Re: blowing air vs drawing air, the object is to increase air flow
over the heat sink (or tube if no heat sink). If one does not have a
plenum directing air over the entire heat sink surface, my bet is
with blowing. Drawing air is effective if there is a plenum
confining the air flow over the heat sink surface.
I you are cooling a tube with fins like some of the 3CX or 4CX types
then you need the extra force of a blower due to the high air
resistance (back pressure) thru the fins. Example a 8877
(3CX1500A). I have both a blower and 7-inch radial exhaust fan on
that amp. Exhaust fan lowers back pressure that the blower works into.
All my other amps are currently configured with fans that blow down
onto the heat sink. I will be installing five fans on a 6m Harris TV
amplifier (1100w with 16 transistors) that draws air. That is needed
as air is drawn thru several holes from the input side of the amp for
cooling the input components by pulling air into the output side.
73, Ed - KL7UW
http://www.kl7uw.com
"Kits made by KL7UW"
Dubus Mag business:
[email protected]
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