I suspect that may be the case, Bob. I will wait until I hear from tech support before I pop open then amplifier for a look-see. It is factory built.
Regarding power output, I was incorrect. On 80 and 40 meters I am seeing similar outputs as you. I am on a 240 source, HV is 74 volts. John K7FD > On Nov 7, 2018, at 5:19 AM, Bob McGraw K4TAX <[email protected]> wrote: > > Zero hum from mine. From other comments, be sure the power transformer is > correctly installed and secured. It may have moved during transportation if > you purchased a factory built unit. > > As to 20 watts drive and 350 watts out, what bands? With 20 watts drive > from my K3S I see 450 to 550 watts out on all bands as seen on the amp LED > indication and on an external {Bird 43} meter. The HV is 62 volts and the > current is 11.5 amps into a dummy load. Amp is operated from a 240 source. > > 73 > > Bob, K4TAX > > >> On 11/6/2018 10:47 PM, Macy monkeys wrote: >> I'm certainly having my troubles with this new KPA500. The level of hum is >> unacceptable. >> >> The manual says it is normal to hear hum. With 20 w drive I'm getting 350 >> watts out but the hum is horrendous when I send CW. SSB not so bad. Is this >> level of hum normal during keydown? It's room filling! >> >> John K7FD >> ______________________________________________________________ >> 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] ______________________________________________________________ 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]
