[Amps] The GU84B and GU78B tubes / some brief history

[Vic K2VCO]

Why do you say that a swamped grid-driven tetrode needs neutralization? I haven't seen 
this in published designs. Isn't a 50-200 ohm swamping resistor enough to stabilize the 
amplifier?

Agreed on the other points!

On 10/28/2012 11:57 PM, Jim Thomson wrote:
> ##  actually, they are not apples and oranges.  One has an extra grid in it,
> requires a regulated screen supply, neutralization, and some method to cancel out
> the Xc between the cathode and control grid, so u just cant slap a 50/200 ohm.
> passive grid resistor in there.

-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/