RE: Regulation for Filament Voltage on 833A Tubes

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mccauley, Daniel H by way of Terry Fritz <teslalist-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>


Actually, my bad.  I made the measurement intially prior to installing the
tubes so the open-load voltage was 11.5V which
is expected.  Under load, the voltage should be about right.  Duh.

The Captain

 > I finally got my 833A VTTC up and running and I noticed that
 > the actual
 > filament voltage coming from my
 > 10V, 10A filament transformers is about 11.6 VAC.
 >
 > The nominal spec for the 833A tube is 10V +/- 0.5V  (either AC or DC).
 >
 > Common sense always says you should abide by the datasheet and that
 > exceeding this limit would either be destructive to the tube,
 > or reduce
 > optimal performance.  However, I have very limited experience
 > with vacuum
 > tubes so I don't know how critical
 > this actually is.
 >
 > What are your thoughts?  Okay as is, or do I need to control
 > this precisely
 > via variac???
 >
 > Thanks
 >
 > The Captain
 >
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