Yes, but the amp is not seeing the mis-match, correct? The tuner is taking care of that mis-match and I would have thought that the amp should be perfectly happy… Yes?
> On May 14, 2023, at 11:35 AM, Dr. William J. Schmidt <b...@wjschmidt.com> > wrote: > > You are trying to transform a mis-match and that burns energy. That’s why > the fan is running. > > > > > -----Original Message----- > From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On > Behalf Of James Bennett via Elecraft > Sent: Sunday, May 14, 2023 12:24 PM > To: Elecraft Reflector Reflector <elecraft@mailman.qth.net> > Subject: [Elecraft] KPA500 Fan Question > > 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 b...@wjschmidt.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
