Re: [time-nuts] HP53132A vs SR625
On 03/17/2013 01:43 AM, Bob Camp wrote: Hi The 53132 is indeed a fine counter. It's got another flaw though - right at 10 MHz the resolution takes a dive. If you are doing time nut stuff, that may be a significant issue. The frequency averaging method can make use of the beating of the reference clock against the incomming clock, to get more information on the frequency difference. If the clocks are near each other, it takes longer averaging to get the same effective resolution. You can expect the same type of effect around frequency ratios like 3/2 etc. This is expected as it is a systematic effect where most of the new samples does not bring any new info as they pop in systematically in the places where they don't give info. Adding noise (sloppy trigger) could actually improve the precission, as it would combat the quantization effect. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP53132A vs SR625
Hi If the gate time is fairly long, the notch in the resolution is quite narrow. You don't have to be very far off of 10 MHz to go back to fairly high resolution. Again, not a knock on this fine counter, just something to watch out for. Bob On Mar 17, 2013, at 7:45 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 03/17/2013 01:43 AM, Bob Camp wrote: Hi The 53132 is indeed a fine counter. It's got another flaw though - right at 10 MHz the resolution takes a dive. If you are doing time nut stuff, that may be a significant issue. The frequency averaging method can make use of the beating of the reference clock against the incomming clock, to get more information on the frequency difference. If the clocks are near each other, it takes longer averaging to get the same effective resolution. You can expect the same type of effect around frequency ratios like 3/2 etc. This is expected as it is a systematic effect where most of the new samples does not bring any new info as they pop in systematically in the places where they don't give info. Adding noise (sloppy trigger) could actually improve the precission, as it would combat the quantization effect. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] HP53132A vs SR625
Hi Bob, On 03/17/2013 02:08 PM, Bob Camp wrote: Hi If the gate time is fairly long, the notch in the resolution is quite narrow. As expected. The gate-time controls the width of this notch. You don't have to be very far off of 10 MHz to go back to fairly high resolution. Again, not a knock on this fine counter, just something to watch out for. Indeed. This is know your tool stuff. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP53132A vs SR625
Volker, The error I have seen was in the high xE-011's to the low xE-010's. the only way around it was to turn on relative measurements, which then subtracted out this error. That error makes the unit almost useless to me. The factory told me as long as it is within specs they will ship it after cal and not bother trying to improve this. The acceptable specs are pretty crappy in tim-nuts terms: +/-350pico * frequency with a 1s gate time. Thats straight from the user manual and assuming no reference error. From the manual: Frequency Accuracy: ± ((100ps typ [350 ps max])/Gate + Timebase Error ) x Frequency That equates to up to +/-3.5E-010 if my math is right! Not so impressive. I can confirm Ricks comment about HP 53132A units not showing that type of error. Not knowing how big the error is without another non-SRS counter to compare to, and if it may actually be bigger than spec is a problem. I don't remember if it shows up when feeding the counter its own reference. Bye Said Sent From iPhone On Mar 16, 2013, at 16:06, Volker Esper ail...@t-online.de wrote: What small error are we speaking about? The statement that SRS users have to tolerates a small error while HP users don't seems a little to general to me. IMHO we might be a bit more precise. Anyone who's already done an error analysis for - say - a 10MHz count and a comparison of the counters? In real life every type of equipment has it's domain, where it has it's specific advantage. Could it be, that's the case for these counters, too? Cheers Volker Am 16.03.2013 19:57, schrieb Rick Karlquist: 1) I paid quite a bit of money and I had it calibrated and fixed by SRS, and it still exhibits a significant frequency offset with a perfect reference and perfect DUT!!! SRS says a small frequency error is normal, well that prevents me from using the unit as a frequency counter, for me it's only useful as a relative display frequency counter. HP doesn't have such a frequency error, so no worries there. I worked with the guy who designed the HP53132A. He would never tolerate as normal a so-called small error. The term frequency counter brings to mind something that digitally counts zero crossings and should never have an error. First of all, even if that is all you do, it is still possible to screw it up. Secondly, counters have relied on analog interpolation even going back to the HP524 circa 1950. There is no theoretical basis of having zero error in this case, but the idea is that you display the number of digits that are commensurate with the worst case accuracy of your interpolator. Again, my colleague who designed the interpolator did very high quality work. I am pleased to learn that our stuff is better than the stuff from the company up the road. Rick Karlquist N6RK HP Santa Clara Division 1979-1998 (still working for Agilent!) ___ 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] HP53132A vs SR625
Hi Said, That equation looks similar in form to the specs for any counter. What are the comparable equations for the 53132A or the 5370(A or B)? Ed On 3/17/2013 10:41 AM, Said Jackson wrote: Volker, The error I have seen was in the high xE-011's to the low xE-010's. the only way around it was to turn on relative measurements, which then subtracted out this error. That error makes the unit almost useless to me. The factory told me as long as it is within specs they will ship it after cal and not bother trying to improve this. The acceptable specs are pretty crappy in tim-nuts terms: +/-350pico * frequency with a 1s gate time. Thats straight from the user manual and assuming no reference error. From the manual: Frequency Accuracy: ± ((100ps typ [350 ps max])/Gate + Timebase Error ) x Frequency That equates to up to +/-3.5E-010 if my math is right! Not so impressive. I can confirm Ricks comment about HP 53132A units not showing that type of error. Not knowing how big the error is without another non-SRS counter to compare to, and if it may actually be bigger than spec is a problem. I don't remember if it shows up when feeding the counter its own reference. Bye Said Sent From iPhone On Mar 16, 2013, at 16:06, Volker Esper ail...@t-online.de wrote: What small error are we speaking about? The statement that SRS users have to tolerates a small error while HP users don't seems a little to general to me. IMHO we might be a bit more precise. Anyone who's already done an error analysis for - say - a 10MHz count and a comparison of the counters? In real life every type of equipment has it's domain, where it has it's specific advantage. Could it be, that's the case for these counters, too? Cheers Volker Am 16.03.2013 19:57, schrieb Rick Karlquist: 1) I paid quite a bit of money and I had it calibrated and fixed by SRS, and it still exhibits a significant frequency offset with a perfect reference and perfect DUT!!! SRS says a small frequency error is normal, well that prevents me from using the unit as a frequency counter, for me it's only useful as a relative display frequency counter. HP doesn't have such a frequency error, so no worries there. I worked with the guy who designed the HP53132A. He would never tolerate as normal a so-called small error. The term frequency counter brings to mind something that digitally counts zero crossings and should never have an error. First of all, even if that is all you do, it is still possible to screw it up. Secondly, counters have relied on analog interpolation even going back to the HP524 circa 1950. There is no theoretical basis of having zero error in this case, but the idea is that you display the number of digits that are commensurate with the worst case accuracy of your interpolator. Again, my colleague who designed the interpolator did very high quality work. I am pleased to learn that our stuff is better than the stuff from the company up the road. Rick Karlquist N6RK HP Santa Clara Division 1979-1998 (still working for Agilent!) ___ 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] HP53132A vs SR625
Ed, the calculation is the same, however the numbers are 100ps for 53132A versus 350ps, and I have not seen an average systemic offset being displayed on any of the 3x 53132A units I use, and I see one on the SR-620. That's why I sent it into SRS for calibration, paid the $$$ and got it back with the same exact offset and a statement that it is operating within specifications so no adjustment is necessary. HP manages to show zero error on average, with the digits bouncing back and forth. The SRS unit manages to show a hard frequency offset. If I remember correctly the SR-620 even shows this offset with it's own reference connected to the inputs, the HP does not. bye, Said In a message dated 3/17/2013 11:26:16 Pacific Daylight Time, ed_pal...@sasktel.net writes: Hi Said, That equation looks similar in form to the specs for any counter. What are the comparable equations for the 53132A or the 5370(A or B)? Ed ___ 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] HP53132A vs SR625
On 3/17/2013 1:56 PM, Ed Palmer wrote: On 3/17/2013 10:41 AM, Said Jackson wrote: The acceptable specs are pretty crappy in tim-nuts terms: +/-350pico * frequency with a 1s gate time. Thats straight from the user manual and assuming no reference error. From the manual: Frequency Accuracy: ± ((100ps typ [350 ps max])/Gate + Timebase Error ) x Frequency That equation looks similar in form to the specs for any counter. What are the comparable equations for the 53132A or the 5370(A or B)? 5370B is similar ±Resolution ±(Time Base Error) x FREQ ± (100 ps Systematic/Gate Time) x FREQ ___ 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] HP53132A vs SR625
Hi, I just powered on my SR and looked for the offset, when the 10 MHz reference is connected to the input (at a gate time of 1s without further averaging). It shows an offset of 0 to 400uHz which should represent a mean error of 2E-11, while the manual predicts an error of about 1E-10 (as Said told us, and as my manual tells me). That's within the spec. Unfortunately I don't have a 53132, but the manual of the HP predicts an error of E-10 - just the same value as with the SR. If I was a manufacturer of such a counter, I wouldn't show the digits beneath the predicted error, but SR does: it shows 13 digits. How many digits does the HP show? Could it be, that the HP shows one or two digits less at this measurement? With only 11 digits displayed, the SR wouldn't show any offset, too. By the way, HP's 100ps isn't the worst case value - that is 500ps. So, what's the big difference beetween them? - the predicted error is the same for both (or am I wrong?). - my SR is within it's specification at 10 MHz (I did the calibration myself). - the uncertain digits (below 1mHz, in this case) are within the error spec, and I guess they are uncertain because they come from an analog circuitry (namely the interpolation circuitry). The statement, that a counter only has to count zero crossings and nothing else, isn't right at that point, and that's the case for both, - and they both have to deal with the analog stuff, such as noise and so on Again, since I don't have a 53132 I can't compare the counters directly, I was just a little concerned about a discussion - no offense! - that compares apples and oranges. Thank you for a still inspiring discussion! Volker Am 17.03.2013 20:05, schrieb saidj...@aol.com: Ed, the calculation is the same, however the numbers are 100ps for 53132A versus 350ps, and I have not seen an average systemic offset being displayed on any of the 3x 53132A units I use, and I see one on the SR-620. That's why I sent it into SRS for calibration, paid the $$$ and got it back with the same exact offset and a statement that it is operating within specifications so no adjustment is necessary. HP manages to show zero error on average, with the digits bouncing back and forth. The SRS unit manages to show a hard frequency offset. If I remember correctly the SR-620 even shows this offset with it's own reference connected to the inputs, the HP does not. bye, Said In a message dated 3/17/2013 11:26:16 Pacific Daylight Time, ed_pal...@sasktel.net writes: Hi Said, That equation looks similar in form to the specs for any counter. What are the comparable equations for the 53132A or the 5370(A or B)? Ed ___ 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] HP53132A vs SR625
Hi Volker, there are some issues here, first the worst case frequency systematic uncertainty is 100ps for the 53132A, not 350ps as on the SRS unit or 500ps as you stated. So they are not the same, they are 3.5x different. From the Agilent manual: Systematic Uncertainty: Agilent 53131A Agilent 53132A tacc tacc typical 100 ps 10 ps worst case 300 ps 100 ps Notice the 10ps typical error, and 100ps worst case error. That compares to a 100ps typical error for the SR-620 or 10x worse typically than the 53132A. So we get 10x worse typically, and 3.5x less for the worst case - in my opinion these units are not even in the same class. Now for practical matters, I just measured the SR-620 we have with a randomly selected 53132A. Both connected to their own reference input. 2-second samples on both, and here are the results: The SR-620 shows a frequency error of -0.00203Hz consistently.That's 2.03E-010. Within its specifications but making the unit useless to me. The 53132A showed an error of only 2E-012 to 8E-012. So about 25x better accuracy! And the 53132A is showing 12 digits on the front panel as well for 2 second gate times at 10MHz. Nor does it require time-consuming and error prone and annoying internal adjustments to achieve this. What's even more damming for the SRS unit: as I increased the sample size (1s gate time is the max front panel selection, so I had to increase sample size instead of gate time) the error stayed persistent independent of sample size or thus measurement length. On the HP unit however, increasing the gate time made the error get smaller and smaller, and at 10+ seconds gate time I got 13 digits of resolution out of the unit, and an error of only 1E-012 at that point. So in summary, the SR-620 requires careful user adjustment of internal adjustment points. I don't have time to do that, so sent it in and paid the $600+ or so (if I remember correctly) for the standard calibration fee they charge. I got a unit back with the error unchanged, which was the original reason I sent it in to them in the first place. An error of 2E-010 makes the unit useless as we are in need of measuring xE-011 accurately. If I had time to learn how to calibrate the unit myself, I may do so, but even then you showed a 2E-011 error on your carefully adjusted unit, whereas I measured a 2 to 8E-012 error on a random non-adjusted 53132A unit here. Still about 3x to 10x difference in performance. If someone is interested in a swap of a working 53132A with input-c option for our SR-620 I would like to talk to you offline. I would even throw-in an FEI Rubidium reference in that swap, even though the SRS' sell for about $2300, and the 53132A'a go for about $1400. bye, Said In a message dated 3/17/2013 13:02:46 Pacific Daylight Time, ail...@t-online.de writes: I just powered on my SR and looked for the offset, when the 10 MHz reference is connected to the input (at a gate time of 1s without further averaging). It shows an offset of 0 to 400uHz which should represent a mean error of 2E-11, while the manual predicts an error of about 1E-10 (as Said told us, and as my manual tells me). That's within the spec. Unfortunately I don't have a 53132, but the manual of the HP predicts an error of E-10 - just the same value as with the SR. ___ 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] HP53132A vs SR625
On 03/17/2013 08:05 PM, saidj...@aol.com wrote: Ed, the calculation is the same, however the numbers are 100ps for 53132A versus 350ps, and I have not seen an average systemic offset being displayed on any of the 3x 53132A units I use, and I see one on the SR-620. That's why I sent it into SRS for calibration, paid the $$$ and got it back with the same exact offset and a statement that it is operating within specifications so no adjustment is necessary. HP manages to show zero error on average, with the digits bouncing back and forth. The SRS unit manages to show a hard frequency offset. If I remember correctly the SR-620 even shows this offset with it's own reference connected to the inputs, the HP does not. You can calibrate it out. SRS techs just being lazy, but it is not a bad design. They could have included it in the autocal thought. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP53132A vs SR625
Hi Be very careful of what the 53132(1) reports with the ref out connected to the input. You are guaranteed to be in the dead zone on the counter when you do that. Bob On Mar 17, 2013, at 5:33 PM, saidj...@aol.com wrote: Hi Volker, there are some issues here, first the worst case frequency systematic uncertainty is 100ps for the 53132A, not 350ps as on the SRS unit or 500ps as you stated. So they are not the same, they are 3.5x different. From the Agilent manual: Systematic Uncertainty: Agilent 53131A Agilent 53132A tacc tacc typical 100 ps 10 ps worst case 300 ps 100 ps Notice the 10ps typical error, and 100ps worst case error. That compares to a 100ps typical error for the SR-620 or 10x worse typically than the 53132A. So we get 10x worse typically, and 3.5x less for the worst case - in my opinion these units are not even in the same class. Now for practical matters, I just measured the SR-620 we have with a randomly selected 53132A. Both connected to their own reference input. 2-second samples on both, and here are the results: The SR-620 shows a frequency error of -0.00203Hz consistently.That's 2.03E-010. Within its specifications but making the unit useless to me. The 53132A showed an error of only 2E-012 to 8E-012. So about 25x better accuracy! And the 53132A is showing 12 digits on the front panel as well for 2 second gate times at 10MHz. Nor does it require time-consuming and error prone and annoying internal adjustments to achieve this. What's even more damming for the SRS unit: as I increased the sample size (1s gate time is the max front panel selection, so I had to increase sample size instead of gate time) the error stayed persistent independent of sample size or thus measurement length. On the HP unit however, increasing the gate time made the error get smaller and smaller, and at 10+ seconds gate time I got 13 digits of resolution out of the unit, and an error of only 1E-012 at that point. So in summary, the SR-620 requires careful user adjustment of internal adjustment points. I don't have time to do that, so sent it in and paid the $600+ or so (if I remember correctly) for the standard calibration fee they charge. I got a unit back with the error unchanged, which was the original reason I sent it in to them in the first place. An error of 2E-010 makes the unit useless as we are in need of measuring xE-011 accurately. If I had time to learn how to calibrate the unit myself, I may do so, but even then you showed a 2E-011 error on your carefully adjusted unit, whereas I measured a 2 to 8E-012 error on a random non-adjusted 53132A unit here. Still about 3x to 10x difference in performance. If someone is interested in a swap of a working 53132A with input-c option for our SR-620 I would like to talk to you offline. I would even throw-in an FEI Rubidium reference in that swap, even though the SRS' sell for about $2300, and the 53132A'a go for about $1400. bye, Said In a message dated 3/17/2013 13:02:46 Pacific Daylight Time, ail...@t-online.de writes: I just powered on my SR and looked for the offset, when the 10 MHz reference is connected to the input (at a gate time of 1s without further averaging). It shows an offset of 0 to 400uHz which should represent a mean error of 2E-11, while the manual predicts an error of about 1E-10 (as Said told us, and as my manual tells me). That's within the spec. Unfortunately I don't have a 53132, but the manual of the HP predicts an error of E-10 - just the same value as with the SR. ___ 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] HP53132A vs SR625
Bob, Thats why the 53132A counter reduces the resolution to one digit less at that frequency, and why we use an external divide by 2 for 10MHz measurements to regain that digit. I wanted to be fair and compare apples to apples. If i use our 5Mhz input, the 53132A will be even better. We are always measuring at the deadzone because our gpsdo's are phase aligned via gps. But I can guarantee that the counter can differentiate xE-011 difference in frequencies, as we measure at this level all the time... And I assume the zero offset error of the Sr-620 is also due to this deadzone issue. Btw I was wrong the 53132A now sells for $999 on Ebay. The SR-620 is about $1450. Bye Said Sent From iPhone On Mar 17, 2013, at 16:22, Bob Camp li...@rtty.us wrote: Hi Be very careful of what the 53132(1) reports with the ref out connected to the input. You are guaranteed to be in the dead zone on the counter when you do that. Bob On Mar 17, 2013, at 5:33 PM, saidj...@aol.com wrote: Hi Volker, there are some issues here, first the worst case frequency systematic uncertainty is 100ps for the 53132A, not 350ps as on the SRS unit or 500ps as you stated. So they are not the same, they are 3.5x different. From the Agilent manual: Systematic Uncertainty: Agilent 53131A Agilent 53132A tacc tacc typical 100 ps 10 ps worst case 300 ps 100 ps Notice the 10ps typical error, and 100ps worst case error. That compares to a 100ps typical error for the SR-620 or 10x worse typically than the 53132A. So we get 10x worse typically, and 3.5x less for the worst case - in my opinion these units are not even in the same class. Now for practical matters, I just measured the SR-620 we have with a randomly selected 53132A. Both connected to their own reference input. 2-second samples on both, and here are the results: The SR-620 shows a frequency error of -0.00203Hz consistently.That's 2.03E-010. Within its specifications but making the unit useless to me. The 53132A showed an error of only 2E-012 to 8E-012. So about 25x better accuracy! And the 53132A is showing 12 digits on the front panel as well for 2 second gate times at 10MHz. Nor does it require time-consuming and error prone and annoying internal adjustments to achieve this. What's even more damming for the SRS unit: as I increased the sample size (1s gate time is the max front panel selection, so I had to increase sample size instead of gate time) the error stayed persistent independent of sample size or thus measurement length. On the HP unit however, increasing the gate time made the error get smaller and smaller, and at 10+ seconds gate time I got 13 digits of resolution out of the unit, and an error of only 1E-012 at that point. So in summary, the SR-620 requires careful user adjustment of internal adjustment points. I don't have time to do that, so sent it in and paid the $600+ or so (if I remember correctly) for the standard calibration fee they charge. I got a unit back with the error unchanged, which was the original reason I sent it in to them in the first place. An error of 2E-010 makes the unit useless as we are in need of measuring xE-011 accurately. If I had time to learn how to calibrate the unit myself, I may do so, but even then you showed a 2E-011 error on your carefully adjusted unit, whereas I measured a 2 to 8E-012 error on a random non-adjusted 53132A unit here. Still about 3x to 10x difference in performance. If someone is interested in a swap of a working 53132A with input-c option for our SR-620 I would like to talk to you offline. I would even throw-in an FEI Rubidium reference in that swap, even though the SRS' sell for about $2300, and the 53132A'a go for about $1400. bye, Said In a message dated 3/17/2013 13:02:46 Pacific Daylight Time, ail...@t-online.de writes: I just powered on my SR and looked for the offset, when the 10 MHz reference is connected to the input (at a gate time of 1s without further averaging). It shows an offset of 0 to 400uHz which should represent a mean error of 2E-11, while the manual predicts an error of about 1E-10 (as Said told us, and as my manual tells me). That's within the spec. Unfortunately I don't have a 53132, but the manual of the HP predicts an error of E-10 - just the same value as with the SR. ___ 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
Re: [time-nuts] HP53132A vs SR625
Hi This brings up the basic how bad is it question. Since the counter is fundamentally a 200 ps gizmo, a simple period measurement at 1 second will give you ~ 10 digits per second. That's with no magic multiple sample stuff at all. At an offset / noise / what ever state where the multiple sample stuff works 100%, you get ~ 12 digits per second. I doubt you ever get everything so perfect that you are down to 10 digits / second. Bob On Mar 17, 2013, at 7:41 PM, Said Jackson saidj...@aol.com wrote: Bob, Thats why the 53132A counter reduces the resolution to one digit less at that frequency, and why we use an external divide by 2 for 10MHz measurements to regain that digit. I wanted to be fair and compare apples to apples. If i use our 5Mhz input, the 53132A will be even better. We are always measuring at the deadzone because our gpsdo's are phase aligned via gps. But I can guarantee that the counter can differentiate xE-011 difference in frequencies, as we measure at this level all the time... And I assume the zero offset error of the Sr-620 is also due to this deadzone issue. Btw I was wrong the 53132A now sells for $999 on Ebay. The SR-620 is about $1450. Bye Said Sent From iPhone On Mar 17, 2013, at 16:22, Bob Camp li...@rtty.us wrote: Hi Be very careful of what the 53132(1) reports with the ref out connected to the input. You are guaranteed to be in the dead zone on the counter when you do that. Bob On Mar 17, 2013, at 5:33 PM, saidj...@aol.com wrote: Hi Volker, there are some issues here, first the worst case frequency systematic uncertainty is 100ps for the 53132A, not 350ps as on the SRS unit or 500ps as you stated. So they are not the same, they are 3.5x different. From the Agilent manual: Systematic Uncertainty: Agilent 53131A Agilent 53132A tacc tacc typical 100 ps 10 ps worst case 300 ps 100 ps Notice the 10ps typical error, and 100ps worst case error. That compares to a 100ps typical error for the SR-620 or 10x worse typically than the 53132A. So we get 10x worse typically, and 3.5x less for the worst case - in my opinion these units are not even in the same class. Now for practical matters, I just measured the SR-620 we have with a randomly selected 53132A. Both connected to their own reference input. 2-second samples on both, and here are the results: The SR-620 shows a frequency error of -0.00203Hz consistently.That's 2.03E-010. Within its specifications but making the unit useless to me. The 53132A showed an error of only 2E-012 to 8E-012. So about 25x better accuracy! And the 53132A is showing 12 digits on the front panel as well for 2 second gate times at 10MHz. Nor does it require time-consuming and error prone and annoying internal adjustments to achieve this. What's even more damming for the SRS unit: as I increased the sample size (1s gate time is the max front panel selection, so I had to increase sample size instead of gate time) the error stayed persistent independent of sample size or thus measurement length. On the HP unit however, increasing the gate time made the error get smaller and smaller, and at 10+ seconds gate time I got 13 digits of resolution out of the unit, and an error of only 1E-012 at that point. So in summary, the SR-620 requires careful user adjustment of internal adjustment points. I don't have time to do that, so sent it in and paid the $600+ or so (if I remember correctly) for the standard calibration fee they charge. I got a unit back with the error unchanged, which was the original reason I sent it in to them in the first place. An error of 2E-010 makes the unit useless as we are in need of measuring xE-011 accurately. If I had time to learn how to calibrate the unit myself, I may do so, but even then you showed a 2E-011 error on your carefully adjusted unit, whereas I measured a 2 to 8E-012 error on a random non-adjusted 53132A unit here. Still about 3x to 10x difference in performance. If someone is interested in a swap of a working 53132A with input-c option for our SR-620 I would like to talk to you offline. I would even throw-in an FEI Rubidium reference in that swap, even though the SRS' sell for about $2300, and the 53132A'a go for about $1400. bye, Said In a message dated 3/17/2013 13:02:46 Pacific Daylight Time, ail...@t-online.de writes: I just powered on my SR and looked for the offset, when the 10 MHz reference is connected to the input (at a gate time of 1s without further averaging). It shows an offset of 0 to 400uHz which should represent a mean error of 2E-11, while the manual predicts an error of about 1E-10 (as Said told us, and as my manual tells me). That's within the spec. Unfortunately I don't have a 53132, but the manual of the HP predicts an error of E-10 - just the same value as
Re: [time-nuts] HP53132A vs SR625
Hi Volcker, Bob, I guess it depends on what one needs. The SR-620 is probably more of a gizmo to play with when one likes to manually adjust things or needs the better time interval resolution. The HP unit is more of a fire-and-forget unit. Me having the benefit to be able to chose, I would generally prefer the HP unit. It's cheaper too! Also if HP says its a 12 digit per second unit, then it probably is doing that, albeit with some caveats as the manual states.. Bye, Said Sent From iPhone On Mar 17, 2013, at 17:23, Bob Camp li...@rtty.us wrote: Hi This brings up the basic how bad is it question. Since the counter is fundamentally a 200 ps gizmo, a simple period measurement at 1 second will give you ~ 10 digits per second. That's with no magic multiple sample stuff at all. At an offset / noise / what ever state where the multiple sample stuff works 100%, you get ~ 12 digits per second. I doubt you ever get everything so perfect that you are down to 10 digits / second. Bob On Mar 17, 2013, at 7:41 PM, Said Jackson saidj...@aol.com wrote: Bob, Thats why the 53132A counter reduces the resolution to one digit less at that frequency, and why we use an external divide by 2 for 10MHz measurements to regain that digit. I wanted to be fair and compare apples to apples. If i use our 5Mhz input, the 53132A will be even better. We are always measuring at the deadzone because our gpsdo's are phase aligned via gps. But I can guarantee that the counter can differentiate xE-011 difference in frequencies, as we measure at this level all the time... And I assume the zero offset error of the Sr-620 is also due to this deadzone issue. Btw I was wrong the 53132A now sells for $999 on Ebay. The SR-620 is about $1450. Bye Said Sent From iPhone On Mar 17, 2013, at 16:22, Bob Camp li...@rtty.us wrote: Hi Be very careful of what the 53132(1) reports with the ref out connected to the input. You are guaranteed to be in the dead zone on the counter when you do that. Bob On Mar 17, 2013, at 5:33 PM, saidj...@aol.com wrote: Hi Volker, there are some issues here, first the worst case frequency systematic uncertainty is 100ps for the 53132A, not 350ps as on the SRS unit or 500ps as you stated. So they are not the same, they are 3.5x different. From the Agilent manual: Systematic Uncertainty: Agilent 53131A Agilent 53132A tacc tacc typical 100 ps 10 ps worst case 300 ps 100 ps Notice the 10ps typical error, and 100ps worst case error. That compares to a 100ps typical error for the SR-620 or 10x worse typically than the 53132A. So we get 10x worse typically, and 3.5x less for the worst case - in my opinion these units are not even in the same class. Now for practical matters, I just measured the SR-620 we have with a randomly selected 53132A. Both connected to their own reference input. 2-second samples on both, and here are the results: The SR-620 shows a frequency error of -0.00203Hz consistently.That's 2.03E-010. Within its specifications but making the unit useless to me. The 53132A showed an error of only 2E-012 to 8E-012. So about 25x better accuracy! And the 53132A is showing 12 digits on the front panel as well for 2 second gate times at 10MHz. Nor does it require time-consuming and error prone and annoying internal adjustments to achieve this. What's even more damming for the SRS unit: as I increased the sample size (1s gate time is the max front panel selection, so I had to increase sample size instead of gate time) the error stayed persistent independent of sample size or thus measurement length. On the HP unit however, increasing the gate time made the error get smaller and smaller, and at 10+ seconds gate time I got 13 digits of resolution out of the unit, and an error of only 1E-012 at that point. So in summary, the SR-620 requires careful user adjustment of internal adjustment points. I don't have time to do that, so sent it in and paid the $600+ or so (if I remember correctly) for the standard calibration fee they charge. I got a unit back with the error unchanged, which was the original reason I sent it in to them in the first place. An error of 2E-010 makes the unit useless as we are in need of measuring xE-011 accurately. If I had time to learn how to calibrate the unit myself, I may do so, but even then you showed a 2E-011 error on your carefully adjusted unit, whereas I measured a 2 to 8E-012 error on a random non-adjusted 53132A unit here. Still about 3x to 10x difference in performance. If someone is interested in a swap of a working 53132A with input-c option for our SR-620 I would like to talk to you offline. I would even throw-in an FEI Rubidium reference in that swap, even though the SRS' sell for about $2300, and the 53132A'a go for about $1400. bye, Said
Re: [time-nuts] HP53132A vs SR625
On 3/17/2013 4:54 PM, Volker Esper wrote: The HP seems to be the more modern design. As I guess, the analog circuits are to blame, maybe HP was able to make use of newer technologies. FWIW, the 53132A design goes back 20 years Rick ___ 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] HP53132A vs SR625
1) I paid quite a bit of money and I had it calibrated and fixed by SRS, and it still exhibits a significant frequency offset with a perfect reference and perfect DUT!!! SRS says a small frequency error is normal, well that prevents me from using the unit as a frequency counter, for me it's only useful as a relative display frequency counter. HP doesn't have such a frequency error, so no worries there. I worked with the guy who designed the HP53132A. He would never tolerate as normal a so-called small error. The term frequency counter brings to mind something that digitally counts zero crossings and should never have an error. First of all, even if that is all you do, it is still possible to screw it up. Secondly, counters have relied on analog interpolation even going back to the HP524 circa 1950. There is no theoretical basis of having zero error in this case, but the idea is that you display the number of digits that are commensurate with the worst case accuracy of your interpolator. Again, my colleague who designed the interpolator did very high quality work. I am pleased to learn that our stuff is better than the stuff from the company up the road. Rick Karlquist N6RK HP Santa Clara Division 1979-1998 (still working for Agilent!) ___ 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] HP53132A vs SR625
What small error are we speaking about? The statement that SRS users have to tolerates a small error while HP users don't seems a little to general to me. IMHO we might be a bit more precise. Anyone who's already done an error analysis for - say - a 10MHz count and a comparison of the counters? In real life every type of equipment has it's domain, where it has it's specific advantage. Could it be, that's the case for these counters, too? Cheers Volker Am 16.03.2013 19:57, schrieb Rick Karlquist: 1) I paid quite a bit of money and I had it calibrated and fixed by SRS, and it still exhibits a significant frequency offset with a perfect reference and perfect DUT!!! SRS says a small frequency error is normal, well that prevents me from using the unit as a frequency counter, for me it's only useful as a relative display frequency counter. HP doesn't have such a frequency error, so no worries there. I worked with the guy who designed the HP53132A. He would never tolerate as normal a so-called small error. The term frequency counter brings to mind something that digitally counts zero crossings and should never have an error. First of all, even if that is all you do, it is still possible to screw it up. Secondly, counters have relied on analog interpolation even going back to the HP524 circa 1950. There is no theoretical basis of having zero error in this case, but the idea is that you display the number of digits that are commensurate with the worst case accuracy of your interpolator. Again, my colleague who designed the interpolator did very high quality work. I am pleased to learn that our stuff is better than the stuff from the company up the road. Rick Karlquist N6RK HP Santa Clara Division 1979-1998 (still working for Agilent!) ___ 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] HP53132A vs SR625
Hi The whole how to align the SR-620's thing has been gone over in great length (and very precisely) on the list. The bottom line is that Stanford's alignment procedure is not quite as good as it should / could be. Oddly enough, I don't remember seeing the residual offset in any brand new SR-620. I've only seen it on repaired units. My guess is that the factory tech's did a bit better alignment than the repair manual outlines. Bob On Mar 16, 2013, at 7:06 PM, Volker Esper ail...@t-online.de wrote: What small error are we speaking about? The statement that SRS users have to tolerates a small error while HP users don't seems a little to general to me. IMHO we might be a bit more precise. Anyone who's already done an error analysis for - say - a 10MHz count and a comparison of the counters? In real life every type of equipment has it's domain, where it has it's specific advantage. Could it be, that's the case for these counters, too? Cheers Volker Am 16.03.2013 19:57, schrieb Rick Karlquist: 1) I paid quite a bit of money and I had it calibrated and fixed by SRS, and it still exhibits a significant frequency offset with a perfect reference and perfect DUT!!! SRS says a small frequency error is normal, well that prevents me from using the unit as a frequency counter, for me it's only useful as a relative display frequency counter. HP doesn't have such a frequency error, so no worries there. I worked with the guy who designed the HP53132A. He would never tolerate as normal a so-called small error. The term frequency counter brings to mind something that digitally counts zero crossings and should never have an error. First of all, even if that is all you do, it is still possible to screw it up. Secondly, counters have relied on analog interpolation even going back to the HP524 circa 1950. There is no theoretical basis of having zero error in this case, but the idea is that you display the number of digits that are commensurate with the worst case accuracy of your interpolator. Again, my colleague who designed the interpolator did very high quality work. I am pleased to learn that our stuff is better than the stuff from the company up the road. Rick Karlquist N6RK HP Santa Clara Division 1979-1998 (still working for Agilent!) ___ 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] HP53132A vs SR625
Hi The 53132 is indeed a fine counter. It's got another flaw though - right at 10 MHz the resolution takes a dive. If you are doing time nut stuff, that may be a significant issue. Bob On Mar 16, 2013, at 8:32 PM, Brooke Clarke bro...@pacific.net wrote: Hi Volker: The HP HP53132A can measure frequency at the rate of 12 digits per second, that's way better than ordinary counters, but when measuring time interval it's the same as any other counter. The big disadvantage of the HP53132A in my opinion is it's user hostile menu system. http://www.prc68.com/I/TandFTE.shtml#HP51132 If you're going to be measuring frequency then this counter may make more sense than the SRS unit. The SR620 was designed to be a time interval counter, and that's what gets measured when working with precision frequency or time signals. It's great for this because it has a large number of digits. In addition there's a way to make 1,000 measurements and average them to increase the precision compared to a one shot measurement. The front panel is much much easier to use than the HP. http://www.prc68.com/I/TandFTE.shtml#SR620 Have Fun, Brooke Clarke, N6GCE http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Volker Esper wrote: What small error are we speaking about? The statement that SRS users have to tolerates a small error while HP users don't seems a little to general to me. IMHO we might be a bit more precise. Anyone who's already done an error analysis for - say - a 10MHz count and a comparison of the counters? In real life every type of equipment has it's domain, where it has it's specific advantage. Could it be, that's the case for these counters, too? Cheers Volker Am 16.03.2013 19:57, schrieb Rick Karlquist: 1) I paid quite a bit of money and I had it calibrated and fixed by SRS, and it still exhibits a significant frequency offset with a perfect reference and perfect DUT!!! SRS says a small frequency error is normal, well that prevents me from using the unit as a frequency counter, for me it's only useful as a relative display frequency counter. HP doesn't have such a frequency error, so no worries there. I worked with the guy who designed the HP53132A. He would never tolerate as normal a so-called small error. The term frequency counter brings to mind something that digitally counts zero crossings and should never have an error. First of all, even if that is all you do, it is still possible to screw it up. Secondly, counters have relied on analog interpolation even going back to the HP524 circa 1950. There is no theoretical basis of having zero error in this case, but the idea is that you display the number of digits that are commensurate with the worst case accuracy of your interpolator. Again, my colleague who designed the interpolator did very high quality work. I am pleased to learn that our stuff is better than the stuff from the company up the road. Rick Karlquist N6RK HP Santa Clara Division 1979-1998 (still working for Agilent!) ___ 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] HP53132A vs SR625
Hello SAID: I am very sorry I almost missed this email in my inbox, and say sorry for reply so late, and I am very appreciate you wrote so many useful word for me. I answred your in quote part in this email. Thanks a lot. After a short consideration, finally I bought SR625, now it on my workbench, I am very satisfied with its work. I still have few quesiton: 1) When I use long gate time to mesure fequency (like as 10s or more), the STOP LED in channel B will light up, at moment in the reading result, the STOP will off few second, and light up again, is this normal? 2) When I use TI mesurement function, I connect GPS's 1PPS to CH1 and use a BNC tee split signal with 1.5m cable to CH2, in the TIME mode, I saw the 0xx etc, if I changed cable length the reading will change, what mean of this reading? Hui, rent one of each if you can before you make your choice. I have both, and the HP unit is much easier to use once you know which button sequence to push to get more than just Frequency/Time-Interval type measurements - these can be single-button events on the HP unit. Even offsetting and normalizing frequencies becomes very easy after a couple of days of using the unit, there is no setting that takes me longer than about 5 seconds to set up, so while not perfect, the user interface can be learned easily. I find the SR620 to have too many buttons(!) I always find myself searching for just that one button. Anyways, more buttons are just more things that can fail. If you are a pilot, and have used a Garmin 430W GPS in your life, then the HP user interface is no challenge whatsoever and seems very easy to use.. The SR-620 has it's advantages, especially when you just do one single type of measurement, but for me it has a huge number of disadvantages, and I mostly use the 53132A for that reason: 1) I paid quite a bit of money and I had it calibrated and fixed by SRS, and it still exhibits a significant frequency offset with a perfect reference and perfect DUT!!! SRS says a small frequency error is normal, well that prevents me from using the unit as a frequency counter, for me it's only useful as a relative display frequency counter. HP doesn't have such a frequency error, so no worries there. I will pay attention and observe those problem 2) The SRS unit is s loud that it's totally annoying and unacceptable for long measurements. Many folks reported this here before. It's just bad. Whining like crazy. Indeed this is little problem but really troube me. 3) The SRS unit is 19 wide, huge, heavy, and clunky. I need my counter portable, only the HP unit will do No problem, I like huge and heavy device, they are usually reliabe. 4) The SRS unit has a much lower MTBF because of all the parts inside, and it needs finicky adjustments, see item 1) above. The HP unit either works, or is just dead. Not much to adjust. Different technology generation. And the coolness factor: a nice florescent tube display is so much more modern looking than those clunky old 7-segment LED's.. Yes I agree you, the SR625 is 90's product, sort of old and vintage, I am very worry about his lift. The only thing I can do it pray god I can have good luck. 5) The SRS unit is usually $1000 more than the HP unit, and you don't know how good the unit is you are buying because of all of the calibration stuff. Usually there is no hit-or-miss issue with the HP units, they either work, or are dead. My SR625's price not bad, very close with HP53132, although it's old. I hope it can work five to ten years that I will be satisfied. That said, the HP unit doesn't measure well at 10MHz, so I mostly use a divide-by-two to get one more digit of resolution out of it, and it's time interval resolution is not as good as the SR620. But for time interval measurements I use a Wavecrest DTS unit that blows the SR620 and the HP out of the water anyways.. Bye, Said Hui In a message dated 2/7/2013 16:39:04 Pacific Standard Time, ba6it at 163.com writes: Hello Dear Group: I am very glad to see so many replies in the morning, and I am very grateful to every time nuts gave me useful information, your proposal has strengthened my determination, in fact, I am also very like SR625, So I will to find and buy a good shape SR625 for my new time interval measure instrument. Thanks again for everyone's advice, which is very useful to make a choice for me. Sorry for not reply everyone's mail. Best Regards! Hui Zhang [time-nuts] HP53132A vs SR625 ___ 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] HP53132A vs SR625
Hi The SR625 is a SR620 with a rubidium time base. If the Rb is in good shape, and you don't have a house standard, then that's a significant plus. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hui Zhang Sent: Thursday, February 07, 2013 9:43 AM To: time-nuts@febo.com Subject: [time-nuts] HP53132A vs SR625 Dear Group: I am intend to buy a second-hand counter, I have not decided yet between SR625 and HP53132A, they have very close price in surplus market of here, so, which is better choice? Any suggestion will be appreciated. Best Regards! Hui Zhang ___ 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] HP53132A vs SR625
The SR625 at the same price of the HP53132A: either the HP is overvalued or the SR625 is a real bargain... On Thu, Feb 7, 2013 at 5:36 PM, Bob Camp li...@rtty.us wrote: Hi The SR625 is a SR620 with a rubidium time base. If the Rb is in good shape, and you don't have a house standard, then that's a significant plus. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hui Zhang Sent: Thursday, February 07, 2013 9:43 AM To: time-nuts@febo.com Subject: [time-nuts] HP53132A vs SR625 Dear Group: I am intend to buy a second-hand counter, I have not decided yet between SR625 and HP53132A, they have very close price in surplus market of here, so, which is better choice? Any suggestion will be appreciated. Best Regards! Hui Zhang ___ 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] HP53132A vs SR625
If the SR is in good shape I would prefer the SR. I love my one not only for it's technical data but also for the way of operation. Less menues, more controls, logically arranged. Volker Am 07.02.2013 17:53, schrieb Azelio Boriani: The SR625 at the same price of the HP53132A: either the HP is overvalued or the SR625 is a real bargain... On Thu, Feb 7, 2013 at 5:36 PM, Bob Campli...@rtty.us wrote: Hi The SR625 is a SR620 with a rubidium time base. If the Rb is in good shape, and you don't have a house standard, then that's a significant plus. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hui Zhang Sent: Thursday, February 07, 2013 9:43 AM To: time-nuts@febo.com Subject: [time-nuts] HP53132A vs SR625 Dear Group: I am intend to buy a second-hand counter, I have not decided yet between SR625 and HP53132A, they have very close price in surplus market of here, so, which is better choice? Any suggestion will be appreciated. Best Regards! Hui Zhang ___ 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] HP53132A vs SR625
Hui Well given what you have shared for information neither answer is right or wrong better or worse. The question that we would need answered to be helpful is how will you use it. What price are you willing to pay. There are tradeoffs. I am not an expert. I have many HP counters that I like well. I have SRS equipment thats equally very fine. I do not have a SRS 620 or 625. But if I ever see one at a really good price. (Really cheap) I would buy it, even if broken. Regards Paul On Thu, Feb 7, 2013 at 1:43 PM, Volker Esper ail...@t-online.de wrote: If the SR is in good shape I would prefer the SR. I love my one not only for it's technical data but also for the way of operation. Less menues, more controls, logically arranged. Volker Am 07.02.2013 17:53, schrieb Azelio Boriani: The SR625 at the same price of the HP53132A: either the HP is overvalued or the SR625 is a real bargain... On Thu, Feb 7, 2013 at 5:36 PM, Bob Campli...@rtty.us wrote: Hi The SR625 is a SR620 with a rubidium time base. If the Rb is in good shape, and you don't have a house standard, then that's a significant plus. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-bounces@**febo.comtime-nuts-boun...@febo.com] On Behalf Of Hui Zhang Sent: Thursday, February 07, 2013 9:43 AM To: time-nuts@febo.com Subject: [time-nuts] HP53132A vs SR625 Dear Group: I am intend to buy a second-hand counter, I have not decided yet between SR625 and HP53132A, they have very close price in surplus market of here, so, which is better choice? Any suggestion will be appreciated. Best Regards! Hui Zhang __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/**mailman/listinfo/time-nutshttps://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-nutshttps://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-nutshttps://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-nutshttps://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] HP53132A vs SR625
Hi Hui: The HP 53132A is called a Universal Frequency Counter can count frequency at 12 digits per second, but that is not the case when it is measuring time intervals. The human interface might be called user hostile. The front panel of the SR 620 is marked Universal Time Interval Counter and is great for making time interval measurements. That's why I traded my 53132 for the SR620. http://www.prc68.com/I/TandFTE.shtml#SR620 If you're doing Time Nuts measurements you probably have a good 10 MHz oscillator that you can feed into either of these counters so getting an optional time base in one of them serves little purpose. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Hui Zhang wrote: Dear Group: I am intend to buy a second-hand counter, I have not decided yet between SR625 and HP53132A, they have very close price in surplus market of here, so, which is better choice? Any suggestion will be appreciated. Best Regards! Hui Zhang ___ 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] HP53132A vs SR625
On 02/07/2013 07:43 PM, Volker Esper wrote: If the SR is in good shape I would prefer the SR. I love my one not only for it's technical data but also for the way of operation. Less menues, more controls, logically arranged. I tend to agree here. The HP/Agilent 53132A lacks the ease of use aspect that older HP counters had. It has better performance than many of the older, but not all. The SR620/625 has (if in good condition) better performance than the 53132A. These days I have both. Cheers, Magnus Volker Am 07.02.2013 17:53, schrieb Azelio Boriani: The SR625 at the same price of the HP53132A: either the HP is overvalued or the SR625 is a real bargain... On Thu, Feb 7, 2013 at 5:36 PM, Bob Campli...@rtty.us wrote: Hi The SR625 is a SR620 with a rubidium time base. If the Rb is in good shape, and you don't have a house standard, then that's a significant plus. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hui Zhang Sent: Thursday, February 07, 2013 9:43 AM To: time-nuts@febo.com Subject: [time-nuts] HP53132A vs SR625 Dear Group: I am intend to buy a second-hand counter, I have not decided yet between SR625 and HP53132A, they have very close price in surplus market of here, so, which is better choice? Any suggestion will be appreciated. Best Regards! Hui Zhang ___ 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] HP53132A vs SR625
Hello Dear Group: I am very glad to see so many replies in the morning, and I am very grateful to every time nuts gave me useful information, your proposal has strengthened my determination, in fact, I am also very like SR625, So I will to find and buy a good shape SR625 for my new time interval measure instrument. Thanks again for everyone's advice, which is very useful to make a choice for me. Sorry for not reply everyone's mail. Best Regards! Hui Zhang At 2013-02-08 05:12:37,Brooke Clarke bro...@pacific.net wrote: Hi Hui: The HP 53132A is called a Universal Frequency Counter can count frequency at 12 digits per second, but that is not the case when it is measuring time intervals. The human interface might be called user hostile. The front panel of the SR 620 is marked Universal Time Interval Counter and is great for making time interval measurements. That's why I traded my 53132 for the SR620. http://www.prc68.com/I/TandFTE.shtml#SR620 If you're doing Time Nuts measurements you probably have a good 10 MHz oscillator that you can feed into either of these counters so getting an optional time base in one of them serves little purpose. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Hui Zhang wrote: Dear Group: I am intend to buy a second-hand counter, I have not decided yet between SR625 and HP53132A, they have very close price in surplus market of here, so, which is better choice? Any suggestion will be appreciated. Best Regards! Hui Zhang ___ 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] HP53132A vs SR625
Hui, rent one of each if you can before you make your choice. I have both, and the HP unit is much easier to use once you know which button sequence to push to get more than just Frequency/Time-Interval type measurements - these can be single-button events on the HP unit. Even offsetting and normalizing frequencies becomes very easy after a couple of days of using the unit, there is no setting that takes me longer than about 5 seconds to set up, so while not perfect, the user interface can be learned easily. I find the SR620 to have too many buttons(!) I always find myself searching for just that one button. Anyways, more buttons are just more things that can fail. If you are a pilot, and have used a Garmin 430W GPS in your life, then the HP user interface is no challenge whatsoever and seems very easy to use.. The SR-620 has it's advantages, especially when you just do one single type of measurement, but for me it has a huge number of disadvantages, and I mostly use the 53132A for that reason: 1) I paid quite a bit of money and I had it calibrated and fixed by SRS, and it still exhibits a significant frequency offset with a perfect reference and perfect DUT!!! SRS says a small frequency error is normal, well that prevents me from using the unit as a frequency counter, for me it's only useful as a relative display frequency counter. HP doesn't have such a frequency error, so no worries there. 2) The SRS unit is s loud that it's totally annoying and unacceptable for long measurements. Many folks reported this here before. It's just bad. Whining like crazy. 3) The SRS unit is 19 wide, huge, heavy, and clunky. I need my counter portable, only the HP unit will do 4) The SRS unit has a much lower MTBF because of all the parts inside, and it needs finicky adjustments, see item 1) above. The HP unit either works, or is just dead. Not much to adjust. Different technology generation. And the coolness factor: a nice florescent tube display is so much more modern looking than those clunky old 7-segment LED's.. 5) The SRS unit is usually $1000 more than the HP unit, and you don't know how good the unit is you are buying because of all of the calibration stuff. Usually there is no hit-or-miss issue with the HP units, they either work, or are dead. That said, the HP unit doesn't measure well at 10MHz, so I mostly use a divide-by-two to get one more digit of resolution out of it, and it's time interval resolution is not as good as the SR620. But for time interval measurements I use a Wavecrest DTS unit that blows the SR620 and the HP out of the water anyways.. Bye, Said In a message dated 2/7/2013 16:39:04 Pacific Standard Time, ba...@163.com writes: Hello Dear Group: I am very glad to see so many replies in the morning, and I am very grateful to every time nuts gave me useful information, your proposal has strengthened my determination, in fact, I am also very like SR625, So I will to find and buy a good shape SR625 for my new time interval measure instrument. Thanks again for everyone's advice, which is very useful to make a choice for me. Sorry for not reply everyone's mail. Best Regards! Hui Zhang ___ 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] HP53132A vs SR625
Hi Normally a 625 is priced above a 620. Rubidium standards have a finite life. You are paying for the Rb when you buy a 625. If the Rb is worn out or nearly at end of life, the 625 is not a good idea. Bob On Feb 7, 2013, at 7:22 PM, Hui Zhang ba...@163.com wrote: Hello Dear Group: I am very glad to see so many replies in the morning, and I am very grateful to every time nuts gave me useful information, your proposal has strengthened my determination, in fact, I am also very like SR625, So I will to find and buy a good shape SR625 for my new time interval measure instrument. Thanks again for everyone's advice, which is very useful to make a choice for me. Sorry for not reply everyone's mail. Best Regards! Hui Zhang At 2013-02-08 05:12:37,Brooke Clarke bro...@pacific.net wrote: Hi Hui: The HP 53132A is called a Universal Frequency Counter can count frequency at 12 digits per second, but that is not the case when it is measuring time intervals. The human interface might be called user hostile. The front panel of the SR 620 is marked Universal Time Interval Counter and is great for making time interval measurements. That's why I traded my 53132 for the SR620. http://www.prc68.com/I/TandFTE.shtml#SR620 If you're doing Time Nuts measurements you probably have a good 10 MHz oscillator that you can feed into either of these counters so getting an optional time base in one of them serves little purpose. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Hui Zhang wrote: Dear Group: I am intend to buy a second-hand counter, I have not decided yet between SR625 and HP53132A, they have very close price in surplus market of here, so, which is better choice? Any suggestion will be appreciated. Best Regards! Hui Zhang ___ 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.
