Absolutely, for QRP levels! With the high impedances come very high RF voltages - voltages in the hundreds, even thousands of volts. That's why compact ATU's like the Elecraft ATU's can't handle those impedances - even if they could affect a match the voltages would destroy the caps, relays and other components at any power above a few watts. There's a reason why the antenna tuners shown in the old textbooks have huge capacitors and big coils wound on ceramic forms or air-wound and everything mounted on big ceramic stand-off insulators! That's what is needed when running more than a couple of watts into a really high-impedance load. Even at 50 watts I've seen a transmitting variable capacitor with 1/4-inch (6mm) plate spacing arc over when coupling to a really high-impedance load. Ron AC7AC -----Original Message-----
Or..... an intermediate simple ATU such as http://www.qrpproject.de/UK/fuchs_ant_.htm This should work? 73, Deni F5VJC GM3SKN _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
