----- Original Message -----
From: "Randall Mullinax" <rcm@mail.icnet.net>
To: <amps@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
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