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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 # 937
MODEL: TM-721A
SUBJECT: AF PA WHITE NOISE WITH SQUELCH ON

Some users of the TM-721A may detect white noise from the speaker with 
the squelch turned on. The noise can be reduced by lowering the gain of 
the Audio Frequency Power Amplifier. To compensate for the reduction, 
the gain of the pre-amplifiers will be increased. In addition, the beep 
level will be raised.

REQUIRED PARTS

12K OHM 1/10 WATT CHIP RESISTOR RK73FB2A123J 
18K OHM 1/10 WATT CHIP RESISTOR RK73FB2A183J

1. Disconnect the power supply and antenna from the transceiver.

2. Remove the top and bottom covers (12 screws). Do not damage the 
   speaker wires when removing the top cover.

3. Unplug all connectors from the TX-RX (VHF) unit on the top of the 
   transceiver. Remove the 7 screws from the board and then pull the 
   board from the transceiver

4. Unplug all connectors from the TX-RX (UHF) unit on the bottom of the 
   transceiver. Remove the 6 screws from the board and then pull the board 
   from the transceiver.

5. Remove the silver colored screws from the front panel chassis (2 on 
   each side, 1 on top, and 1 on the bottom).

6. Pull the front panel assembly away from the body of the transceiver 
   (do not disconnect any cables).

7. Remove the 6 screws from the Control unit (A/3) which is mounted on 
   the body of the transceiver.

8. Pull the board away from the transceiver, but do not disconnect the 
   red and black wires. Keep track of the two short coax cables that 
   run under the Control unit. The cables connect between both TX-RX units.

9. On the component side of the Control board (the side with the
   majority of connectors) replace R7 with an 18K ohm chip resistor

10. Assemble the front panel by reversing steps 5 - 8. Do not forget to
    run the two short coax cables (mentioned in step 8) under the
    Control Unit.

11. On the foil side of the TX-RX (UHF) unit, remove chip resistors R37
    and R41.

12. On the foil side of the TX-RX (VHF) unit, replace R43 with a
    12 K ohm chip resistor.

13. Assemble the transceiver by reversing steps 1 - 4.