude of the 5MHz, it's almost exactly linear: With the 10MHz at 200mV and a time shift of 66ns, I measured the following spacings: 5MHz voltage in mV spacing in ns 20055 10027.5 5013.0 25 6.5 12.5 3.3 6.3 1.6 3.2 0.86 1.6 0.44 0.8 0,24 The functional relation of voltage ratio and spacing is quite obvious. I have to admit, that my counter is not at it's optimal calibration. I will adjust it first before I can tell you more. To be precise: all these findings were made while trying to adjust the trigger circuits of the counter. To do that I needed a well designed 180 degrees power splitter - but I didn't have one at the time. I've received a Mini Circuits ZSCJ-2-2 recently, now I can go on with my adjustments. Though the SR620 TIC is a great instrument when hunting the pico seconds we have to realize, that it's a thermal design desaster (I have to apologize to all sr620 friends). I have to run it for at least 12 hours if not 24 to be shure, that every single part is at a more or less stationary thermal state. Some (NERC) say ...never switch it off. I can't do that during the week, we have to wait till weekend. Thanks for your response Volker Am 28.11.2012 00:25, schrieb Azelio Boriani: Very interesting indeed. Two questions: after adding the 66nS phase shift, were the two peaks at 66nS when at the same amplitude? Then, while reducing the amplitude of the 5MHz, were they getting closer (until the 240pS)? On Tue, Nov 27, 2012 at 9:21 PM, Bob Campli...@rtty.us wrote: Hi Phase does indeed matter, it just messes up the math. Most multiplier / filter combinations have significant phase shift between the sub-harmonic and the carrier. You rarely know what the phase shift is, but you can read the sub-harmonic. The simple db to jitter ratio gets you close enough to make rational decisions on how much filtering you need. You could play with filter phase but I've never seen that done in practice. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Volker Esper Sent: Tuesday, November 27, 2012 2:34 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3805 two frequency maxima I followed your argument and tried to synthesize such a signal. I built a simple power combiner (3 times 18 ohms resistors) and combined the 10 MHz reference output of my signal generator with a 5 MHz signal from the same generators regular output at the same amplitude. My oscilloscope showed the locked phase of the two signals. I applied this combo signal to the SR620 and observed a wonderful two-maxima histogram. When reducing the amplitude of the 5 MHz signal (while keeping the 10 MHz amplitude) the peaks distance decreased linearly with the voltage reduction, until the peaks melted togehter at about -20dBc. On the one hand it was a success, but why only 20dBc? My experiences with the Z3805 showed a 5 MHz subharmonic at 62dBc and the peaks spaced at 60 ps. So I startet to add phase delay to the 5 MHz signal by looping-in some meters of coax cable. When coming to a delay time of 66 ns I could distinguish the two peaks at a spacing of 240 ps down to an amplitude ratio of about 1000, that is, 60dB. Volker Am 18.11.2012 03:36, schrieb Bob Camp: Hi Just good old Fourier series. Bob On Nov 17, 2012, at 9:12 PM, Volker Esperail...@t-online.de wrote: I'm impressed - but what law is behind this? Am 17.11.2012 21:26, schrieb Bob Camp: Hi 60 db isn't to bad a number. More or less: 100 ns -100 ps is 1000:1. 20 log of that is 60 db. 100 ps to 60 ps is about 4.4 db. That would sum up to -64.4 dbc. The main gotcha is that you *might* also have some 15 MHz (and higher) energy in the signal as well. Also phase gets into the calculation. Still, pretty close. Bob On Nov 17, 2012, at 12:50 PM, Volker Esperail...@t-online.de wrote: So let's have a look into the machine... and what do we see? There's a nice little Symmetrcom oven, with the sign reading 5.000 MHz - bingo! May be there's a time saving way to determine the energie of the sub harmonic: using my spectrum analyzer. It tells me, that there's a 5 MHz subharmonic at the level of -62dBc. How would you have calculated the energy? What would be your ansatz? Thanks so far Volker Am 17.11.2012 17:55, schrieb Bob Camp: Hi That's what you get if you have sub harmonic energy in the output of your OCXO. I'd bet you a warm glass of beer that you have a 5 MHz / doubled to 10 MHz MTI
Re: [time-nuts] EIP545A 18GHz counter query
Boy great thread running here. I have a number of older EIPs that all work and have been repaired. Hard to pass up the $25ers. I also have several newer ones 545 and 585s. EIP became a bit more clever on these in how they process the YIG signals and thats the place I am having issues on all 3. Its one of those I'll have to get back to that soon. Lots of good comments in the thread. Thanks Paul WB8TSL On Tue, Nov 27, 2012 at 5:20 PM, Chris Wilson ch...@chriswilson.tv wrote: Hi Chris, The first thing you should do is join the EIP_Microwave group at yahoo: http://tech.groups.yahoo.com/group/EIP_Microwave There's lots of info and help there for EIP counters. Don't worry about the signature analyzer for now. It would normally be used if the processor was dead. The fact that Band 1 works means that the processor/memory is okay. If the processor / memory / display related diagnostics like 02, 03, 04, 05 also pass, then signature analysis is unlikely to tell you anything more. The first thing you have to do is replace that missing chip. Bands 2 and 3 require the VCO and phase-lock circuitry to be working. As far as I can see, U6 is not optional. Until the 200 MHz test passes, you can't get any further. Be sure to check for obvious problems. I bought a 545A parts unit that wouldn't pass the 200 MHz test. It turned out that some of the board-to-board cables were plugged into the wrong connectors! I'm in the same position as you regarding testing at high frequencies. You might be able to get a signal at the second or third harmonic of your generator by cranking the level to the maximum and then using the counter's Band 3 frequency limits feature to only look at that frequency. My HP 8647A only goes to 1 GHz, but I can see harmonics up to 3 GHz. I've also picked up a few cheap YIG oscillators that have allowed me to test in the 1-10 GHz range. Watch out for the signal levels. YIG oscillators have lots of output! By the way, I'd be reluctant to purchase anything else from that vendor. Chips don't evaporate overnight. Mind you, I guess chips have fallen out of sockets. Any strange rattling noises when you shake it? :-) Ed 27/11/2012 22:08 Thanks Ed, someone else kindly e-mailed me and told me of the existence of the Yahoo reflector for EIP equipment. Sadly U6 is definitely not rattling about in the case :( Happily I didn't pay a lot for this thing :) I have had all the boards out and double checked all the cables are correctly connected. The only issue apart from the missing chip is that installing the GPIB board kills the thing completely. I am not sure why, but I can live without that. It seems it may the power meter and DAC options, at least the buttons are present, but pressing them gives Error 13. Are the buttons present on all the front panels? The processor, memory and display tests pass AOK. If I get it running further I may try and boorow a friends microwave sig gen, rather than try getting clever and break it agin with too high an input signal. Thanks very much for the tips Ed, much appreciated. -- Best Regards, Chris Wilson. ___ 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] Z3805 two frequency maxima
Greetings! I just joined the list a few hours ago and you have already peeked my interest in this aside: On Tuesday, 27 November 2012, Volker Esper wrote: Though the SR620 TIC is a great instrument when hunting the pico seconds we have to realize, that it's a thermal design desaster (I have to apologize to all sr620 friends). I have to run it for at least 12 hours if not 24 to be shure, that every single part is at a more or less stationary thermal state. Some (NERC) say ...never switch it off. We have an application in which we plan to travel 7 hours with an SR620 turned off, then turn it on for 1 hour and take measurements we expect to be accurate to less than 1ns. I would appreciate more information about how to get reliable data out of this instrument. Thanks, Paul ___ 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] EIP545A 18GHz counter query
Chris, Put a ohmmeter across any of the capacitors on the GPIB board and see what the resistance is. Since that kills the unit, I suspect the resistance is low (?shorted tantalum) or there is a problem with one of the chips that takes the 5 VDC buss down. Make sure of the polarity of your DMM, + to + and - to ground. Alternatively, there is a short on the +5 VDC line at the connector on the mother board that is 'actuated' by plugging the board in. Measure the resistance to ground of the +5 VDC buss (power off) with the GPIB board plugged in and not plugged in. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Wilson Sent: Tuesday, November 27, 2012 4:20 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] EIP545A 18GHz counter query Hi Chris, The first thing you should do is join the EIP_Microwave group at yahoo: http://tech.groups.yahoo.com/group/EIP_Microwave There's lots of info and help there for EIP counters. Don't worry about the signature analyzer for now. It would normally be used if the processor was dead. The fact that Band 1 works means that the processor/memory is okay. If the processor / memory / display related diagnostics like 02, 03, 04, 05 also pass, then signature analysis is unlikely to tell you anything more. The first thing you have to do is replace that missing chip. Bands 2 and 3 require the VCO and phase-lock circuitry to be working. As far as I can see, U6 is not optional. Until the 200 MHz test passes, you can't get any further. Be sure to check for obvious problems. I bought a 545A parts unit that wouldn't pass the 200 MHz test. It turned out that some of the board-to-board cables were plugged into the wrong connectors! I'm in the same position as you regarding testing at high frequencies. You might be able to get a signal at the second or third harmonic of your generator by cranking the level to the maximum and then using the counter's Band 3 frequency limits feature to only look at that frequency. My HP 8647A only goes to 1 GHz, but I can see harmonics up to 3 GHz. I've also picked up a few cheap YIG oscillators that have allowed me to test in the 1-10 GHz range. Watch out for the signal levels. YIG oscillators have lots of output! By the way, I'd be reluctant to purchase anything else from that vendor. Chips don't evaporate overnight. Mind you, I guess chips have fallen out of sockets. Any strange rattling noises when you shake it? :-) Ed 27/11/2012 22:08 Thanks Ed, someone else kindly e-mailed me and told me of the existence of the Yahoo reflector for EIP equipment. Sadly U6 is definitely not rattling about in the case :( Happily I didn't pay a lot for this thing :) I have had all the boards out and double checked all the cables are correctly connected. The only issue apart from the missing chip is that installing the GPIB board kills the thing completely. I am not sure why, but I can live without that. It seems it may the power meter and DAC options, at least the buttons are present, but pressing them gives Error 13. Are the buttons present on all the front panels? The processor, memory and display tests pass AOK. If I get it running further I may try and boorow a friends microwave sig gen, rather than try getting clever and break it agin with too high an input signal. Thanks very much for the tips Ed, much appreciated. -- Best Regards, Chris Wilson. ___ 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] Z3805 two frequency maxima
You might get better answers by starting a new thread rather than hiding your question in an existing thread. (Use your New message button rather than Reply, and cut-paste the To address from an old message, then type in the new Subject.) Using a useful Subject also helps people find things in the archives. paul.destef...@willamettealumni.com said: We have an application in which we plan to travel 7 hours with an SR620 turned off, then turn it on for 1 hour and take measurements we expect to be accurate to less than 1ns. I would appreciate more information about how to get reliable data out of this instrument. What do you mean by accurate to less than 1ns? What are you trying to measure? The internal clock in the SR620 may be off a bit. The specs should be in the users manual. In general, you have to wait a while for it to warm up and it will depend on which options you have. (Some units have good crystals. Some have low cost crystals to save $$ if they will normally run off an in-house reference clock.) Suppose it's worst case 1 part in 1E9, just to pick a handy number to work with. If you measure the width of a 1 microsecond pulse, the error from the clock will be 1E-15 seconds or 1E-6 ns. If you measure the time between 2 consecutive PPS pulses, the error from the clock will be 1E-9 seconds or 1 ns. -- These are my opinions. I hate spam. ___ 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.
