I had the exact same problem with my KPA500. I inadvertently left it connected in a lightning storm in the Caribbean and, after some diagnosis on my RF bench, I found that the PIN diodes on the receive side were blown. Replacing them cured the problem. While in there be advised that there is an upgrade kit for some components in that circuit. Contact Elecraft techs for more info.
Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ email: [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Barry Simpson Sent: Sunday, September 8, 2019 1:34 AM To: Elecraft Mailing List <[email protected]> Subject: [Elecraft] KPA 500 Attenuated Receive Signals My KPA 500, which is several years old, has just developed an issue which so far I have been unable to resolve. What has happened is that when I put the amplifier into OPER, the received signal strength drops by several S units. It transmits normally and also receives normally in STBY. The issue occurred when I was changing rigs to use with the KPA500. Specifically I connected a Ten Tec Omni 6 but I cannot see how that could have caused the issue. However, the KPA500 now exhibits the same issue with my TS990 which it never has before. I believe that some considerable time ago, I did experience a similar situation and after reading all the manuals etc I found a way to resolve it. However, I have read the manual until I am blue in the face but I cannot find an answer this time. Of course I may have initiated a fault in the KPA500 but I would be surprised as it has taken all the mistakes I have thrown at it over the years and it has not so much as blinked. Any suggestions on how to sort the issue out, or what damage I might have caused to the switching circuitry, would be appreciated. Thanks in advance. Barry Simpson VK2BJ ______________________________________________________________ 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] --- This email has been checked for viruses by AVG. https://www.avg.com ______________________________________________________________ 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]
