Re: Filament Issue

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

Original poster: FutureT-at-aol-dot-com 

In a message dated 12/1/03 10:13:01 AM Eastern Standard Time, 
tesla-at-pupman-dot-com writes:

>Hi, I was testing the voltage to the filament on my 813 tube in my VTTC,
>and I noticed that it was like 4v, when the 813 has a 10v filament!  I am
>wondering, is this a bad thing?  The filament does get hot, and the VTTC
>works, but it doesn't work optimum, could low heater voltage cause this?
>
>Regards - Jim Mitchell
>


Jim,

4 volts on the filament is very bad.  The voltage should be
about 10.4 volts at the tube pins for best results.  Low voltages
will ruin the tube and give very weak performance.  Measure
the voltage right across the two tube filament pins while the
filament voltage is applied to the tube.

John