Dave, Yes well xyl problems can be very tricky to resolve. If money was no barrier a remote K0/K3 setup may have solved the aesthetics issue, and cut the feedline length to small numbers. Not sure how you measured the loss on the 75 ohm coax?
A ocf dipole fed with a Balun designs 4115ocf balun will outperform a fan dipole any day, and is less obvious apart from the balun. T Length 41.5m fed 36% point; 27.5m long leg 14m short leg. Worked 4A4A & T31A with best VK results using this one antenna for all bands worked. Only you would want to go to low loss 50 ohm coax like lmr etc. Of course balanced line and unbalanced antennas don't mix so coax is necessary with the ocf. The dual core choking - true current 4:1 balun keeps the radiation in the antenna and not the feedline. The antenna develops gain on the long leg lobes on higher bands and for USA a long leg to south and short leg to North would suit your position with some slope to cover nth /sth. Adrian ... vk4tux Adrian, I sent this on the reflector but I thought I would also send it to you directly. The 72 ohm coax I am using is what the cable company used to get from the main line pole to a house. It is about 10 mm or 3/8" in diameter with a "carrier" wire molded onto it. The coax is not too lossy because I measured the loss when I first installed it several years ago to be sure. I use a choke balun at the feed point made with cores slipped over a 3 ft. piece of RG-213. I must have long runs of transmission line to get my antennas away from my wife's eyes. When I got back into the hobby in 1989 I put up a center fed wire in a field 1,200 feet from my shack near the back of my property and fed it with ladder line and a tuner. Nobody could hear me so I took that down. I still have plenty of ladder line and some great places to put up antennas but they are far away and ladder line cannot lay on the ground in the woods out of sight like coax. Having ladder line in the air hanging off trees or some other supports on the way to an antenna from my house is not acceptable. Maybe I just need to get more creative about placing my dipoles closer to the house and yet out of sight. I am open to any reasonable ideas. Dave - KO4KL -----Original Message----- From: Adrian [mailto:vk4...@bigpond.com] Sent: Wednesday, April 04, 2012 10:51 PM To: 'David Stratton' Subject: RE: [Elecraft] K3 power reduction due to high SWR You have some serious performance limitations with this setup. If I have to use your antenna, then my move would be to replace the 250' of 75 ohm coax with 250' of 450 ohm ladder line, check the fan dipole legs are exactly the same to provide a balanced load. Get a balun and short 50 ohm coax section to get from the ladder line back into the shack, if you can't get the balanced line in to a balanced line tuner etc. As it is you are losing 57% @ 20m of your power in that feedline. A mfj-986 or similar with balanced line is probably the go on a limited budget. You will reduce loss from 57% to 9%. Adrian ... vk4tux -----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of David Stratton Sent: Thursday, 5 April 2012 10:34 AM To: Elecraft Reflector Subject: [Elecraft] K3 power reduction due to high SWR At what point does the SWR have to rise up to before the K3/10 output power begins to decrease? I have been using a TS-830 which is not bothered by SWR up to at least 3:1. I cannot get the tuner now so will I be forced to run very low power if my SWR is 2 or 3 to 1? What about the K3/100? My antennas are resonant fan dipoles (80, 40, 20, 17) fed with 250 feet of 72 ohm cable TV coax. Dave - KO4KL ______________________________________________________________ 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
