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                             K E N W O O D
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                        Kenwood Service Centers

   Kenwood Service Corporation             Kenwood Service Center, East
   2201 East Dominguez Street              829 Lynnhaven Parkway, Suite 130
   Long Beach, California 90801            Virginia Beach, Virginia 23452
   Telephone 1-310-639-5300                Telephone 1-804-340-1702

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BULLETIN # 1019
MODEL: TS-950
SUBJECT: Low Power Output after Temp. Protection 

Symptom:

After transmitting for approximately 2 hours at 50% duty with 150 watts output
the temperature protection circuit activates reducing the output power to 
about 50 watts. Normally, full output power will be restored after the fans 
have had a chance to cool things down.  Occasionally the power output will 
not return to normal, even after extended receive operations.

Cause:

The temperature sensor is attached to the main transformer and is set to
activate at 80 degrees C.  This setting was selected to reduce power before 
the internal fuse on the transformer opens.  

Corrective Action:

After thorough testing, we have found that the temperature sensor should be 
set to 90 deg C to allow proper return to full power transmit.  This setting 
will also allow the radio to be used at higher ambient room temperatures 
without worrying about the power output dropping in the middle of a QSO.  
Replace S1 the temperature sensor.
 
Parts Required:

Qty     Description                Kenwood Part No.      Circuit Description

1       90 deg C Thermal switch    S59-1416-05            S1

Caution:   This modification requires soldering equipment rated for CMOS type
circuits.  It also requires familiarity with surface mount soldering
techniques.  If you do not have the proper equipment or knowledge do not
attempt this modification yourself.  Seek qualified assistance.

Time required for this modification is 30 minutes or less.
Service code A:93 B:20 C:S1 D:91