Uploaded April 2026 | Updated September 2026, 2 weeks ago
In this video, I explore a piece of Cold War history: the Romanian R-3931 HF Radio (1.5 - 30 MHz). This modular military rig features USB, LSB, AM, and CW modes with 100 Hz precision.
⚠️ Project Status:
• Missing Modules: Power Amplifier (20W) and Automatic Antenna Tuner (ATU).
• The Issue: When connected to 12V, there is a dead short. The power supply protection trips immediately.
🔍 The Challenge:
I lack the technical schematics for the internal boards like the P-11S (Synthesizer) or P-152P (Power Supply). I've spotted some BD140 transistors and DC-DC converters, but troubleshooting without a map is tough.
How would you locate a short in a modular military radio without diagrams?
If you have experience with the R-3111 or R-3931 series, please leave a comment!
Thank you for watching!!
☕ Support the channel buymeacoffee.com/radiodiogenes
Thank you! ❤️
#MilitaryRadio #R3931 #Restoration #Electronics #HF #HamRadio #Repair
In this video, I explore a piece of Cold War history: the Romanian R-3931 HF Radio (1.5 - 30 MHz). This modular military rig features USB, LSB, AM, and CW modes with 100 Hz precision.
⚠️ Project Status:
• Missing Modules: Power Amplifier (20W) and Automatic Antenna Tuner (ATU).
• The Issue: When connected to 12V, there is a dead short. The power supply protection trips immediately.
🔍 The Challenge:
I lack the technical schematics for the internal boards like the P-11S (Synthesizer) or P-152P (Power Supply). I've spotted some BD140 transistors and DC-DC converters, but troubleshooting without a map is tough.
How would you locate a short in a modular military radio without diagrams?
If you have experience with the R-3111 or R-3931 series, please leave a comment!
Thank you for watching!!
☕ Support the channel buymeacoffee.com/radiodiogenes
Thank you! ❤️
#MilitaryRadio #R3931 #Restoration #Electronics #HF #HamRadio #Repair
