Congratulations Jim! I have been watching this thread with interest to see how it worked out. I would like to know a bit more. Is your feed point at the same elevation as your counterpoise, or at ground level? If at ground level, describe your transition to five feet for the counterpoise. What do you use for a support and how high is your transition to horizontal? Is your transformer a true isolation transformer with two windings and DC isolation or an UnUn wound transformer? Is your powdered iron core a rod or toroid? What is the Amidon model number?
Again, congratulations! I love this kind of dialog! 73! Willis 'Cookie' Cooke K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart ________________________________ From: Jim Bennett <w6...@mac.com> To: elecraft@mailman.qth.net Sent: Thursday, March 8, 2012 2:19 AM Subject: Re: [Elecraft] OT: Need Antenna Tuning Help Folks - back on the 28th of Feb I started this thread, looking for assistance getting the K2AV Folded CounterPoise (FCP) to work on my 80 meter Inverted L antenna. Got several good suggestions and wound up having a long series of off-line email exchanges with Guy, K2AV. With his help, we got the thing working perfectly. I now have an antenna that has a 100 kHz wide segment of the band with zero reactance, and an SWR that is 1.5:1 or below for 125 kHz. I learned quite a bit about antenna tuning, and the fact that the MFJ-259B does NOT show minus reactance. When I put the Resistance ( R ) and Reactance ( X ) figures on a graph - they were quite whacky. Turns out that there were several negative values that I'd "assumed" as being positive. Once adjusted, the chart looked reasonable. I also had another antenna on the property, resonant on 80 meters, that was messing up the works. With Guy's guidance, I adjusted dimensions of the FCP and the Inverted L radiator and bingo - it works great! I opted to build my own isolation transformer, saving a couple bucks. The FCP is mounted about five inches out from a property line wooden fence, about five feet off the ground. I used schedule 40 PVC pipe for the FCP wire supports. The PVC and enclosure for the isolation transformer were purchased at a local Ace Hardware. The powdered iron core and teflon wire insulation came from Amidon and the wire for the FCP and isolation transformer came from The Wireman. The W0UCE web site has detailed information, including parts information. If you don't have room for a bazillion radials on 80 or 160 meters, by all means look into using an FCP with your Inverted L. Many thanks to K2AV for his gracious help and his putting up with my lack of technical knowledge! ______________________________________________________________ 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 ______________________________________________________________ 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
