Don and Bob, The K2 and amp are both powered from the amp's supply.
I used a known good DVM to measure the voltage across R7, and it agrees with old Beckman. I now think my old kit-built Ten Tec power meter may be badly out of calibration. I have a dead LP-100 that is on its way back to Larry for upgrade and calibration, so I'll just wait until it is back to finish calibrating the KPA's power setting. Here are what I measured and calculated at the approximate center of each band, in cw, when the K2's LCD read 100W: 10M: .067V, 13.4A 12M: .049V, 9.8A 15M: .064V, 12.8A 17M: .065V, 13A 20M: .048V, 9.6A 30M: .056V, 11.2A 40M: .052V, 10.4A 60M: .056V, 11.2A 80M: .054V, 10.8A The current seems to vary significantly between bands, but maybe that's normal? Thanks again. 73, Jim KO5V -----Original Message----- >From: Don Wilhelm <donw...@embarqmail.com> >Sent: Nov 9, 2018 11:37 AM >To: Jim KO5V <k...@earthlink.net>, Bob McGraw K4TAX <rmcg...@blomand.net>, >Elecraft List <elecraft@mailman.qth.net> >Subject: Re: [Elecraft] K2: KPA100 fan issue + current question > >Jim, > >That 11 amps would sound more reasonable to me if you can say that the >base K2 is being powered separately, but I would expect something closer >to 50% efficiency rather than 66%. > >73, >Don W3FPR > >On 11/9/2018 12:42 PM, Jim KO5V wrote: >> Thanks Bob, >> >> That makes me feel a bit better. I'm still going to remeasure it with a >> newer meter and see if the measurements check. >> >> 73, Jim KO5V >> >> >> -----Original Message----- >>> From: Bob McGraw K4TAX <rmcg...@blomand.net> >>> Sent: Nov 9, 2018 10:29 AM >>> To: Jim KO5V <k...@earthlink.net> >>> Cc: Elecraft List <elecraft@mailman.qth.net> >>> Subject: Re: [Elecraft] K2: KPA100 fan issue + current question >>> >>> At 13.8 volts, 11amps is about 152 watts input. 100/152 = .658 * 100 for >>> about 66% efficiency. >>> >>> All in all , looks about right to me. AKA - I wouldn't be concerned. >>> >>> >>> Bob, K4TAX >>> >>> ______________________________________________________________ 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
