[Hammarlund] Tube shields and heat

[Robert Moses]

The rate at which chemical reactions such as those involved in the
degradation of tubes takes place increases 2.3 times for each 10 degree
C increase in temperature. Cooler is always better as long as it is warm
enough to work.

On 09/27/2014 12:54 PM, Kenneth G. Gordon wrote:
> On 27 Sep 2014 at 13:31, Guido Santacana wrote:
>
>> As for tube shields, if they are not IERC shields, paint will not do much. 
> Guido: on the basis of experiment, FLAT black painted tube shields reduces 
> the heat in the tube by 17%, so yes, it does do something worthwhile. For 
> instance, reducing the heat of 300 degrees to 249 degrees, or -51 degrees. 
>
> You may not think this is worthwhile, but I do.
>
> According to my reading on the subject, reducing tube heat by even 1 degree 
> contributes significantly to longer tube life.
>
>> Better to leave the tubes uncovered and use the fan. 
> True.
>
> Ken W7EKB
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