[Amps] TL-922 grid chokes

[Carl]

----- Original Message ----- 
From: "Randall Mullinax" <rcm at mail.icnet.net>
To: <amps at contesting.com>
Sent: Wednesday, August 04, 2010 11:34 AM
Subject: [Amps] TL-922 grid chokes


The grid chokes in my TL-922 were replaced with 10 ohm resistors
by the previous owner.  The amp works fine except on 10 M where the
resistors go up in smoke within a few seconds.

This bring up several questions.

1. Is the amplifier oscillating on 10 M?


** Probably not, are they metal film or wire wound?



2. Should I replace the resistors with the factory 470 uH chokes
or directly ground the grids?

** They worked well for Kenwood.

3. Where can I get replacement grid chokes?

** Any of the catalog outfits, the value isnt very critical, the SB-220 used 
1 mH @ 300 ma for about 26 Ohms DC resistance.

4. I've read about adding/increasing negative feedback.  Does anyone
have suggestions?

** Do you have excess drive to burn up?  If so add some R in series with the 
drive at the socket.

Carl
KM1H

Thanks for any and all comments.

Randy
AD5RM




===================================================================
Sent Internet Complete! Webmail  http://www.icnet.net
===================================================================


_______________________________________________
Amps mailing list
Amps at contesting.com
http://lists.contesting.com/mailman/listinfo/amps