Ribamodel Team

Portuguese Radio Control Airplanes, RPV/FPV/UAV


Adding a BNC plug to a JR-X3810 Radio

Due to my project of hacking a CB antenna, I needed to have an easy connection to my radio so that it would be more easy to change between the stock and external antenna. This is how I did it.

1 => The radio

The one I used for this project was a a JR-X3810 35Mhz radio.
JR X-3810

2 => Adding the BNC female plug

- Carefully open the radio, and look for the connection of the stock antenna radio.

2.2 - With a 50ohm coax cable, make a small extension to a BNC female plug to make it possible an external connection as shown below.
Coax extension cable

 2.3 - Close your radio again and you are ready to go. The picture below shows the final result.
Final result

3 => FAQ about this project

[Q]: Does this works only for this radio?
No, it works in any other radio available in the market. You just need to follow the same basic rules as described before on this page.

[Q]: Does any type of cable works to make the small extension inside the radio?
No, you will need to use a 50ohm coaxial cable for this project.

[Q]: What do I do when I want to use the external antenna or the stock one?
The method is easy. When you need to use the external antenna, you unplug the stock antenna to use the external one. When you need to use the stock antenna, you unplug the external antenna and connect the stock one.

[Q]: Can I use both stock and external antennas at the same time, will it give me more range?
[A]: No, doing so will result in a HUGE range loss. You cannot use both antennas at the same time in ANY circumstances.

[Q]: Can I use another type of plugs, like SMA or RCA?
[A]: Yes, you can you any type of plugs that best suit to your project.

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