[Amps] Meaning of "conduction cooled"

[Vic K2VCO]

Floyd Sense wrote:
> Most amps today use convection cooling.  To me, radiation cooling would 
> imply no airflow used and that isn't seen very often.

I would say that external anode tubes like the 3Cx800, etc. are 
convection (or more precisely, forced-air) cooled, while glass-envelope 
internal anode tubes like the 3-500Z are primarily radiation cooled. 
The air cooling keeps the envelope and base temperature within limits, 
but the anode itself is cooled by radiation.

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco