[Elecraft] MFJ-4125 Fan Noise

[John H Gibson]

Question for the List:

I recently bought an MFJ-4125 switching power supply to use with my K3/100 
transceiver. While otherwise satisfactory, the MFJ-4125 has an objectionably-
noisy fan.

On my MFJ-4125, over half of the fan exhaust openings on the back of the 
supply are blocked by the fan's motor housing, which makes me believe that the 
power supply originally was designed for a different fan (perhaps a quieter one), 
and this fan is an expedient substitute by MFJ.

I would like to know if other users also are bothered by the MFJ-4125's fan 
noise, and what they have done about it. 

Have you substituted a quieter fan? Have you installed a series resistor to slow 
down the fan, and with what result? Have you installed a thermostatic switch to 
run the fan only when needed? Or have you given up and simply bought a 
quieter power supply?

Any advice would be appreciated.

73,
John, no8v