[Amps] Input tuning

[Peter Voelpel]

Hi Rich,

his intention is a grounded grid configuration.
The cathode input impedance will be around 120 Ohm which will be best suited
by a low Q Pi-Circuit
Grid swamping would be a bad idea

73
Peter

-----Original Message-----
From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
Behalf Of R; Measures

>
> I'm building an amp using a pair of 4-400's in a grounded grid
> configuration. I was wondering about the input tuning and what the  
> best way
> of approaching it.

Make the reactance of C-in 25-ohms on each band if u want a low swr  
input.

> I have heard of using everything from a 50 ohm swamping
> resistor

For AB1, a grid-swamping R is needed.