The GM300 series radios are line of two-way radios manufactured by Motorola Solutions. They are popular choice for amateur radio operators due to its features, performance, and affordability. GM300 is also a very durable radio. It is built to withstand the elements and can handle even the most demanding conditions. Similarly, the Motorola GM338 is a two-way radio that is designed for businesses and organizations that need a reliable and affordable way to communicate. It has a 128-channel capacity, 25 watts of power, and a variety of features that make it ideal for a variety of uses.
I have both radios in my shack and got them from a ham meet.For first few months, i was not able to programme them for ham bands due to complexity in obtaining a program cable suitable for them. i tried few diy designs available from online and inputs from few friendly hams. Later i figured out issues in homemade cable and made it work in said radios.
For programming Motorola radio, we need below items.
- Good Programming cable (Don’t buy overpriced cable from online. Instead build one from cheaply available components. Refer DIY Programme cable for GM300 Series radios)
- Working computer with any windows operating system (Little old systems doing better)
- Programming software.
Programming cable
The programming cable is used to program the Motorola GM300/GM338 radio. It is used to connect the radio to a computer so that the radio can be programmed using software. The cable is connected to the radio’s microphone jack and the computer’s serial port or USB port. There are different types of programming cables available, including those that require a RIB (Radio Interface Box) and those that do not require a RIB. You can build a programmer for the GM300/GM338 radios that does not require a RIB by connecting the BUS+ and GND wires from the circuit to the appropriate pins on the microphone connector as shown in the programming cable schematic.
The cables and connectors required to program your Motorola GM300 radio will vary from computer to computer. If you have a newer model computer, chances are that you do not have a serial port. However, the above programme cable use USB-TTL converter module, so you need not worry about serial port.
Motorola programming software
Motorola RSS (Radio Service Software) is the official software for programming Motorola radios. It is available for free download from the Motorola website. Motorola Solutions Radio Service Software is a free, Windows-based software that can be used to program a wide range of Motorola two-way radios. It includes a graphical user interface that makes it easy to configure radio settings, such as channels, frequencies, and privacy codes.
Motorola Radio Doctor is a free programming software for Motorola Radius GM300, GP300, M10, and M120 radios. It is a third-party software that is not officially supported by Motorola.
Fig – Radius GM300 Radio doctor – editing code plug
Motorola RSS and GM338 Radio
Important Update