Modeling and experimentation verify that the 20 meter version has only MINOR radiation from the vertical portion over the entire band, and using a 50 to 450 ohm (3:1 turns ratio) unun gives an SWR of 1.3:1 or less over the entire 20 meter band.
The pattern of radiation shown on EZNEC is essentially a dipole's pattern for the same height and ground from one end of the band to the other. The differences are seen at angles and directions of NULLS for a dipole. As you move away from the Windom's center frequency, these nulls become less pronounced from the increasing miscellaneous radiation from the vertical. In the good ole days they didn't have EZNEC and GHz PC's to COMPUTE or EXPERIMENT with the design. My ancient notes from the 50's for this antenna were substantially off. They used dipole lengths and 44% tap. The horizontal needs to be slightly longer at the lowish heights typically used by QRPers hanging stuff in trees on walkabouts. So we wind up with 34' and 36% tap. Turns out there is a lot of hay to be made revisiting the old-time designs with the snazzy new tools. IF one can actually find the zero vertical radiation point on a Windom, then the width where the vertical radiation is down 30 db from main probably IS very narrow, but practically speaking, the thing is a dipole over the entire twenty meter band. What is neat is to wind the entire thing up on a small spool and throw it in the suitcase along with the K2. And a sharp op with that antenna and a K2 can whup a lid with a beam and a KW any day, from one end of the band to the other. 73, Guy. ----- Original Message ----- From: "Ron D'Eau Claire" <[EMAIL PROTECTED]> > > Unfortunately, that only works at ONE frequency! Most Hams like to QSY a > bit, even back in the days of crystal control! _______________________________________________ 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
