==============================================================================
                             K E N W O O D
   >>>   A M A T E U R   R A D I O   S E R V I C E   B U L L E T I N   <<<
==============================================================================

                        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

==============================================================================

BULLETIN # 935
MODEL: TM-321A
SUBJECT: LOSS OF TX AUDIO WITH MC-48B

When an MC-48B is used with the TM-321A, transmit audio may be suppressed 
due to RF feedback. This occurrence is restricted to mobile operation 
where the antenna is in close proximity to the microphone.

The audio can be restored by adding a 100pF capacitor directly to the mic 
element terminals.

REQUIRED PARTS:

100pF, 50V CAPACITOR KENWOOD PART NUMBERS CK45BlHlOlK OR CC45BlH101K

1. Remove the 3 screws from the mic case (Figure 1). 
   Carefully open the case.

2. Pull the PC board, PTT knob, and PTT micro switch out of the mic case 
   to expose the mic element cover (Figure 2).

3. Remove the 3 screws and mounting clips (Figure 3) securing the element 
   cover. Remove the PTT spring. Pull the mic element and cover out of 
   the case.

4. Remove the element from the rubber cover.

5. Install and solder the capacitor directly to the mic element terminals 
   where the brown and white wires are connected (Figure 4). 
   To avoid damaging the element, use a low wattage soldering iron.

6. Carefully assemble the mic by reversing steps 1 - 4.