I am considering building a multi-band doublet fed with ladder line to the window and then 10-12 feet of coax to the K3 from the window interface. I would let the K3 ATU tune the beast. I have been playing with a coax calculator and with low loss coax and 10:1 SWR the losses in the short run of coax up to 30MHz are manageable to ½ dB. The ladder line can handle the mismatch with small losses. I was thinking of putting a sleeve balun at the window interface from the coax to ladder line. I could of course put two different length doublets in parallel at the feed point if that would tame problem bands. I dont need this antenna to go to 50 MHz as I will have a separate antenna for 6M. I dont have antenna modeling software. I know I will have pattern issues if I try to push a long antenna too high in frequency. I am not thinking right now of pushing this antenna to 160M.
So now the questions: 1. Is there a magic doublet antenna length that will end up with less than 10:1 SWR on the most bands? I know Cebik likes 88 feet or 44 feet depending on lowest operating band but I dont know that he has solved my exact problem for 10:1 SWR or less on all bands. 2. Is there a magic feed line length to make this all work? 3. Have any of you tried something similar to this with the K3 ATU? I have read the reports of just tuning up any old antenna that you have and you get it to work at some unknown efficiency. I have done this too. I know it is time for me to bite the bullet and purchase some real antennal modeling tools. Mike Scott AE6WA Tarzana, CA K3/100 SN508 _______________________________________________ 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
