As an example, I used a 40m Extended Double Zepp for field day. This is an 180' wire center fed with ladder line. My FD installation had about 60' of ladder line hanging down to the rig. Ordinarily, I would use a toroid to make a balun to the rig, but I didn't have a suitable form in my junk box, so I hooked the ladder line to a BNC to dual banana binding post adapter. The KX3 ATU did fine in matching from 80 to 10m, except on 40m. On the other bands, the match was 1:1 or close, but on 40m, the tuner struggled to get down to 3:1 or so. I added a 33' "radial" wire to the ground side of the banana adapter and ran it under the antenna, keeping it 2 to 3' above the ground. With this addition, the ATU could usually get close to 1:1 on 40m. The antenna seemed to play well, so the efficiency must not have been too bad. I was impressed with the KX3 for many reasons, including its ATU.
73, Phil, NS7P -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Wayne Burdick Sent: Tuesday, June 26, 2012 9:09 PM To: Jeff Herr Cc: 'Elecraft Reflector' Subject: Re: [Elecraft] "random wire" and the KX3 ATU Jeff, The KXAT3 has a very wide tuning range and is specifically designed for use with random-length antennas. Typically any wire longer than 20' or so can be tuned up on 40-6 meters. A 74-foot antenna will probably be tunable to reasonable SWR on 160-6. A random wire antenna can work very well -- comparable to a vertical or dipole depending on the band, radiation angle, and your ground system (if the random wire is worked against radials). I use random wires almost exclusively. The KXAT3 does an excellent job with them. It will also do other magic tricks like make an 80-meter dipole work on all bands, or a 20-meter yagi work on 30-6 meters, etc. Efficiency will vary, but the transmitter will be happy. 73, Wayne N6KR On Jun 26, 2012, at 7:55 PM, Jeff Herr wrote: > I know folks who have had bad experiences using a "random" wire with > an ATU. > > Although I ordered a buddipole with the kx3 I still am interested in > getting > A 74 foot length of wire up in the pine trees (I will have a > counterpoise) > while up in the > Lassen national forest.....we go there a lot. > > When I mention this I am met with much skepticism. > > Am I way off base? Is this beyond the capabilities of the tuner? > Is there a descriptive spec for the tuner that describes the range > of it > matching capability? > > WW6L > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
