Figure 3-1. Control Intercommunication Set C-1611()/AIC.

TM 11-5821-285-12-1

Table 3-2. Control, Radio Set C-70881ARC-131, Controls and Indicators (fig. 3-2).

Controls/indicators

Function

Mode control switch (four-position switch).

Applies power to respective FM radio and selects mode of operation.

OFF ............. Turns off power to FM radio.

T/R .............. Applies power to and places FM radio in normal com-

munication mode (reception). (To transmit,

associated U-94A/U headset push-to-talk switch

must be pressed with proper ICS box position

selected.)

RETRAN ..... Applies power to and places FM radio in

a two-way relay station mode, when properly con-

figured.

HOME. ........ Applies power to and places FM radio in

a homing facility mode, when properly configured.

VOL control

Adjusts audio output level of the FM radio.

SQUELCH switch (three-position rotary switch). Selects desired squelch mode as follows:

DIS disable). Squelch circuits are disabled.

CARR (carrier) Squelch circuits operate normally in

presence of any carrier.

TONE .......... Squelch opens (unsquelches) only on

selected signals (signals containing a 150 Hz tone

modulation).

Tens megahertz frequency selector.

Selects ten megahertz digit of operating frequency.

Units megahertz frequency selector.

Selects units megahertz digit of operating frequency.

Tenths megahertz frequency selector.

Selects tenths megahertz digit of operating frequency.

Hundredths megahertz frequency selector.

Selects hundredths megahertz digit of operating frequency.

Frequency indicators.

Displays operating frequency of FM radio in megahertz.

3-2