AT&T Bell System Plant Series Alignment Instructions

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BELL SYSTEM PRACTICES
Plant Series
SECTION 107-302-500
Issue 1, September, 1964
AT&TCo Standard
906A DATA DISTORTION TEST EQUIPMENT
TEST, INSPECTION, AND ALIGNMENT
CONTENTS
1. GENERAL
2. PURPOSE
3. APPARATUS . . . • .
4. OVER-ALL OR SECTIONALIZING TESTS
DISTORTION CALIBRATOR CIRCUIT
Fl /F2 MODULATOR . .
SIGNAL GENERATOR AND DISTORTION
MEASURING CIRCUIT . •
F1/F2 DEMODULATOR .
CHANNEL SELECTOR . .
BRIDGING AMPLIFIER AND CHANNEL
SELECTING CIRCUITRY .
CHANNEL DEMODULATOR
PAGE
. . • 2
... 2
• .. 2
2
. 2
. 3
. 3
• 3
• 3
• 3
• 13
CIRCUIT FOR MEASUREMENT OF DISTORTION
ON 4-WIRE WIDE-BAND CIRCUIT • 14
SUPERVISORY-DEMODULATOR-
DEMULTIPLEXER .
A. Supervisory Input Signal .
. 15
. . . 15
B. Supervisory Lamp States-Bias Adjustment 15
C. Distortion Check • . • . • • • . • 16
5.TROUBLE LOCATION TESTS .
F1/F2 MODULATOR
DEMODULATOR •
16
. 16
• 17
CONTENTS
PAGE
CHANNEL SELECTOR . . . . .
A. Bridging Amplifier and Channel
. . . . • 18
Selecting Circuit
B. Gain Adjustment .
C. Cbannel Bandpass Filters . .
D. Channel Demodulator
E. Data Distortion (Narrow-Band)
F. Carrier Supply . .
SUPERVISORY-DEMODU LATOR-DEMU L TIP LEXER
A. Demodulator
18
18
. 20
• 20
• 21
• 21
21
. 22
B. Demultiplexer Clock and Steering Memory 22
C. Demultiplexer Sync Recovery .
. 23
D. E Lead Desampling, Steering, and Memory 25
E. Test of Sync Loss Indicator •
SIGNAL GENERATOR .
. 26
. 26
A. Circuit Package 1-Oscillator Output Amplitude 26
B. Circuit Package 2-Oscillator Countdown Output 26
C. Circuit Package 2-Clock Frequencies 26
D. Circuit Package 3-6-Stage Binary
Counter Outputs . . • 27
E. Circuit Package 4-Output Circuits . . 27
F. Circuit Package 5-Stop-Start Signals . . • 28
G. Circuit Packages 6 and 7-Quasi-Random
Bit Sequence .
DISTORTION MEASURING CIRCUIT
• 28
29
A. Measuring Frequency with the EPUT Meter 29
B.
Description of Tests . . • •
30
©
American Telephone and Telegraph Company, 1964
Printed in U.S.A.
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