I did as you Roy but if I press my ear to the top of the KPA500 case I can hear a faint hum. It is the same with my 12v linear power supply underneath the bench. I do not believe it is a fault but fairly normal for linear power supplies. Occasionally both the KPA500 and the power supply under the bench will hum more loudly for a short time. I have always put this down to variations in the mains supply waveform as referred to by Ian GM3SEK in his earlier message.
As regards the "sticky relay" phenomenon - I have experienced this a couple of times. Switching the KPA500 off and then back on again has cured it. 73 to all Geoff G3UCK -----Original Message----- From: Roy Morris Sent: Tuesday, September 27, 2011 7:33 PM I snugged the transformer against the rubber bumpers, and I can see light between the transformer and the Z-Bracket. I have not experienced any hum at all. Roy W4WFB ______________________________________________________________ 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
