[AMRadio] filament voltages---my two cents worth...

[Vince Wesa Werber]

On Monday 16 August 2004 08:36 pm, Geoff/W5OMR wrote:
> > >Of course, we know that running voltages that are too high will kill the
> > >life expectancy of the tube, by why is running too little voltage bad
> > > for the tube, if it's developing full emmission at a lower voltage?
> >
> > I think low voltage would be ok as long as you are not exceeding the
> > current rating of the tube, starving the filament emission by running too
> > low filamrnt voltage, or exceeding the rated plate dissipation.
Now my two cents worth (ref: GE GL814 info sheet)

"The filament should not fluctuate more than plus or minus five percent from 
the rated value; otherwise, a loss of filament emission may result.  The 
filament voltage may be removed for stand-by periods greater than fifteen 
minutes.  There should be no reduction of filament voltage for periods of 
less than five minutes.  Filament voltage may be reduced to eighty per cent 
during periods of greater than five minutes if desired."

Remember... this is for the 814....  A'filament type tube', 

Does this help????

73
vince
ka1iic
-.--.