On 20/02/17 06:00, Roger Parsons <ve3zi@yahoo.com> wrote:
[...] Is it permissible to run the tube with only filament voltage and no air
for a short period? If so, what is a short period?
The filament current draw and corresponding terminal voltage will vary
according to filament temperature anyway, so if you do run it for a
short time, then at full temperature it will be different again.
When I wound my GS-35b filament transformer I added taps in the
secondary for soft start (also used a standby/quickstart, and also
filament low/operate/high/highest. I don't know that there was any need
to make it more finely adjustable than that.
A PWM arduino controller would be interesting (and probably unreliable),
but my old TL-922 has been given a solid workout over the years and it's
meter lamps vastly out-lived the tube filaments.
Steve
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|