Manfred said:
>With a loaded Q of 20 and a coil Q of 400, which is about the highest
you can hope to get, at 1500 watts output you still have 75 watts
heating the coil! That would make it quite warm even if a fan blows at it!<
Adding to this, I have a conference paper from 1963 describing a 75kW HF tx.
There, the tank coil was a variable, made from silver plated copper tube, with
a sliding contact of silver loaded graphite, and air was forced down the tube
for cooling....Rich Measures always advocated that one ensures that there is
some air flow to cool tank coils, and I am somewhat in agreement.
I'd hate to have their electricity bill...
73
Peter G3RZP
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