[Elecraft] K2 fan turns on high with CW QSO 22 watts

[Michael Harris]

Hi Andrew,

> In a CW QSO tonight at about 22 watts my K2's fan came on twice at high
> speed and the heat sink was getting warmer that I'd expect for 22 W
> operation.  On the other hand this is only the first day running my KPA100
> kit so I'm not sure if it's normal.

I have been running my K2/100 as a QRSS  beacon on 40 metres for a
propagation study.  I was running 12W output which took the strain off the
base K2 PA's.

Anyway, with dots of 10 seconds and dashes of 30 seconds the KPA100 heatsink
would settle at about +46C with the fan running.  No harm done after about
300 hours of cooking.

Remember to tighten down the KPA100 PA's after about 8-10 hours of
operating, the screws tighten up by about a quarter of a turn.  No change
detected after the first tighten.  I replaced the split lock washers on Q3
and Q4 with star washers.  There have been cases of the split lock's
cracking the plastic package of Q3/4.  Stars are kinder.

I eventually took the KPA100 and fitted it externally with the KAT100.
Makes a nice unit and keeps 40C air out of the K2.  The basic K2 is pretty
stable without the KPA100 fitted but takes a little while to settle with the
KPA100 lid on.

I have fitted the BFO and PLL stability modes just for the sake of it, my K2
is #1400, yours might not need them.

Good luck,

Mike VP8NO (IOTA SA-002)
GQRP 10148
QRP-Canada #57
K2/100 #1400