[Amps] GS-35B efficiency

[Steve Thompson]

There's nothing subtle about a GS35b. See 
www.qsl.net/g8gsq/gs35a.jpg and www.qsl.net/g8gsq/gs35g.jpg for 
pics of a dead one that I opened up.

If the 8877 is a Ferrari, the GS35b is a sidevalve V8, or maybe a 
diesel tractor.

Steve
> I suspect the difference is probably in the grid structure. This tube was
> originally designed as a radar pulse tube and is no doubt optimized for that
> service, not for linear amplifier service. I have not taken one apart, but I
> would bet the grid does not have the fine control over emitted electrons that an
> 8877 does, for example. Some of the electrons slip by, so to speak, and do not
> effectively contribute to the RF output. Thus the lower efficiency.
> 
> Old timers will recall the receiving tubes from years ago that were designed as
> "variable mu" or "remote cut-off". Their grid structure was make of wires with
> uneven spacing so the gain changed with different bias levels. Something similar
> may exist in the design of the GS-35b.
> 
> This is just a guess and should be taken with a grain of salt until the real
> facts are known.
> 
> 73, Bill W6WRT