Nexus TP-120 commercial U-174 telephone plug.

This video shows you how to wire the TP-120 and compares this telephone plug to the TP-101 and TP-102 military versions.

Similar to the TP-101, TP-102 military grade 4 conductor connectors by Nexus marked U-174/U and U-93A/U.

TP-120 Plug Wiring Diagram

Civilian Helicopter HeadsetsAviation Headset TP-120 Wiring Diagram
(Each terminal is marked 1-4 on the connector)

  1. Positive microphone channel
  2. Positive earphone channel (mono)
  3. Negative microphone channel
  4. Negative earphone channel (mono)