Capacitor plate corrosion

[w1vtp]

I should have supplied the diagram in earlier post....  sorry, Jim.

The tuner is a copy of one developed by Jim Heys G3BDQ .... in about 1990. <snip>

A reverse of the famous "Ultimate Transmatch"  which I built into my 500 watt AM transmitter, designed by Lew McCoy.  See attached schematic.  Credit:  http://www.coutant.org/tuner/

It worked very well.

Al

[w1vtp]

FWIW

http://www.tasrt.ca/AntennaTips/AntennaTips.htm

Al

[Opcom]

People say that the Ultimate Transmatch circuit shown, and others like it, will pass the transmitter's harmonics. I've used them very successfully but never tried to measure harmonic attenuation.

I realize the device's intent is to transform impedance and compensate for reactance, and that transmitters should have low harmonics to begin with.

Others say the kind of matcher that looks like a PI section helps lower any harmonics. What is the experience on these things?

I believe them and 'designed' my tuner project based on copying a balanced version of the L or pi network instead of the ultimate transmatch. image from R. Measures' page.