[time-nuts] HP 10544A Repair

Richard (Rick) Karlquist richard at karlquist.com
Mon Feb 29 00:28:20 UTC 2016



On 2/28/2016 7:01 AM, Bob Camp wrote:
> Hi
>
> It’s not an electrical issue as much as a heat issue ….
>
> Before you start, consider that you will be doing something like:
>
> Move trimmer 1 turn CW
> Wait 10 minutes
> read frequency
> Move trimmer 1 turn CW
> wait / read
> Move trimer 1/2 turn CCW
> wait / read
> Move trimmer 1/4 turn CW
> wait / read
> Move trimmer 1/8 turn CCW
> wait / read
> Move trimmer 1/16 turn CW
> wait / read
> Move trimmer 1/32 turn CW
> wait / read
>
> That is indeed an ideal version. You likely will do multiple steps at each of the stages rather
> than get it right the first time. The part needs to be warmed up for a few days before you
> can get to the 1/32 turn level. You also need a good standard to compare to.
>
> Bob
>

Instead of that, start with the pot at max temp, and have the counter 
make measurements at, say, 1 second intervals as the oven warms up.
You can tell by looking at the plot what the peak frequency is.  Now
that you know the peak frequency you are shooting for, it will take
a lot less trial and error to find the oven setting that produces it.

Rick



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