Page 3 - WARRANTY
WARRANTY Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one (1) year from the date of shipment. If any such product proves defective during this warranty period, Tektronix, at its option, either will repair the defective product without ch...
Page 5 - Table of Contents; Introduction and Specifications
760A / 760D / 760N i Table of Contents List of Figures iv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . List of Tables v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General Safety Summary vii . . . . . . ...
Page 6 - Contents; ii; Maintenance; Section 4 Maintenance; Performance Check and Calibration; Section 5 Performance Check and Calibration Procedures; Theory of Operation; Section 6 Theory of Operation
Contents ii 760A / 760D / 760N Maintenance Section 4 Maintenance 4–1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preventive Maintenance 4–1 . . . . ....
Page 7 - iii; Options; Section 7 Options; Replaceable Electrical Parts; Section 8 Replaceable Electrical Parts; Diagrams and Circuit Board Illustrations; Section 9 Diagrams/Circuit Board Illustrations; Replaceable Mechanical Parts; Section 10 Replaceable Mechanical Parts
Contents 760A / 760D / 760N iii DAC 6–6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LOW VOLTAGE POWER SUPPLY <6> 6–6 . . . . . . . . . . . . . . . . . . . . . . . . . . Line Rectifier and Filter 6–7 . . . . . . . . . . . . . . . . . ....
Page 8 - iv; List of Figures
Contents iv 760A / 760D / 760N List of Figures Figure 1–1: LED Bar Graph scales for the 760A, 760D, and 760N 1–1 . . . . . Figure 2–1: 760A Front Panel 2–2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2–2: 760A Rear Panel 2–3 . . . . . . . . . . . . . . . . . . . . . . ...
Page 9 - List of Tables
Contents 760A / 760D / 760N v List of Tables Table 1–1: Response Time 1–3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–2: Return Time 1–3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–3: Electrical Characteristics 1–4 . . . . ....
Page 11 - General Safety Summary; Only qualified personnel should perform service procedures.; To Avoid Fire or
760A / 760D / 760N vii General Safety Summary Review the following safety precautions to avoid injury and prevent damage tothis product or any products connected to it. To avoid potential hazards, use thisproduct only as specified. Only qualified personnel should perform service procedures. Use Prop...
Page 12 - viii; CAUTION indicates a hazard to property including the product.; Symbols on the Product.; The following symbols may appear on the product:
General Safety Summary viii 760A / 760D / 760N DANGER indicates an injury hazard immediately accessible as you read themarking. WARNING indicates an injury hazard not immediately accessible as you read themarking. CAUTION indicates a hazard to property including the product. Symbols on the Product. ...
Page 13 - ix; Service Safety Summary; Do Not Service Alone.
760A / 760D / 760N ix Service Safety Summary Only qualified personnel should perform service procedures. Read this ServiceSafety Summary and the General Safety Summary before performing any serviceprocedures. Do Not Service Alone. Do not perform internal service or adjustments of this product unless...
Page 15 - xi; Preface; Features; Section 1, Introduction and Specification,; Operators Part
760A / 760D / 760N xi Preface This manual documents the TEKTRONIX 760A/760D/760N Stereo AudioMonitor and is intended for instrument operators and service technicians.Operatorsare assumed to be familiar with basic television terms and measure-ments. Qualified service technicians are also assumed to b...
Page 16 - Contacting Tektronix
Preface xii 760A / 760D / 760N Section 6, Theory of Operation, provides an overall block diagram and detailed circuit descriptions. The detailed circuit descriptions should be used with theblock diagram and schematic diagrams in the foldout pages for specificinformation about the individual circuits...
Page 19 - CRT Display
760A / 760D / 760N 1–1 Section 1Introduction and Specifications Introduction The 760A Stereo Audio Monitor is a simple yet accurate tool that the audioengineer can use to perform setup, monitoring, measuring, and troubleshootingtasks in the studio. There are two special versions of the 760A Stereo A...
Page 20 - SECTION 3 INSTALLATION; In the absence of an input signal, Z–Axis dimming prolongs CRT life.; Bar Graph
Introduction and Specifications 1–2 760A / 760D / 760N The display is set for a “Sound Stage” orientation when the 760A is shippedfrom the factory. This provides a display where monaural amplitudes areoriented on the vertical axis of the CRT. An alternate XY graticule is shipped as a standard access...
Page 21 - Table 1–1: Response Time; Table 1–2: Return Time; Inst; Return Time
Introduction and Specifications 760A / 760D / 760N 1–3 Table 1–1: Response Time Inst Tone Burst (mS) Response (dB) 760A 100.0 0 " 0.5 10.0 2 " 0.5 5.0 4 " 0.75 1.5 9 " 1.0 0.5 17 " 2.0 760D760N 10.0 1 " 0.5 760N 5.0 2 " 1.0 3.0 4 " 1.0 0.4 15 " 2.0 Return Time is ...
Page 22 - Specifications; SECTION 5, PERFORMANCE; Table 1–3: Electrical Characteristics
Introduction and Specifications 1–4 760A / 760D / 760N Specifications The Performance Requirements listed in Table 13 are warranted over an ambienttemperature range of 0 ° C to 50 ° C only when the 760A has been calibrated at 25 ° C ± 5 ° C, following a warm–up period of 20 minutes. A Performance Ch...
Page 23 - Characteristic
Introduction and Specifications 760A / 760D / 760N 1–5 Table 1–3: Electrical Characteristics (Cont.) Characteristic Perf Check Step No. Supplemental Information Performance Requirement Display Range 760A –Normal–Expanded +8 dB to –45 dB 5 dB to –11 dB 760D –Normal–Expanded +5 dB to –50 dB –5 dB to –...
Page 24 - Table 1–4: Environmental Limits; Table 1–5: Physical Characteristics
Introduction and Specifications 1–6 760A / 760D / 760N Table 1–4: Environmental Limits Characteristic Supplemental Information Temperature Stored –55 ° C to +75 ° C. Operational 0 ° C to +50 ° C. Humidity Operational Will operate at 95% relative humidity for up to five days. Do not operate with visi...
Page 25 - Table 1–6: Certifications and Compliances
Introduction and Specifications 760A / 760D / 760N 1–7 Table 1–6: Certifications and Compliances EC Declaration of Conformity – EMC 1 Meets intent of Directive 89/336/EEC for Electromagnetic Compatibility. Compliance wasdemonstrated to the following specifications as listed in the Official Journal o...
Page 27 - Operating Instructions
Page 29 - Control
760A / 760D / 760N 2–1 Section 2Operating Instructions Introduction This section of the manual will familiarize you with the 760A Stereo AudioMonitor’s operation. The contents include a brief description of the controls,connectors, displays (including a discussion of the graticules), and the basic u...
Page 30 - GRATICULE; Rear–Panel Connectors
Operating Instructions 2–2 760A / 760D / 760N POSITION FOCUS TRACE ROT GRATICULE INTENSITY HORIZ VERT Figure 2–1: 760A Front Panel Rear–Panel Connectors The three rear–panel AUDIO INPUTs: LEFT, RIGHT, and AUXILIARY, arebalanced bridging male XLR connectors. The connectors are wired as follows: Pin 1...
Page 31 - FUSE; AUDIO; SECTION 3, INSTALLATION; Display Orientation
Operating Instructions 760A / 760D / 760N 2–3 FUSE 333–3321–02 SA LEFT RIGHT AUXILIARY DIE IN DIESEM GERAT ENTSTEHENDERONTGENSTRAHLUNG IST AUSREICHEND ABGESCHIRMT BESCHLEUNIGUNGSSPANNUNG KLEINER ALSACCELERATION VOLTAGE LESS THAN X–RAY EMISSION GENERATED WITHIN THISINSTRUMENT HAS BEEN SUFFICIENTLY SH...
Page 32 - Figure 2–3: 760A Sound Stage Graticule; Graticule
Operating Instructions 2–4 760A / 760D / 760N The graticule provides calibrated reference marks for a variety of uses. Bothgraticule options have the same markings and differ only in their orientation.Figures 2–3 and 2–4 show the Sound Stage and XY graticules. L=R R L L= –R AMPLITUDEMARKS PHASEMARKS...
Page 33 - Phase Marks and Phase Tangent Lines; LED BARS
Operating Instructions 760A / 760D / 760N 2–5 L indicates signal amplitude from the LEFT channel input.R indicates signal amplitude from the RIGHT channel input.L= R indicates monaural amplitudes and “in phase” left and right signalamplitudes.L=–R indicates “out of phase” left and right signals. A p...
Page 34 - Connect power to the 760A / 760D / 760N and set the instrument POWER; Initial Alignment
Operating Instructions 2–6 760A / 760D / 760N 760N The 760N uses a scale in accordance with Technical Recommendation N9 of the Nordic broadcast authorities, with a range of +15 to –36 dB. The scale isdB linear from +15 dB to –24 dB, and is progressively compressed to –36 dBwith scale marks at 3 dB i...
Page 35 - Level Setups
Operating Instructions 760A / 760D / 760N 2–7 760A When a ppm such as the 760A is used in conjunction with vu meters. it is important to consider the difference in dynamic characteristics when aligningsystem levels. The vu meter is an average reading meter with a relatively longintegration time. Its...
Page 36 - Figure 2–5: Ellipse with approximately 13; of the L=R axis. The line may tilt if the; Figure 2–6: Strong left content; Energy Distribution
Operating Instructions 2–8 760A / 760D / 760N Figure 2–5: Ellipse with approximately 13 ° phase error If the ellipse closes to a single line, the LEFT and RIGHT channels are in phaseas long as the line is within 45 ° of the L=R axis. The line may tilt if the amplitudes are unequal. A line within 45 ...
Page 37 - Figure 2–7: Well balanced stereo; Monaural Compatibility
Operating Instructions 760A / 760D / 760N 2–9 Figure 2–7: Well balanced stereo Transmitting a mono–compatible stereo television signal is, and will remain,critical for broadcasters since most viewers have monaural receivers. The 760Apattern display and the L+R bar indicate the fitness of your audio ...
Page 38 - Figure 2–9: Severe clipping of stereo signal; Clipping
Operating Instructions 2–10 760A / 760D / 760N wave into both channels of the system and checking outputs stage by stage, thesource of the phase reversal can be quickly identified. Another problem illustrated clearly by the 760A is clipping. Regardless of itssource, clipping manifests itself on the ...
Page 39 - WARNING
The following servicing instructions are for use only by qualified personnel. Toavoid injury, do not perform any servicing other than that stated in the operatinginstructions unless you are qualified to do so. Refer to all Safety Summaries beforeperforming any service. WARNING
Page 41 - Installation
Page 43 - SECTION 6, MAINTENANCE; Electrical Installation; For your protection and to avoid damage to the instrument, unplug; Table 3–1: Factory Set Input Sensitivity; Instrument Type; Unpacking
760A / 760D / 760N 3–1 Section 3Installation At installation time, save the shipping carton and packaging materials forrepackaging in case shipment becomes necessary. See Repackaging forShipment in SECTION 6, MAINTENANCE , for repackaging instructions. Electrical Installation This instrument is inte...
Page 44 - where R
Installation 3–2 760A / 760D / 760N To enable the 760A bar graph to indicate 0 dB with an input of 0, +4, +8, +12, or+16 dBm, move the jumpers on J185 (LEFT), J385 (RIGHT) and J657 (AUX-ILIARY) to the desired sensitivity, which is marked on the Main circuit board(Assembly A3) at each jumper location...
Page 45 - FRONT
Installation 760A / 760D / 760N 3–3 graticule supplied with the instrument. Detailed instructions for removing thebezel can be found under the Mechanical Assembly/Disassembly topic in SECTION 4, MAINTENANCE . Then move two jumpers on the Main circuit board, J273 and J373, to the position labeled X–Y...
Page 49 - Preventive Maintenance; Clean the dust from the outside of the instrument by wiping or; Introduction
760A / 760D / 760N 4–1 Section 4Maintenance This section discusses preventive maintenance, general troubleshootinginformation, and corrective maintenance. If the instrument does not functionproperly, troubleshooting and other corrective measures should be takenimmediately to prevent any additional p...
Page 50 - CORRECTIVE MAINTENANCE; NOTE
Maintenance 4–2 760A / 760D / 760N CAUTION. Do not allow water to get inside any enclosed assembly or component. Do not clean any plastic materials with organic cleaning solvents, such asbenzene, toluene, xylene, acetone, or similar compounds, because they maydamage the plastic. After cleaning, care...
Page 51 - Figure 4–1: Using the foldout pages; Block and circuit diagrams are the most often used aids to trouble-; Circuit Board Illustrations.; Electrical components, connectors, and test points are; Theory of Operation.; These pages can be turned to and read while the schematic
Maintenance 760A / 760D / 760N 4–3 CIRCUIT BOARDILLUSTRATIONS PARTS LOCATING CHART SCHEMATIC THEORY OF OPERATION ORADJUSTMENT PROCEDURE SCHEMATIC Figure 4–1: Using the foldout pages Diagrams. Block and circuit diagrams are the most often used aids to trouble- shooting. The circuit number and electri...
Page 52 - Replaceable Electrical Parts List.; The Replaceable Electrical Parts List is; Parts Locating Charts.; The schematic diagrams are assigned location grids. A; Assembly and Circuit Numbering.; . The circuit board assemblies are assigned
Maintenance 4–4 760A / 760D / 760N Replaceable Electrical Parts List. The Replaceable Electrical Parts List is arranged in assembly–by–assembly order, as designated by ANSI StandardY32.16–1975. The circuit number in the parts list is made up by combining theassembly number and the circuit number. EX...
Page 53 - Instrument Type or Number; TROUBLESHOOTING INFORMATION; Position 0; selects normal scale.; Position 1; is the Expanded scale that is also enabled when the EXPAND SCALE; Position 2; leading zero positions and two all–ones positions for markers.; Obtaining Replacement
Maintenance 760A / 760D / 760N 4–5 NOTE . The parts lists in this manual should be used when ordering replacement parts. Replacement parts are available from or through the local Tektronix, Inc., fieldoffice or representative. Changes to Tektronix instruments are sometimes made to accommodateimprove...
Page 54 - PAL Signal Specification
Maintenance 4–6 760A / 760D / 760N Position 3 a step function used to check DAC linearity and bit transition glitches. The first nine addresses are one–bit steps. Single transitions are present untilone–quarter scale where three successive bits are used for position markers.Since maximum glitch occu...
Page 55 - Power Supply Troubleshooting Procedure
Maintenance 760A / 760D / 760N 4–7 PIN 18 DELAY makes a low–to–high transition when the current signal valueis ≥ the stored peak value. This clocks the current value into the peak value latch and starts the peak–hold time–out circuit. PIN 19 BAR ENABLE goes low when a segment should be lit. The foll...
Page 56 - Table 4–1: Power Supply Fault Symptoms; Symptom; Preliminary Checks; Test Point; Low Volts Supply
Maintenance 4–8 760A / 760D / 760N Table 4–1: Power Supply Fault Symptoms Symptom Procedure Line fuse open Rectifier/Switcher Check (Low Volts) Power supply cycles OFF/ON Output Check (Low Volts), orHigh Voltage Oscillator Check (High Volts) Does not power up Control Circuit Check (Low Volts) 5 V no...
Page 57 - a. Connect the negative output from the 20 VDC Power Supply to TP1.
Maintenance 760A / 760D / 760N 4–9 CAUTION. Do not proceed until the the drain of Q9 is near 0 V. Dangerous voltage potentials are present in the circuit until the capacitors discharge. 2. Rectifier/Switcher Check a. Use the digital multimeter to measure the voltage between TP2 and the tab (drain) o...
Page 58 - Table 4–3: Control Circuit Test Points; Circuit Location; Error Amplifier Check; cathode of CR15 should be approximately 20 V.; High Volts Supply
Maintenance 4–10 760A / 760D / 760N b. Table 4–3 lists the signal present in a properly functioning control circuit. Table 4–3: Control Circuit Test Points Circuit Location Signal U5, pin 1 Approximately 5 VDC U5, pin 2 Approximately 2 VDC U5, pin 3 0 V U5, pin 4 80 kHz triangle wave, 2 V p-p U5, pi...
Page 59 - Table 4–4: High Volts Supply Fault Symptoms; Focus Amplifier Check
Maintenance 760A / 760D / 760N 4–11 Load the Low Volts Supply with the instrument, or with the 20 W resistor as stated at the beginning of the Troubleshooting Procedure. Table 4–4: High Volts Supply Fault Symptoms Symptom Procedure Unable to focus CRT using the front-panelcontrol Focus Amplifier Che...
Page 60 - CRT Voltage Check
Maintenance 4–12 760A / 760D / 760N H Using the digital multimeter, measure the voltage between TP1 and thecathode of CR5. It should vary between approximately +75 and +200 Vas R58 (CRT Bias) is adjusted. H Connect the oscilloscope probe to the anode of CR5 and the probeground to TP1. The signal sho...
Page 61 - MECHANICAL DISASSEMBLY AND ASSEMBLY; For your protection and to avoid damage to the instrument, when; Remove the two bezel retaining screws.; Figure 4–3: Bezel removal; Bezel Removal
Maintenance 760A / 760D / 760N 4–13 MECHANICAL DISASSEMBLY AND ASSEMBLY Before removing parts from the 760A, disconnect the power cord and thenremove the instrument from its cabinet. Reassembly is performed by reversingthe steps used to disassemble the instrument. WARNING. For your protection and to...
Page 62 - Graticule Light Removal
Maintenance 4–14 760A / 760D / 760N 2. Grasping the bottom of the bezel, pull out and upward. The bezel has two hinges that hold the top in place that need to be cleared. 3. To replace, reverse the procedure. 1. Remove the bezel, following the preceding procedure. 2. Using a pair of needle nose plie...
Page 63 - Remove the five screws from the rear panel.; Rear Panel Removal and
Maintenance 760A / 760D / 760N 4–15 2. Slip the CRT part way back into position and feed the trace rotation wires (and plug) back through the hole in the Main board. WARNING. The CRT may retain a dangerous charge. Ground the the anode connector to discharge the CRT. Do not allow the conductor to tou...
Page 64 - Push the trace rotation lead through its hole in the Main board.; LED Bar and Socket
Maintenance 4–16 760A / 760D / 760N b. Remove the four screws from the rear. c. The board may now be separated from the front panel and the compo-nents should be accessible. 5. To reassemble, reverse the procedure. NOTE . When remounting the Front Panel board to the front panel, carefully line up th...
Page 65 - Figure 4–4: Retaining screw locations; shafts clear the front and then lift it out.; Power Supply Board
Maintenance 760A / 760D / 760N 4–17 REAR A1 Power Supply board retaining screws A3 Main board retaining screws ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ FRONT J1 J3 J2 J4 Ground strap Figure 4–4: Retaining screw locations 5. To remove the board, slide it toward the rear panel until...
Page 66 - Remove the board by sliding it forward and lifting it up.; REPACKAGING
Maintenance 4–18 760A / 760D / 760N 7. Remove the board by sliding it forward and lifting it up. 8. To replace the board, reverse this procedure. REPACKAGING If the instrument is to be shipped to a Tektronix Service Center for service orrepair, attach a tag to the instrument showing: 1. Owner (with ...
Page 67 - Seal the carton with shipping tape or an industrial stapler.
Maintenance 760A / 760D / 760N 4–19 For best results, save and reuse the package in which your instrument wasshipped. If the original package is unfit for use or not available, repackage theinstrument as follows: 1. Obtain a carton of corrugated cardboard having inside dimensions of six inches, or m...
Page 71 - SECTION 1, INTRODUCTION AND SPECIFICATION; Leveled Audio Frequency Signal Generator; impedance; Variable Autotransformer; (General Radio Metered Auto Transformer W10MT3W)
760A / 760D / 760N 5–1 Section 5Performance Check and Calibration Procedures This section of the manual consists of two procedures. The Performance Checkprocedure is a guide to verifying warranted specifications of the 760A, while theAdjustment procedure, when properly performed, will result in a 76...
Page 72 - Performance Check and Calibration Procedures; Performance Check Procedure; a. Set the 760A for a “Sound Stage” orientation (on A3 Main board, J273; DISPLAY; TOP; LEGEND
Performance Check and Calibration Procedures 5–2 760A / 760D / 760N Performance Check Procedure 1. Initial Alignment NOTE . This step must be performed prior to beginning this procedure. a. Set the 760A for a “Sound Stage” orientation (on A3 Main board, J273 and J373 to pins 2 and 3) and install the...
Page 73 - d. Set the VERTICAL and HORIZONTAL POSITION controls so the; h. Set the INTENSITY control for an easily visible trace and set the
Performance Check and Calibration Procedures 760A / 760D / 760N 5–3 b. Connect the 760–series AC power cord to the variable autotransformer. Turn power on and set the autotransformer to the local nominal mainsvoltage (either 110 or 220 volts). Set the GRATICULE illumination sothe graticule markings ...
Page 75 - Input Sensitivity Jumper; Check AGC Control Range; that the size of the CRT display changes very little.
Performance Check and Calibration Procedures 760A / 760D / 760N 5–5 Check the RIGHT and AUXILIARY bars in the same manner, connect-ing the input signal to one 760A AUDIO INPUT at a time. f. (760A only) Set S340 to position 6. g. CHECK – (760A only) that each bar indicates 0 dB " 0.3 dB (6 segmen...
Page 76 - d. CHECK – that the trace ends within one–half division of the center; amplitude mark of the “R” graticule line.; Check Gain Tracking; RIGHT AUDIO INPUT, set the DISPLAY GAIN control to AUTO.; b. Align the trace with the “R” graticule line.; INPUT and set the DISPLAY GAIN control to MANual.
Performance Check and Calibration Procedures 5–6 760A / 760D / 760N d. CHECK – that the trace ends within one–half division of the center amplitude mark of the “R” graticule line. 7. Check Gain Tracking a. With the leveled audio signal generator output still connected to the RIGHT AUDIO INPUT, set t...
Page 80 - This concludes the 760A / 760D / 760N Performance Check Procedure
Performance Check and Calibration Procedures 5–10 760A / 760D / 760N 16. Check Dynamic Response (760A only) Attack Timea. Set S340 to position 6, and turn off (release) the PEAK HOLD control. b. Connect the output of the audio signal generator to the LEFT AUDIO INPUT. Set the generator frequency to ...
Page 81 - Calibration Procedure; Preliminary Set Up; mV; b. Set the 760A front panel controls as follows:
Performance Check and Calibration Procedures 760A / 760D / 760N 5–11 Calibration Procedure 1. Preliminary Set Up NOTE . Unless otherwise stated, always set the Leveled Audio Signal Generator for a 1 kHz sine wave at the following level: 760A 775 mV rms 760D 550 mV rms 760N 777 mV rms a. Set the disp...
Page 82 - CAUTION; Figure 5–2: 760–Series Adjustment Locations; Remove the signal at the LEFT AUDIO INPUT.
Performance Check and Calibration Procedures 5–12 760A / 760D / 760N R759 ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ CAUTION MAINS VOLTAGE A1 PWR...
Page 84 - Adjust Vertical Dynamic Stability; the audio generator is turned on and off.; Adjust Vertical/Horizontal Gain Balance; and LEFT AUDIO INPUTs.; b. Ensure the DISPLAY GAIN control is set to AUTO.; Set the audio signal generator frequency to 20 kHz.
Performance Check and Calibration Procedures 5–14 760A / 760D / 760N c. ADJUST – R463 (Orthogonality) on the A3 Main board, to align thetrace with the dotted horizontal line. 9. Adjust Vertical Dynamic Stability a. ADJUST – R782 to eliminate updown motion of the horizontal trace as the audio generat...
Page 85 - CHECK – that the display shows no separation of the trace.; Adjust for 6 segments lit.; Table 5–3: LED Bar Reference Adjustment
Performance Check and Calibration Procedures 760A / 760D / 760N 5–15 e. Set the audio signal generator frequency to 20 Hz. f. CHECK – that the display shows no separation of the trace. 13. Adjust LED Bar Gains a. Connect the leveled audio signal generator output to all three AUDIO INPUTs. b. Set the...
Page 89 - The inputs may be terminated by 150
760A / 760D / 760N 6–1 Section 6Theory of Operation INTRODUCTION This section is intended to give a thorough understanding of the 760A / 760D /760N Stereo Audio Monitor’s operational theory. A block diagram is providedto show the relationships between major functional blocks of circuitry. Eachblock ...
Page 90 - The Left and Right signals are added in U179 and subtracted in; counterclockwise, so that the Left signals are indicated; CRT Orthogonality Correction.; A small amount of the signal from the horizontal
Theory of Operation 6–2 760A / 760D / 760N 45 ° Matrix. The Left and Right signals are added in U179 and subtracted in U379 to produce L+R and L–R signals. These signals, if applied to the CRT,will rotate the pattern 45 ° counterclockwise, so that the Left signals are indicated along the left 45 ° d...
Page 91 - LEVEL INDICATORS
Theory of Operation 760A / 760D / 760N 6–3 Trace Rotation. A dc current through the trace rotation coil magnetically corrects rotation. Gain Control Logic. The signal from the Input Amplifier is full wave rectified in the precision rectifier, U462, and filtered and compared by U361 to determinethe l...
Page 92 - Figure 6–2: Simplified Level Indicator block diagram; SECTION; Dynamic Response
Theory of Operation 6–4 760A / 760D / 760N Comparator Filter & Rectifier Decoder / Driver LED Bar DAC ROM Lookup Table Counter Clock DAC Ramp Input Signal –+ Figure 6–2: Simplified Level Indicator block diagram The LED segments of a 100–segment bar are scanned from top to bottom about300 times p...
Page 95 - Line Rectifier and Filter
Theory of Operation 760A / 760D / 760N 6–7 The Low Voltage Power Supply is called a Flyback Switcher. When switchermosfet Q9 is turned on, its drain voltage drops to approximately 0 V. Thecurrent through the 350 m H primary winding of T3 begins ramping up. The voltages present at all secondaries is ...
Page 96 - Output Filters
Theory of Operation 6–8 760A / 760D / 760N U5 pin 2 is the inverting input of an internal op-amp. The noninverting input isset to 2.5 V by an internal voltage reference. Current from the peak detectorflows through R83 and R79. R84 provides a 100 m A offset. The voltage at U5 pin 1 will vary in order...
Page 97 - HIGH VOLTAGE POWER
Theory of Operation 760A / 760D / 760N 6–9 within 50 ms of power up, U3B will shut down the switcher. The power supplywill then cycle on and off every couple of seconds. The High Voltage Power Supply generates the heater, cathode, control grid, focusanode, and post accelerating potentials required t...
Page 98 - Power Supply Outputs
Theory of Operation 6–10 760A / 760D / 760N CR4 is the high voltage rectifier. Filter capacitors C3, C4, and C8 work withCR4 to provide –2530 V to the CRT cathode. U1 is a four-times multiplierproviding +11 kV to the CRT anode. Q1 and Q2 form an operational amplifier that sets the voltage at the bot...
Page 99 - Pin; Figure 6–3: Pinout of the CRT Socket
Theory of Operation 760A / 760D / 760N 6–11 pull-down transistor. C6 speeds up the amplifier by coupling AC signals to thebase of Q3. CR2 and R41 protect the amplifier during CRT arcing. The pinout for the CRT is shown in Figure 6–3. Pin Description 1 Filament (f) 2 Cathode (k) 3 GRID (g1) 4 FOCUS (...
Page 103 - OPTIONS; Table 7–1: Power Cord Options; Option; SECTION 10 REPLACEABLE MECHANICAL
760A / 760D / 760N 7–1 Section 7Options This section describes instrument options available for the 760–Series. OPTIONS The standard instrument is shipped with a P31 (green) phosphor CRT installed.If Option 74 is ordered, the instrument is shipped with a P4 (white) phosphorCRT installed. The CRT par...
Page 107 - Parts Ordering Information; Part number; Using the Replaceable Electrical Parts List
760A / 760D / 760N 8–1 Section 8Replaceable Electrical Parts This section contains a list of the electrical components for the 760A, 760D, and760N. Use this list to identify and order replacement parts. Parts Ordering Information Replacement parts are available through your local Tektronix field off...
Page 108 - Parts List Column Descriptions; Column; A2
Replaceable Electrical Parts 8–2 760A / 760D / 760N Parts List Column Descriptions Column Column Name Description 1 Component number The component number appears on diagrams and circuit board illustrations, located in the diagramssection. Assembly numbers are clearly marked on each diagram and circu...
Page 109 - Manufacturers Cross Index; Manufacturer
Replaceable Electrical Parts 760A / 760D / 760N 8–3 Manufacturers Cross Index Mfr.Code Manufacturer Address City, State, Zip Code D5243 ROEDERSTEIN ERNST GMBH LUDMILLASTRASSE 23 8300 LANDSHUT GERMANY TK0435 LEWIS SCREW CO 4300 S RACINE AVE CHICAGO IL 60609–3320 TK0515 EVOX–RIFA INC 100 TRI–STATE INT...
Page 110 - Address
Replaceable Electrical Parts 8–4 760A / 760D / 760N Manufacturers Cross Index (Cont.) Mfr.Code City, State, Zip Code Address Manufacturer 11236 CTS CORPORATIONRESISTOR NETWORKS DIVISION 406 PARR ROAD BERNE IN 46711–9506 11502 IRC, INC PO BOX 1860 BOONE NC 28607–1860 12697 CLAROSTAT MFG CO INC 12055 ...
Page 112 - Replaceable Electrical Parts List
Replaceable Electrical Parts 8–6 760A / 760D / 760N Replaceable Electrical Parts List ComponentNumber TektronixPart Number Serial no.effective Serial No.Discont’d Name & Description Mfr.Code Mfr. Part Number A1 671–2890–10 CIRCUIT BD ASSY:POWER SUPPLY 80009 671289010 A2 670–9532–01 CIRCUIT BD AS...
Page 141 - Symbols; Abbreviations are based on ANSI Y1.1–1972.; Component Values; Capacitors
9–1 760A / 760D / 760N Section 9Diagrams/Circuit Board Illustrations Symbols Graphic symbols and class designation letters are based on ANSI StandardY32.2–1975. Logic symbology is based on ANSI Y32.14–1973 in terms of positive logic.Logic symbols depict the logic function performed and may differ fr...
Page 142 - Diagrams/Circuit Board Illustrations; Assembly Numbers; Grid Coordinates
Diagrams/Circuit Board Illustrations 9–2 760A / 760D / 760N The following information and special symbols may appear in this manual. Assembly Numbers Each assembly in the instrument is assigned an assembly number (e.g., A20).The assembly number appears on the diagram (in circuit board outline), circ...
Page 143 - A3 Main Board Diagram Component Locator
C125 1 G3 C127 1 G3 C132 1 G3 C145 1 H3 C148 1 G2 C149 3 G4 C165 4 G3 C172 1 G2 C179 1 G2 C187 1 C2 C190 1 B2 C206 2 H1 C211 1 H3 C215 3 H1 C251 3 G5 C254 1 F5 C255 1 F5 C258 1 F5 C261 1 H3 C262 1 G3 C263 1 H2 C267 1 G4 C268 1 H2 C279 1 G4 C287 1 C3 C290 1 B3 C324 1 G3 C328 1 G3 C332 1 H3 C333 1 H3 ...
Page 148 - Schematic Diagram <3> Component Locator Chart
Schematic Diagram <3> Component Locator Chart Assembly A3. C149 G4 C215 H1 C251 G5 C718 A3 C755 A1 C815 C3 C818 C2 C819 B3 C841 D1 C854 B1 C855 C1 C858 C1 CR846 E1 CR850 B1 CR851 B1 CR852 B1 CR853 B1 CR854 B1 CR855 B1 R247 G4 R248 G4 R252 G4 R253 G4 R315 H1 R336 D5 R337 D5 R344 D5 R355 C1 R356...
Page 150 - Schematic Diagram <4> Component Locator Chart
Schematic Diagram <4> Component Locator Chart Assembly A3. C165 G3 C369 D1 C458 D2 C459 D3 C461 D4 C502 G5 CR458 D2 CR459 D2 CR558 D2 CR559 D2 CR563 D3 CR564 D3 CR565 D3 CR566 D3 J273 B2 J373 B3 J413 A4 J419 H5 Q603 G5 Q604 G5 R157 C4 R158 C4 R168 D4 R169 C4 R170 C4 R174 A2 R175 A2 R176 A2 R26...
Page 152 - Schematic Diagram <5> Component Locator Chart
C510 E3 C570 C4 C573 B5 C574 B4 C575 A4 C578 A4 C581 A1 C584 B1 C586 A1 C587 B2 C588 C1 C616 D3 C618 D3 C695 D1 C712 C3 C768 D4 C772 B4 C776 G3 C778 F4 C785 B1 C870 E4 C872 E4 C876 F5 C891 E2 C895 F2 C897 F1 CR616 D3 CR780 G3 CR790 G3 CR791 H3 CR876 G3 J409 E3 J862 H4 J886 H1 L513 E3 Q620 D3 Q695 G2...
Page 156 - Assembly A1. Partial Assembly A1 also shown on Schematic 6.
C1 C4 A4 C2 D3 D1 C3 D3 A2 C4 D3 A2 C5 D4 B3 C6 C4 B4 C7 F3 B1 C8 D3 B2 C9 E2 B2 C10 C5 B4 C11 E2 B1 C12 D2 C4 C13 D2 C4 C14 D2 C4 C15 F2 C4 C16 C2 C3 C17 F2 D4 C18 F3 E1 C19 C1 D4 C20 C2 D4 C21 C1 D4 C22 B2 E2 C23 B2 E3 C24 D1 E4 C25 A3 E2 C27 B1 E3 C28 B1 E3 C34 D1 F4 C65 B2 F4 C66 A2 E2 CR1 E2 B1...
Page 163 - Using the Replaceable Mechanical Parts List
760A / 760D / 760N 10–1 Section 10Replaceable Mechanical Parts This section contains a list of the replaceable mechanical components for the760A, 760D, and 760N. Use this list to identify and order replacement parts. Parts Ordering Information Replacement parts are available through your local Tektr...
Page 164 - Abbreviations
Replaceable Mechanical Parts 10–2 760A / 760D / 760N Parts List Column Descriptions Column Column Name Description 1 Figure & index number Items in this section are referenced by figure and index numbers to the exploded viewillustrations that follow. 2 Tektronix part number Use this part number ...
Page 166 - Replaceable mechanical parts list
Replaceable Mechanical Parts 10–4 760A / 760D / 760N Replaceable mechanical parts list Fig. &IndexNumber TektronixPart Number Serial No.Effective Serial No.Discont’d Qty Name & Description Mfr.Code Mfr. Part Number 1–1 426–2174–02 1 FRAME,CRT:BEZEL *MOUNTING PARTS* 80009 426217402 –2 211–069...