I’m having an issue with the KPA500 amp and my 160-meter Inverted L antenna; I wonder if anyone on the list has ever experienced something like this or has a suggestion where to look for the problem?
My setup is a K3 transceiver, the KPA500 amp and a Ten-Tec 238C antenna tuner, connected to a collection of antennas, switched either in the tuner or using a couple of external coax switches (the tuner only has four outputs). One of the outputs is routed to the 160-meter Inverted L. The KPA500 is seeing about a 1.2:1 SWR to the Inverted L through the tuner. It loads well and shows no problems transmitting, either low power when disabled, or high power when the amp is enabled. The problem is, when I push the button to OPER on the amp, the received signal on 160 drops about 20dB (as evidenced by the signal level display on the P3). There’s no change in the loading, and the amp still puts out full power with no problem, but understandably this makes it much more difficult to hear the station I’m trying to work. All the other antenna selections and bands, using my quad or the G5RV work just fine and I don’t see anything like this happening. I’ve checked grounds throughout, including the connection to the radial system on the Inverted L and haven’t found anything visibly abnormal. I’ve also connected the Inverted L feedline directly to the KPA500, taking the tuner and the coax switches out of the circuit. In this configuration, the amp sees about a 1.7:1 SWR to the feedline. There is no change, I still get a huge drop in received signal strength when I switch in the KPA500. I would appreciate any ideas you may have about where I may have a problem. TIA. 73, John K8AJS jbast...@me.com ______________________________________________________________ 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
