( JRC

NVT-56 NVT-57 NVT-58.



PIN 1 UP
PIN 2 EARTH.
PIN 3 DOWN.
PIN 4 + 9 VOLTS.
PIN 5 PTT GROUND.
PIN 6 PTT.
PIN 7 MIC GROUND.
PIN 8 MIC.
NVT-56 SCHEMATIC.pdf (courtesy AA2ZS )