[AMPS] smoked TL922

[km1h @ juno.com]

On Sun, 7 Dec 1997 11:26:57 EST JW KIMBALL <JWKIMBALL@aol.com> writes:
>Well the old saying of keep the smoke inside or it will quit working 
>seems to
>be true. 
>
>My TL922 smelled so I turned it off. Upon opening I found:
>L7 on V1 smoked
>R22 on V1 smoked
>C33 and C32 on V2 smoked
>
>Any help on causes and solutions would be greatly appreciated.
>
>Any suggestions on updates. It's worked super for several years.
>
>Thanks
>73
>Jim K5aup
>

Sounds like a simple case of internal arcing in the tube.  A 10-20 Ohm
resistor in the HV lead would possibly have minimized the damage. 
The grid chokes are also way too large in current capacity. Replace with
150-200 ma types which have both extra resistance to provide a bit of
degeneration and will act better as current absorbers. 

In extreme cases when the tube arcs or shorts you will also take out the
Zener D-2, and Bias diode D-1 and caps C-3 and C-26.

If the amp failed while on 10/12M best to check PC-1 and PC-2  R values
also. Replace with metal oxide.

GL  Carl   KM1H


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