[Elecraft] 4mhz osc and Firmware change.

[Ron D'Eau Claire]

Steve, GU3MBS wrote
...Use an insulated tuning tool (the Elecraft tool is rather poor for
this job) to adjust Control Board C22 so that the two signals coincide -
final proximity may show a beat which can be reduced to zero.  If WWV
isn't very strong you won't see its breakthrough signal so you'll have
to alternately connect and disconnect the antenna until you have the two
signals giving the same frequency on spectrogram.
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Trimmers like C22 are pretty hard on non-metallic adjustment tools. I've
chipped to bits a set of nice E.F. Johnson ceramic tools I used in land
mobile as well as ruined a number of plastic tools - including ripping
the metal insert out of one of those that uses a tiny metal blade stuck
into a plastic handle. I HATE to be dropping little metal bits into the
guts of a powered-up rig! 

I use a simple METAL SCREWDRIVER to adjust C22. The amount of "detuning"
it causes is inaudible when setting the 5th harmonic of the 4 MHz to WWV
at 20 MHz. That is, if there is any effect on the frequency by using a
metal screwdriver, it's too small to be able to detect. If C22 is
installed correctly, the metal slot is at ground potential. The rest of
the circuit is insensitive enough not to be affected by the screwdriver.

Of course, you MUST take care not to jab the metal screwdriver into
other parts of the circuit on that board causing random short-circuits. 

Adjusting caps in higher powered circuits or where one side of the
trimmer is NOT at ground potential can require non-metallic tools, but
the K2 is designed to keep that trimmer adjustment slot at ground
potential.

Ron AC7AC
K2 # 1289