Ed, Hanging it out the window is the best idea.
That "counterpoise" is the other half of your 40 meter antenna - so if you want best results, put it up in the air at whatever height you can manage - treat it like an antenna radiator - because that is exactly what it is. Caution: an antenna with 32 foot elements each side of the feedpoint will present a high feedpoint impedance on 20 meters - so if you have trouble feeding it on 20, that is the problem. It should respond quite nicely on 15 meters where it is approximately 3/2 wavelengths long. The challenge is to use an antenna (or antenna and tuner combination) that will present a 50 ohm resistive load to the transceiver. In the old days of transmitters with PI network output tank circuits, we have enough matching capability in the transmitter output to allow tuning into a variety of loads. Modern transceivers are designed to operate properly into a 50 ohm load. The Tuning elements to match an antenna to that 50 ohm requirement have been moved into the ATU - whether that be a manual tuner or an automatic tuner. We still have to have some means of matching the output of the transmitter load impedance to the antenna feedpoint impedance. The alternate solution is to have a resonant dipole for each band that presents a 50 ohm load to the transmitter. That is not practical for everyone. Even the much acclaimed G5RV does not have an SWR of 1:1 on all bands. The reason I mention this is that the KAT2 will have the most trouble matching high impedance loads. As a compromise, extend both sides of the antenna to 44 feet, or better yet, use the W3EDP lengths of 85 feet with a 17 foot "counterpoise" - that will create something like an off-center-fed 80 meter antenna that is usable on most HF bands (with a tuner like the KAT2). 73, Don W3FPR On 8/11/2011 10:59 PM, EMD wrote: > Guy > > Thanks for the advice. I think I'm getting out okay. I hooked up my > MFJ-267 Watt meter dummy load and when I have the power set to 10 watts I'm > getting close to 10 watts forward but the reflected is about 5 so that tells > me the antenna is the issue. I have a KAT2 ready to install so I would bet > I will get better results once I install the tuner. I will lengthen the > counterpoise to 32' and see what happens. Since I'm upstairs in a spare > bedroom as an office /shack should I run the counterpoise on the floor, > which I'm doing now or hang it out the window? I don't think hanging out > the window is the right idea. > > Thanks again. > > 73, > Ed ke7hga > ______________________________________________________________ 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
