Re: [time-nuts] FE-5680A Results so far
My TDS210 has an extremely stable display, even at the max sweep speed. Of course, the vertical amplifier has the noise you would expect from a broad band amplifier, and if the signal is too low, that noise will contribute to some jitter, but 200mV at 10MHz will show a very stable display on my scope. Try to get another method for confirmation, like a ham or broadcast receiver that can tune 10 or 20 MHz Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Azelio Boriani azelio.bori...@screen.it Sender: time-nuts-boun...@febo.com Date: Thu, 29 Dec 2011 09:33:14 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] FE-5680A Results so far Artifacts from the TDS210, not from the Rb. On Thu, Dec 29, 2011 at 8:14 AM, mike cook michael.c...@sfr.fr wrote: Hi, Just got my cheapo 5680A. It was accompanied by a little teddy bear clutching a L7805CV ! Got a couple of questions. 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to indicate 0,5V but I am getting only 200mv. 2) What is the sensitivity to 15V input level. I am only measuring 14,722 (stable) on Pin1. 3) Could this low input voltage affect output voltage? The box locks after a couple of minutes but my TDS 210 is showing a very jittery ( 9,98-10,02 MHz ) but well formed sine wave for 8 hours of being powered on. Could this also be an artefact of low main power? regards, Mike __**_ 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. ___ 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] FE-5680A Results so far
On Wed, Dec 28, 2011 at 11:14 PM, mike cook michael.c...@sfr.fr wrote: Hi, Just got my cheapo 5680A. It was accompanied by a little teddy bear clutching a L7805CV ! Got a couple of questions. 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to indicate 0,5V but I am getting only 200mv. I'm getting a lot more, about 2V peak to peak. What are you loading it with, I'm using a 10X scope probe. How are you measuring the voltage? 2) What is the sensitivity to 15V input level. I am only measuring 14,722 (stable) on Pin1. The voltage in pin 1 is up to you. The spec says you need to supply anything in the range of 15V to 18V. I've been using about 16V from a variable bench type power supply. 3) Could this low input voltage affect output voltage? I was thinking the same thing. I you sure you are looking at the correct pin? I noticed a very low signal on pin-6. The box locks after a couple of minutes but my TDS 210 is showing a very jittery ( 9,98-10,02 MHz ) but well formed sine wave for 8 hours of being powered on. Could this also be an artefact of low main power? Could be your counter has trouble with low amplitude sine wave. Or it is loading the signal. My HP counter has trouble with mV level signals too. But I found my scope has a vertical amp output. Makes the scope work like an RF amp -- . 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] FE-5680A Results so far
Artifacts from the TDS210, not from the Rb. On Thu, Dec 29, 2011 at 8:14 AM, mike cook michael.c...@sfr.fr wrote: Hi, Just got my cheapo 5680A. It was accompanied by a little teddy bear clutching a L7805CV ! Got a couple of questions. 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to indicate 0,5V but I am getting only 200mv. 2) What is the sensitivity to 15V input level. I am only measuring 14,722 (stable) on Pin1. 3) Could this low input voltage affect output voltage? The box locks after a couple of minutes but my TDS 210 is showing a very jittery ( 9,98-10,02 MHz ) but well formed sine wave for 8 hours of being powered on. Could this also be an artefact of low main power? regards, Mike __**_ 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] FE-5680A Results so far
Le 29/12/2011 09:28, Chris Albertson a écrit : 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to indicate 0,5V but I am getting only 200mv. I'm getting a lot more, about 2V peak to peak. What are you loading it with, I'm using a 10X scope probe. How are you measuring the voltage? Loaded just by the scope input which I guess is 50ohm. probe is a 1x. 2) What is the sensitivity to 15V input level. I am only measuring 14,722 (stable) on Pin1. The voltage in pin 1 is up to you. The spec says you need to supply anything in the range of 15V to 18V. I've been using about 16V from a variable bench type power supply. I'm going to rewire the breadboard. I have a Toshiba 3A 15V supply putting out 15,04. Must be leaking somewhere along the line. I'll see if I have something with a bit more to spare. 3) Could this low input voltage affect output voltage? I was thinking the same thing. I you sure you are looking at the correct pin? I noticed a very low signal on pin-6. I am looking at the right pin, measuring the voltage with TDS function. The box locks after a couple of minutes but my TDS 210 is showing a very jittery ( 9,98-10,02 MHz ) but well formed sine wave for 8 hours of being powered on. Could this also be an artefact of low main power? Could be your counter has trouble with low amplitude sine wave. Or it is loading the signal. My HP counter has trouble with mV level signals too. But I found my scope has a vertical amp output. Makes the scope work like an RF amp -- . Probable. I tried T-ing to an independent counter and the wave form dropped near flat. Thanks for your inputs guys ___ 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] FE-5680A Results so far
I gave my 5680a several firm whacks with a backscratcher and it did not seem to flinch. On the other hand I've used taps with a jeweler's screwdriver to fine tune my counter's timebase. On 12/29/2011 10:37 AM, Said Jackson wrote: Hello Mike, We measured a couple of these 5680As on a tsc5125a analyzer. With different quality supplies. Very noisy buggers, huge number of spurs and very high noise floor -130dBc or so if I recall correctly. Thats probably the jitter you are seeing. Probably due to the dds generating the output not a crystal. ADEV was parts in E-011 while good, not very good. Frequency accuracy was +5E-010 then tap the box hard and it goes to -1ppb. Good enough as a portable frequency counter reference, as the offset can be compensated, and the output is fairly stable... These units could really use gps disciplining and a crystal post filter. Great stuff for $40, new they must have been over $1000. Bye, Said On Dec 29, 2011, at 1:14, mike cookmichael.c...@sfr.fr wrote: Hi, Just got my cheapo 5680A. It was accompanied by a little teddy bear clutching a L7805CV ! Got a couple of questions. 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to indicate 0,5V but I am getting only 200mv. 2) What is the sensitivity to 15V input level. I am only measuring 14,722 (stable) on Pin1. 3) Could this low input voltage affect output voltage? The box locks after a couple of minutes but my TDS 210 is showing a very jittery ( 9,98-10,02 MHz ) but well formed sine wave for 8 hours of being powered on. Could this also be an artefact of low main power? rega Mike ___ 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. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 attachment: whack.gif___ 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] FE-5680A Results so far
On Wed, Dec 28, 2011 at 11:14 PM, mike cook michael.c...@sfr.fr wrote: 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to indicate 0,5V but I am getting only 200mv. 2) What is the sensitivity to 15V input level. I am only measuring 14,722 (stable) on Pin1. 3) Could this low input voltage affect output voltage? The box locks after a couple of minutes but my TDS 210 is showing a very jittery ( 9,98-10,02 MHz ) but well formed sine wave for 8 hours of being powered on. Could this also be an artefact of low main power? IME 9.98 to 10.02 is about as good as it gets measuring 10 MHz on the TDS210. I'd guess it's measuring the time between two zero crossings and inverting it. With a horizontal resolution of 1024 divisions, your +/- 0.02 MHz isn't surprising. I got similar frequency measurements on my TDS210 using a 10x probe, but got about 2V pk-pk voltage. The fact you are a factor of 10 out is suspicious - check your probe! Orin. ___ 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] FE-5680A Results so far
Hello Mike, We measured a couple of these 5680As on a tsc5125a analyzer. With different quality supplies. Very noisy buggers, huge number of spurs and very high noise floor -130dBc or so if I recall correctly. Thats probably the jitter you are seeing. Probably due to the dds generating the output not a crystal. ADEV was parts in E-011 while good, not very good. Frequency accuracy was +5E-010 then tap the box hard and it goes to -1ppb. Good enough as a portable frequency counter reference, as the offset can be compensated, and the output is fairly stable... These units could really use gps disciplining and a crystal post filter. Great stuff for $40, new they must have been over $1000. Bye, Said On Dec 29, 2011, at 1:14, mike cook michael.c...@sfr.fr wrote: Hi, Just got my cheapo 5680A. It was accompanied by a little teddy bear clutching a L7805CV ! Got a couple of questions. 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to indicate 0,5V but I am getting only 200mv. 2) What is the sensitivity to 15V input level. I am only measuring 14,722 (stable) on Pin1. 3) Could this low input voltage affect output voltage? The box locks after a couple of minutes but my TDS 210 is showing a very jittery ( 9,98-10,02 MHz ) but well formed sine wave for 8 hours of being powered on. Could this also be an artefact of low main power? rega Mike ___ 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] FE-5680A Results so far
On Thu, Dec 29, 2011 at 10:37 AM, Said Jackson saidj...@aol.com wrote: Good enough as a portable frequency counter reference, as the offset can be compensated, and the output is fairly stable... These units could really use gps disciplining and a crystal post filter. Great stuff for $40, new they must have been over $1000. I had actually thought about a crystal latice filter I think I can find three 10MHz crystals and put them in series. The trouble is I'm not sure what problem the filter might introduce and I don't have a way to measure the filter's performance I'm thinking of adding an RF amplifier using just one 2n5109 and an LC filter. 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] FE-5680A Results so far
Tried crystal lattice filters, their bw is usually too large (1 to 2khz) I would use a simple pll, such as an exor gate driving a single gate vcxo with 10hz bw. Most crystal oscillators would improve the noise from the dds. So you could do this with four parts: Nc7sz86 exor gate driven by the dds and the crystal, the output driving a 10uf to 100uf tant cap through say a 10k ohm resistor, feed the signal on the cap into a Crystek 10 MHz vcxo. Done. Use an inverter on the exor output for negative slope vcxos. Use an at cut crystal discrete vcxo to avoid paying for the Crystek vcxo. An lc filters bw is even worse (10s of kHz).. Bye, Said On Dec 29, 2011, at 17:53, Chris Albertson albertson.ch...@gmail.com wrote: On Thu, Dec 29, 2011 at 10:37 AM, Said Jackson saidj...@aol.com wrote: Good enough as a portable frequency counter reference, as the offset can be compensated, and the output is fairly stable... These units could really use gps disciplining and a crystal post filter. Great stuff for $40, new they must have been over $1000. I had actually thought about a crystal latice filter I think I can find three 10MHz crystals and put them in series. The trouble is I'm not sure what problem the filter might introduce and I don't have a way to measure the filter's performance I'm thinking of adding an RF amplifier using just one 2n5109 and an LC filter. 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. ___ 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] FE-5680A Results so far
Just FYI, this current batch of FE-5680As has a different RF architecture than the old ones - one of the most notable changes is that although they still have a DDS in them it's not in the output path anymore - the VCXO now runs at 60MHz, and this is divided down (in a CPLD) to produce the 10MHz output - so it's likely that your output measurements are not really applicable to these units. On Fri, Dec 30, 2011 at 2:37 AM, Said Jackson saidj...@aol.com wrote: Hello Mike, We measured a couple of these 5680As on a tsc5125a analyzer. With different quality supplies. Very noisy buggers, huge number of spurs and very high noise floor -130dBc or so if I recall correctly. Thats probably the jitter you are seeing. Probably due to the dds generating the output not a crystal. ADEV was parts in E-011 while good, not very good. Frequency accuracy was +5E-010 then tap the box hard and it goes to -1ppb. Good enough as a portable frequency counter reference, as the offset can be compensated, and the output is fairly stable... These units could really use gps disciplining and a crystal post filter. Great stuff for $40, new they must have been over $1000. Bye, Said On Dec 29, 2011, at 1:14, mike cook michael.c...@sfr.fr wrote: Hi, Just got my cheapo 5680A. It was accompanied by a little teddy bear clutching a L7805CV ! Got a couple of questions. 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to indicate 0,5V but I am getting only 200mv. 2) What is the sensitivity to 15V input level. I am only measuring 14,722 (stable) on Pin1. 3) Could this low input voltage affect output voltage? The box locks after a couple of minutes but my TDS 210 is showing a very jittery ( 9,98-10,02 MHz ) but well formed sine wave for 8 hours of being powered on. Could this also be an artefact of low main power? rega Mike ___ 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] FE-5680A Results so far
I got twenty 10 MHz rocks from a guy in China a while ago. It was just a few dollars for 21 pieces. The original purpose was to build a 10 MHz TRF receiver. I don't think any of my legacy signal generators are stable enough to characterize these rocks, but the 5680a should do nicely with a bit of hacking into the rs232 port. On 12/29/2011 03:53 PM, Chris Albertson wrote: On Thu, Dec 29, 2011 at 10:37 AM, Said Jacksonsaidj...@aol.com wrote: Good enough as a portable frequency counter reference, as the offset can be compensated, and the output is fairly stable... These units could really use gps disciplining and a crystal post filter. Great stuff for $40, new they must have been over $1000. I had actually thought about a crystal latice filter I think I can find three 10MHz crystals and put them in series. The trouble is I'm not sure what problem the filter might introduce and I don't have a way to measure the filter's performance I'm thinking of adding an RF amplifier using just one 2n5109 and an LC filter. 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. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] FE-5680A Results so far
Just a bit! :) From: time-nuts-boun...@febo.com [time-nuts-boun...@febo.com] On Behalf Of Chuck Forsberg WA7KGX N2469R [c...@omen.com] Sent: Tuesday, December 27, 2011 9:28 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FE-5680A Results so far I had the elevation and signal level masks set too tight on the Tbolt. It ran out of birds and freaked out. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] FE-5680A Results so far
Just got my fe5680 yesterday. Seems to work but the fe5680 is the most accurate reference I have. So how to test it? I plan to buy a Thunderbolt but until then, anyone have any creative ideas? I have an HP5328A with unknown calibration. It reads 10,000,026 Hz I have an FCC 1 kit I assembled a few years ago and it says 9,999,993 Hz. (I can make the FCC1 read exactly 10MHz if I place it on top of the hot FE5680, the FCC1 is very temperature sensitive. My old Tek scope says the period is about 0.1 uS and the sine wave looks pretty good. BTW, 5 VDC is 76.5 mA with RS232 not connected.15 VDC is 1.5 ~ 0.8 A. The unit does get warm. A 3/16 x 5 x 16 inch aluminum plate worked is a good enough heat sink. Going to have to get a Thunderbolt. I have an Oncore UT+ the provides a good pulse per second but that will not help 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] FE-5680A Results so far
Chris Albertson wrote: Just got my fe5680 yesterday. Seems to work but the fe5680 is the most accurate reference I have. So how to test it? I plan to buy a Thunderbolt but until then, anyone have any creative ideas? snip Going to have to get a Thunderbolt. I have an Oncore UT+ the provides a good pulse per second but that will not help You can take the FE-5680 10MHz and divide it down to a derived 1 PPS. Use the time interval measurement on your HP5328A to measure the TI between the Oncore 1 PPS (start) and the derived 1 PPS (stop). You might want to set a finite TI (for example, 100 usec) by adjusting the phase of the derived 1 PPS so the measurement doesn't get confused. I have done this using an HP5316B with good results. The jitter on the GPS 1 PPS might limit your short term resolution, but over a day or so you should be able to measure the drift of the FE-5680A. I have used a Ref Tek 111A GPS clock for the 1 PPS. That unit has a lot (several usec) of jitter. I recently started using a 111C that has much lower jitter (a few 10's of nsec). I believe your OnCore unit will be similar. Here are some results from my tracking my FE-5680A: http://c-c-i.com/image/tid/4 Most recent: http://c-c-i.com/node/159 Hope this helps. -- Bob Smither, PhD Circuit Concepts, Inc. Patriotism is supporting your country all the time, and your government when it deserves it. - Mark Twain smit...@c-c-i.com http://www.C-C-I.Com281-331-2744 attachment: smither.vcf___ 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] FE-5680A Results so far
I haven't checked it, but the FE5680A has 1pps on pin 6. There is no documented way to sync the FE5680A 1pps to an external reference. You could set an extreme value in the freq offset and wait for the 1pps to drift into place. Measurements of the delay between 1pps signals depend on the accuracy of the measuring device - e.g., the timebase in the counter of oscilloscope X axis. On 12/28/2011 10:45 AM, Bob Smither wrote: Chris Albertson wrote: Just got my fe5680 yesterday. Seems to work but the fe5680 is the most accurate reference I have. So how to test it? I plan to buy a Thunderbolt but until then, anyone have any creative ideas? snip Going to have to get a Thunderbolt. I have an Oncore UT+ the provides a good pulse per second but that will not help You can take the FE-5680 10MHz and divide it down to a derived 1 PPS. Use the time interval measurement on your HP5328A to measure the TI between the Oncore 1 PPS (start) and the derived 1 PPS (stop). You might want to set a finite TI (for example, 100 usec) by adjusting the phase of the derived 1 PPS so the measurement doesn't get confused. I have done this using an HP5316B with good results. The jitter on the GPS 1 PPS might limit your short term resolution, but over a day or so you should be able to measure the drift of the FE-5680A. I have used a Ref Tek 111A GPS clock for the 1 PPS. That unit has a lot (several usec) of jitter. I recently started using a 111C that has much lower jitter (a few 10's of nsec). I believe your OnCore unit will be similar. Here are some results from my tracking my FE-5680A: http://c-c-i.com/image/tid/4 Most recent: http://c-c-i.com/node/159 Hope this helps. ___ 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. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] FE-5680A Results so far
Chris posted: So how to test it? anyone have any creative ideas? That's easy, get a couple more of them. The using a scope, trigger on one unit and watch the phase drift of the others. With most basic scopes you can detect sub ns phase changes of 10MHz signals this way, which allows you to see a 1e-11 frequency difference in a couple minutes. (1ns/sec change = 1e-9 freq offset) Or you could use the basic x y display and count how many minutes it takes to complete one cycle. That will allow you to see the same resolution after a few hours. (a 100ns cycle per sec = 1e-7 freq offset) ws * [time-nuts] FE-5680A Results so far Chris Albertson albertson.chris at gmail.com Wed Dec 28 18:21:54 UTC 2011 Just got my fe5680 yesterday. Seems to work but the fe5680 is the most accurate reference I have. So how to test it? I plan to buy a Thunderbolt but until then, anyone have any creative ideas? I have an HP5328A with unknown calibration. It reads 10,000,026 Hz I have an FCC 1 kit I assembled a few years ago and it says 9,999,993 Hz. (I can make the FCC1 read exactly 10MHz if I place it on top of the hot FE5680, the FCC1 is very temperature sensitive. My old Tek scope says the period is about 0.1 uS and the sine wave looks pretty good. BTW, 5 VDC is 76.5 mA with RS232 not connected.15 VDC is 1.5 ~ 0.8 A. The unit does get warm. A 3/16 x 5 x 16 inch aluminum plate worked is a good enough heat sink. Going to have to get a Thunderbolt. I have an Oncore UT+ the provides a good pulse per second but that will not help 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] FE-5680A Results so far
Just got my fe5680 yesterday. Seems to work but the fe5680 is the most accurate reference I have. So how to test it? I plan to buy a Thunderbolt but until then, anyone have any creative ideas? I assume you have a GPS with PPS. Get one of TVB's picPETs. (or do it yourself) Clock it from your FE5680. Collect the data... If you have a good scope, you can use your GPS to calibrate the oscillator in the scope. Trigger on a PPS pulse, delay 1 second to look at the next pulse. That pulse will be slightly off. That offset is due to the error in your scope oscillator. -- These are my opinions, not necessarily my employer's. 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.
Re: [time-nuts] FE-5680A Results so far
Chuck Forsberg WA7KGX N2469R wrote: I haven't checked it, but the FE5680A has 1pps on pin 6. There is no documented way to sync the FE5680A 1pps to an external reference. You could set an extreme value in the freq offset and wait for the 1pps to drift into place. On mine if you put in extreme offsets it seems to lose sync. Not sure if this is typical. To adjust the phase between the GPS 1 PPS and the 1 PPS derived from the FE-5680A I put a switch in the divide by 1E7 logic used to get a 1 PPS from the FE-5680A. Pushing the switch changes the divide so that the 1 PPS can be slewed to a known phase WRT the GPS 1 PPS. Measurements of the delay between 1pps signals depend on the accuracy of the measuring device - e.g., the timebase in the counter of oscilloscope X axis. Yes, but for a time interval of (for example) 100 usec even a very poor counter timebase would be accurate to sub nsec. Of course, the FE-5680A could be used as the counter timebase :-). On 12/28/2011 10:45 AM, Bob Smither wrote: Chris Albertson wrote: Just got my fe5680 yesterday. Seems to work but the fe5680 is the most accurate reference I have. So how to test it? I plan to buy a Thunderbolt but until then, anyone have any creative ideas? snip Going to have to get a Thunderbolt. I have an Oncore UT+ the provides a good pulse per second but that will not help You can take the FE-5680 10MHz and divide it down to a derived 1 PPS. Use the time interval measurement on your HP5328A to measure the TI between the Oncore 1 PPS (start) and the derived 1 PPS (stop). You might want to set a finite TI (for example, 100 usec) by adjusting the phase of the derived 1 PPS so the measurement doesn't get confused. I have done this using an HP5316B with good results. The jitter on the GPS 1 PPS might limit your short term resolution, but over a day or so you should be able to measure the drift of the FE-5680A. I have used a Ref Tek 111A GPS clock for the 1 PPS. That unit has a lot (several usec) of jitter. I recently started using a 111C that has much lower jitter (a few 10's of nsec). I believe your OnCore unit will be similar. Here are some results from my tracking my FE-5680A: http://c-c-i.com/image/tid/4 Most recent: http://c-c-i.com/node/159 Hope this helps. ___ 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. -- Bob Smither, PhD Circuit Concepts, Inc. = Those who would give up essential Liberty, to purchase a little temporary safety, deserve neither Liberty nor safety. -- Benjamin Franklin: November 11, 1755 = smit...@c-c-i.com http://www.C-C-I.Com 281-331-2744(office) -4616(fax) attachment: smither.vcf___ 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] FE-5680A Results so far
My FE5680A came with a 0 offset. For my unit the correct offset is something like -1343. I sometimes set an offset of 0 to slew the phase difference to 180, at which time I change it to -1343 (give or take). If you take an FE5680a to a friend's lab and dial it in the act of powering it down and transporting it back could throw it off by 1e-9 or more. The thing I'm learning here is that everything affects everything when working at this level of resolution. Remember the stories about solar flares or something affecting the rate of radioactive decay? On 12/28/2011 11:05 AM, ws at Yahoo wrote: Chris posted: So how to test it? anyone have any creative ideas? That's easy, get a couple more of them. The using a scope, trigger on one unit and watch the phase drift of the others. With most basic scopes you can detect sub ns phase changes of 10MHz signals this way, which allows you to see a 1e-11 frequency difference in a couple minutes. (1ns/sec change = 1e-9 freq offset) Or you could use the basic x y display and count how many minutes it takes to complete one cycle. That will allow you to see the same resolution after a few hours. (a 100ns cycle per sec = 1e-7 freq offset) ws * [time-nuts] FE-5680A Results so far Chris Albertson albertson.chris at gmail.com Wed Dec 28 18:21:54 UTC 2011 Just got my fe5680 yesterday. Seems to work but the fe5680 is the most accurate reference I have. So how to test it? I plan to buy a Thunderbolt but until then, anyone have any creative ideas? I have an HP5328A with unknown calibration. It reads 10,000,026 Hz I have an FCC 1 kit I assembled a few years ago and it says 9,999,993 Hz. (I can make the FCC1 read exactly 10MHz if I place it on top of the hot FE5680, the FCC1 is very temperature sensitive. My old Tek scope says the period is about 0.1 uS and the sine wave looks pretty good. BTW, 5 VDC is 76.5 mA with RS232 not connected.15 VDC is 1.5 ~ 0.8 A. The unit does get warm. A 3/16 x 5 x 16 inch aluminum plate worked is a good enough heat sink. Going to have to get a Thunderbolt. I have an Oncore UT+ the provides a good pulse per second but that will not help 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. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] FE-5680A Results so far
Is it possible to feed the FE5680 to an external input reference of the 5328A (I presume it has one) then use the FE5680 as the source whose frequency/intervals is to be read and then use the Oncore UT+ as both the 'Start' and 'Stop' to count the number of intervals (cycles) that went by? If so, that might be a beginning. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Wednesday, December 28, 2011 12:22 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FE-5680A Results so far Just got my fe5680 yesterday. Seems to work but the fe5680 is the most accurate reference I have. So how to test it? I plan to buy a Thunderbolt but until then, anyone have any creative ideas? I have an HP5328A with unknown calibration. It reads 10,000,026 Hz I have an FCC 1 kit I assembled a few years ago and it says 9,999,993 Hz. (I can make the FCC1 read exactly 10MHz if I place it on top of the hot FE5680, the FCC1 is very temperature sensitive. My old Tek scope says the period is about 0.1 uS and the sine wave looks pretty good. BTW, 5 VDC is 76.5 mA with RS232 not connected.15 VDC is 1.5 ~ 0.8 A. The unit does get warm. A 3/16 x 5 x 16 inch aluminum plate worked is a good enough heat sink. Going to have to get a Thunderbolt. I have an Oncore UT+ the provides a good pulse per second but that will not help 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. ___ 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] FE-5680A Results so far
Hi, Just got my cheapo 5680A. It was accompanied by a little teddy bear clutching a L7805CV ! Got a couple of questions. 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to indicate 0,5V but I am getting only 200mv. 2) What is the sensitivity to 15V input level. I am only measuring 14,722 (stable) on Pin1. 3) Could this low input voltage affect output voltage? The box locks after a couple of minutes but my TDS 210 is showing a very jittery ( 9,98-10,02 MHz ) but well formed sine wave for 8 hours of being powered on. Could this also be an artefact of low main power? regards, Mike ___ 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] FE-5680A Results so far
I just got back from running an other test on my 5680 and for 24 days now it has been reading consistently 9.944 MHz! I average over 1000 seconds because feeding two Tbolts into a Tracor 527E I do see up to +_2 E-11 changes off and on, and one runs all my instruments. I am waiting for aging changes before I modify the C field circuit. Bert Kehren In a message dated 12/27/2011 11:52:27 A.M. Eastern Standard Time, c...@omen.com writes: After a few days of fooling around it appears my $38.00 Rb frequency standard is meeting its specs except for the current draw on the 5 volt supply. The attached plot shows phase readings between the Rb and a ThunderBolt made by a Racal-Dana 1992 counter read out by Fedora Linux 16 and a National Instruments PCI GPIB interface. I entered various frequency offsets with my own comms software downloadable from omen.com. The transients are manual slewing events where I set an offset of 0 until the phase swings around to 180 degrees. The last such event covered 360 degrees in about 100 seconds; the result agrees with the specified resolution of 1e-12. The Rb seems to be meeting its 10-11/day spec. If I did the math correctly, that corresponds to measuring the distance to the Moon within tenths of an inch. My next step is to leave it alone for a day or two. -- Chuck Forsberg WA7KGX N2469R c...@omen.comwww.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231503-614-0430 ___ 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] FE-5680A Results so far
I had the elevation and signal level masks set too tight on the Tbolt. It ran out of birds and freaked out. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 attachment: tboltfoo.gif___ 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.
