How Richard wired the ICS Controller Single M controller to my Motorola Mitrek UHF radios to create a GMRS repeater

I wanted a GMRS repeater, and I didn't want to do any fancy mods to the Motorola Mitrek radios. So here is how I did it with the absolute minimal mods to the radios
(Almost no mods at all actually, just pulling COS from Point E)

  1. Get the 2 motorola Mitreks and insure they are operable and work with no problems, its best to do this with a control head.
  2. Recrystal the radios, I used Bomar crystals and sent them the elements, and had them do the re-crystaling for me. This proved to be extremely helpfull since I screwed them up and had to send them back, they fixed them and returned them at no charge. I will definately be using them again.
  3. Get a Single M controller from ICS controllers. Granted you can probably get away with only using the Basic, for a couple more bucks I can get a bunch more features (Even though I will probably never use them)
  4. Get a Motorola Mitrek Manual, probably the most important item in this modification
  5. Tune the mitreks to the new crystals. I did this with a digital volt meter, it took me almost 8 hours to get them both fully operational, this probably proved to be the most difficult part of the project
  6. Start wiring, below are the pinouts I used to hook everything up. To be honest, the controller manual was not very helpfull for me when initially setting the repeater up. After getting help from several hams, I got everything working using the pinouts below.
RX Radio
Controller
Single M Controller
TX Radio
Comments
Pin#
Pin#
     
GND
1
GND
GND
Main Ground
HOT
2
HOT
HOT
Main Hot
 
3
PTT
13
Orange Black
 
4
GND2
   
 
5
Mic
1
currently through resistor
11
6
Audio
   
14
7
SQL
   
E
8
COS
 
Test point E on radio
 
9
NA
   
 
10
Fan
 
Ground for fan

 

Also need to hook up to make the radios operational

Pin #
Hook To
4
Hot (Usually hooked to ignition)
6
Ground (Channel Select 1)
7
Ground (Channel Select 1)
12
Hot (Transmit enable)
16
Ground (PL Enable)
17
Ground (Main Ground)
19
Hot (Main Hot)

I still have some tuning issues with my radios, but currently my repeater is operational with the above wiring.