Practice Section 1306
Issue 2, May 1992
1
Figure 1. 4TOLB-3L1 Channel Unit
with Loopback
Pulsecom
T
E
S
T
4TOLB-3L1
LB
®
D105177-1
REV A
ON
OFF
MAN
1. INTRODUCTION
This practice describes the Pulsecom
®
4TOLB-3L1 4-Wire, 600-Ohm Transmission Only
Channel Unit with Loopback, shown in Figure 1. Installation instructions and engineering
references are included.
Trademarks used in this manual:
CLEI is a trademark of Bellcore.
Pulsecom is a registered trademark of Hubbell Inc.
SLC is a registered trademark of AT&T.
The Recognized Component Mark is a registered trademark of Underwriters Laboratories Inc.
©1992 Pulse Communications Inc. All rights reserved.
CONTENTS PAGE
1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . 1
A. Reason for Reissue . . . . . . . . . . . . . . . . . . 2
B. Features . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . 3
3. INSTALLATION AND ALIGNMENT . . . . . . . . . 4
A. Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
B. Connections . . . . . . . . . . . . . . . . . . . . . . . . 7
C. Adjustments . . . . . . . . . . . . . . . . . . . . . . . . 7
4. CIRCUIT DESCRIPTION . . . . . . . . . . . . . . . . 11
A. VF Transmit Operation . . . . . . . . . . . . . . . 11
B. VF Receive Operation . . . . . . . . . . . . . . . 16
C. Loopback Circuit. . . . . . . . . . . . . . . . . . . . 16
5. SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . 17
6. MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . 17
7. CUSTOMER SERVICE. . . . . . . . . . . . . . . . . . 20
D4 CARRIER SYSTEM
4TOLB-3L1 4-WIRE, 600-OHM TRANSMISSION ONLY
CHANNEL UNIT WITH LOOPBACK
UL RECOGNIZED TELEPHONE EQUIPMENT
CLEI™ Code D4C0P885AA
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