Black Box Balun G.703 User manual

1000 Park Drive • Lawrence, PA 15055-1018 • 724-746-5500 • Fax [phone]
© Copyright 1998. Black Box Corporation. All rights reserved.

JUNE 1998
MT243A
MT243C-F
RM243A
G.703 Balun Module Panel Unit
G.703 Balun Module
G.703 Balun Chassis
CUSTOMER SUPPORT INFORMATION
Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday: 877-877-BBOX
FREE technical support, 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]
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1
CE NOTICE
CE Notice
The CE symbol indicates that the product is in
compliance with the Electromagnetic Compatibility
(EMC) directive and the Low Voltage Directive (LVD)
of the Union European (EU).
TRADEMARKS USED IN THIS MANUAL
Any trademarks mentioned in this manual are
acknowledged to be the property of the trademark
owners.

2
G.703 MODULES, MODULE PANEL, AND CHASSIS
1. Specifications
Data Rate — 2.048 Mbps
Transmission Line — CCITT G.703 (unstructured)
Connections — 75-ohm: Dual coax BNC connectors,
female (RG59 or 2002 coax); 120-ohm: Shielded RJ-45
jack
Link-to-Data Isolation — 500 volts AC/DC
Operating Temperature — 32 to 122°F (0 to 50°C)
Power Supply — None required
Size — Without handles, 3.5"H x 19"W x 1.9"D
(8.9 x 48.3 x 4.8 cm)

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CHAPTER 2: Description
2. Description
2.1 Introduction
The G.703 Balun Module Panels match multiple sets of
dual 75-ohm coax connections to multiple 120-ohm
twisted-pair connections. This allows carriers to provide
120-ohm G.703 service to customers retaining 75-ohm
CPE hardware. It also allows carriers who have
standardized on 75-ohm coax to provide 120-ohm
terminations to their customers (in keeping with
European ONP requirements).
Supporting E1 data rates to 2.048 Mbps, the G.703
Balun Module Panels bi-directionally match not only
signal impedance, but also the pulse shapes of the
signals according to the CCITT G.703 standard. The
panels mount in a standard 19-inch rack and are
available with 1 to 16 modules per rack.

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G.703 MODULES, MODULE PANEL, AND CHASSIS
2.2 Features
• Connects 75-ohm dual coax to 120-ohm twisted
pair.
• Bi-directional signal conversion according to
CCITT G.703.
• Data rates up to 2.048 Mbps.
• Low-profile design.
• Mounts in standard 19-inch rack.
• No AC power or batteries required.
• Strap-selectable modular (RJ-45) pinouts.

5
CHAPTER 3: Configuration
3. Configuration
Each G.703 Balun Module is equipped with four
jumpers that you may use to configure several
grounding options. This chapter shows the jumper
locations and describes their functions.
There are five configuration jumpers on the back of the
Module’s printed circuit board. These jumpers are
labeled JP1, JP2, JP3, JP4, and JP7. Figure 3-1 shows their
positions on the PC board as well as the relative pin
numbers on the jumpers.

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G.703 MODULES, MODULE PANEL, AND CHASSIS
Figure 3-1. Jumper Location.
Figure 3-2 shows the orientation of the rear interface-
card straps. Note that the strap can either be on posts 1
and 2, or on posts 2 and 3.
Figure 3-2. Possible Positions for the Jumpers.
1 2 3 1 2 3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
JP4
JP3
JP1
JP2
JP7

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CHAPTER 3: Configuration
The jumper straps allow you to set shielding and
grounding options. The settings for each jumper strap
are shown in the table below. Following the table are
more detailed explanations of each jumper.
Table 3-1. Strap Summary Table
Strap Function Position 1&2 Position 2&3
JP1 Coax TX Shield & RJ-45 Pin 3 Open* Connected
JP2 Coax TX Shield & RJ-45 Shield Connected* Open
JP3 Coax RX Shield & RJ-45 Shield Connected* Open
JP4 Coax RX Shield & RJ-45 Pin 6 Open* Connected
JP7 RJ-45 Shield & Chassis Ground Connected* Open
*Indicates default setting