AT&T Bell System Plant Series Adjustment Procedure

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BELL SYSTEM PRACTICES
Plant Series
SECTION 024-120-500
Issue 1, March, 1958
AT&TCo Standard
KS-16575-L 1 AMPLIFIER (MclNTOSH)
TESTS, ADJUSTMENTS
AND REQUIREMENTS
CONTENTS
1. GENERAL
2. TESTS AND ADJUSTMENTS ..................... .
Primary Power Voltage Measurement ..... .
Electron Tube Tests ............................ ....... .
Gain and Gain-Frequency Tests .... ........... .
Noise Test ............... ....... ........................ ... .
M·axlmum Output Test ............................... .
PAGE
1
1
1
2
2
3
4
3. TROUBLE LOCATING TESTS.. . .. ........ ........... 4
Operating· Voltage Measurements............ 5
~esistance Measurements ... .. ....... .......... .. 5
Distortion . . . . . . . . . . .. . . . .. . . . . . . . . . . . . . . .. . . .. . . . . .. . . . . . . . 6
Electrolytic Capacitor Testing and Re-
placement . . . .. . . . . . . . . . . ... . . . . . . . . . . . .. . . . . . . .. . . . . . . . 6
1. GENERAL
1.01
This section describes the tests, adjust-
ments and requirements associated with
the KS-16575-Ll amplifier. It .includes routine
maintenance and trouble investigation tests.
1.02
Section 024-120-300 lists the initial and
routine tests, as well as information on
the frequency of routine maintenance tests, on
_ the KS-16575-Ll amplifier .
1.03
A description of the component parts of
the amplifier is included in Section
024-120-100.
1.04
Test Equipment: The tests throughout
this section require the use of the follow-
ing test equipment:
1- KS-14510 Volt-Ohm-Milliammeter or
Weston 779A Analyzer
1 - KS-15560 or KS-15750 Tube Tester
1- 21A or equivalent Transmission Measur-
ing Set
1 - Pad as described in Paragraph 2.16
1 - Oscilloscope, Dumont 304 or equivalent
2 - W3AE Shielded Cord or equivalent
equipped with a 241A plug
1 - 600-ohm Resistor, 106A or equivalent
1.05
Tests should be made in the order listed.
2. TESTS AND ADJUSTMENTS
·Primary Power Voltage Measurement
2.01
The purpose of this test is to determine
which terminals on the terminal strip in
the amplifier are to be connected to the ac sup-
ply. It is important that the line voltage adjust-
ment be made correctly on this amplifier. If the
line voltage is consistently high (disregarding
momentary peaks or surges) the electron tube
life will be shortened. If the line voltage is con-
sistently lower than the nominal voltage for
which the amplifier is adjusted the power han-
dling capacity of the amplifier will be reduced.
This may cause distortion of program signals.
2.02
Apparatus:
KS-14510 Volt,-Ohm-Milliammeter or Weston
779A Analyzer
2.03
Procedure:
(1) Adjust the voltmeter for an ac voltage
reading of over 100 volts.
(2) Measure the supply voltage at the fuse
box or other convenient point between the
fuse box and the amplifier.
Required Strapping: The correct terminals
for the connection of primary power are as
follows:
SUPPLY VOLTAGE
110-120
120-130
TERMINALS
19-20
18-20
Copyright, 1958, by American Telephone and Telegraph Company
Printed in U. S. A.
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