Theory of Operation
Section 4
4-13
Figure 4-9. Source Circuits Block Diagram.
4-67.
Detector selection is controlled by the data latched
in U1 by the control program. Dual one-of-four decoder
U8 decodes the latched data to analog switches U9 and
U11.
4-68. A6 Source Circuits.
The source oscillator is a
digitally tuned, automatically leveled state-variable os-
cillator. The source circuits generate a sinusoidal audio
waveform at a constant amplitude over a frequency range
of 10 Hz to 140 kHz. Refer to Figure 4-9.
4-69.
The source oscillator consists of a state-variable
oscillator and a automatic level control (ALC) loop. In
operation the oscillator is coarse tuned tot he selected
frequency and then the actual frequency is measured by
the counter circuits and fine adjustments are made by the
control program to achieve an accurate frequency.
4-70.
Coarse frequency tuning is achieved by adjusting
the time constant of the two integrators. The individual
integrators are identical, so only one will be described in
detail. The output from summing amplifier U12a is applied
to a series of eight resistors. The values of these
resistors, R49 through R56, are chosen in a binary
se-resistors are selected for frequency tuning within a
selected frequency band by FET switches Q18 through
Q25. Capacitors C18 through C22 are selected by FET
switches Q14 through Q17 for integrator tuning over five
frequency bands. Integrating amplifier U12b completes
the integrator (TP1). Coarse tuning of the oscillator is
provided by the selection of resistor and capacitor com-
binations by the control program. Data from the control
program is latched in data latches U15 and U16. The 12
comparators contained in U13, U14, and U17 and
associated pull-up resistors R61, R62, and R63 act as
level translators to convey the latched TTL data to gate
drive levels necessary to operate the FET switches.
4-71.
The oscillator output is generated at the output of
integrating amplifier U12b (TP1). A limiter circuit formed
by CR9 through CR14 and R38 through R40 prevent
overload transients in the output which may occur during
frequency transitions.
4-72.
The leveling and fine tuning of the oscillator is
controlled by adjusting the in-phase and quadrature
components of the source signal at the output of U12b.
The ALC circuits sample the positive peak of the sine
wave and compare the peak level to a voltage reference.
The difference is sampled by an error integrator and
applied to gain control circuits which work to reduce
leveling errors by adjusting the feedback of the in-phase
component.
Содержание 1121A
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Страница 12: ...VIII MODEL 1121A AUDIO ANALYZER ...
Страница 18: ...Section 1 General Information 1 6 This page intentionally blank ...
Страница 21: ...Installation Section 2 2 3 Figure 2 1 Packing and Unpacking Diagram ...
Страница 22: ...Section 2 Installation 2 4 This page intentionally blank ...
Страница 24: ...Section 3 Operation 3 2 Figure 3 1 Model 1121A Front View Figure 3 2 Model 1121A Rear View ...
Страница 25: ...Operation Section 3 3 3 ...
Страница 26: ...Section 3 Operation 3 4 ...
Страница 27: ...Operation Section 3 3 5 ...
Страница 30: ...Section 3 Operation 3 8 ...
Страница 37: ...Operation Section 3 3 15 TABLE 3 9 ERROR CODES ...
Страница 38: ...Section 3 Operation 3 16 TABLE 3 8 OPTION SWITCH A4S1 ...
Страница 39: ...Operation Section 3 3 17 TABLE 3 9 ERROR CODES ...
Страница 41: ...Operation Section 3 3 19 ...
Страница 42: ...Section 3 Operation 3 20 ...
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Страница 50: ...Section 4 Theory of Operation 4 4 Figure 4 3 CPU Circuits Block Diagram ...
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Страница 64: ...Section 5 Maintenance 5 2 ...
Страница 71: ...Maintenance Section 5 5 9 TABLE 5 3 ANALYZER DC LEVEL ACCURACY TEST RECORD ...
Страница 73: ...Maintenance Section 5 5 11 TABLE 5 4 ANALYZER AC LEVEL ACCURACY TEST RECORD ...
Страница 74: ...Section 5 Maintenance 5 12 TABLE 5 5 ANALYZER AC LEVEL FLATNESS TEST RECORD ...
Страница 76: ...Section 5 Maintenance 5 14 TABLE 5 9 SOURCE LOW LEVEL ACCURACY TEST RECORD ...
Страница 77: ...Maintenance Section 5 5 15 TABLE 5 12 FILTER ACCURACY TEST RECORD ...
Страница 78: ...Section 5 Maintenance 5 16 TABLE 5 14 RESIDUAL SIGNAL TO NOISE TEST RECORD ...
Страница 79: ...Maintenance Section 5 5 17 ...
Страница 80: ...Section 5 Maintenance 5 18 TABLE 5 17 CCIR FILTER ACCURACY TEST RECORD ...
Страница 81: ...Maintenance Section 5 5 19 TABLE 5 18 A WEIGHTING FILTER ACCURACY TEST RECORD ...
Страница 82: ...Section 5 Maintenance 5 20 ...
Страница 83: ...Maintenance Section 5 5 21 ...
Страница 84: ...Section 5 Maintenance 5 22 ...
Страница 90: ...Section 5 Maintenance 5 28 TABLE 5 23 DIAGNOSTIC ERROR CODE DESCRIPTION ...
Страница 92: ...Section 6 Parts List 6 2 Figure 6 1 Model 1121A Programmable Audio Analyzer ...
Страница 93: ...Parts List Section 6 6 3 ...
Страница 94: ...Section 6 Parts List 6 4 Figure 6 2 1121A Frame Assy Sheet 1 of 2 ...
Страница 95: ...Parts List Section 6 6 5 Figure 6 2 1121A Frame Assy Sheet 2 of 2 ...
Страница 97: ...Parts List Section 6 6 7 Figure 6 3 PWA 1121A Input A0 ...
Страница 100: ...Section 6 Parts List 6 10 Figure 6 4 PWA 1121A Main Filter A1 ...
Страница 102: ...Section 6 Parts List 6 12 Figure 6 5 PWA 1121A Notch A2 ...
Страница 105: ...Parts List Section 6 6 15 Figure 6 6 PWA 1121A Detector A3 ...
Страница 109: ...Parts List Section 6 6 19 Figure 6 7 PWA 1121A Freq Counter ...
Страница 111: ...Parts List Section 6 6 21 Figure 6 8 PWA 1121A CPU A5 ...
Страница 113: ...Parts List Section 6 6 23 Figure 6 9 PWA 1121A Source A6 ...
Страница 114: ...Section 6 Parts List 6 24 ...
Страница 115: ...Parts List Section 6 6 25 ...
Страница 116: ...Section 6 Parts List 6 26 Figure 6 10 PWA 1121A Output A7 ...
Страница 119: ...Parts List Section 6 6 29 Figure 6 11 Front Bezel Assy A17 ...
Страница 120: ...Section 6 Parts List 6 30 Figure 6 12 PWA 1121A Keyboard A13 ...
Страница 122: ...Section 6 Parts List 6 32 Figure 6 13 Bezel Sub Assy ...
Страница 123: ...Parts List Section 6 6 33 Figure 6 14 PWA 1121A Display A12 ...
Страница 126: ...Section 6 Parts List 6 36 Figure 6 15 Front Panel Assy ...
Страница 127: ...Parts List Section 6 6 37 Figure 6 16 Rear Panel Assy A21 Sheet 1 of 2 ...
Страница 128: ...Section 6 Parts List 6 38 Figure 6 16 Rear Panel Assy A21 Sheet 2 of 2 ...
Страница 129: ...Parts List Section 6 6 39 Figure 6 17 Heat Sink Assy A20 ...
Страница 131: ...Parts List Section 6 6 41 Figure 6 18 Power Amplifier A24 ...
Страница 132: ...Section 6 Parts List 6 42 Figure 6 19 Transformer Assy T1 ...
Страница 133: ...Parts List Section 6 6 43 Figure 6 20 1121A Card Cage Assy A18 ...
Страница 134: ...Section 6 Parts List 6 44 Figure 6 21 PWA 1121A Mother A10 ...
Страница 137: ...Parts List Section 6 6 47 Figure 6 22 PWA 400 Hz High Pass Filter ...
Страница 138: ...Section 6 Parts List 6 48 ...
Страница 139: ...Schematic Diagrams Section 7 7 1 SECTION VII SCHEMATIC DIAGRAMS TABLE 7 1 LIST OF SCHEMATICS ...
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Страница 141: ...Schematic Diagrams Section 7 7 3 Figure 7 1 Main Frame Schematic ...
Страница 142: ...Section 7 Schematic Diagrams 7 4 Figure 7 2 Input Board A0 Parts Location Diagram ...
Страница 143: ...Schematic Diagrams Section 7 7 5 Figure 7 3 Input Board A0 Schematic ...
Страница 144: ...Section 7 Schematic Diagrams 7 6 Figure 7 4 Filter Board A1 Parts Location Diagram ...
Страница 145: ...Schematic Diagrams Section 7 7 7 Figure 7 5 Filter Board A1 Schematic ...
Страница 146: ...Section 7 Schematic Diagrams 7 8 Figure 7 6 Notch Board A2 Parts Location Diagram ...
Страница 147: ...Schematic Diagrams Section 7 7 9 Figure 7 7 Notch Board A2 1Schematic ...
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Страница 149: ...Schematic Diagrams Section 7 7 11 Figure 7 8 Notch Board A2 2 Schematic ...
Страница 150: ...Section 7 Schematic Diagrams 7 12 Figure 7 9 Detector Board A3 Parts Location Diagram ...
Страница 151: ...Schematic Diagrams Section 7 7 13 Figure 7 10 Detector Board A3 1 Schematic Figure 7 11 Detector Board A3 2 Schematic ...
Страница 152: ...Section 7 Schematic Diagrams 7 14 Figure 7 12 Counter Board A4 Parts Location Diagram ...
Страница 153: ...Schematic Diagrams Section 7 7 15 Figure 7 13 Counter Board A4 Schematic ...
Страница 154: ...Section 7 Schematic Diagrams 7 16 Figure 7 14 C P U Board A5 Parts Location Diagram ...
Страница 155: ...Schematic Diagrams Section 7 7 17 Figure 7 15 C P U Board A5 Schematic ...
Страница 156: ...Section 7 Schematic Diagrams 7 18 Figure 7 16 Source Board A6 Parts Location Diagram ...
Страница 157: ...Schematic Diagrams Section 7 7 19 Figure 7 17 Source Board A6 1 Schematic ...
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Страница 159: ...Schematic Diagrams Section 7 7 21 Figure 7 18 Source Board A6 2 Schematic ...
Страница 160: ...Section 7 Schematic Diagrams 7 22 Figure 7 19 Output Board A7 Parts Location Diagram ...
Страница 161: ...Schematic Diagrams Section 7 7 23 Figure 7 20 Output Board A7 Schematic ...
Страница 162: ...Section 7 Schematic Diagrams 7 24 Figure 7 21 Mother Board A10 Parts Location Diagram ...
Страница 163: ...Schematic Diagrams Section 7 7 25 Figure 7 22 Mother Board A10 Schematic ...
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Страница 165: ...Schematic Diagrams Section 7 7 27 Figure 7 25 Power Supply A11 2 Schematic ...
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Страница 167: ...Schematic Diagrams Section 7 7 29 ...
Страница 168: ...Section 7 Schematic Diagrams 7 30 Figure 7 26 Display Board A12 Parts Location Diagram ...
Страница 169: ...Schematic Diagrams Section 7 7 31 Figure 7 27 Display Board A12 Schematic Sheet 1 ...
Страница 170: ...Section 7 Schematic Diagrams 7 32 Figure 7 28 Key Board A13 Parts Location Diagram ...
Страница 171: ...Schematic Diagrams Section 7 7 33 ...
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Страница 173: ...Schematic Diagrams Section 7 7 35 ...
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Страница 176: ...Section 7 Schematic Diagrams 7 38 Figure 7 35 CCITT Board A1A31 Schematic ...
