I've now got it back out to have another bash at it and in my google searches there is some software called Radius GM300 Radio Doctor which runs under Windows, I haven't found the software tho just references to its existence and I was wondering if this software had the expanded channel options? May 05, 2019 Most Viewed Pages. Watching Movies With The Sound Off Download Audiocastle; Practical Guidelines On Fluid Therapy Pdf; Download Lagu Klasik Untuk Kecerdasan Bayi Mp3.

View and Download Motorola GM300 service manual online. 146-174 MHz 449-470 MHz. GM300 radio pdf manual download. The Motorola MaxTrac, Radius, GM300. Covers the GMC and GMR models of the GM300 radio. Service manual is avaialble for download from the Zetron page at. This is a short tutorial on how to program the Motorola Radius GM300 radio with the. Download Motorola Radius GM-300 Radio Programming Software Ham radio, amateur radio, two way radio, cb radio, walkie talkie service manuals and reapir information.

#240869 (In Topic #220854)

Hi there I've dug out my old Motorola GM300 its programmed with 8 channels with the 8 70cms simplex frequencies which I did some years back on an old computer running MS-DOS 6.22
If I can remember rightly a file in the GM300 programming software can be modified so that the radio can then be programmed with 40 channels instead of just 8 channels, however I could not find out how to do it as I'm no good when it comes to things like using Hex Editor so I gave up and packed the radio away.
I've now got it back out to have another bash at it and in my google searches there is some software called Radius GM300 Radio Doctor which runs under Windows, I haven't found the software tho just references to its existence and I was wondering if this software had the expanded channel options?
It be nice to have 40 channels on this radio because then I can have all my local 70cms repeater channels on it as well as the 8 simplex channels.
Any help would be appreciated.
Thanks.

I remember converting a 2 Channel to 16 channel and a 8 channel to 16 not sure if I remember it being 40 channels . let me double check … I've had many of these radio's back in the 90's but remembering converting the 2 to 8 and 8 to 16 only ….

GM300/M120

General Information

The GM300 and the M120 are the same series of radio. The M120 is just the limited version, not unlike the Maxtrac 50 compared with the Maxtrac 300.

Look here for the pinout of the accessory connector for the 8 channel radio (which use a masked logic board) or 16 channel radio (which use an expanded logic board).

If you want an easy way to connect to the Accessory Connector on these radios, you can order the HLN9242A or HLN9457A Accessory Connector kits. These include an accessory connector housing, some pins, and some wires with pins already attached. One thing to note, the HLN9242A kit also includes a pin extractor for removing previously installed pins.

Motorola Radius Gm300 Radio Doctor Download Free

Here is the pinout of the microphone connector.

Are you having problems getting your radio to power up? Well, check here for some information that might help.

This radio can decode and display up to 126 PTT IDs. But how, you ask, since it only has a 2 digit display? It encodes (in HEX) the first two numbers of the PTT ID. See below:

Good luck in adding scan to a GM300 8 Channel radio, tried it by editing the .mdf file, and the RSS just crashes when you try to load a codeplug. You may find that the radio already has user-selectable scan, enabled off the front panel. Try it and see if it works.

If you happen to mess up the codeplug in your radio, and for some reason consider it necessary to make it into a Maxtrac.. you can follow this procedure to do the conversion.

If you want to build a nice little programmer for the GM300/M120 radios, one that does not require a RIB, check out this link. Just connect the BUS+ and GND wires from the circuit to the appropriate pins on the microphone connector as shown in the programming cable schematic. You can also check the RIB page for some additional circuits.

Linking Radios for Repeater/Crossband Operation

If you need a repeater interface cable to connect a couple of GM300, M120, or M10 radios together, look here.

Need to connect a couple of GM300 radios together? Here is a schematic of the R.I.C.K. (Repeater Interface Controller Kit) to get you started. Order the service manual part number 6880901Z79 from Motorola. Note: If you try and print this schematic with your brower, it probably won't work. So, save the image and print it using a graphics program.

9600 Baud Packet Modifications

The GM300 Series are 9600 baud packet capable. They do need a minor modification though. For RX, its no big deal, just take RX audio from PIN 11 of the Accessory Connector and swing JU551 to the (A) position (Flat RX Unmuted).

For TX audio, you will have to run a jumper to the junction of R223, C228, R222 on the RF board to inject the data (if applicable you may need to set the deviation pot in the radio to maximum). You might want to put a pot on your TX line somewhat like the setup Motorola uses (voltage divider) to adjust the deviation.

It would be wise to do some measurements to make sure you have the deviation correct. You might also want run the RX and TX pins to the unused pins on the front mic connector after the mods are done.

Out of band programming

To program frequencies outside of the rated bandsplit in the GM300 can be very simple, follow the listed steps:

Hold the shift key down while entering the frequency you want
You MUST release the shift key when you enter the decimal point
You MUST fill the entire field -use zeros (while holding down shift)
When you are done, hit enter like normal, and the frequency you entered will appear in regular decimal like any other frequency.

If you are in need of the programming cable, look here.

Out of band by modifying the .MDF file

There is another method of programming the radio out of band, it is a little more complicated than the method described above, but it will work just fine.

In the GM300.MDF file make a Checksum-16 of the whole file (the F12 option in Hex Workshop), in our case we ended up with 0x5D53 (RSS V 05.00), write this down, you might need it later.

Motorola Radius Gp300 Programming

Look starting at about offset 0x2AC, you should see something like: Camtasia studio 6 download free.

The highlighted area contains all the possible bandsplits that a GM300 could be.

A single bandsplit entry looks like:

The bytes to take note of are:

05 00 = Bandsplit identifier (Note: the bandsplit identifier is at the end of the frequency list)

94 11 = 4500 in decimal, ie 450.0000 MHz

5C 12 = 4700 in decimal, ie 470.0000 MHz

Note there are 3 occurances of the strings 94 11 and 5C 12, the first set is the limits displayed in the Radio Wide menu (F4-F2). The second set are the TX limits for the radio. The third set are the RX limits for the radio (note that if the TX and RX limits are not set the same the RX limits are screwed up).

To figure out what hex to enter for your bandsplits you can either use the Base Convertor (in Hex Workshop), or use a calculator with a HEX --> DECIMAL conversion function.

If you are using a calculator enter your limit (ie 4400 for 440.000 MHz) and convert it to hex, you should get 0x1130. When you enter the data into the .mdf file you have to reverse the bits such that you would actually enter 0x3011 in the field you are changing.

If you are using Hex Workshop, launch the Base Converter utility and select 'Intel Byte Order'. Then, enter your desired frequency and write down the hex result.

You can then directly enter the hex result (0x3011) into the bandsplit field.

In this example we are changing the lower bandsplit of a 450-470MHz radio to 440-470MHz.

Save the new file (you might want to make a backup copy of the original if you haven't already.

Some of the RSS packages (we don't have codeplugs for everything, so we can't check them all) check the checksum of the .mdf file when you try and load a codeplug and return an err