Computer Automation Technology

Connecting a CAT to the Motorola Maxtrac
and Radius line of mobile transceivers.

Connecting a CAT controller to a Motorola Maxtrac and Radius series transceiver radios can be accomplished by following the interconnections below.

 

Build a cable with a Male DB25 connector on one end of a 5-wire conductor cable (Plugs into the CAT controller). The other end of the cable will be soldered to the accessory connector that plugs into the Motorola radio. Wire the cable as follows:

FUNCTION
CAT controller
Accessory Connector.
Signal Function
 Signal and Logic Grounds  Pin 17  Pin 7  Ground
 Receiver COR #1  Pin 6  Pin 8  COR
 Receiver Audio  Pin 13  Pin 11  Discriminator Audio
 Transmitter Audio  Pin 11  Pin 2  TX Microphone Audio
 PTT #1  Pin 10  Pin 3  Transmitter PTT

 

GM300

 

 

Notes:
1) A jumper connection on the accessory connector between pin 15 and pin 16 will activate the internal speaker.

2) Since the transmit audio input to the Motorola radio is microphone audio, it's advisable to attenuate the TX audio output of the CAT controller. Some CAT controllers have a 100 ohm resistor from the TX audio output to ground that can be inserted with a jumper plug. If your controller does not have the 100 ohm resistor jumper option, solder a 100 ohm resistor between the TX audio output and ground.

3) The Accessory connector (16 pins) carry the following part numbers:
    A) Connector housing AMP 104422-1
    B) Connector pins (Tin Crimp) AMP 1-87309-3