http://www.am-dx.com/zmatch.htm

Very interesting, and nice pictures.

A circuit diagram would be nice, and perhaps a comment or two on how well it works.

Also what length is your antenna?

I took the Z-Match, my portable LW-MW-SW radio and a coil of wire on a recent mini-vacation with my wife. With the wire strung out from our B & B suite to a tree and a water pipe for ground, it worked quite well. A big increase in signal strength compared to the radio's whip, and quite sharp peaks in the tuning. After checking it out on the BC band I tuned up to 160M and heard some W4s chatting, then went higher still to 2182 kHz. I heard some east coast marine traffic there, so over all the Z-Match proved itself useful. I'll use it at home on my 200 foot longwire and my single-tuned xtal set over the winter.