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

[DF3KV at aol.com]

frank_goenninger at t-online.de (Frank Goenninger)wrote:

>Hi Peter, Rich, & all the others on this list,
>
>thx for replies. Having expose myself as mostly new to tubes and such, I
>see that the GU-84b allows for -150V on the grid.

-150V is the maximum allowed, the tube will be cut off then

>
>Given a 50 Ohm input circuit about 100V peak will be produced by 100W
>drive power.
>
>This would require to bias the grid at about -100V which is within
>limits of tube parameters.
>
>What would be the consequences out of this? Rich, you mentioned a
>typical value of about -80V for the grid bias. Sorry, I still do not
>have any suitable datasheet (and found none on WWW too)...
>
>So my parameters for the GU-84b are:
>
>Ua  = 3000V  (Anode)
>Ug1 = -100V  (Grid)
>Ug2 =  375V  (Screen)
>
>What would be the resulting values for
>
>Ia
>Ig2
>
>???
>
>Thx for all the assistance so far!


Hi Frank,

You will get the correct idling current with -80V on the grid.

Check this webpage: http://i5uxj-2.cln.it/amp/amphf3/amp1.html

I also suggest to read through Richs webpage at:

http://www.somis.org/

73
Peter