Hi All, Problem solved! The problem was in my K3S. A simple Transmitter Gain calibration procedure fixed it. (This calibration you start in the K3 PC utility). Now I am very curious to better understand why this calibration fixed it. Also curious to know why a 6 week old K3S, built by the factory, needed a calibration. Bad luck? Any config settings I could have done that affect this behavior?
Many thanks to both Jack Brindle and Craig Smith from Elecraft who both jumped on this to help me troubleshoot. Jack contacted me while he was on vacation (!). Craig called me (!) to help me troubleshoot, just from reading this discussion thread. The reason it took a while to fix is because I first had to order a dummy load so I could perform the TX gain calibration procedure. Jack, Craig, you guys rock!! Barthold AD0RM -----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Barthold Lichtenbelt via Elecraft Sent: Wednesday, November 16, 2016 1:25 PM To: 'iain macdonnell - N6ML'; 'Jack Brindle' Cc: 'Elecraft Reflector' Subject: Re: [Elecraft] KPA500 power output starts out low, then goes up > I didn't see anything in this thread that suggested that the problem wasn't observed on all bands. Maybe I missed it? I see it on 20m, 40m, 80m, on two different antennas. Haven't tried any other bands. > Also haven't noticed anyone suggest using the K3's "TUNE" function, instead of SSB modulation, as a test. Excellent idea! It does NOT happen when I use the TUNE function. Not with the KPA500 in standby nor in operation. Tried 20m and 40m. > If it doesn't, it might be an issue of insufficient audio input for > SSB modulation. (AFAIK) the K3 will automatically boost the audio input if it detects that there's not enough (a feature that I'm not particularly fond of). I carefully tuned the Mic gain and Compression as per the manual. ALC goes up to 5 or 6 bars, compression below 10 dB when I speak in my normal voice. So that suggests input side is OK? Barthold AD0RM -----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of iain macdonnell - N6ML Sent: Wednesday, November 16, 2016 11:12 AM To: Jack Brindle Cc: Elecraft Reflector Subject: Re: [Elecraft] KPA500 power output starts out low, then goes up I didn't see anything in this thread that suggested that the problem wasn't observed on all bands. Maybe I missed it? Also haven't noticed anyone suggest using the K3's "TUNE" function, instead of SSB modulation, as a test. If the output ramps up with the TUNE function, it's an output problem. If it doesn't, it might be an issue of insufficient audio input for SSB modulation. (AFAIK) the K3 will automatically boost the audio input if it detects that there's not enough (a feature that I'm not particularly fond of). 73, ~iain / N6ML On Wed, Nov 16, 2016 at 9:56 AM, Jack Brindle <jackbrin...@me.com> wrote: > A TR switch failure would affect all bands. This one is a bit different. It will be interesting to see the cause when we finish troubleshooting. > > Jack Brindle, W6FB > Elecraft Engineering > > Sent from my iPhone > >> On Nov 16, 2016, at 12:04 PM, Arie Kleingeld PA3A <p...@xs4all.nl> wrote: >> >> This might be a problem with the pin diode T/R switching in the KPA500. >> >> >> 73, >> >> Arie >> >> >> >> >> ______________________________________________________________ >> 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 >> jackbrin...@me.com > ______________________________________________________________ > 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 > a...@dseven.org ______________________________________________________________ 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 bartho...@yahoo.com ______________________________________________________________ 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 bartho...@yahoo.com ______________________________________________________________ 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
