- J61 - Provides connection, in parallel, to the driver’ s C-2297/VRC through vehicle wiring.
- J62 - Provides connection to the external signal lamp, attached to the waterproof box.
- RAD TRANS-INT - Functions only if C-2297/VRC has EXT selected. In the INT position the operator will monitor the audio selected by the driver’s C-2297/VRC, and may key the intercom. In the spring loaded RAD TRANS position, the operator may key the radio (selected by the driver).
- VOLUME - Adjusts the loudness of the audio signal heard at the H-207/VRC.
- Key switch - The key switch on the H-207/VRC is used to key the radio or intercom set. It is also used to flash the light on the driver’s C-2297/VRC, if he has selected OFF on the SIG-E XT-OFF switch, by pressing and releasing the switch.