Section II. TYPICAL VF CIRCUIT AND PATCH PANEL

TM 11-5895-878-14&P

Figure 2-15. Special Intelligence Bay IDF, Front View.

Section II. TYPICAL VF CIRCUIT AND PATCH PANEL

module A on panel 1. Jacks 1 and 2 of module A, panel

2-4. Typical VF Circuit Connections

1 are cabled to the send side of the line vf equipment.

(fig. FO-3)

c. Receive Circuit. The receive circuit is similar to

a. General. The circuit is one that is typical to the

the transmit circuit, except the signals travel in the

P&T at the Pentagon. The box in the top left hand

opposite direction. The REC FROM VF EQUIP line, at

corner of the diagram represents line connections to the

the top of the diagram, is cabled to pins 3 and 4 of

telephone company or multiplex equipment. The box in

module A on panel 1. The second row of six jacks (7

the lower left hand corner, represents the equipment

through 12) of module A, panel 4 are cabled to the No. 2

side of the circuit. The circuit is a two-way (transmit and

set of jacks (REC) of patch panel No. 1 in bay 1.7.

receive) four-wire communications circuit.

These jacks are normal through wired to provide a

b. Transmit Circuit. The transmit circuit begins

complete circuit from jacks 1 and 2 to jacks 3 and 4 of

with the cable pair from the equipment at the bottom of

module A, panel 4. The receive side of the equipment

the diagram. The RECEIVE FROM pair is connected to

(SEND TO) pair is cabled from jacks 3 and 4 of module

pins 1 and 2 of connector J-1 on the rear of IDF panel 8

A, panel 8 to the receive side of the equipment. To

of bay 1.1. These two pins are connected to jacks 1 and

connect this circuit two dual-plug cross-connect patch

2 on cross-connect module A of panel 8. The pair for

cords are used at the IDF. One from jacks 3 and 4 of

RECEIVE FROM wires are cross-mounted from panel 8

module A, panel 1 to jack 1 and 2, row 2 of module A,

to jacks 3 and 4 of module A on panel 4, with a dual

panel 4. The second cross-connect patch cord, is

plug cross-connect patch cord. The first six jacks of

connected from jacks 3 and 4, row 2, module A, panel 4

module A on panel 4 are wired to jack set No. 1

to jacks 3 and 4, row 1, module A, panel 8.

(TRANS) of patch panel No. 1 in bay 1.7 as shown in

the diagram. The equipment jacks are connected to

2-5. VF Patch Panel

jacks 3 and 4 of crossconnect module A in panel 4 of

a. General. The VF patch panels are Lexington-

bay 1.1. The line jacks of the same patch. panel are

Blue Grass Army Depot (LBAD) D-33674 Two-Wire

connected to jacks 1 and 2 of the same cross-connect

Audio Patch Panels (fig. 2-16). Each patch panel has

module. The EQUIP and LINE patch panel jacks are

24 sets of four jacks. One set of jacks is used to access

wired normal-through (para 2-5).

This provides a

a two-wire circuit. When a four-wire circuit (transmit and

complete circuit from jacks 3 and 4 of module A panel 4

receive) is built, two sets of jacks are used. The

to jacks 1 and 2 of the same module. To complete the

description in b below covers the use of the panel in a

circuit to the line equipment, a second cross-connect

four-wire circuit similar to that discussed in paragraph 2-

dual plug,, 1 and 2 of patch cord is connected from

jacks 1 and 2 of module A, panel 4 to jacks 1 and 2 of

2-16