[Drake] Cooling fans - blow in or out?

[Ron Wagner]

I mounted mine to the rear of the RF cage with black wire ties, and 
grommets to "back off" the fan so that it does not scrape any paint.

For power, I went inside the radio, and used a diode and cap on the 
filament supply line.  They mounted to the terminal strip beside the RF 
cage w/o anything extra needed.  Routed the wire through existing holes in 
the chassis.  I used a 24 volt fan on a half wave 12 volt supply.  Fiddled 
with the cap value for consistent start.  The speed is very whisper like. 
Things are now nice and cool.

I believe that this is best way to proceed as the fan turns on/off with 
the rig, the noise level is very low, if not non-existent.  The cabinet 
still opens w/o any fuss for service if needed.

73,
Ron

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Visit my astronomy home page.   http://www.dma.org/~wagner
Amateur Radio Station: WD8SBB - Ron  and  KB8NRP - Joann
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