On Wed, 6 Aug 2003 15:48:01 -0700, wrote:

Well, Richard, tho in jest, serves purpose, that even with 30 watts lost on
surface of a balun , (or any other surface, for thatr matter), that by
doubleing the size of the SURFACE, that it would take something like 4 TIMES
as much heat to destroy it.

Hi Jim,

No, this is incorrect. When discussing power dissipation, it follows
a linear relationship to surface area - not square law (you are mixing
radius and surface area arguments). Even letting this pass, power
dissipation does not even conform to doubling with doubling of surface
area. This departure from expectation arises in the increased
distance the heat has to travel to find the surface. This is usually
found in having too many fins in an effort to maximize that same
surface area (and leads to an increase in Thermal Resistance).
Further, more fins also diminish heat transfer through convection
(again increasing Thermal Resistance). 4 or 5 fins is usually
optimal.

73's
Richard Clark, KB7QHC