> It might be more convenient to add the resistor in series with the
> transformer's primary, where the resistance needed will be higher in
> value, but will produce a bit (not much) more heat. The current in the
> primary will be about 1/30th of the secondary current (since you are
> stepping down the voltage by about 230/8.3 ~ 30), so the value of
> resistor will be about 30x larger -i.e. something around 3 Ohms.
I use the old Henry trick of installing a 10 ohm slider type power resistor
in the primary of the filament transformer. (25 or 50 watts, as required)
The proper voltage can be set at the tube pins by adjusting the slider, and
the resistor limits inrush current if there happens to be any.
(((73)))
Phil, K5PC
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