[AMPS] Kenwood TL-922A Grid Current

[KA2YKC@aol.com]

In a message dated 3/2/99 10:13:54 PM Eastern Standard Time, km1h@juno.com
writes:

<< >
 >I have changed tubes between three different amps and three different 
 >sets of 3-500Z's and it happens with all tubes.  I am sure the problem 
 >is in the amp.  In addition, I have checked the shunt resistors in the 
 >grid circuit, and they all check good.
 
 What shunt resistors??  In an un -voodooed TL-922 there are no resistors,
 just a pair of grid chokes plus  220pf caps per pin. Those original
 chokes are too big, current and low resistance wise. I suggest replacing
 with something in the 750uh to 1.5mH 160ma and 25 Ohms DC resistance
 range...as used in the SB-220. If there are some strange parts in the
 amp, it might be best to throw them away and follow the original design.
 
  >>
?????

In a factory-stock TL922A there is a 470 ohm resistor in parallel with the
grid choke -actually the resistor is wrapped & soldered to the leads of the
choke. A real pain in the ass to measure each individually during
troubleshooting.

Eric
KK2ED

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