[Boatanchors] Tube shields CORRECTION

[Nick England]

Black shield interior for radiative heat transfer to the shield and black
exterior for radiative heat transfer to the surroundings. And conductive
heat transfer is more effective than radiative so the best (commonly found)
are the IERC shields with inserts that contact the tube bulb, and that have
solid connections to the shield base and chassis. Not anecdotal, but a
quite well-studied topic. References:

Guide Manual of Cooling Methods for Electronic Equipment
NAVSHIPS 900,190  1955  by Cornell Aeronautical Lab
 18 MB pdf - http://www.navy-radio.com/manuals/900190-cooling.pdf

Design Manual of Natural Methods for Cooling Electronic Equipment
NAVSHIPS 900,192  1956  by Cornell Aeronautical Lab
 90 MB pdf - http://www.navy-radio.com/manuals/900192-cooling.pdf

Design Manual of Methods of Forced Air Cooling Electronic Equipment
NAVSHIPS 900,194  1958  by Cornell Aeronautical Lab

Design Manual of Methods of Liquid Cooling Electronic Equipment
NAVSHIPS 900,195  1960  by Cornell Aeronautical Lab

Reliability/Design Thermal Applications
MIL-HDBK-251  1978 Supersedes 4 manuals listed above
50 MB pdf -
http://www.assistdocs.com/search/document_details.cfm?ident_number=53966

Cheers,
Nick K4NYW
www.navy-radio.com


On Mon, May 26, 2014 at 11:57 AM, Glen Zook via Boatanchors <
boatanchors at mailman.qth.net> wrote:
>
> There are a number of people who have tried painting the "shiny" shields
with flat black paint, both inside and outside, that have found a reduced
tube temperature.  Over the years, I have tried this a few times and the
temperature of the tubes did seem to be lower.  However, I never actually
measured the temperature and, as such, the reduction in temperature is more
anecdotal than scientific.