Jim, Yes, you can run parallel verticals for 160 and 80 -- I do it now, and have also had double inverted-Ls with the top wires going in opposite directions.
In my experience, the key to making it work reliably is to get 24" or more separation between the vertical wires. With my present 100' toploaded 160M vertical, I attach a cord to the center of the 80M wire and adjust the spacing for the best match. 73, Gary K9AY Date: Tue, 5 Nov 2013 07:27:50 -0700 From: "Jim Garland" <[email protected]> To: <[email protected]> Subject: Topband: 160m/80m duoband vertical question Message-ID: <[email protected]> Content-Type: text/plain; charset="us-ascii" My 160m vertical is 79ft high (wire running up a 26m Spiderbeam fiberglass pole), with a capacity hat. Is it workable to put an 80m 1/4 wave wire on the same mast join both antennas at the base, in the same way people make multiband fan dipoles? The idea would be that when operationg on 80m, the 160m antenna would present a high Z, and vice-versa when operating on 160m. I don't have a feeling for how much interaction there would be between the two wires, separated by only a couple of inches. Another option would be to electrically isolate the wires and select one or the other with a relay. If possible, I'd like to avoid matching networks and complicated switching arrangements, because the antenna is 700 ft from my station. Any advice is most welcome. 73, Jim W8ZR _________________ Topband Reflector
