Section IV. WIDEBAND CIRCUITS AND PATCH PANEL

TM 11-5895-878-14&P

Section IV. WIDEBAND CIRCUITS AND PATCH PANEL

2-12. Wideband Circuits, General

(3) The KG-24 is used to connect the

encrypted signals to clear text.

a. There are three locations where wideband

circuits may be accessed in the P&T. The black side of

circuits are accessed at five patch panels in bay 1.8 (fig.

2-14. Wideband Patch Panel

1-3). Special intelligence circuits are accessed at three

a. Description (fig. 2-37). The wideband patch

patch panels in -bay 2.1 (fig. 1-8).

panel contains 20 sets of 3 associated 75-ohm Twinax

b. Wideband circuits may contain video signals or

jacks. Each jack set is used for one circuit (send or

vf group signals. A typical wideband circuit is discussed

receive). The send circuit jack set is usually on the left

in paragraph 2-13. The wideband patch panel is

of the receiver circuit jack set. The top row of jacks are

discussed in paragraph 2-14.

LINE jacks. The second row of jacks are EQUIP jacks.

The bottom row of jacks are MON jacks.

identification card holder strip is mounted across the

2-13. Typical Wideband Circuit (fig. FO-8)

bottom of the jack sets.

a. General. The cable connecting equipment to

b. Circuit Function (fig. 2-38). The equipment

the patch panels is 75-ohm Triax type cable. The patch

cable is connected to the EQUIP jack. When there is no

panels are 75-ohm Twinax type. Therefore, Triax-to-

plug in the EQUIP jack, closed contacts in the EQUIP

Twinax adapters are used to connect the Triax cables to

jack connect that jack in series with the LINE jack. The

the patch panels.

LINE jack is similar to the EQUIP jack and completes a

b. Send Circuit.

The send signals from the

through circuit to the line cable connector. When a plug

Pentagon user are in clear text, and connected to the

is inserted into the EQUIP jack the normal through

LINE jack of a jack set in red patch bay 2.18. The jack

circuit to the line connector is broken. The equipment

set is wired normal through the LINE and EQUIP jacks

cable is connected to the plug in the EQUIP jack and the

of the jack set. The signals out of the jack set are from

line cable is terminated across a 75-ohm resistor (the

the EQUIP jack and connected to the input of a KG-24

impedance of the cable). When a plug is inserted into

crypto equipment. The *output signals from the KG-24

the LINE jack, the normal through is also broken. The

are encrypted and connected to the EQUIP jack of a

line cable is connected to the plug in the LINE jack. The

jack set in black patch bay 1.8. The jack set is normal

equipment cable is terminated across the 75-ohm

through wired. The output from the LINE jack is

resistor. A MON jack. is parallel connected across the

connected to the commercial radio send input.

line cable connection, through two 560ohm isolation

c. Receive Circuit. The receive circuit is similar to

resistors and a 75-ohm termination resistor. The

the send circuit except for the following:

isolation. resistors provide a monitoring signal that is 30

(1) Signals are received from the commercial

dB below the line signal.

radio in a secure crypto form.

(2) Receive jack sets are used in both the

black and red patch bays.

Figure 2-37. Wide Band Patch Panel, Front View.

2-47