> When operating CW the > fan turns on high during every transmission and the heat sink gets hot to > the touch. I'm a ragchewer so my transmissions do run to several minutes > and, regardless of power setting, the fan will kick on high after several > minutes of transmitting. ... > Does anyone have an idea what may be wrong?
I think this is normal. I had the same experience and asked about it and in the end realized that's how it behaves. It's the primary reason I went back to the QRP cover. Fan is just too noisy and comes on too often. It also failed to turn off by itself after going back into RX mode -- it took a deliberate keying event to, apparently, force the firmware to re-evaluate the temp and disable the fan (which of course causes a transmission and confuses the op on the other end!). Where or not that part was normal I don't know, but it's the way mine behaved (on two different KPA100's). I don't know which firmware it had so don't know if that's been addressed in a newer version. If I remember correctly, the amp is most efficient at about 75 watts, so operating there might help cut down the heat and delay the fan turn-on. You might also look into other cooling methods -- larger, slower fan; remote fan with custom duct work; active cooling; etc. --Andrew, NV1B _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com