Four-Wire VF User with Integral Signalling

TM 11-5895-1012-10

echoes arising from four-wire to two-wire conversions.

2-8 ). The users of this circuit can be either a four-

The circuit makes an appearance at the Primary Patch

wire switchboard or individual user which uses loop

Bay by way of outside plant cables. Between the Pri-

signalling. The circuit flow is the same as in h above

mary and Equal Level Bays, conditioning is provided

except that an E&M/DC loop converter is used instead

by pads, amplifiers, and two-wire/four-wire terminat-

of an E&M/20 Hertz converter.

ing sets. Signalling conversion is provided by E&M/20

j. Four-Wire Data User Cable to TCF Without Sig-

Hertz converters and 2600 Hertz signalling unit. This

nalling (fig. 2-8

This circuit is for high speed

configuration can apply to "hotline" or dedicated cir-

data users, AUTODIN interswitch trunks, and data

cuits, orderwires, and switchboard trunk circuits.

lines for secure voice circuits. In addition to level ad-

d. Two-Wire Voice User With Loop Signalling (fig.

justment, amplitude or delay equalization units may

2-8

). The users for this circuit a either two-wire

be required in the strings of conditioning equipment.

switchboards or two-wire individual users which use

k. Two-Wire or Four-Wire Voice User Using Non-

loop signalling. The circuit is the same as that in c

Standard Inband Signalling (fig. 2-8

). After enter-

above with the exception of using E&M/dial loop sig-

ing the TCF by way of the Primary Patch Bay, the

nalling converters instead of E&M/20 Hertz convert

non-standard inband signalling is converted to stand-

ers.

ard inband signalling before it appears at the Equal

e. Two-Wire Voice User with E&M Signalling (fig.

Level Bay. This is accomplished by using a signalling

2-8 ). The user for this circuit is either a two-wire

unit compatible to the non-standard inband signal be-

mitchboard or individual user with E&M signalling. It

ing received, converting it to E&M signalling, and ap-

is noted in this circuit that a separate cable is used

plying the E&M pulses to the SF 2600 unit through a

in the on-base cable to carry the E&M (dc) lea& from

pulse link repeater.

the user location through the Primary Patch Bay to

l. Four- Wire PBX or User with DX Signalling (fig.

2-8 ). The users for this circuit are either au

the SF 2600 unit. Conditioning items are two

wire/four-wire terminating set, repeat coil, echo sup

AUTOVON PBX access line or an AUTOVON four-

pressor, and pads and amplifiers for level adjustment.

wire user. DX-1 signal units and repeat coils are used

These configurations have applications as user to cen-

at the user locations either to conserve cable pairs or

tral officer inter-connections and user-to-user link.

where loop resistance exceeds 50 ohms. If the AUTO-

f. Two-wire Voice User with Standard Integral Sig-

VON switch is off base, the circuit proceeds to the

nalling (fig. 2-8

). The user of this circuit is a two=

Equal Level Bay with the necessary conditioning and

wire w who has 2600 Hertz inband signal incorpo-

telephone signal conversion units located between the

Primary and Equal Level Patch Bay appearances. If

rated into the terminal telephone equipment. A two

wire/four-wire terminating set performs the necessary

the AUTOVON switch is collocated on-base, the cir-

cuits do not access the Equal Level Patch Bay, but

hybrid functions, and pads and amplifiers are installed

after passing the Primary Patch Bay, the circuits are

for level adjustment. This circuit is for special applica-

tion to users with this requirement and may have an

conditioned for proper levels and E&M signalling, and

make another appearance at the Primary Patch Bay

echo suppressor added if so specified.

and connect to the AUTOVON switch.

g. Four-Wire VF User with Integral Signalling (fig.

m. Four- Wire PBX or User with E&M Signalling

2-8 ). This user provides his own 2600 Hertz in-

to AUTOVON (PBX Cable to TCF) (fig. 2-8

). This

band signalling at the user station or the circuit may

user circuit is similar to the circuit described in l above

be a data circuit. In any cam, no signalling conversion

except there is no requirement for DX-1 signal units

is required at the Technical Control Facility. Between

at the user or the TCF. This is because the user and

the Primary and Equal Level Bay appearances, repeat

TCF are closely located and plant cable pairs with less

coils, pads, and amplifiers are supplied for conditioning

than 50 ohms loop resistance can be used.

and level adjustment Amplitude equalizers may be re-

n. Four-Wire Data User With DX Signalling (fig.

quired depending on the service.

2-8 ). This circuit is similar to makeup to that dis-

h. Four-Wire VF User with 20 Hertz Signalling (fig.

cussed in l above, with necessary amplitude or delay

2-8 ). The users for this circuit are either a four-

equalization devices. The circuit is of high speed data

wire switchboard or an individual four-wire user which

quality but can be called up by way of the AUTOVON

uses 20 Hertz signalling. A four-wire physical circuit is

switch when required.

used for the on-base cabling. Conditioning between the

o. Two-Wire PBX Cable Access Line to Local

Primary and Equal Level Bays consists of pads and

AUTOVON Switch (Two to Four-Wire Conversion at

amplifiers for level adjustment. E&M/20 Hertz con-

the PBX) (fig. 2-8 ). This circuit involves connec-

verters and SF 2600 units are required for telephone

tion of a two-wire on-base telephone switchboard to an

signalling conversions. This configuration can be ap-

AUTOVON switch which is also located on the same

plied to dedicated lines, and orderwire circuits.

base. This PBX (access circuit appears only on the Pri-

i. Four-Wire VF User with Loop Signalling (fig.

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