From owner-qrp-l@Lehigh.EDU Sun Oct 19 13:24:09 1997 Received: from fidoii.CC.lehigh.EDU (fidoii.CC.lehigh.EDU [128.180.1.4]) by oucsace.cs.ohiou.edu (8.8.5/8.8.5) with ESMTP id NAA16221 for ; Sun, 19 Oct 1997 13:24:08 -0400 (EDT) Received: from Lehigh.EDU ([127.0.0.1]) by fidoii.cc.Lehigh.EDU with SMTP id <35193-31096>; Sun, 19 Oct 1997 13:23:47 -0400 Received: from nss4.cc.Lehigh.EDU ([128.180.1.13]) by fidoii.cc.Lehigh.EDU with ESMTP id <35091-33910>; Sun, 19 Oct 1997 13:21:39 -0400 Received: from moose.ncia.net (moose.ncia.net [207.140.8.2]) by nss4.cc.Lehigh.EDU (8.8.5/8.8.5) with ESMTP id NAA60058 for ; Sun, 19 Oct 1997 13:21:35 -0400 Received: from lizard (ncia121b.ncia.net [207.140.8.121]) by moose.ncia.net (8.8.7/8.6.12) with SMTP id NAA22291; Sun, 19 Oct 1997 13:20:37 -0400 (EDT) Message-Id: <3.0.1.16.19971019113945.2c27cc7e@mailhost.ncia.net> Date: Sun, 19 Oct 1997 11:39:45 Reply-To: kd1jv@moose.ncia.net Sender: owner-qrp-l@Lehigh.EDU Precedence: bulk From: Steven Weber To: "Low Power Amateur Radio Discussion" Subject: Re: W3EDP feed? In-Reply-To: <3.0.1.16.19971019013416.42a7581c@postoffice.worldnet.att.n et> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-To: cwgreg@worldnet.att.net X-Cc: qrp-l@Lehigh.EDU X-Sender: kd1jv@mailhost.ncia.net X-Mailer: Windows Eudora Light Version 3.0.1 (16) X-Listprocessor-Version: 8.1 beta -- ListProcessor(tm) by CREN Status: RO Hi Greg, By now you might know all that I'm about to say, but here goes it, The W3EDP is end fed, so there is no transmision line. I just saw the note that said they just used a MFJ tuner. That is not the way to do it. You should use a LC tank circuit, with the end of the wire (84-85 ft) connected directly to the top of the tank. You feed it with a link coil on the tank inductor. The offical version also uses a 17 ft counter poise, connected to the ground side of the tank. I calculated that the wire is about 0.3 wave lenghts long on 80, 0.6 on 40 , etc. This puts the feed point somewhere in the high voltage position of the wave. Idealy, one could calcualte the impeadance of that point on the wire and make the LC tank to have that impeadance. I simply took a coil and variable cap out of the junk box and found the tap on the coil which tuned to 40 meters. I added a two turn link to the bottom of the coil to go to the radio. I can tune it to pretty close to 1:1 SWR. I had to add a few feet of wire to make the SWR low on the low end of 40. I probably had to do this to make the feed point match the coil/cap combination I happened to end up with. The tuning capacitor looks like it's set to about 150 pfd and the coil is a 0.9" dia ceramic form with about 14 turns spread out over an inch. (that's for 40) I understand the "rainbow" tuner can easialy be configured to tune this antenna. I just put one up a couple of days ago myself. I have the tuner in a box next to the window (ground floor). The wire runs out the window, up to a flag pole and then back over to a tree. Not the best way to string it, but only way I could do it. I've only make a few QSO's with it so far and have nothing to compair it to, but does seem to work. Might not be as good as a dipole at a decent hieght, but is better than nothing. One should be able to make this antenna fairly "stealthy" if need be. Also a pretty good portable antenna. I saw an article in *73* a while ago where the 84 ft of wire was wound in a spiral on a wooden "X" frame and the auther claimed it worked pretty good. I would recomend this antenna if, like me, it is not possable to put up a dipole. 73, Steve, KD1JV....In the White Mountains of New Hampshire "Melt Solder"