[Boatanchors] Johnson KW Matchbox - Problem with the "matching capacitor

[Rob Atkinson]

To solve the slip problem the Matchbox will have to be opened.  The
rotors have threaded shafts with nuts on them and if they're like
other a.v. caps they hold the spring wiper, and affect the rotation
friction.  It's a good time to learn about the mechanics of a.v. caps.
  It might be wise to find a sacrificial a.v. cap to experiment with
first so you don't screw up the MB caps by getting the centering of
the rotating plates out of whack.  It may be the stator plates that
move back and forth to adjust the centering, I can't remember.   The
nut that buts up against the wiper may just need to be tightened with
a C wrench.

Here's some advice:  Remove the MB cover and put the 5 thousand screws
that hold it in a film can or pill bottle and set it and the cover
somewhere safe and forget about it until you sell it if that ever
happens.  Put the knobs back on the shafts and run the network in the
open, then any time you have to futz with it there's no problem
getting into it and you won't need to worry about the knob other than
needing them there to turn the shafts because you'll look at the cap
plate mesh instead.  This also makes clipping in extra capacitance a
breeze.   The KW MB works just as well with no cover as it does with
one.   Adjust it with an analyzer and forget about the coupler and
vswr meter they built into some of them.

73
Rob
K5UJ