Limitations of SC Communications

TM 11-5820-890-10-8

4.2b.

Limitations of SC Communications

LOCATING

When using the SC mode of communication, it is important to

remember that an enemy with direction finding capability can

pin-point your location. It may be necessary for you to move

frequently, or limit transmission times, to avoid enemy action.

JAMMING

In that the SC mode uses only one frequency at a time to send or

receive messages, the enemy may be able to jam your

communications fairly easily.

4.2c.

Required Usage

COLD START

To employ the Cold Start net opening procedure, it is necessary to use

the MAN channel for sending and receiving the electronic remote fill

(ERF) which contains FH data and sync time for frequency hopping

operations.

When an operator needs to enter an FH net and does not have the

CUE PROCESS

required FH data, or a radio with FH capability, it is necessary to "cue"

(press PTT) on CUE channel or frequency with COMSEC set to PT.

(For detailed procedure, see Figure 4-3, below.)

Calling operator sets CHAN to CUE; MODE to SC;

(1)

COMSEC to PT;

RF PWR to HI; presses PTT

Calling operator changes from PT to CT

(2)

immediately after pressing PTT

This procedure is repeated about every 15

(3)

seconds until answer is received.

Receiving NCS sees "CUE" in RT display.

(4)

NCS changes to CUE, responds in CT

(5)

NCS directs caller to change to MAN.

(6)

On MAN chan, in CT mode, NCS determines what

(7)

calling operator needs.

Figure 4-3. HOW TO "CUE" AN NCS

4-5