[Amps] More instability problems

[Bill Turner]

ORIGINAL MESSAGE (may be snipped): 
On Tue, 16 Apr 2013 10:43:21 -0400, N1BUG wrote:

>
>The present input configuration is a 50 ohm RF load resistor with a 
>.01 cap coupling to the cathode. I am trying (again) to figure out 
>some practical method of adding tuned input to this amp but I am at 
>a loss. Lack of space and switching problems are problematic.

REPLY: 
One way to add a tuned input is a bit clunky, but works:  At the input to
the amp you no doubt have an SO-239 coax connector. Just connect a T-fitting
there and that will give you a place where you can connect a parallel
resonant circuit. Use a Q of between 2-5. That will at least tell you
whether your problem is related to lack of tuned input or not. 

Bill, W6WRT