[Test-Equipment] Phase lock on military version of HP 8640Bgenerator?

[John Miles]

There's no locking feature at all on the option-323 units.

It can't be left on all the time, at any rate, because it uses the frequency
counter hardware to derive the comparison signal.  You have to turn it off
before doing any manual tuning.

-- john, KE5FX


> I have one of the big, yellow AN/USM-323 signal generators, also known as
> the HP 8640B with option 323. I read that the commercial version
> has a front
> panel control that allows phase locking the output to an internal
> reference
> oscillator for stability. The question is how this relates to the yellow
> military version. In some places I've read that it does not have the
> external control and that the phase lock is on all the time, and
> elsewhere I
> read that it does not even have the phase lock. I don't know which is
> correct.
>
> My unit drifts slowly for several hours before finally settling
> in. Is that
> normal for this unit, not having the phase lock circuitry, or perhaps it
> does have it but it's broken?
>