[Amps] Advice

[Ron Youvan]

> With that given, if the tube (3CX-800) requires 19 CFM you *WILL* have 
> 0.50" of pressure at the socket. Conversely IF you have 0.50 inches at 
> the socket you will have 19 CFM. However if there is a down stream 
> restriction the pressure will rise and the flow will drop which would be 
> quite unusual. I'd not think this would be a normal situation, but when 
> designing an amp it is possible to not leave enough venting area for the 
> cooling to maintain proper flow.

   Not at all unusual at all, it takes is airborne lint to accumulate in the fins of the blower to 
reduce air flow, a few broadcast engineers have been known to log manometer readings down to the 
solder melting out of the anode fins.  (and tube destruction)
   Designing and keeping are two different things.
   I have removed so much lint and fuzz stuff from computers that live on the carpeted floors (at 
work) that I don't understand how they were operating.  (every 6 months)
-- 
    Ron  KA4INM - The only real problem is death is so final.