You can find all the information you need on these links on Motorola Maratrac radios. Here's a few pictures on a split site 10 meter repeater.
Motorola Maratrac
TX RADIO WITH PTT, MIC AUDIO , AND GROUND FROM CONTROLLER
RX RADIO WITH JUMPER ON J21 PINS 13 & 11
J22 - Option Connector
1 Digital Ground
2 Switched B+
3 Keyway
4 Vol Control Top
5 Decoded Audio Out **
6 Mic Hi Out **
7 Analog Ground
8 9.6V DC
9 Switched 5V DC
10 B+
11 SCI + ???
12 Option-To-Audio Spare Line (goes to J21-13)
13 REF-MOD
14 Lock
15 Detected Audio In ** (Discriminator)
16 VCO-MOD
17 PTT
18 Mic Hi In **
The only signal conspicuously absent from J22 is COR/COS, but never fear... It's available on the adjacent Audio Board connector, J21. By soldering a jumper between pins 11 and 13 of J21, you can make the SQUELCH_DECISION (read: COS) signal, appear at J22-12, the spare line. This is an active low that can provide COS to your controller or other equipment. Now, all the commonly desired signals are available on the easily accessible Option Connector.
www.hamradiorepeater.info
Maratrac Hex Editing
Using Hex Workshop
