Purpose. and Use

TM 11-5831-201-20

1-5. Purpose. and Use

8 max.

Receivers

2 pounds

Weight . .

Set C-1611D/AIC

a. Control, Intercommunication

27.5.5vdc.

Input voltage

(control set) is used as part of a multistation inter-

5.6 watts.

Power requirements

communication and radio control system in Army

Power output

aircraft. The system may include maximum of six

60 mw.

Transmitter

control sets, eight radio receivers, and four radio

200 mw.

Headset

transmitters.

b. The control sets are used by aircraft crewmen

1-6.1. Item Comprising an Operable

Equipment

(1) Control intercommunication through the air-

Control, intercommunications Set C-1611D/AIC (NSN

craft's interphone system.

583 1-00-933-9822) comprises an operable equipment.

(2) Control voice radio communication (air-to-air

or air-to-ground) through a maximum of four radio

1-7. Description

transmitter-receiver combinations.

The C-1611D/AIC consists of a wraparound type metal

(3) Monitor the output of a maximum of three

housing with removable front and rear mounting plates

navigational type radio receivers.

(covers). Multiconnector pin receptacle J 1 and relay K1 are

(4) Route the output of an emergency radio re-

mounted on the rear cover. Connector J 1 mates with air-

ceiver directly to the earphones independent of the con-

craft cable assembly plug connector providing connections

trol set.

to and from the other associated equipment in the system.

c. A typical system using the control set is shown

The controls; RECEIVERS switches, VOL, Transmit-inter-

In figure 1-2. The actual number and types of radio

phone selector switch, and two panel lights are mounted

transmitters and receivers, and the numbers of con-

on the front mounting plate and extend through cutouts in

the front panel. All control markings are engraved on the

trol sets used in an aircraft are determined by the

translucent front panel which is edge-lighted by the two

type of aircraft in which they are installed. All con-

panel lights. The front panel is secured to the front mount-

trol sets are normally connected to the same radio

ing plate by four screws. A plastic switch guard is mounted

receivers. Usually, only two control sets (such as

over RECEIVERS switches. There are eight Dzus fasteners

chose used by the pilot and copilot) are connected to

on the front mounting plate which secure the control set

the radio transmitters. All control sets in the air-

to the airframe. The interior of the control set housing

craft are connected to the interphone line. The navi-

contains three printed circuit boards designated as follows:

gational-type equipment (marker beacon, low fre-

A2, Headset Amplifier

quency navigation, very high frequency (vhf), and

A3, Microphone Preamplifier

navigation receivers) are monitored as a group. The

A4, Microphone Amplifier

emergency receiver output is always connected to

Switch board Al, is mounted on the front mounting

the earphones and cannot be turned off at the control

plate. Printed circuit boards A2, A3, A4, are removed

set. A crewmember may select and use any one of

by sliding out toward the front, after removing front

four radio transmitters connected to a particular

panel and mounting plate, and U-shaped aluminum

control set.

bracket.

d. The private interphone line (fig. 1-2) is an option

that provides intercommunication between any two

1-8. Additional Equipment Required

stations in an aircraft that is specifically wired to use

this option. The private interphone line cannot be

Control Set, C-1611D/AIC requires a power source of

monitored by other stations connected in the inter-

27.5 vdc for normal operation. A typical aircraft in-

communication system.

stallation consists of the following

a. Radio Transmitters. A maximum of four radio

1-6. Technical Characteristics

transmitters may be used with the control set. Ra -

Input impedance:

dio transmitters, such as the transmitter portion of

R e c e i v e r . . . . . . .150 ohms.

Receiver-Transmitter, Radio RT-348/ARC-54 ( part Of

Microphone . . . . . . . . . . . . ..8 ohms.

Radio Set AN/ARC-54), may be used to transmit

Output impedance

voice signals to other aircraft or ground stations.

Transmitter . . . 150 ohms"

b. Radio Receivers. A maximum of eight radio

Headset . . . . . . . . . . . . . ..8 ohms.

receivers may be used with the control set. Four

Radio facilities

of the radio receivers, such as the receiver portion

Transmitters . . . . . . . 4 max

Change

1-2