Just to make sure we're all on the same page ... When the tuner (at the radio) gets an acceptable match, that just means the transmitter will _think_ there is a good antenna system out there. The feedline between the antenna and the tuner will know otherwise and can have points of very high voltage that could cause insulation breakdown, and points of very high current that can cause overheating and will be a source of power loss. This isn't really a problem in QRP operations, but when you head into the QRO world it can make a difference. The antenna also has issues. In an earlier post K3KO had the calculated feedpoint impedance, and it was very far from the 'nominal' 50 ohms of your feedline or the ~75 ohms of a dipole at altitude. W6GF also gave this info in terms of SWR to show how bad it was. All in all a resonant 40M dipole makes an unhappy antenna system on 20 meters.
I understand that if that is all you have you're stuck with it, but it is really time to consider something else. Maybe a fan dipole, or trap dipole? Mark AD5SS On Sat, Dec 8, 2012 at 3:30 PM, Jerry Weisskohl <[email protected]> wrote: > Right now, I have the coax from the antenna directly connected to the > KAT500. I could try using my Delta-4 switch, have the coax go to that and > then a small run to the KAT500 to see if that makes a difference. The high > swr is an issue on 40 and 10 meters, however, ten is manageable, it's about > 1.9 - 1 and I am working around the issue but using my 80 meter vertical on > 20 meters. So this is not a "show-stopper" but just wanted to understand > why it was happening. > > Jerry - AC4BT > ______________________________________________________________ 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
