Jack, did you build the KPA500 yourself? In any case, one point that can cause trouble is where the hot (center conductor) lead goes to the RF Output connector. See Figure 40 on page 28 in the kit assembly manual (if you bought yours built, you can download the manual from the Elecraft web site (http://www.elecraft.com/manual/E740149%20KPA500%20Kit%20Assembly%20Manual%2 0Rev%20F4.pdf). That lead needs to be dressed away from the sharp edge of a shield as shown in the figure to avoid the possibility of an RF arc.
If that's the problem, just move the wire away as described in the manual. What the KAT500 does not tell you is the SWR on the line between the amp and the ATU. If it's fairly high you can build up some substantial RF voltages there. 73, Ron AC7AC -----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of W4GRJ Sent: Monday, October 19, 2015 5:20 AM To: elecraft@mailman.qth.net Subject: [Elecraft] KPA500 troubles All of a sudden my KPA500 is misbehaving. It sounds like it is arcing inside and smells the classic something is burning smell. SWR LED's are dancing upwards as it arcs. KAT500 tuner has the SWR around 1.3:1 I will probably send it off to Elecraft but thought I would ask here for suggestions to look at before I send it off. Thanks, Jack W4GRJ -- View this message in context: http://elecraft.365791.n2.nabble.com/KPA500-troubles-tp7609284.html Sent from the Elecraft mailing list archive at Nabble.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 Message delivered to r...@elecraft.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 Message delivered to arch...@mail-archive.com
