Figure 7. CVC helmet (T56-6) and AVC helmet (DH-132).
See Figure 8. First, let's identify the jacks and their use on the AM-1780. Jack J501 (A)
provides power and audio and control interface signals from the A-RT (receiver-transmitter) when used
with radio. Jack J503 (B) provides audio signals and controls interface signals from the C-RT (receiver-
transmitter) when used with radio. Jacks J509 and J511 (C) provide connections