Hi Ron, You gave a nice summary of the antennas used on boats and aircraft in response to the question asked by "mc". I especially enjoyed your description of the Zepp, an excellent but often misunderstood antenna.
There are a few other antennas that have been and are used on airplanes that I have learned about over the years. In the late 1970s I was working at Bell Labs in NJ and got to work with AT&T's "air force" regarding flight operations manuals and such. They flew a number airplanes including some Gulfstream 4s and several smaller corporate-type jets. In discussions with the pilots, some of whom had been pilots for the commercial airlines, these additional designs came to light. 1. The leading edge of the vertical stabilizer is typically an insulating strip that either contains a wire or metal bar that is used as a short vertical fed by a wide-range ATU that covers HF and/or VHF frequencies. 2. The insulated leading edge can instead be used to form a tunable slot antenna. The gap so formed is effectively embedded is a large, although not infinite, metal surface. The length of the slot and the position at which the slot is fed can be varied to adjust the resonant frequency and matching condition. 3. Just yesterday I was having lunch with a corporate pilot and a few other ham friends. He said another technique is to run a wire from near the front of the plane to the vertical stabilizer tip to form a loop consisting of the body of the plane and the wire. I presume the loop is fed by an ATU, probably installed inside the vertical stab or near the nose with one side tied to the plane's metal shell and the other to the wire. I'm sure there are many other ways to put an antenna on a boat or plane that we haven't mentioned yet, and others yet to be dreamed up. Cheers, Gus Hansen / KB0YH _______________________________________________ Elecraft mailing list Post to: [email protected] 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
