If you look at the schematics of the C-field adjustment circuits, you'll
find where the tweaking is available for fine tuning the Rb system. I
think that's the only "frequency adjustment" spot to worry about. The
other is the tweak for the crystal oscillator to accommodate long term
drift there, if its tuning range hits a limit. This an internal, seldom
needed adjustment, so the C-field is likely the only one that would be
useful externally, to (very) fine tune the output frequency. I have some
similar M-100 units, which have access to the C-field pot through a hole
in the back end heat sink and case. An external adjustment port would be
either a substitute for the internal pot, or something to add to or
subtract some current from the C-field coil, that's mostly controlled by
the internal pot.
So, look for an internal pot. If there is one, then the external stuff
likely just modifies what it does. If there isn't one at all, then the
external circuit may have to provide the proper current, so it may be a
little more complicated. It could also be that the C-field is set up to
some nominal value, with fixed resistors, without any internal pot, and
an external one just moves it around a bit.
If you just run it, and it locks, it should be good to go, and you can
figure out these fine tuning issues later.
Ed
_______________________________________________
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.
