Cable, CompactFlash and Accessory Specifications

Balun for E1 or PRI NIM Cards

Some overseas electrical systems require that you use a balun and grounding shunt when utilizing an E1 or PRI NIM card on the XSR. A balun is an adapter employed to connect a 75-ohm coaxial cable pair (2 BNC connectors) to a 120-ohm twisted pair cable (RJ-48C connector).

The balun and its connectors are shown in Figure A-14. The grounding shunt is also required to insulate (ground) unused pins of the RJ-48C connector.

To install the balun, attach the 75-ohm coaxial cables to the BNC connectors and a 120-ohm E1/ PRI cable to the RJ-48C port (see below for details).

J2 Receive BNC male connector

75-ohm connection to your network

Figure A-14 Balun for E1 or PRI Connection

 

 

 

 

 

 

 

 

 

 

J12 Transmit BNC

 

 

 

male connector

 

 

 

 

 

 

75-ohm connection

 

 

 

 

 

 

to your network

 

 

 

 

 

 

 

 

RX

 

 

 

 

 

 

TX

In

NIM

 

 

 

 

 

-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E1

 

 

 

 

 

 

 

 

 

 

 

-

 

G

Out

 

 

 

 

CO

 

 

 

 

 

 

 

.

 

 

 

 

 

 

 

 

 

 

Model

 

 

 

AX

703

 

 

 

 

BLN

 

B

 

 

 

 

 

 

-

460

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

alun

 

 

 

 

 

 

 

 

 

 

 

MC

 

 

 

 

 

120-ohm

 

 

 

 

 

 

 

 

 

 

 

connection to XSR

XSR Getting Started Guide A-13

Page 99
Image 99
Enterasys Networks XSR-3150 manual Balun for E1 or PRI NIM Cards, Figure A-14 Balun for E1 or PRI Connection