Radio Circuits Blog
This site provides schematics of various radio projects that you can experiment yourself.
Tuesday, 30 December 2025
NanoVNA Test Jig: A Practical Guide for Accurate RF Measurements
Saturday, 27 December 2025
Crystal Radio Explained – How to Build Your Own No Power Radio
DIY Programming cable for a Motorola GM 300 series two-way radio
Programming Motorola GM300 and GM338 with homemade cable
DIY Motorola Programming: Save Money & Build Your Own Cable! 🔌
Radio enthusiasts often struggle with the "Motorola tax"—expensive, hard-to-find programming cables for legacy gear. But if you have a GM300 or GM338, you don’t need to buy one!
VU3DXR has published a great walkthrough on creating a homemade programming cable. Whether you're setting up a repeater or just putting a local frequency into your mobile rig, this DIY solution is a lifesaver.
What’s inside: ✅ Pinout diagrams for GM300 & GM338. ✅ Circuit interface details. ✅ Tips for successful communication with the radio.
Read the full guide here:
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#MotorolaRadio #HamRadio #DIY #ProgrammingCable #GM338 #GM300 #RadioRepair #VU3DXR