Let me re-do that 'superb' graphics again. Just made a mistake in 'signs'.
(G)--/////------<|
(+)----'
That ought to make a little more sense.
The above privides one variable, the (+) tap point. If you want two variables, make either the antenna, or (G) points variable. Or you can have three variables by making all of them taps that can be varied.
If you have at least a 'ball-park' guess as to the size of that coil, you can probably make do with just the one tap point of the center conductor. If you aren't sure about the size of the coil at all, making all three taps variable, then adjusting each separately for nearest reading, makes it sort of inevitable that you'll find the 'right' match. ... eventually.
- 'Doc
(All us geniuses gotta make dumb mistakes like this every once in a while. Other wise, people start expecting too much! You know? It's a 'genius' thing!)
If you won't go for that one, I can always tell about being in my second childhood and being one'a them prodigies... I get to ride that 'special' bus to Wal-Mart too!