[Amps] Power-off tube cooling

[Phil Clements]

Subject: [Amps] Power-off tube cooling


> I am curious about the origin of this mythology. It would
be nice to see some
>  factual data, or, at least, logic to support it. (snip)
>
>> Is there really some good physics to rely on here, or is
this just another
> piece of folklore that won't go away?

Assuming you have a  tube large enough and hot enough to
warrant cooling after power-down, the idea is to force the
residual hot air up and out the chimney instead of into
other components on and under the chassis. This is about a
$50 addition to an amp; one has to weigh the cost against
the protection provided to tank components that may suffer
long-term damage. Since many large amps I have seen do have
this feature, I can only assume the cool-down feature is
prudent in those cases.

(((73)))
Phil, K5PC