[TowerTalk] Johnson Matchbox Question

[Tom Hellem]

I have a Johnson KW Matchbox that doesn't seem to be working quite right.
It's very hard to accomplish a perfect match at times even though the load
is well within the claimed capability of the tuner. The RF input from the
TX is injected into an approx. 5 turn coil which surrounds a smaller
diameter coil of many more turns. Looking at the 5 turn coil I can see that
some previous owner had tried tapping different points on it for injecting
the RF.
Question- how critical is the tap point on this coil for proper operation
of the tuner?
The 5 turn coil is grounded on one end and open on the other, and is
currently tapped approx. 1-1/4 turns from the grounded end.
Does anybody know where Johnson tapped this coil when they built the tuner?

Any input gratefully accepted.

Tom
K0SN