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Brazilian Jiu-Jitsu Power Rangers (Ages 4 and up)

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Motorola Gm300 Programming NEW!

The first thing you need to do is get your hardware setup. Plug in your USB Serial Port Adapter to your computer. Attach the Motorola RIB to the USB Serial Port Adapter. Finally, attach the programming cable to the RIB and your transceiver.

Motorola Gm300 Programming

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The cable is probably the problem. I did order a programming cablf withe the serial plug off of eBay but I think it was one of the cheaper ones. I clicked on the link for programming cables on your site and it sent me to one on Amazon that was sold out.

Ok here is my experience with programming a Gm300 with dosbox. According to the setup procedures in most blogs say to set you cycles to 191. For some this works for others this dose not work. However with that said what does work regardless of where the cycles are set (default is 3000 when set to auto), you need to set you serial port in windows manager to 1200 baud and that your reboot your computer after that. Also I would set you cputype in dosbox options to 386_slow.

Hi just wondering if you had a chance to try this same concept out with a Motorola HT1000 portable.Also is it ok to use the standard Motorola R.I.B. along with the Motorola R.I.B. to computer interface cable along with a Motorola programming cable?

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.

  • Out of band programmingTo 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 frequencyyou want

  • You MUST release the shift key when you enter thedecimal point

  • You MUST fill the entire field -use zeros (whileholding down shift)

  • When you are done, hit enter like normal, and the frequencyyou entered will appear in regular decimal like any other frequency.

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

It seems that some radio's are very particular when it comes to programming voltages from the RIB. Try using a brand new battery fresh out of the package or use an external voltage source for the RIB and see what happens.

The Motorola GM300 was a robust radio in its heyday, part of the Radius family of devices that was also compatible with MaxTrac accessories. It has long-since been discontinued but continues to be sought after and coveted by collectors and operating hams alike. Edouard Lafargue from is one such operator and wrote some interesting pointers on programming the GM300, via this clever FTDI to RJ45 circuit:

It probably goes without saying that the portable radios and the mobile radios in the Radius GM/GP series have different programming cables. The portable radio is programmed via the back of the radio. Whereas the mobile (vehicle) are programmed using a cable that plugs into the front of the radio*.

The portable radios in this series are programmed using a cable that connects to the back of the radio. Because the programming kit replaces the battery, you will also need a 9v supply. Unfortunately, the original cable is long since discontinued by Motorola. But there are some aftermarket replacement cables.

Last I saw, people were using the original Motorola programming software (Motorola Radio Service Software) in a throttled DOSBox. If I remember correctly, there's also a user-written Windows software ("GM300 RadioDoctor" or so) that can do the same, but it's from the Windows 9x era, so chances are going for the original DOS software in an emulated DOS environment works more reliable.


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