>G3JVC wrote:
>Would it be considered good practice to put a small variac in the primary
>circuit of
>the filament transformer, supplying a transmitting tube, and run the applied
>voltage up slowly, thus allowing the filament current to be more controlled,
>during that destructive switch on surge..
It sure would do the job, John, but an automatic means to accomplish the
same thing would be the use of a Keystone Carbon Co.'s NTC (negative
temperature coefficient) thermister. It will slow ramp up the voltage and
you won't have a variac to contend with plus its size, cost and weight are
much less. GL!
73,
Marv, W6FR
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