I don't contest in RTTY (I don't use that mode other than for Dxpeditions) and rarely even do FT8. I mostly operate CW and a bit of SSB and that's it.
I have no idea why it would fail. I did have some issues in the past with antennas going stupid on me or the HF-Auto tuner failing to match when it was supposed to, but those always hard-faulted instantly. I never attempted to push RF through more than about a 2:1 without a tuner, and for CW, all my antennas are resonant on the bottom of all the bands. That it happened on 20 where I'm about 1.2:1 is very strange. - pjd -----Original Message----- From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On Behalf Of j...@kk9a.com Sent: Saturday, February 16, 2019 12:35 PM To: elecraft@mailman.qth.net Subject: [Elecraft] KPA-1500 failed! Sorry to hear this happen Peter, especially during a contes. LDMOS devices are suppose to be pretty tough and the KPA1500 is not pushing their limits. There are videos of a different LDMOS showing it to be indestructible: https://www.youtube.com/watch?v=8ziYqjMQGEQ Is the KPA1500 cooling and heat sink adequate? Personally if I owned this amp I would leave the fan on at a tolerable speed 100% of the time. Did you use the amp during the RTTY contest last weekend? John KK9A Paul Baldock wrote: It sounds like one of the output devices have failed. Half power out is usually the indicator. A number here have reported this happening. It would be nice to know why this problem is occurring and if Elecraft are working on a fix. - Paul > >On 2/16/2019 7:28 AM, lists at w2irt.net wrote: > > I was operating in the ARRL-CW contest this morning and on 20m, with > > a > > 1.2:1 SWR on the Yagi, all of a sudden I saw my power drop to about > > 450-500W with about 40W in. Worked a few stations but not as easily > > as when I turned everything on this morning. Switched over to phone > and made a few contacts. > > Audio is fine barefoot with 100W out of the K3s-which suffered blown > > finals itself during CQWW SSB last fall, but with the amp in I got > > reports that my audio was badly distorted. > > > > Before I send it in, is there anything I should look at or any > > diagnostics I can easily perform? For the cost of this, I'd have > > thought protection would have kicked in to prevent anything untoward > > from happening. I'm in complete disbelief, to be honest. > > > > --------------------------------------------- > > 73 and Good DX > > Peter, W2IRT ______________________________________________________________ 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 li...@w2irt.net ______________________________________________________________ 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
