[Amps] cathode to ground in tetrode amp

[gdaught6@stanford.edu]

On 30 Jan 2006 at 13:12, Sam's Mail wrote:

> I have built several grid driven tetrode amps, The cathode is
> grounded, The screen does not go to ground through anything. The
> screen supply should be shunt regulated to be able to handle positive
> and negative screen current. Try Ian Whites web site for good
> information . 

You'll notice that Ian still recommends a shunt resistor to ground.

> If you care to build a grid driven tetrode I suggest
> using his tetrode boards. 

That's very good advice, in my opinion!

> ----- From: "Gary Schafer" <garyschafer at comcast.net> To:
> 
> > >From what I saw it is a conventional grid driven amp. The screen
> > >resistor to
> > ground is to prevent negative screen current from raising the screen
> > voltage. The cathode resistor is obviously a mistake.

IMHO, the cathode resistor is not "obviously a mistake."  Rich 
Measures' website (and I) often recommend some cathode degeneration, 
aka negative feedback, primarily to help linearity.

73,

George T. Daughters, K6GT