[Elecraft] OT: fan control in MFJ-4225MV switching P/S

[Nick-WA5BDU]

That's a pretty good solution.  When I was making measurements I noted 
that when I turned the supply voltage down to the 10 to 11 volt range 
the fan got very quiet.  In fact, I was going to forget about the 
thermostatic control solution.  But when I put the cover on, the noise 
worsened quite a bit at the same voltage.  Pulling air through those 
case perforations seems to do it.

Since the K3 is spec'd for 11 to 15 volts, I wanted to run at a little 
over 14 V or so.  The fan really gets noisier as voltage climbs, so I 
definitely needed either the resistor solution or fan control.

73-

Nick, WA5BDU


NZ0T wrote:
> As I'm not a very technical person I just used a couple of resistors in
> parallel to slow the fan down in my 4225.  I can't remember the values this
> early in the morning but it seems to be working just fine.  The supply does
> run a little warmer but not hot and the fan is no longer heard.
>
> Bill NZ0T
>
>