20 Mar 2026 2 min read earmor

Wiring a Cheap U-94 Clone PTT for Earmor/Military Headsets

Bought a cheap U-94 clone PTT, got an Earmor M32 Plus, plugged them together and nothing worked. Turns out there are two different NATO U-174/U wiring standards and three wire swaps is all it takes to fix it.

A long time ago I bought a cheap laryngophone with PTT to use in airsoft games. I thought the mic quality was ok after watching a few videos — in reality it wasn't.

Recently I bought an Earmor M32 Plus and tried to use the PTT with it but it didn't work. I was hearing the radio very quietly. So I thought I needed to order a new PTT to fix that. Before buying something new I gave it a try to see if I could fix it myself. Then I learned that there are 2 types of NATO U-174/U layouts — civilian and military. The main difference is the position of MIC+ and EARPH+.

Here's picture before rearranging the wires.

ORIGINAL (broken):

Baofeng Contact	Wire	NATO Pin
2.5mm SLEEVE	🟡 Yellow	Pin 4
2.5mm TIP	🔴 Red	Pin 3
3.5mm TIP	🟢 Green	GND (no number)
3.5mm SLEEVE	⚪ White → button → ⚫ Black	Pin 1

So we need to do this things to fix the issue

Move 🔴 Red from Pin 3 → Pin 1
Move 🟢 Green from GND (no number) → Pin 3
Move ⚪ White/⚫ Black (button) from Pin 1 → GND (no number)
Leave 🟡 Yellow on Pin 4 — don't touch it
Leave the Pin 4+5 bridge — don't touch it

Baofeng Contact	Wire	NATO Pin
2.5mm SLEEVE	🟡 Yellow	Pin 4
2.5mm TIP	🔴 Red	Pin 1
3.5mm TIP	🟢 Green	Pin 3
3.5mm SLEEVE	⚪ White → button → ⚫ Black	GND (no number)

Wiring after the fix *(yes, the soldering job is rough and the wires are barely hanging in there — it works though)*

Afterwards everything should work. The PTT is not amplified so don't expect top quality audio. This is a dirty hack for the cheap PTTs you have lying around at home.