[time-nuts] HP 5370A Frequency counter Problem(s)

Bill Janssen billj at ieee.org
Thu Mar 22 15:20:49 UTC 2007


OK that gives me some hope that I can make this thing work. I have 
started the calibration
process and got to the second step that requires a short duration 
pulse.  I don't know
how I will do that yet. Maybe I will skip that item and go to the next.

The processor seems to work OK so I assume the ROMs are seated. I did 
re-seat them anyway.

Thanks for the comments and now back to work :-)

Bill K7NOM

John Miles wrote:
> It's normal for those last few digits to bounce around when measuring
> frequency.  The shorter the gate time, the less-consistent the LSDs will be.
> How do the tolerances compare to what's in the manual's self-check
> procedures?  You'll note that they don't tell you to expect 10.000 000 000
> MHz, but 10.000 000 0XX MHz.
>
> The important things to look at with a 5370 are: 1) verify that the trigger
> levels are 0.00 +/- 0.01 with the controls set to PRESET; 2) verify that the
> +T.I. ONLY interval is within 1 ns of 100.0 ns; and 3) verify that the
> jitter when measuring its own clock reference is less than 100 ps (all of
> the ones I have seen are under 50.)  If all of that is OK, then chances are
> everything else will work properly including frequency measurement.
>
> I've found that many of them need their front-panel input assembly taken
> apart and the switches carefully cleaned/lubed.  That alone may clear up a
> lot of flakiness.  There have also been some reports of poorly-seated ROMs,
> and/or socket contact problems.
>
> -- john, KE5FX
>
>
>   
>> I got a HP 5370A off of Ebay and although it looks terrible I thought it
>> would probably work OK.
>> But it doesn't :-(  I downloaded the manual and have yet to print it out.
>>
>> Question;
>> When doing a self check by feeding the 10 MHz from the back into the
>> counter it counts cycles OK
>> but the last 3 or 4 digits are erratic. I am starting to do as much
>> alignment as I can but am
>> wondering if this is a known problem and if a cure is known.
>>
>> Anyway I think I paid too much for this box of problems but will
>> continue to try to repair.
>>
>> Any suggestions (on repair only) is appreciated
>>
>> Bill K7NOM
>>
>>     
>
>
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
>
>
>   






More information about the Time-nuts_lists.febo.com mailing list