What is the correct knob positioning for the Johnson KW matchbox?
On the left knob, Tuning, I assume 0 is minimum capacitance. Correct?
On the right knob, Matching, is 0 also minimum? That would make 50 max and 100 minimum again.
Alternately, if 100 is maximum then 0 and 50 are minimum. Either that or I'm not looking at the split stator capacitor correctly.
Jon
Hi Joe,
I'll try to offer a helpful reply.
I have several Matchboxes, love them, excellent units, very robust and low loss.
I doubt if any of my models, even the very clean ones, have not yet had the knobs removed and reinstalled, so I can not speak to how it was done at the factory.
What I do here, and I always open up the Matchboxes for inspection, as often the T/R is jumped out to use on a transceiver.
Or I sometimes need to change the tap for the receiver antenna to match the expected feedpoint impedance.
When I reinstall the knobs, I use the "0" setting for a fully unmeshed cap, and the "100" for fully meshed.
Its really a moot point, as the number is just a relative "logging scale".
What I do is generate a small cheat sheet with the various settings for each freq that I wish to operate.
I really don't care if its 20, 30 or 40, always as it is consistent.
Does that help?
73 Bruce W1UJR
