Hello Ed, I don't think that you are in class AB with 80% efficiency, in fact you cannot be. Class B can theoretically achieve 78.5% but this is seldom achieved in practice, especially on VHF. Most likely there is a problem with instrumentation.
________________________________ From: [email protected] <[email protected]> on behalf of K9MA <[email protected]> Sent: 11 February 2020 17:11 To: [email protected] <[email protected]> Subject: Re: [Elecraft] QRO - KPA500 Failure That's very high efficiency for a solid-state amplifier. Are they operating in class C? Are there any IMD specs at those output levels? 73, Scott K9MA On 2/11/2020 03:18, Edward R Cole wrote: > I checked the operating specs on two of my QRO amps. Not a KPA500. > > 2m-1500w PA using a MRF1K50 in class AB: > 945w 1398w dc 67% eff 453w disp > 1511w 1888w dc 80% eff 377w disp > > 2m-1200w PA using a MRFE6VP61K25H in class AB: > 566w 1200w dc 47% eff 634w disp > 1133w 1542w dc 73% eff 409w disp > > less heat dissipated when running full power RF ouput. > Both are W6PQL amps. > > 73, Ed - KL7UW > http://www.kl7uw.com > Dubus-NA Business mail: > [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] -- Scott K9MA [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]
