JH
Jerry Hancock
Mon, Apr 24, 2017 7:06 PM
This is an exercise more than anything. It started when I noticed the counter in a 3586B I purchased was +1 count unless I dropped the input frequency .25hz. I was using my GPSDO reference for it and the 3336 it was counting. I then took my GPSDO and tried reading that directly and I see the same thing. This is annoying more than anything and I assume there is a slight gate phase related issue. I don’t have anything to read the jitter on my GPSDO which is a Lucent RFTG-U with the REF1 and REF0 but since I am using it as the reference and the signal under test, it shouldn’t matter at .1hz. If I run the count over 3 minutes, the count is .923hz high consistently. To put a finer point on it, reading 10,000,000.00hz from my GPSDO, It will read consistently 10,000,000.1 or 10,000,000.0 with the distribution of each to average 10,000,000.923 over 5 minutes. If I drop the input frequency by .25hz, it will read 10,000,000.0 without a 10,000,000.1 until the cows come home. I’ve let it run about a day to check.
So I was thinking, o.k., let’s put a frequency counter on the back to read the F0 output signal rom the 3586B and see what it reads but I then realized I don’t have anything that accurate. I do have a lot of micro processors around, everything from the lowly PIC thru the DSPIC to the STM32F7’s, F4’s and if I have to, I will get a FPGA and go from there. I could purchase an HP 12 digit counter if I could find one locally as I am tired of paying shipping but haven’t found one to date.
So no really pressing reason for the counter other than just curious as to what is causing the issue with the 3586B. By the way, when I read any of the WWV signals they count +.1hz as well under constant signal. I am pretty sure the 3586B is recognizing my reference input as the OCXO is dialed to 10,000,000.0 and the standard oscillator is a little high at +.4 (if I disconnect the OCXO strap) and I haven’t looked into it yet.
Thanks for the interest and help
Jerry
This is an exercise more than anything. It started when I noticed the counter in a 3586B I purchased was +1 count unless I dropped the input frequency .25hz. I was using my GPSDO reference for it and the 3336 it was counting. I then took my GPSDO and tried reading that directly and I see the same thing. This is annoying more than anything and I assume there is a slight gate phase related issue. I don’t have anything to read the jitter on my GPSDO which is a Lucent RFTG-U with the REF1 and REF0 but since I am using it as the reference and the signal under test, it shouldn’t matter at .1hz. If I run the count over 3 minutes, the count is .923hz high consistently. To put a finer point on it, reading 10,000,000.00hz from my GPSDO, It will read consistently 10,000,000.1 or 10,000,000.0 with the distribution of each to average 10,000,000.923 over 5 minutes. If I drop the input frequency by .25hz, it will read 10,000,000.0 without a 10,000,000.1 until the cows come home. I’ve let it run about a day to check.
So I was thinking, o.k., let’s put a frequency counter on the back to read the F0 output signal rom the 3586B and see what it reads but I then realized I don’t have anything that accurate. I do have a lot of micro processors around, everything from the lowly PIC thru the DSPIC to the STM32F7’s, F4’s and if I have to, I will get a FPGA and go from there. I could purchase an HP 12 digit counter if I could find one locally as I am tired of paying shipping but haven’t found one to date.
So no really pressing reason for the counter other than just curious as to what is causing the issue with the 3586B. By the way, when I read any of the WWV signals they count +.1hz as well under constant signal. I am pretty sure the 3586B is recognizing my reference input as the OCXO is dialed to 10,000,000.0 and the standard oscillator is a little high at +.4 (if I disconnect the OCXO strap) and I haven’t looked into it yet.
Thanks for the interest and help
Jerry
BK
Bob kb8tq
Mon, Apr 24, 2017 8:35 PM
Hi
One advantage of keeping this on list — There are 3586B Guru’s running around here.
I’m sure one of them will hop in to explain a bit more about what’s going on inside that
beast. Since (as you point out) you can put the same signal in as the reference, it may
be as simple as cranking pot R358242 to zero the reading …. maybe not.
The road from “I wonder” to a full bench of TimeNut gear can be an amazingly short one.
Before you get into a build it yourself precision counter project, at least take a look at
things like the HP 5334 and 5335 on the usual auction sites. They (and a large number
of other candidates) will do this job for you and do a number of future jobs as well.
Depending on how the market is going, cost should be sub $150 delivered and sub
$100 with some time spent shopping (and maybe some risk). There’s also the 5386
out there, not my favorite counter, but a wonderful thing if you have dyslexia and are
typing 3586 :)
While the “I can wait for the reading” idea sounds good in theory. It rarely works well in
practice. Temperature variations, warmup drift, and other stuff do happen in a lot less
than 10,000 seconds (or even 1,000 seconds). If you have to adjust something, even
100 seconds can be a major pain. The constant 9 digits a second that the bench
counters provide can be very useful.
Bob
On Apr 24, 2017, at 3:06 PM, Jerry Hancock jerry@hanler.com wrote:
This is an exercise more than anything. It started when I noticed the counter in a 3586B I purchased was +1 count unless I dropped the input frequency .25hz. I was using my GPSDO reference for it and the 3336 it was counting. I then took my GPSDO and tried reading that directly and I see the same thing. This is annoying more than anything and I assume there is a slight gate phase related issue. I don’t have anything to read the jitter on my GPSDO which is a Lucent RFTG-U with the REF1 and REF0 but since I am using it as the reference and the signal under test, it shouldn’t matter at .1hz. If I run the count over 3 minutes, the count is .923hz high consistently. To put a finer point on it, reading 10,000,000.00hz from my GPSDO, It will read consistently 10,000,000.1 or 10,000,000.0 with the distribution of each to average 10,000,000.923 over 5 minutes. If I drop the input frequency by .25hz, it will read 10,000,000.0 without a 10,000,000.1 until the cows come home. I’ve
let it run about a day to check.
So I was thinking, o.k., let’s put a frequency counter on the back to read the F0 output signal rom the 3586B and see what it reads but I then realized I don’t have anything that accurate. I do have a lot of micro processors around, everything from the lowly PIC thru the DSPIC to the STM32F7’s, F4’s and if I have to, I will get a FPGA and go from there. I could purchase an HP 12 digit counter if I could find one locally as I am tired of paying shipping but haven’t found one to date.
So no really pressing reason for the counter other than just curious as to what is causing the issue with the 3586B. By the way, when I read any of the WWV signals they count +.1hz as well under constant signal. I am pretty sure the 3586B is recognizing my reference input as the OCXO is dialed to 10,000,000.0 and the standard oscillator is a little high at +.4 (if I disconnect the OCXO strap) and I haven’t looked into it yet.
Thanks for the interest and help
Jerry
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.
Hi
One advantage of keeping this on list — There are 3586B Guru’s running around here.
I’m sure one of them will hop in to explain a bit more about what’s going on inside that
beast. Since (as you point out) you can put the same signal in as the reference, it may
be as simple as cranking pot R358242 to zero the reading …. maybe not.
The road from “I wonder” to a full bench of TimeNut gear can be an amazingly short one.
Before you get into a build it yourself precision counter project, at least take a look at
things like the HP 5334 and 5335 on the usual auction sites. They (and a large number
of other candidates) will do this job for you and do a number of future jobs as well.
Depending on how the market is going, cost should be sub $150 delivered and sub
$100 with some time spent shopping (and maybe some risk). There’s also the 5386
out there, not my favorite counter, but a wonderful thing if you have dyslexia and are
typing 3586 :)
While the “I can wait for the reading” idea sounds good in theory. It rarely works well in
practice. Temperature variations, warmup drift, and other stuff do happen in a lot less
than 10,000 seconds (or even 1,000 seconds). If you have to adjust something, even
100 seconds can be a major pain. The constant 9 digits a second that the bench
counters provide can be very useful.
Bob
> On Apr 24, 2017, at 3:06 PM, Jerry Hancock <jerry@hanler.com> wrote:
>
> This is an exercise more than anything. It started when I noticed the counter in a 3586B I purchased was +1 count unless I dropped the input frequency .25hz. I was using my GPSDO reference for it and the 3336 it was counting. I then took my GPSDO and tried reading that directly and I see the same thing. This is annoying more than anything and I assume there is a slight gate phase related issue. I don’t have anything to read the jitter on my GPSDO which is a Lucent RFTG-U with the REF1 and REF0 but since I am using it as the reference and the signal under test, it shouldn’t matter at .1hz. If I run the count over 3 minutes, the count is .923hz high consistently. To put a finer point on it, reading 10,000,000.00hz from my GPSDO, It will read consistently 10,000,000.1 or 10,000,000.0 with the distribution of each to average 10,000,000.923 over 5 minutes. If I drop the input frequency by .25hz, it will read 10,000,000.0 without a 10,000,000.1 until the cows come home. I’ve
> let it run about a day to check.
>
> So I was thinking, o.k., let’s put a frequency counter on the back to read the F0 output signal rom the 3586B and see what it reads but I then realized I don’t have anything that accurate. I do have a lot of micro processors around, everything from the lowly PIC thru the DSPIC to the STM32F7’s, F4’s and if I have to, I will get a FPGA and go from there. I could purchase an HP 12 digit counter if I could find one locally as I am tired of paying shipping but haven’t found one to date.
>
> So no really pressing reason for the counter other than just curious as to what is causing the issue with the 3586B. By the way, when I read any of the WWV signals they count +.1hz as well under constant signal. I am pretty sure the 3586B is recognizing my reference input as the OCXO is dialed to 10,000,000.0 and the standard oscillator is a little high at +.4 (if I disconnect the OCXO strap) and I haven’t looked into it yet.
>
> Thanks for the interest and help
>
> Jerry
> _______________________________________________
> 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.
OE
Orin Eman
Mon, Apr 24, 2017 8:39 PM
Hi Jerry,
See AN4776 on st.com. Section 2.6 looks particularly interesting.
Orin.
On Mon, Apr 24, 2017 at 12:06 PM, Jerry Hancock jerry@hanler.com wrote:
This is an exercise more than anything. It started when I noticed the
counter in a 3586B I purchased was +1 count unless I dropped the input
frequency .25hz. I was using my GPSDO reference for it and the 3336 it was
counting. I then took my GPSDO and tried reading that directly and I see
the same thing. This is annoying more than anything and I assume there is
a slight gate phase related issue. I don’t have anything to read the
jitter on my GPSDO which is a Lucent RFTG-U with the REF1 and REF0 but
since I am using it as the reference and the signal under test, it
shouldn’t matter at .1hz. If I run the count over 3 minutes, the count is
.923hz high consistently. To put a finer point on it, reading
10,000,000.00hz from my GPSDO, It will read consistently 10,000,000.1 or
10,000,000.0 with the distribution of each to average 10,000,000.923 over 5
minutes. If I drop the input frequency by .25hz, it will read 10,000,000.0
without a 10,000,000.1 until the cows come home. I’ve
let it run about a day to check.
So I was thinking, o.k., let’s put a frequency counter on the back to read
the F0 output signal rom the 3586B and see what it reads but I then
realized I don’t have anything that accurate. I do have a lot of micro
processors around, everything from the lowly PIC thru the DSPIC to the
STM32F7’s, F4’s and if I have to, I will get a FPGA and go from there. I
could purchase an HP 12 digit counter if I could find one locally as I am
tired of paying shipping but haven’t found one to date.
So no really pressing reason for the counter other than just curious as to
what is causing the issue with the 3586B. By the way, when I read any of
the WWV signals they count +.1hz as well under constant signal. I am
pretty sure the 3586B is recognizing my reference input as the OCXO is
dialed to 10,000,000.0 and the standard oscillator is a little high at +.4
(if I disconnect the OCXO strap) and I haven’t looked into it yet.
Thanks for the interest and help
Jerry
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.
Hi Jerry,
See AN4776 on st.com. Section 2.6 looks particularly interesting.
Orin.
On Mon, Apr 24, 2017 at 12:06 PM, Jerry Hancock <jerry@hanler.com> wrote:
> This is an exercise more than anything. It started when I noticed the
> counter in a 3586B I purchased was +1 count unless I dropped the input
> frequency .25hz. I was using my GPSDO reference for it and the 3336 it was
> counting. I then took my GPSDO and tried reading that directly and I see
> the same thing. This is annoying more than anything and I assume there is
> a slight gate phase related issue. I don’t have anything to read the
> jitter on my GPSDO which is a Lucent RFTG-U with the REF1 and REF0 but
> since I am using it as the reference and the signal under test, it
> shouldn’t matter at .1hz. If I run the count over 3 minutes, the count is
> .923hz high consistently. To put a finer point on it, reading
> 10,000,000.00hz from my GPSDO, It will read consistently 10,000,000.1 or
> 10,000,000.0 with the distribution of each to average 10,000,000.923 over 5
> minutes. If I drop the input frequency by .25hz, it will read 10,000,000.0
> without a 10,000,000.1 until the cows come home. I’ve
> let it run about a day to check.
>
> So I was thinking, o.k., let’s put a frequency counter on the back to read
> the F0 output signal rom the 3586B and see what it reads but I then
> realized I don’t have anything that accurate. I do have a lot of micro
> processors around, everything from the lowly PIC thru the DSPIC to the
> STM32F7’s, F4’s and if I have to, I will get a FPGA and go from there. I
> could purchase an HP 12 digit counter if I could find one locally as I am
> tired of paying shipping but haven’t found one to date.
>
> So no really pressing reason for the counter other than just curious as to
> what is causing the issue with the 3586B. By the way, when I read any of
> the WWV signals they count +.1hz as well under constant signal. I am
> pretty sure the 3586B is recognizing my reference input as the OCXO is
> dialed to 10,000,000.0 and the standard oscillator is a little high at +.4
> (if I disconnect the OCXO strap) and I haven’t looked into it yet.
>
> Thanks for the interest and help
>
> Jerry
> _______________________________________________
> 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.
>
JH
Jerry Hancock
Mon, Apr 24, 2017 10:26 PM
Orin, Thanks, this goes beyond interesting and I don’t know how you found it. I’ll be staring at this doc for the rest of the week. I have a dozen or so of the Nucleo boards around include the high end F7 types so I’ll see if I can duplicate their code on the System Workbench they reference (and I have installed).
This afternoon I hooked up the output of my 3586 F0 (with the GPSDO reference) set to 15,000,000.0Mhz and then used my 3336 set to the same (again with the GPSDO) to see if I had any creep on my TDS3054B scope after syncing the two signals. Just setting the 3336 to .001 higher causing the sine waves to go out of sync noticeably in a minute. It’s been running about 2 hours and they still overlap perfectly when set to the same frequency.
I think we all know what the issue is here in that the 3586 counter is probably adding a count here or there. It’s just curious that it never seems to drop a count. I would have thought I would see +.1 and -.1 with an equal distribution over a reasonable period of time of a few minutes but I don’t; I always see the +.1 or .0, never a 999.9 count (-.01).
If someone has a 5335 counter in the SF bay area they would like to unload, please send me a note at meters at hanler dot com.
By the way, your Geller ref is still running perfectly. I’ll have to send it back to you for calibration soon as I think I have had it a year.
Jerry
Orin, Thanks, this goes beyond interesting and I don’t know how you found it. I’ll be staring at this doc for the rest of the week. I have a dozen or so of the Nucleo boards around include the high end F7 types so I’ll see if I can duplicate their code on the System Workbench they reference (and I have installed).
This afternoon I hooked up the output of my 3586 F0 (with the GPSDO reference) set to 15,000,000.0Mhz and then used my 3336 set to the same (again with the GPSDO) to see if I had any creep on my TDS3054B scope after syncing the two signals. Just setting the 3336 to .001 higher causing the sine waves to go out of sync noticeably in a minute. It’s been running about 2 hours and they still overlap perfectly when set to the same frequency.
I think we all know what the issue is here in that the 3586 counter is probably adding a count here or there. It’s just curious that it never seems to drop a count. I would have thought I would see +.1 and -.1 with an equal distribution over a reasonable period of time of a few minutes but I don’t; I always see the +.1 or .0, never a 999.9 count (-.01).
If someone has a 5335 counter in the SF bay area they would like to unload, please send me a note at meters at hanler dot com.
By the way, your Geller ref is still running perfectly. I’ll have to send it back to you for calibration soon as I think I have had it a year.
Jerry
BK
Bob kb8tq
Mon, Apr 24, 2017 11:31 PM
Hi
I believe what you are going to find is that the 3586 has an IF strip in it.
It does a heterodyne process to the IF center frequency and then indicates
things from there. If the IF strip is out of alignment, you get a reading error.
Probably worth digging into the service manual on the 3586.
Bob
On Apr 24, 2017, at 6:26 PM, Jerry Hancock jerry@hanler.com wrote:
Orin, Thanks, this goes beyond interesting and I don’t know how you found it. I’ll be staring at this doc for the rest of the week. I have a dozen or so of the Nucleo boards around include the high end F7 types so I’ll see if I can duplicate their code on the System Workbench they reference (and I have installed).
This afternoon I hooked up the output of my 3586 F0 (with the GPSDO reference) set to 15,000,000.0Mhz and then used my 3336 set to the same (again with the GPSDO) to see if I had any creep on my TDS3054B scope after syncing the two signals. Just setting the 3336 to .001 higher causing the sine waves to go out of sync noticeably in a minute. It’s been running about 2 hours and they still overlap perfectly when set to the same frequency.
I think we all know what the issue is here in that the 3586 counter is probably adding a count here or there. It’s just curious that it never seems to drop a count. I would have thought I would see +.1 and -.1 with an equal distribution over a reasonable period of time of a few minutes but I don’t; I always see the +.1 or .0, never a 999.9 count (-.01).
If someone has a 5335 counter in the SF bay area they would like to unload, please send me a note at meters at hanler dot com.
By the way, your Geller ref is still running perfectly. I’ll have to send it back to you for calibration soon as I think I have had it a year.
Jerry
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.
Hi
I believe what you are going to find is that the 3586 has an IF strip in it.
It does a heterodyne process to the IF center frequency and then indicates
things from there. If the IF strip is out of alignment, you get a reading error.
Probably worth digging into the service manual on the 3586.
Bob
> On Apr 24, 2017, at 6:26 PM, Jerry Hancock <jerry@hanler.com> wrote:
>
> Orin, Thanks, this goes beyond interesting and I don’t know how you found it. I’ll be staring at this doc for the rest of the week. I have a dozen or so of the Nucleo boards around include the high end F7 types so I’ll see if I can duplicate their code on the System Workbench they reference (and I have installed).
>
> This afternoon I hooked up the output of my 3586 F0 (with the GPSDO reference) set to 15,000,000.0Mhz and then used my 3336 set to the same (again with the GPSDO) to see if I had any creep on my TDS3054B scope after syncing the two signals. Just setting the 3336 to .001 higher causing the sine waves to go out of sync noticeably in a minute. It’s been running about 2 hours and they still overlap perfectly when set to the same frequency.
>
> I think we all know what the issue is here in that the 3586 counter is probably adding a count here or there. It’s just curious that it never seems to drop a count. I would have thought I would see +.1 and -.1 with an equal distribution over a reasonable period of time of a few minutes but I don’t; I always see the +.1 or .0, never a 999.9 count (-.01).
>
> If someone has a 5335 counter in the SF bay area they would like to unload, please send me a note at meters at hanler dot com.
>
> By the way, your Geller ref is still running perfectly. I’ll have to send it back to you for calibration soon as I think I have had it a year.
>
> Jerry
>
> _______________________________________________
> 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.
