I would avoid coaxial cable in any situation where there can be a large impedance mismatch because of just the losses mentioned. Even though low power might not burn up 3 feet of coax, that's still a chunk of power thrown away.
The ideal CM choke at the OUTPUT of a tuner feeding a balanced line would be made of open wire line. The old air-core chokes did just that but, to have the choking impedance needed, they are physically B-I-G, especially if used on 80 or 160 meters. Some look like 'steampunk' art with huge coils occupying a whole wall, not unlike what one sees in some photos of early spark transmitting stations. A parallel pair of wires wrapped on suitable toroid cores would be my first choice today, but never with coax between the choke and the matching network. With a little ingenuity one can make a very clean, neat open wire line installation running across a ceiling using small insulators attached to the ceiling if the operating position is far from the point of egress to the outside. 73, Ron AC7AC -----Original Message----- Dean Nice analysis of the issues. K9YC also presents baluns done with wire pair rather than coax, RG213 or otherwise. Might not they be a better solution than coax when constructing a CM choke for driving windowline? Jim ab3cv ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
