It turns out that I unfairly maligned the 1992 (and the 9462
oscillator, option 04E) when I accused it of poor oscillator
"settability." I was inspired by the recent discussions to have
another crack at mine, and they can, in fact, be set very
accurately. One of mine has been reading "000.000000 E-3" for about
24 hours now, hooked to a Thunderbolt and using the 10-second
gate. The other has been toggling between "999.999999 E-3" and
"000.000000 E-3." (This is how mine are used --- perpetually reading
the shop standards to give an independent reality check on their condition.)
Walking the oscillators to 0 is tedious and time-consuming, but not
difficult. I think I must not have been sufficiently patient in the
past. The fine adjustment has detents -- if you adjust it slowly,
you can count the clicks. On both of mine, each click adjusts the
oscillator frequency about 3 mHz (CW lowers the oscillator
frequency/raises the displayed frequency). Interestingly, when you
are close to zero and adjusting the oscillator only a few clicks at a
time, it takes off in the opposite direction and peaks at a MUCH
greater offset than the eventual increment, then returns and
overshoots in the direction of the adjustment (again, quite a bit
further than the eventual increment), and finally settles to its new
value, with another cycle or two of smaller +/- overshoots around the
final value. It takes at least 1/2 hour to settle within a count or
two of the eventual final value, and several hours before you can be
confident that it has settled to its new value.
Best regards,
Charles
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