Mark, Thanks for the reply. I received quite a few replies pointing out exactly what you said. Because it wouldn't load on 20 meters I was using my other antenna, which works fine with the KAT500 (80 meter vertical). However, I was trying to understand why the 40 meter dipole wasn't working well on 20 and I thank all those that replied. This reflector is a wealth of knowledge! Now I realize my KAT500 is working as it should. Having two antennas comes in handy!
Thanks, Jerry - AC4BT On Sat, Dec 8, 2012 at 5:49 PM, Mark Bayern <[email protected]> wrote: > 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
