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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 # 852
MODEL: MC-46
SUBJECT: MIC USEAGE WITH OLDER EQUIPMENT

The MC-46 DTMF (Dual Tone Multi Frequency, or Touchtone (TM)) microphone
may be adapted for operation  with any VHF or UHF radio by changing the
supplied six pin mic connector to a five pin, four pin, or other connector,
as required.  Radios not originally supplied with regulated, filtered B+ at
the mic connector need also to be modified to power the microphone.

The MC-46 standard six pin mic connector is part no E07-0651-05, and is
wired:

     Pin 1 White    Mic Output
         2 Red      PTT
         3 Blue     Down
         4 Green    Up
         5 Brown    B+ (8.5 VDC +/- 10%)
         6 Shield

The Four pin connector part no is E07-0403-05.  Radios built with a four
pin jack do not supply B+ to operate the mic, and must be modified to
deliver a constant source of DC to operate the mic and DTMF keyboard.  Any
Kenwood product of this vintage will have a B+ line designated "C9" (Common
9V DC), wich is regulated, filtered, and noise-free.  Rewire the mic as
described below:

     Pin 1 White    Mic Output
         2 Red      PTT
         3 Shield   Common Ground
         4 Brown    C9

Rewire the radio mic jack: pin 3 to common ground, pin 4 to C9.

Rewire the stock mic for pin  3 common ground.  Otherwise, the mic element
will be returned to C9, instead of ground.  Note this change on the radio
schematic.

The Five pin connector part no. is E07--551-05.  Radios built with a 5 pin
jack supply correct B+ for a DTMF mic (originally designated MC-45, and no
longer available).  Wire the mic as described below:

     Pin 1 White    Mic Output
         2 Red      PTT
         3 Brown    B+
         4,5 Shield Common Ground

Mating chassis connectors are:

     Four Pin       E06-0403-05
     Five Pin       E06-0552-05
     Six Pin        E06-651-05