I have the same problem with S/N 64. I thought it might be a cable but the problem occurs on all bands, both antenna outputs and into a dummy load. I'm only about 90% sure that it is related to temperature - I was too busy working the contest to do much more troubleshooting. And I agree with the fan noise comments - the pitch of the noise comes right through my Bose noise canceling headphones.
73, Bud N7CW On Sun, May 6, 2018 at 3:43 PM Don Butler <[email protected]> wrote: > Mike I had the very same thing happen last night while operating the 7QP > contest..... which is the first contest I have operated with the KPA1500 > .... the heatsink temperature was down in the mid 40s C at the time .... > and > in my case it occurred on 160 meters only .... SWR as per other meters as > well as the digital readout on the 1500 were reading 1.2:1 ... and did not > change even when the LED flashing occurred ..... but I was getting > intermittent flashing of all LEDs on the amp's SWR meter .... > > During the contest I was continuously running on CW with hourly QSO rates > running between the 70s and 110s .... I opted to manually switch on the fan > to keep the temperature below 60 degs C ..... level 2 seemed to keep it > there most of the time .... but I did move up to level 3 a few times (and > BTW, at that speed the KPA1500 is clearly the noisiest amp I have ever > owned > .... but, arguably, it may very well be the "coolest" also ..... headphones > were absolutely necessary with that noisy fan ..... clearly much noisier > than the Alpha 9500 sitting right next door ... which I also used during > the > same contest... > > So Mike, you're not the only one experiencing this phenomenon.... whatever > it is.. > > Don, N5LZ (KPA1500 #45) > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Mike Crownover > Sent: Sunday, April 29, 2018 8:13 AM > To: [email protected] > Subject: [Elecraft] KPA1500 SWR meter > > I have noticed that after my KPA1500 gets above 50C the SWR indicator light > starts to show intermittent high SWR. My KPA500 did not do that. I'm using > resonant yagis and the digital SWR meter shows 1.1:1 and doesn't change nor > does the SWR indicator on the K3S. It seems the SWR indicator lights are > acting independent of the meter on the KPA1500 screen. RF? I have not had > any faults or shut downs as a result of the indicated high SWR. The amp > operates wonderfully, but the indicator lights are a bit bothersome. Anyone > have similar issues? > 73, > Mike AD5A > ______________________________________________________________ > 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]
