I am currently evaluating a trap antenna design that is described in the 19th edition of the ARRL Antenna book. There are two different dipoles represented there: one using a 60pF capacitor and twin-lead feed, the other using a 100pF capacitor and coax feed.
The described advantage of both of these antennas is that they operate on 80, 40, 20, 15 and 10 meter bands to some degree. I have modeled these with little success using EZNEC. I expect that this is partly because I do not know how to add in the resistive component of the trap design. Please also note that I only have the DOS version of EZNEC. Any way my reason for all this is that I would like to build a portable vertical antenna for field use that has the touted characteristics. Obviously I would need to provide and attachment point for guy wires as well as an appropriate number of radials. My expectation is that the radials would be mounted about 2 feet above rock at the top of a mountain (East coast definition) where there is little or no support for a horizontal antenna. My question is: Does anybody know of a commercially available antenna that might serve? I have looked at a couple and find that they are very expensive (>>$100) and very short (<30 feet tall). Alternate question is: Does anybody know why EZNEC does not seem to confirm that this design works well on all 5 bands? Fran _______________________________________________ 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
