The fan noise depends on the fan setting, which in turn depends not only on the duty cycle but also on the ambient temperature.
On mine (#1595), FAN1 is almost inaudible (almost completely drowned out by the noise of my computer's fan), FAN2 is audible but not obtrusive, and FAN3 and FAN4 get progressively louder and more noticeable. During operation, I don't believe I have ever heard them get beyond FAN2, and that only in data modes with relatively long transmissions. In CW, the speed has never gotten above FAN1, even while running stations in a contest. Ambient temperature may have a lot to do with it, though. The fan speed depends on PA temp, and if the ambient temperature starts out high, it takes less heating to reach the next set point. The temperature in my shack right now is a balmy 15C (that's just about 60F), so my K3 has to work pretty hard just to get up to the FAN1 set point. In summer, when even with A/C running it is about 10 degrees C warmer in here, I expect the fans will be more noticeable. 73, Rich VE3KI _______________________________________________ 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