Hi Jim! Hope you are enjoying Idaho. I hear it is a great place to be! The fan in the KPA500 goes to level 3 at 60 degrees. It goes to full-on at 80 degrees. The levels are: level 1 - 50C degrees level 2 - 55C degrees level 3 - 60C degrees level 4 - 65C degrees level 5 - 70C degrees level 6 - 80C degrees The amplifier will fault at a temperature is 90C.
What mode are you operating? And, for those using TS-890s, why would the KPA behave any differently than it does with a K3? Has anyone checked for spurs or harmonics coming out of the transmitter? (NOT suggesting there are any, mind you). I’m looking for reasons the KPA would heat up any faster than with a K3. Are you seeing anything else, like strange band changes? But, rest assured that the KPA will run just fine at 60 or 65 degrees. The fan sound is just telling you the KPA is doing its normal great job at protecting itself. 73, Jack, W6FB p.s. I didn’t want the snow, so I went the other way, going home to Louisiana… > On May 14, 2023, at 12:23 PM, James Bennett via Elecraft > <elecraft@mailman.qth.net> 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 jackbrin...@me.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
