My brand new Icom 2200H 2 meter rig runs really hot when it transmits, so I
put a 12v dc cooling fan on top of it's cooling fins. The fan is supposed
to be for a computer power supply and it has 3 wires, black, red and white,
but I just put the red wire on +, and the black on -, and the white wire
isn't connected to anything. Because the rig only heats up when
transmitting, the fan doesn't need to be on all the time, so I put a 10k
variable resisitor in series with the fan and I can adjust the speed of the
fan or stop it altogether (if I had an on-off switch I would have used that
instead, but I don't right now and won't be able to get one for a while).
So, my questions a

-- Is this arrangement OK?
-- Am I running the risk of burning something out or damaging it?
-- What is the white wire on the fan for?



--
73
Tom
VA7FAB