[time-nuts] HP 5061A problem

[Adrian]

Corby,

well, the OP Amp was shot.
When I pulled it out, I saw a marking 'BAD 7-8-97' on the side cover.
I was hoping to get it fixed because the 1uF ceramic cap at +15V was 
shorted and had burned the 75R resistor.
But, after some serious investigation, I'm realizing that it is 
incompatible with the unit I have.

The OP Amp module is marked 05061-6134 Ser. 2136. On the chassis under 
the module it says 05061-6092. The 5061A SN prefix is 1540A.
It has an Intech A-240 and 1826-0471 (OP07CJ). The inverting input of 
the OP07 is connected to J2/9 by a white wire, as on the schematic.
However, the plug has pins 8 and 9 bridged internally, so the inv. input 
is hard wired to -16V. J2/3 is n.c. inside the plug. And, the 8uF cap is 
connected between the amp input and output (J1 and J2/5).

I had the OP07 removed and the output of U1 bridged to J2/5 and it was 
locking. However, the response to fine adjust changes was very slow.
So, at least the basics are there and I should be able to get it running 
if I find the correct OPamp.

Adrian


cdelect at juno.com schrieb:
> Adrian,
>
> You say it does  not lock.
>
> When you put in operate and push the logic reset button does the green
> light come on?
>
> What is the 2nd harmonic meter reading?
>
>   If too low the logic will not turn on the green light. Raise the reading
> via the A7 gain adjust thru the front panel hole.
>
> Is the green light burnt out?
>
> In operate and looking at the control voltage on the meter does the
> control voltage "follow" a slow adjustment back and forth of the fine
> Quartz adjust?
>
> Corby
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>