[time-nuts] Introduction

[Mark Spencer]

I've found with my HP5370B's they perform best over a fairly narrow range of input signal levels.    (1 to 2 volts If I recall correctly ?)  Some experiments might be in order for yours.   Virtually all my testing was done with 5 or 10 MHz sine waves so this may or may not be helpful in your case.   I found in line attenuators and an oscilloscope to be helpful in making measurements using my HP5370B's.

I've never done a full alignment of mine so this behaviour may not be typical.

All the best
Mark S


Sent from my iPhone

>> On Feb 24, 2016, at 1:36 AM, Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:
>> 
>> On Wednesday, February 24, 2016 12:55:42 AM Enrico Bellotti wrote:
>> Hello to all,
>> 
>> first of all, thank you for the great and useful work that the time-nuts
>> have done over the years.
>> 
>> I have finally been able to gather all my counters (HP5335A, HP51131A,
>> HP5370A, HP5370B #1, HP5370B #2) and try to do some "simple" measurements.
>> 
>> I have started testing and comparing the instruments I have available using
>> the approach that was discussed a while ago on the list and also outlined
>> by John Ackermann (http://www.febo.com/pages/hp5370b/). Specifically, the
>> Adev for a time interval measurement on a (90ft of) RG58A/U cable.
>> 
>> I have attached a PDF file with the results and some additional details of
>> the test setup.
>> 
>> From what I have understood the Adev at one second is related to the
>> counter resolution. The results I have obtained seem to be reasonable
>> except for HP5370B #2. This instrument seems to be marginal at best. Does
>> anybody know if the measured value for HP5370B #2 is a symptom of a
>> multifunction or simple need for calibration?
>> 
>> Thank you for any comments/suggestions/corrections you may have.
>> 
>> Best.
>> Enrico
> Try repeating the test with a low noise external reference/If that doesn't 
> improve the results try realigning the filters etc in the 10-200MHz multiplier.
> 
> Bruce
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