On Fri, 16 Nov 2007 11:50:44 -0800, you wrote: >I want to try and build an HF two Element Vertical Antenna for 20 meters. > >While there are several java scripted web-sites that will calculate and >provide the physical measurements for the Driven, Reflector elements and >spacing. > >I would like to use my MJF-259 to complete the fine tuning during construction >and given that the frequency of the Driven element will not be the resonant >frequency of the reflector. > >What would a good equation be to determine the resonant frequency for the >reflector based on the desired frequency for the Driven element? > >Some references that I have found state the Reflector is approximately 4% >longer than the Driven and the Director is 4% shorter, with element spacing >0.15 to 0.25 of the desired freq. I would like something a little more >specific. Not that I can build it to spec or that the MFJ259 will be that >accurate, I would still like to work with figures that provide something other >than approximate. > >73 K2CG >Chuck G. > [snip]
Back when I was a Novice I built a 15m 2 element Yagi using the information for Yagi's in the ARRL antenna book. I chose to build a driven/reflector style beginning with a reflector length of (468/f in mc) X 1.05 and DE length of 468/f in mc. It worked very well. Tom, N5GE http://www.n5ge.com http://www.eQSL.cc/Member.cfm?N5GE _______________________________________________ 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
