Martin, To be a Zepp antenna, the parallel feedline would have to be an odd multiple of a quarter wavelength, and that quarter wave a;so serves in place of a 'counterpoise wire', so your 15 feet is a futile effort in that regard. Just as well to use a single wire for the 15 feet to the end (and thaat makes your end fed antenna 15 feet longer too).
You will also need something for a ground reference from your 2nd floor shack location. A ground (earthing)wire will have length to it and that causes it to NOT be a good RF Ground. You may have to resort to using a counterpoise wire cut for each band. Cut one insulated wire to 66 feet (80 meters), another to 33 ft (40 meters) and another to 16 ft (20 meters). Connect one end all of these wires to the ground point on your tuner, and fan out the other ends as best you can. Keep the far end of the wires insulated and away from reach of people and pets because they will have high RF voltage on those ends. You may have to trim the wire length a bit to make them resonant on each band, but doing so will eliminate RF in the Shack. 73, Don W3FPR > -----Original Message----- > > Hi Guys, I have moved my shack to an upstairs bedroom and > consequentially I > will need to feed my 130 feet wire at the end rather than at the > centre (it > was a dipole fed with coax). I want to work 80/40/20m. I have made some > open wire feeder (about 15 feet) to get me from the chimney to the bedroom > and have left one end of the open wire feeder open circuit. I think I am > making a Zepp antenna. > > Now to match this arrangement to my K1 on the above bands, I want to build > a tuner. I have just been looking at the design on this web site > (http://www4.tpgi.com.au/users/ldbutler/SingleCoilZMatch.htm) and it looks > just the ticket. It is suitable for balanced lines and would allow QRO up > to 100W in the future. Before I commence construction I just want to check > that it will match the very high Z of an end fed half wave wire. > > Any thoughts. > > Martin > M0KWV > K1 #1534 > > -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.11.13/126 - Release Date: 10/9/2005 _______________________________________________ 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
