Chapter 3. COMPONENT DESCRIPTION AND DATA

TM 115895-45-14

CHAPTER 3

COMPONENT DESCRIPTION AND DATA

3-1. Multiplexer TD-204/U

3-2. Multiplexer TD-7654/G

a. .Use.

a Use. The TD-754/G provides the capability for

Multiplexer TD-204/U (fig. 3-1) is a

12/24/48-channel pcm cable transmission interface unit.

transmission of pulse-code-modulation (pcm) pulses

Its transmit section accepts tdm pcm output signals from

through cable transmission systems. Pcm pulses from

a TD-660/U or TD 660A/G or- from another TD-204/U or

Multiplexer TD-660/G, or similar equipment, are applied

TD-7564/G, and processes these signals for cable

to the TD-754/G. In the TD-754/G, the pcm pulses are

transmission. The receive section accepts a pcm signal

encoded into another pcm format and transmitted at a

from the transmission cable, processes and retimes it.

2304-kHz rate through a cable link to another TD-754/G

In addition, the TD-204/U provides for up to 39 TD-

or TD-204/U. The TD-754/G, or TD- 204/U at the

206/G's in the transmission cable, and contains an order-

opposite end of the cable link decodes the pcm pulses

wire facility.

into their original pcm format and applies them to a TD-

b. Technical Characteristics.

660/G or similar equipment.

The TD-754/G also

provides cable current to power Restorers, Pulse Form

TD- 206/G installed in the cable link. Order wire facilities

Channel capacity .............. 12, 24, or 48

that operate over the cable link are also contained in the

Input voltage ..................... 109 to 121 volts, 47 to 63

TD-754/G to provide a phone link between terminals.

Hz.

b. System Information.

Power consumption .......... 62 watts maximum

(1) Two TD-754/G's can be operated on a

Pcm input or output signal:

cable link that extends to 40 miles. The pcm pulses

Impedance ................... 91 ohms

from a TD-754/G are transmitted through Cable

Amplitude

Pulses go positive to ap-

Assembly, Special Purpose, Electrical CX-

proximately 0 volt from a

11230/G or CX-4245/G that connects between

baseline of approximately

each TD-206/G spaced between each mile of

-2 volts.

cable.

Pulse type......................... Binary (full width)

c. Technical Characteristics.

Pulse rate and interval:

12-channel operation... 576 kHz; 1.736 psec

24-channel operation... 1,152 kHz; 868 nsec

Number of audio channels .... 6 or 12

48-channel operation... 2,304 kHz; 434 nsec

Compatible radio set ............. AN/GRC-103

Timing input or output signal:

Compatible cable .................. CX-11230/G or CX24/G.

Impedance ................... 91 ohms

Order wire:

Amplitude..................... Positive going pulses, 2

Facility ............................ Baseband channel in-

volts amplitude.

dependent of pcm traffic.

Pulse type .................... Sharp spike

Frequency response ....... 300 to 1,700 Hz

Pulse width .................. 150 nsec

Signaling frequency ........ 1,600 Hz

Repetition rate ........ .... 576 kHz

Transmit level

9 volts rms min at 880

Repetition rate:

ohms

12-or24-channel operation 576 kHz

(at cable transmit am-

48-channel operation... 2,304 kHz

plifier output).

Pulse width .................. 150 nsec (max.)

Receive level .................. Adjustable 150 mV rms to

Cable input or output signal:

16 volts rms across 880

Impedance ................... 62 ohms

ohms (at cable receive

Amplitude:

amplifier input).

To-cable signal .... Leading edge of pulses

swing 2 volts from zero to

peak.

From-cable signal 30 mV pp nominal

Pulse type .................... Binary dipulse

Bit rate ......................... 2,304 kHz

Pulse width ........ ......... 180 to 230 nsec

Compatible cable .......... CX-4245/G or CX-11230/G

3-1