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Old August 13th 03, 12:58 AM
Brian Kelly
 
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(Art Unwin KB9MZ) wrote in message om...
Russ,
The point I am making is that some comments are repeated
so many times they take a life of their own
Think about it, the resistors of old are a far cry from
the carbon resistors of today which are not as porous,
if it is a worry then coat it with epoxy !


And there goes the heat transfer characteristics of the
purpose-designed/built resistors used for liquid cooled dummy loads.

Then there is the "rust" question, the paint cans of today
have a teflon liner !


Paint cans are not resistors, they do not have to be surface-cooled
and the reason for the coatings is the water in todays the water-based
paints. Nobody I know uses water or latex paint in their dummy loads.

Even the latest ham data states that
motor oil CAN be used ( no, it will not explode !) but raise
a question of "life", possibly a suggestive comment that you
change the oil every 5000 qso's.
Certainly industry gives a good guide as to what is the best
to use for their circumstances but it doesn't rule out every
thing else for all time, and this includes motor oil of which
there are many types.


Maybe 50,000 qso's later with the 'ole Cantenna on the side I'm still
running like new on drugstore mineral oil. Get back to us when your
reserch indicates which motor oil beats mineral oil.

Maybe ten years ago I had to wire brush, prime and repaint the can, it
was rusting from the *outside*.

Regards
Art


w3rv