Greeting to everyone I have read the KPA500 operator manual in hopes of solving my issue and have found nothing that solves/fixes the problem.
This amplifier has been a workhorse for many years and today after the KAT500 antenna tuner searched/found a 'match' for a new antenna, I selected OPER on the KPA500, and applied drive power to the amplifier. Immediately, the amplifier displayed a momentary overload indicated by the top row of LEDs (power indicator ones) all flashing ON after which, the amp FAULTED and shut down. The RF drive level was around 20-watts and should have provided about 300-watts output at the time this occurred. I tapped the OPER/STBY button and tried to activate the amplifier and found there is no response to incoming RF drive. I removed/reapplied 'mains' power, pressed the 'EDIT' and ON keys simultaneously to reset everything and that did not correct the problem. The power supply voltage is in spec so no issue there. With the OPER light GREEN and slowly increasing the RF drive level to the amp, there is a point where an internal relay 'click' can be heard, the 50-watt LED on the top row of LEDs turns red and the FAULT light turns red. I could not detect any sign of smoke (nose/eyes) so have not opened the case to look for burned parts. Before I open the 'case' and look for obvious problems, any observations or suggestions received here will be appreciated. Kinda looks like blown amp power FETs. Dick - w7wkr ______________________________________________________________ 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
