Hi Ed,
At a distance of only six feet to your antenna, perhaps your amplifier is trying to warn you that you may also have a human RF safety issue. 73 Frank W3LPL ----- Original Message ----- From: [email protected] To: [email protected] Cc: [email protected] Sent: Saturday, April 18, 2020 7:53:06 PM Subject: Re: [Elecraft] Excessive SWR Faulting KPA500 Bob, You mentioned: "Also you can bypass the KPA500 to STBY mode and check the system by observing the SWR on the K3." I think you meant the KAT500 instead of the K3. The K3 has to be bypassed to work with the tuner. Anyway, I have made some progress. I tried running through my dummy load and I got the run-up condition to fault on 17 and 20. I had to run reduced power since the load is only rated for 300W. The odd thing is that I had to use the tuner to make things happy with the load. Thanks to AI4VZ, I have the schematics for the KPA500 and the LPF details. The schematics are from 2011 or so and my gear is from 2017 but I doubt the design changed significantly. After testing with the dummy load, I re-connected to my patch panel only to find that all the settings in the KAT500 were gone. I had to retune from 80 through 10; what a PITA! However, my efforts were rewarded with the amp working fine on CW everywhere except 12 meters. I may have an intermittent on 12 since the best I can do is 2.9:1 SWR after the tuner shuts up. Since both the 12 and 17 meter Vs are off the same feed point, the 17 may be guilty as well; it settles around 1.9:1. As for the amp faulting, I may have an RFI issue. The 6BTV is only six feet from the shack. Another possibility: the fault surfaced when running the amp on FT8. The long duty cycle plus RFI may have done me in. Tnx for your help. 73 de Ed ______________________________________________________________ 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 Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
