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)
- Get the 2 motorola Mitreks and insure they are operable and work with no problems, its best to do this with a control head.
- 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.
- 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)
- Get a Motorola Mitrek Manual, probably the most important item in this modification
- 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
- 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 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.