I’m in the process of checking out my amp. I have two dipoles (40 and 80). At resonance both show a 1.2:1 SWR with ATU totally bypassed. With ATU on, it remains bypassed on 80, but shows only the ATU ON LED on 40. In both cases the resultant SWR is 1.2:1. SWR measurements are from the KPA1500 display.
When I use the amp with my K3 and drive it up to 1500W, I am occasionally getting an excessive PA current fault at 63A. From a cold start it’s 60A, but as it warms up in contest usage I find the power drops off, so I have to adjust the K3 to bring it back up to 1500W. At that point the PA current goes over 60A. Interestingly, into a dummy load the 1500W point shows a PA current of only 55A. So the 1.2:1 SWR, be it via a bypassed ATU or using the ATU, is sufficient to raise the PA current eventually to excessive levels. Suggestions? I don’t want this to be flipping out during a contest. I also don’t want to reduce power into what should be a totally acceptable load. 73 Gary W2CS ______________________________________________________________ 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
