The first six characters are pretty much standard Motorola convention. Here's a front view photo of a 16-channel MaxTrac, a 16-channel GM300, and a 2-channel MaxTrac: The masked logic board also has limited code plug space, hence fewer channels and less capabilities. The 8ch GM300 and the M-series all use the masked logic board that has no programmable pins.

The 16ch GM300 radio uses the expanded logic board with firmware in an EPROM that gives you the ability to program several of the accessory jack pins and also gives you several signaling systems, such as MDC1200. There is also an M10 single-channel radio, and an M130 2-channel radio that is an M120 with the GM300's signaling capabilities. The M120 radio is just about the same as a GM300 but has 'less features' - this would be the 2-channel version, equivalent to a MaxTrac 50. They use the same accessories (loudspeakers, microphones, accessory plugs, power cords, mounting brackets, etc.) as the MaxTracs. GM300 mobile radios cover the VHF (136-174 MHz in two ranges) and UHF (403-520 MHz in four ranges) bands, with 8 or 16 channels, 12.5 or 20/25/30 kHz channel spacing, and 10, 25, and 35-45 watt power levels. See below for more info on the RSS and programming. Naturally, you need different programming software (RSS), but if you've ever programmed a MaxTrac, you'll be right at home with the GM300. Throughout this article, reference to MaxTrac radios implies Radius radios as well. Like the MaxTrac, the GM300 line has been discontinued by the manufacturer.

You can even interchange some boards between the GM300 and MaxTrac radios. The GM300 was Motorola's next step in the MaxTrac / Radius mobile product lines. When I run the program and try to connect to the GM300 via the mike socket pins 4 and 7 I get the following problem. Subject: Re: RadioDoctor Motorola GM300 programming with Radio Doctor? At 11:33 PM, you wrote: I have downloaded the Radio Doctor software and installed it in my XP machine. By นายจักรพงศ์ รักษ์สังข์ ANY MANUAL OR PAGE WHERE TO SEE MEANING OF FUNCTIONS IN RADIO DOCTOR. I need a program Software radius gm300 radio doctor please help me. I came across something in yahoo called Radio Doctor witch is Windows based and apparently runs under XP on a modern computer and it allows you to add more channels to the radio. I'm assuming that MS-DOS versions won't work for the GM300 that I have however I've not found any windows versions of the software.

Motorola radius m120 programming cable