Overall Block Diagram Description of Digital Data Combiner 1A12

TM 11-5820-695-35

cable clock output of 1A12A11. The retimed pcm and

processing. After the pcm signal, has been processed,

2304 kHz radio-to-cable clock output from 1A12A9 are

it is recombined with the orderwire signal (from

sent to radio digital processor 1A12A10. The retimed

orderwire assembly 1A13) and the cable direct current

pcm output from 1A12A9 is also applied to cable digital

and applied to the cable system The following

processor 1A12A4. Cable digital processor 1A12A4 is

discussion applies for the synchronous and

used to process the retimed pcm signal for the radio

asynchronous modes, except as follows 1. In the

repeater mode of operation (3) Radio digital processor

asynchronous mode the frequency of voltage controlled

1A12A10 reformats the retimed pcm signal for cable

oscillator 1A12A18 is 9830.4 kHz 2. The radio-to-cable

system compatibility. Radio digital processor 1A12A10

clock frequencies are 2457.6 (48-channel) and 4915.2

produces a half-baud pcm signal from the full baud

(96-channel)

retimed pcm and the 2304 kHz radio-to-cable clock

inputs from 1A12A9. The reformatted pcm is combined

(1) Radio traffic consisting of the pcm/orderwire

in 1A12A10 with the ow and direct current signals for

signal is applied to radio digital regenerator 1A12A8 and

application to the cable system. The cable loopback

to radio amplifier detector 1A12A7. In radio digital

pcm signal is applied to radio digital processor 1A12A10

regenerator 1A12A8, the pcm signal is separated from

from cable digital processor 1A12A4 for testing

the orderwire signal. The pcm signal which is distorted

purposes.

after radio transmission, is reshaped by generating

squarewave pulses under control of the input pcm

2-4.1.

Overall Block Diagram Description of Digital

signal. The reshaped pcm signal is applied to radio

Data Combiner 1A12. (fig. 2-1.2)

control comparator 1A12A9 and radio amplifier-detector

1A12A7. Radio control comparator 1A12A9 functions in

Interface. Radio Sets AN/GRC144-V)3 and (V)4

conjunction with 4608 kHz vco 1A12A11 to generate the

signal voltage which controls the output frequency of

transmit data and orderwire signals from a local DGM

1A12A11. Radio amplifier-detector 1A12A7 uses the

(data), a local DLED, a local OCU (orderwire) and return

reshaped pcm signal (from 1A12A8) in conjunction with

signals received by radio from the remote site to the

the pcm/orderwire signal from Receiver, R-

local DGM, DLED and OCU. Digital data combiner

1467(P)/GRC-144(V) to separate the radio orderwire

1A12 is the interface between the DGM/DLED/OCU and

signal from the pcm component. The orderwire signal is

the radio set. Its function in the transmit direction is to

then applied to orderwire assembly 1A13 where it is

convert balanced input signals to TTL levels for internal

distributed to the orderwire stations and back (thru ow

processing

(regeneration,

timing,

scrambling,

send) to af amplifier 1A12A6. The ow signal is then

multiplexing, level adjustment) and route the output

transformer coupled (1A12A12A2T2) and combined with

signals to the transmitter modulator circuits. In the

the direct current and applied to radio digital processor

receive direction, digital data combiner 1A12 retimes,

1A12A10. The ow and direct current signals are

regenerates, descrambles and demultiplexes the radio

combined with the pcm signal in 1A12A10 for

received signals. At the output it converts them to

application to the cable system.

balanced signals at specified levels for routing by cable

to the local DGM, DLED and OCU. The signals are data

(2) Radio

control-comparator

1A12A9

signals to and from the local DGM and either two digital

compares the phase of the 2304 kHz radio-to-cable

orderwire signals (DOW at 2 kb/s and DVOW at 16 kb/s)

clock signal with the phase of the incoming pcm signal

or one analog orderwire signal (AVOW) The data signal

and generates a dc control voltage which is proportional

rate (in both directions) is determined at the local and

to the phase difference between the two signals. The dc

remote DGM's (both must use the same rate). When

control signal is used to correct the frequency of the

this rate has been determined, digital data combiner

4608 kHz radio-to-cable clock output of voltage

1A12 is set for the selected rate by means of the front

controlled oscillator 1A12A11 to the frequency of the

panel DATA RATE SEL (MB) switch (1A12S4). The

pcm signal. The 2304 kHz radio-to-cable clock signal is

local OCU's determine whether the orderwire signal is to

developed within 1A12A9 from the 4608 kHz radio-to-

be digital or analog, both must be

Change 6 2-8.3