SYNCHRONIZATION

TM 11-6625-3056-12

2-3.

SYNCHRONIZATION

CORRELATOR

The TS-3981 must be synchronized to the input data for proper

LOOP

operation. The CORRELATOR LOOP control provides two modes

of operation:

OPEN

Synchronization is automatic and requires no operator attention.

Input data bits are continuously loaded into the receiver PR

Generator and compared to the generator output. Any difference

is an error.

The error count will be incorrect if more than one error occurs

every 15 bits.

CLOSED

Synchronization is manual and is achieved by momentarily

setting the CORRELATOR LOOP to OPEN and then to

CLOSED.

After 15 input data bits are loaded into the receiver PR

Generator, the CLOSED mode allows the generator to operate

independently. The input data bits are compared to the generator

output. Any difference is an error.

Loading the 15-stage PR Generator requires only 15 data bits.

Even at the lowest data rate of 600 bits per second, the loading

operation (CORRELATOR LOOP OPEN) requires less than 0.03

seconds.

The receiver generally requires resynchronization whenever the

PATTERN, DATA ON/OFF, or RATE SELECT controls are

changed. A nonsynchronized condition is indicated by a very

rapidly changing ERRORS display.

2-4.

PREPARATION FOR USE

Ground

On rear panel, press in cap on ground lug to expose internal slot.

Connection

Place heavy-gage ground wire not supplied) in slot and release pressure on cap.

Connect other end to suitable ground. In the shelter this ground can be an equipment

rack. Outside the shelter this ground can be a ground rod.

Power

Connect power cable to a 115-volt power source.

Connection

2-5