*in battery tubes, you would be correct, in the early days of radio, the tubes
could not run on AC...they would hum...their thin filaments would vibrate, and
not keep a constant temp, but the filaments we are discussing are thick, made
to run on AC
jeff millar <wa1hco@adelphia.net> wrote:
If Voltage across the filament caused bias/linearity/gain variation
problems, then all amplifiers with AC on their filaments would have hum
on the transmitted signal.
60 Hz on the filament varies very slowly compared to RF...its almost
DC...so DC doesn't hurt...except for hypothetical wearout issues.
*at $150.00 a pop, the wearout issue is very important
jeff, wa1hco
Steven Grant, W4IIV wrote:
>thanks for the tip...your correct...wouldnt using DC cause a bias condition
>that may cause linearity problems?.......steven
>
>
STEVEN GRANT W4IIV
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