"Jimmie D" wrote in message
...
I am trying to modify a 1 tube amp for 6 meters using a 6146. I think the
amp was origionally used for CB though it does tune up on 10 meters. It
worked OK before I removed the input circuit and put in one for 6M. The
problem is I cant neutralize the damn thing. It makes a great osc.I was
thinking of scraping the tuned input and replacing it with a 200 ohm
resistor and a 4:1UNUN. I figure this low of an impedance on the grid would
swamp out any feedback that might me causing it to osc. I have about 5
watts PEP of drive.

Jimmie


It could be the screen bypassing--it is critical.

If you can find an old VHF ARRL Handbook
from the sixties you might find some ideas, tips and tricks regarding using
these tubes on VHF. Another problem is unwanted inductive feedback, such
as when the ground ring lugs on some style sockets were used for the
bypass caps... Those rings had enough inductance at VHF to cause unwanted
coupling... Can you neutralize the tube using the conventional neutralizing
stub method??

Pete k1zjh