Greetings, It is interesting that this topic has arisen now, as I am wrestling with some of the same challenges previously posted. I recently remarried and moved across town to ‘her house’ I bought half of it … the north half :). I put up a 110' long attic loop at about 25' above ground which is fed with a short length of 300 ohm ladder line down through the ceiling to my shack. It works very well from 40M on up, but although the K2's ATU will 'tune' itself for 80M and even 160M duty, the loop is essentially a dummy load on those low bands.
I would like to try to cut the loop at its center so as to have a 'convoluted doublet' (for lack of a better term) 55' long per side. I think it would do relatively well on 80M but I have no idea what effect doing so would have on noise levels and efficiency on the other bands. I'm trying to avoid extensive experimentation. The low head room and the thick insulation (I have to put plywood sheets down to avoid going down through the ceiling) make negotiating the attic very difficult. The main challenge is finding the exact center of the loop opposite the feedpoint. There is no way this 63-year-old body is going to measure every inch of the antenna to find this point where I would make the cut. Does anyone have an 'elegantly-crafted' method of finding this point, perhaps electronically? Best regards, Todd N9NE Oshkosh, WI -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.408 / Virus Database: 268.13.17/505 - Release Date: 10/27/2006 _______________________________________________ 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
