My setup is like yours and the response is exactly the same. Starting use on fan speed 4 delays the temp rise for a short time. Mine has run many many hours at temps up to 70 with no problems. Hottest on 20m and requires the most drive on that band also.
On Sun, May 14, 2023, at 10:23 AM, James Bennett via Elecraft wrote: > Got a question (problem?) regarding the fan in my KPA500. I'm driving > the amp at 29 watts from a Kenwood TS-890S. The amp is connected to a > KAT500, which in turn is hooked to a 30 foot tall Zerofive flagpole > vertical. The tuner has provided me with a nice 1.2:1 SWR, as displayed > on the amp. The resting temp of the amp shows 42C. At 29 watts input to > the amp, I’m seeing about 480 watts of power from the amp. The amp has > nothing sitting on top of it, and the wall behind it is over 12” away. > There is about 2” clearance on either side of the amp, and it is > sitting on top of the KAT500. > > The issue: The fan comes on in a very short time - less than 20 seconds > - and the temp display runs up to 50+ degrees. If I start calling CQ or > get into a QSO, it doesn’t take long for the temp to show over 60 > degrees and the fan is running at max. > > When I had a K3 and more recently, a K4D - this did NOT happen. The fan > would come on but NEVER at the max, loud level. Interestingly, many > moons ago I also had a KX3 and had it connected to the KPA500. I > noticed that the fan would also come on fairly quickly with that rig > driving the amp, but I never thought too much about it. Until now... > > But now, I think there is some sort of problem. It seems to me that the > temp shouldn’t get that high that fast nor should the fan start roaring > in that short amount of time. I could understand it if the SWR was > really bad, but at 1.2:1???? > > Any ideas why the amp fan should be acting this way with a non-K3 or > non-K4 driving it? > > Jim / K7TXA > ______________________________________________________________ > 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 al...@mooseaviation.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
