The Motorola Radius M120 transceiver is a very affordable radio. They are abundantly available on Ebay and many other websites. There are a few things that you need to look out for if you plan to purchase one of these transceivers.
16 Pin Accessory Plug – The first thing I look for is to make sure the transceiver has a 16 pin accessory plug in the back. Some of the Motorola Radius M120 transceivers only come with a 5 plug accessory plug. This is only important if you plan to connect anything to the transceiver (i.e. – repeater controller, IRLP, Allstar Link, etc.).
Input Voltage – 13.2 VDC
Power Output – (Varies)
Frequency Range – (Varies)
Tone Encoded Squelch () – Yes
Digital Private Line (DCS) – Yes
I found that programming the Motorola Radius M120 can be quite a challenge. The article linked in the previous sentence explains how to accomplish this task.
trying to find pinout of rj45 mike connector Motorola Radius M120
I got the below information from this page (http://www.repeater-builder.com/motorola/maxtrac/maxtrac-interfacing.html). Hopefully it is what you are looking for.
1 – unused, but fed to the logic board *
2 – unused, but fed to the logic board *
3 – PL defeat (a.k.a. the mic hook switch)
4 – ground
5 – microphone audio in
6 – PTT in (ground to transmit)
7 – SCI+ (bidirectional programming lead – used by the RIB for programming the radio – leave this floating)
8 – handset audio
* only on the low band, high band and UHF radios… on 900 MHz radios the two unused pins never leave the front panel board.