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          Radio Mods Database        

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Modifications for the Kenwood MC-46
MC-46 DTMF Mic. 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
All mods found on this database are offered to me by other amateur radio hams or captured by Packet system. 
KB2LJJ  take no responsibility or liability for any damage done resulting from any modification.  
 I have been trying to help our ham radio with the radio modifications and have asked for any type of new radio mods.
 However, I haven't received too many.  If all of you contributed a little more,  I believe I would be able to help 
all the other ham's that are looking for these mods. I know it is possible to get more mods from all the Ham's because of
 the wide range that exist throughout the world.  By doing this we can  flourish and enjoy more of this hobby that 
we've taken part in for so many years. Furthermore, I ask you not to forget to send me any modifications that you might
 have through email.  I would really appreciate it.

      Email                webmaster@kb2ljj.com

 73's
   John Ribeiro
             KB2LJJ