Re: QCX 40 Up in smoke !
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Paul I have run mine on 40m WSPR for days and days and no issues…supply was 13.8 volts…even the voltage regulator did not get that warm.
From: QRPLabs@groups.io [mailto:QRPLabs@groups.io] On Behalf Of K2DB Paul Mackanos
Thinking about this further, the day before it went up in smoke I came in the back door and thought that I smelled a slight Electronics burning smell. I walked all around the house and couldn't find it. It was the next day that I got on and started to call CQ when it went up in smoke. Here is what I think happened, from the day I got it working and all aligned, I had never turned it off, I had it installed in the qrp labs CW transceiver box I bought from Germany. My thought is that the heat eventually built up over that time and when I stressed it by hitting the key, that's when the parts went kabang. I'm thinking about buying a miniature little 5 or 12v fan, cutting a little hole in the back where the output transistors are, and cooling it down. I would think that the way it was designed and with the enclosure, that that would have all been taken into account. But, I've been wrong before it may have just been a faulty part or something, I just got the replacement transistors from digikey and tomorrow I will try and fix it. I guess another thing I could do is not leave the power on it 24/7.
73 Paul K2DB
On Fri, Jul 12, 2019, 12:18 AM Dan Pflugrath <dpflugrath@...> wrote: