[AMRadio] 100 V filament transformer primary

Bob Bruhns bbruhns at erols.com
Tue Feb 20 17:55:24 EST 2007

A rheostat is cheaper and smaller than a variac, offers a softer start on the filament, and because of the temperature
coefficient of the filament, there is a small reduction in filament voltage variation over line voltage fluctuations, although
that isn't much.  A rheostat generates more heat, though.

   Bacon, WA3WDR

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