[Amps] 4-250B or QB3.5/750 in GG operation

[DF3KV at aol.com]

In einer eMail vom 10.05.03 19:45:18 (MEZ) - Mitteleurop. Sommerzeit schreibt 
pe2six at xs4all.nl:


> One other question on the 4-250B or qb3.5/750 in GG configuration.
> When using aprox. 2.7 Kv I'm building an amp with two of those tubes 
> parallel. Now i'm looking for the value of the bias zener to get them to
> run in class AB.
> 

Hi Erwin,

With 2,7KV there will be no need for Zeners in highµ configuration,
idling current will be quite low (class B).
If used as tetrodes you are better off with adjustable grid -voltages

73
Peter