I was one of the fellows who helped John test the PLL VCO temperature stability mod. To do that I wanted to heat up the K2 to in internal air temperature of my K2 up to about 120F or so for a period of time and then do drift measurements.
I did that by loading a memory with CW, then putting the K2 into "repeat" mode at 100 watts into a dummy load, then going away for half an hour or so while it slammed out 100 watts of CW. I used no additional cooling - only what the little internal fan provides. Transmit times were at least 30 minutes, continuous CW, at 100 watts output. There were no issues with the heat produced. The CW speed doesn't matter, by the way. It's the duty cycle that determines how much heat is produced. The duty cycle is the ratio of key down to key up time. While higher speeds mean the key goes down more rapidly, the ratio of key down to key up remains unchanged no matter what speed a given text is sent. IMPORTANT; It is very important to remember to tighten the final amplifier mounting screws after an initial "run-in" period as described in the KPA100 manual. If your experience is like mine, you'll find them loose and in danger of not maintaining good thermal contact with the heat sink if you don't go back and tighten them. Once I did the initial re-tightening per the manual, I've not found them loose again. I've used my KPA100 for about three years now. Ron AC7AC _______________________________________________ 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
