[Johnson] vfo tracking

[radioman]

the high and low band edge adjustments will and do interact.

Thus, you have to juggle back and forth... several times.. and split the
difference slightly..untill your arrive at the proper result.

If the coil is wildly out of normal position you arent going to get good
tracking.

Sometimes it pays to go at it bass-ackwards.. AFTER you have it close
but not perfect.. by seeing what the cap adjustment does at the low
end..and the coil at the high.

Don't go to extremes with this backwards approach.. but don't over look
it if all else fails...

There is no way you can set each end once..and expect to have it be
correct.

I would NOT mess around with the fixed caps inside the VFO. Micas just
dont change, if they are the molded type.
I have a hundred overhauled radios out in the field with thier original
1930's mica caps in oscillator circuits.. working just fine.

Temperature compensating  disc ceramic caps are used in the VFO..and not
readily available.

These are NOT your off the shelf 10 cent caps.  Leave them alone +ACE-

Temperature compensation is a black art.. almost impossible to practice
at home without extensive test gear, lots of experience, and a big
handfull of temp compensating caps.

I prefer a relatively stable vfo.. what ever the calibration.. to one
that wanders +ACE-
Counters and digital recievers are cheap, and more reliable than your
vfo.
When in doubt.. zero beat, and measure.

larry