Tech Bulletin: M4-B Connector for Baofeng UV 9R & GT-3WP Connector 2 Way Radios

Ahh, the Baofeng Radio, perhaps the best and worst 2-way radio on the market. Its low cost feature rich package, high power ratings and (relative) ease of programming has made it perhaps the most ubiquitous hand held “ham” radio in the market today. It cannot be denied the Baofeng (or Btech) company has made some good products and tapped into a market in the US.

One knock on Baofeng has been quality. Some products got out into the market which were not reliable. Also there have been connector portissues that we have had to deal with in the past. The latest issue relates to the UV 9R and GT-3WP products. Btech wanted to create a more water-resistant product and one of the most susceptible areas for water intrusion is the accessory port.

Much like the “borrowed” Kenwood standard 2-pin connection on the stalwart UV-5R, these radios use a copy of the Motorola HT series radio for the waterproof multi-pin accessory connection. Btech appears to have gotten everything correct on this connector except the screw size. The Motorola uses an inch standard #4 screw, but Btech chose a metric M2.5x.45 thread pitch. Any screw will work here, and the screw length should be 8-10mm long depending on the connector.

The HT series connector, our M4, can be easily modified with the correct screw. At codeRED we are offering to modify this connector for use with the UV 9R and GT-3WP for any headset we currently offer with the M4 connection. We are differentiating this connector as the M4-B for Baofeng. If you need this connection, be sure to choose the correct one, or, just as easily, pick up an M2.5x.45x8mm thumb screw to modify the M4 yourself. You can also use one of our M4 to M adapters to convert the radio to use Motorola’s 2-pin connector. Be careful though, the M connector is different than the Kenwood K 2-Pin used on many Baofeng radios.

Find M4-B 2-Way Radio accessories on our website at
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