random. When the intercom is used without FM radio, power is applied to jack J508. When used with
FM radio, power is applied to jack J501. The binding posts on the control panel of the AM-1780,
labeled AUDIO INPUT, are for use with an additional FM receiver. The binding posts labeled
TEL/REMOTE are used to connect a field telephone, a switchboard, or another intercom system to the
Figure 2. AM-1780/VRC jacks, control, and indicator.
g. See Figure 3. The C-2298/VRC is a control device (box) located at each crew member
position. The C-2298 amplifies the voice signals from the microphone and controls the volume to the
audio accessory earphone(s). The two jacks J802 and J803, located on the bottom of the C-2298,
provide a connection for the audio accessory. The two jacks J801 and J804, located on the left and right
sides of the C-2298, provide a connecting point for the interconnecting cable CX-4723 from the AM-
1780 and for connecting an additional C-2298 in tandem. A volume control is located between jacks
J802 and J803. The MONITOR switch is located on the face (front) of the C-2298.