I'm not sure I see the advantage. A full wave end fed antenna would theoretically have the same very high feedpoint impedance, and would additionally blow most of it's radiated energy at a fairly high angle off the ends of the antenna instead of broadside at a lower angle. If you find it that easy to tune, I suspect that electrically it really isn't that close to a full wavelength ... possibly because of coupling to earth (if it is low) or nearby structures. Either that or there is a lot of loss in the system somewhere.
73, Dave AB7E On 8/24/2011 2:14 PM, Niel Wiegand wrote: > Phil, > > You might try a 67' length of wire (EFFW antenna). I've used that (and a > 32' EFHW) on 20 a lot with my K1 with the KAT1 installed...tunes to > close to 1:1 just fine. > > Have fun at Crater Lake. There are some neat places along the rim for > hamming. It's a 2000 mile drive (one way) for me but I've gotten there > twice within the past several years. See > http://www.prismnet.com/~nielw/qrp/CraterLake_july04.jpg and > http://w0vlz.blogspot.com/2009/08/after-three-weeks-5300-miles-and-12.html > > 73, > Niel - W0VLZ > > > >> Message: 2 >> Date: Tue, 23 Aug 2011 16:00:17 -0700 >> From: "Phillip Shepard"<ph...@riousa.com> >> Subject: [Elecraft] KAT2 with EFHW antenna >> To:<elecraft@mailman.qth.net> >> Message-ID:<lnejjggbopigkcikmckdeegoiaaa.ph...@riousa.com> >> Content-Type: text/plain; charset="us-ascii" >> >> I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire >> for portable use (like SOTA). The 20m antenna is 33' long and I use one or >> two 16' counterpoise wires. It seems to work well for what it is and 10W. >> I just built and installed the KAT2 ATU into the K2 to lighten my pack by >> the loss of the MFJ. The KAT2 tuner checked out fine on the bench, but it >> had a very hard time getting a good match to the antenna. In AUTO mode, it >> only got the SWR down to about 5:1. I put it in ALT mode, and it spent a >> long time searching before it got down to between 3:1 and 4:1, depending on >> the 20m frequency. I added about 2" of wire to the antenna, and the tuer >> got down to about 2:1 to 2.5:1. I added another foot of wire (now 36'), and >> it got down to about 1.5:1. Five or six feet added yielded a perfect match >> (1:1). So I now have a 39' wire for 20m use. >> >> Is this normal? Should the KAT2 be able to more easily match the 33' >> halfwave antenna? Thank you. >> >> 73, >> Phl, NS7P >> >> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
