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Old May 5th 10, 12:18 AM posted to rec.radio.amateur.homebrew
Scott[_4_] Scott[_4_] is offline
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First recorded activity by RadioBanter: May 2008
Posts: 115
Default HP 5245L Counter Oscillator adjust?

K7ITM wrote:


Yes, most certainly the oven should be noticeably warm, unless your
ambient temperature is already really hot. You can also monitor the
current the oven draws (perhaps with some difficulty, depending on how
the oven is wired into the circuit). You should see moderately high
current when the oven is first turned on, and the current should drop
to (very roughly) half as much as the oven reaches operating
temperature. I'd expect the oven control loop to be reasonably
damped, so the current falls from the startup value to the idling
value within just a few seconds and stabilizes without overshoot, or
with only minor overshoot. At least that's what I've seen on several
models, including the HP10811.

These days, you can get some remarkably small and low-power oven
oscillators, down to TO-5 transistor can size I believe, and possibly
even smaller. The power to run them is low milliwatts. Even
temperature-compensated oscillators have gotten remarkably good...I
have some 3x5 millimeter ones that are rated half a part per million
max deviation over -20C to +55C (and run on about 2.5 milliwatts), and
you can get better than that.

Cheers,
Tom


I don't think it's POSSIBLE to get REALLY HOT here in WI (by some
standards, that is...to me, 75 is really hot!)