[Amps] Re: GU-84b: Drive power required for full power output ?

[gdaught6 at stanford.edu]

On 29 Mar 2004 at 9:50, Ian White, G3SEK wrote:

> john devoldere wrote:
> >-150V  is CUT -OFF bias
> >
> >in AB1 or AB2 I use approx -65 V if I remember correctly.
> >
> 
> -65V seems about right, with Vg2=375V. Those voltages should allow
> "ultra-linear" operation, with a zero-signal anode current that is
> reasonable for a tube of this size.

I'd like to add that the variability in this factor is about +/- 20% 
for the Russian tubes I've used.  I designed an amplifier based on 
the published figures, with Eg1= -56 volts.  I found that different 
tubes needed voltages from about -40v to -65 volts.  When the bias 
was adjusted to give the desired no-signal anode current, the tubes 
all put out the specified power (or more).

73,

George T. Daughters, K6GT