Instruction Manual 760A/760D/760N Stereo Audio Monitors (760A S/N B050000 & Above) (760D/760N S/N B030000 & Above) 070-5992-05 Warning The servicing instructions are for use by qualified personnel only. To avoid personal injury, do not perform any servicing unless you are qualified to do so. Refer to all safety summaries prior to performing service. Please check for change information at the rear of this manual.
Copyright © Tektronix, Inc. All rights reserved. Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes that in all previously published material. Specifications and price change privileges reserved. Printed in the U.S.A. Tektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070–1000 TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
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 charge for parts and labor, or will provide a replacement in exchange for the defective product.
Table of Contents List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents Maintenance Section 4 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Visual Inspection . . . . . . . . . . . . . . .
Contents DAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LOW VOLTAGE POWER SUPPLY <6> . . . . . . . . . . . . . . . . . . . . . . . . . . Line Rectifier and Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pulse Width Modulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Output Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents List of Figures iv Figure 1–1: LED Bar Graph scales for the 760A, 760D, and 760N . . . . . 1–1 Figure 2–1: 760A Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2–2: 760A Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2–3: 760A Sound Stage Graticule . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2–4: 760A X–Y Graticule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents List of Tables 760A / 760D / 760N Table 1–1: Response Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–2: Return Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–3: Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–4: Environmental Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–5: Physical Characteristics . . . . . . . . . . . . . . . . . . . . . . .
Contents vi 760A / 760D / 760N
General Safety Summary Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it. To avoid potential hazards, use this product only as specified. Only qualified personnel should perform service procedures. To Avoid Fire or Personal Injury Use Proper Power Cord. Use only the power cord specified for this product and certified for the country of use. Ground the Product.
General Safety Summary DANGER indicates an injury hazard immediately accessible as you read the marking. WARNING indicates an injury hazard not immediately accessible as you read the marking. CAUTION indicates a hazard to property including the product. Symbols on the Product.
Service Safety Summary Only qualified personnel should perform service procedures. Read this Service Safety Summary and the General Safety Summary before performing any service procedures. Do Not Service Alone. Do not perform internal service or adjustments of this product unless another person capable of rendering first aid and resuscitation is present. Disconnect Power. To avoid electric shock, disconnect the mains power by means of the power cord or, if provided, the power switch.
Service Safety Summary x 760A / 760D / 760N
Preface This manual documents the TEKTRONIX 760A/760D/760N Stereo Audio Monitor and is intended for instrument operators and service technicians. Operatorsare assumed to be familiar with basic television terms and measurements. Qualified service technicians are also assumed to be familiar with television terms and measurements, and have moderate experience with analog and logic circuits. The manual is divided into two parts: Operator’s Information and Service Information.
Preface Section 6, Theory of Operation, provides an overall block diagram and detailed circuit descriptions. The detailed circuit descriptions should be used with the block diagram and schematic diagrams in the foldout pages for specific information about the individual circuits. Section 7, Options, documents available instrument options. Section 8, Replaceable Electrical Parts List, includes order information and part numbers for all rep,aceable electrical parts.
Introduction and Specifications
Section 1 Introduction and Specifications Introduction The 760A Stereo Audio Monitor is a simple yet accurate tool that the audio engineer can use to perform setup, monitoring, measuring, and troubleshooting tasks in the studio. There are two special versions of the 760A Stereo Audio Monitor: the 760D and the 760N. All three operate in exactly the same manner, but are set to use different scales for the Bar Graph displays. The three different scales are shown in Figure 1–1.
Introduction and Specifications The display is set for a “Sound Stage” orientation when the 760A is shipped from the factory. This provides a display where monaural amplitudes are oriented on the vertical axis of the CRT. An alternate XY graticule is shipped as a standard accessory with the 760A. This graticule can be installed if you are familiar with or desire the display orientation provided by an XY monitor. Instructions for installing the XY graticule are found in SECTION 3 INSTALLATION.
Introduction and Specifications 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 10.0 1 "0.5 5.0 2 "1.0 3.0 4 "1.0 0.4 15 "2.0 760D 760N Return Time Return Time is the elapsed time for the reading to decay a specified amount after the abrupt removal of a tone. See Table 1–2. Table 1–2: Return Time Inst Return Time 760A 2.8 "0.3 seconds to fall 24 dB 760D 1.5 "0.2 seconds to fall 20 dB 760N 1.7 "0.
Introduction and Specifications Specifications The Performance Requirements listed in Table 13 are warranted over an ambient temperature 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 Check procedure is provided in SECTION 5, PERFORMANCE CHECK AND CALIBRATION PROCEDURES, to verify the Performance Requirements listed in the following table.
Introduction and Specifications Table 1–3: Electrical Characteristics (Cont.) Characteristic Performance Requirement Display Range 760A –Normal –Expanded Supplemental Information +8 dB to –45 dB 5 dB to –11 dB 760D –Normal –Expanded +5 dB to –50 dB –5 dB to –13 dB 760N –Normal –Expanded +15 dB to –36 dB +3 dB to –6 dB Scale 760A 760D 760N dB linear from +8 to 20 dB. Progressively compressed. dB linear from +15 to –24 dB. Resolution 760A 0.4 dB/segment, from +8 to20 dB. 0.
Introduction and Specifications Table 1–4: Environmental Limits Characteristic Temperature Stored Operational Humidity Operational Altitude Stored Operational Supplemental Information –55° C to +75° C. 0° C to +50° C. Will operate at 95% relative humidity for up to five days. Do not operate with visible moisture on boards. 50,000 feet. 15,000 feet. Vibration Operational 15 minutes each axis at 0.
Introduction and Specifications Table 1–6: Certifications and Compliances EC Declaration of Conformity – EMC 1 Meets intent of Directive 89/336/EEC for Electromagnetic Compatibility.
Introduction and Specifications 1–8 760A / 760D / 760N
Operating Instructions
Section 2 Operating Instructions Introduction This section of the manual will familiarize you with the 760A Stereo Audio Monitor’s operation. The contents include a brief description of the controls, connectors, displays (including a discussion of the graticules), and the basic uses of the instrument. Front–Panel Controls Table 2–1 contains a brief description of the front–panel control functions. The front panel is shown in Figure 2–1.
Operating Instructions GRATICULE INTENSITY POSITION FOCUS VERT HORIZ TRACE ROT Figure 2–1: 760A Front Panel Rear–Panel Connectors The three rear–panel AUDIO INPUTs: LEFT, RIGHT, and AUXILIARY, are balanced bridging male XLR connectors. The connectors are wired as follows: Pin 1: Ground Pin 2: + Pin 3: – The LEFT and RIGHT AUDIO INPUTS are for the left and right channels of your stereo signal. The AUXILIARY input can be used for an externally derived monaural signal or a SAP signal.
Operating Instructions 760 SERIES 333–3321–02 DIE IN DIESEM GERAT ENTSTEHENDE RONTGENSTRAHLUNG IST AUSREICHEND ABGESCHIRMT BESCHLEUNIGUNGSSPANNUNG KLEINER ALS ACCELERATION VOLTAGE LESS THAN 20kV ÏÏ ÏÏ ÏÏ ÏÏ X–RAY EMISSION GENERATED WITHIN THIS INSTRUMENT HAS BEEN SUFFICIENTLY SHIELDED.
Operating Instructions Graticule The graticule provides calibrated reference marks for a variety of uses. Both graticule options have the same markings and differ only in their orientation. Figures 2–3 and 2–4 show the Sound Stage and XY graticules.
Operating Instructions 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 signal amplitudes. L=–R indicates “out of phase” left and right signals. A pattern display oriented along this line is poorly suited for monaural reception. Phase Marks and Phase Tangent Lines are used in conjunction with one another to make system phase error measurements.
Operating Instructions 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 is dB linear from +15 dB to –24 dB, and is progressively compressed to –36 dB with scale marks at 3 dB intervals. The resolution of this scale is 0.5 dB from +15 to –24 dB. With the EXPAND SCALE button depressed the resolution is increased to 0.1 dB and the scale range is +3 to –6 dB (shown in blue).
Operating Instructions Level Setups 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 aligning system levels. The vu meter is an average reading meter with a relatively long integration time. Its slow response causes it to indicate between 6 and 15 dB below actual audio peaks, depending on program content. The ppm is a quasi–peak meter with a short (but not instantaneous) attack time and very slow decay.
Operating Instructions Figure 2–5: Ellipse with approximately 13° phase error If the ellipse closes to a single line, the LEFT and RIGHT channels are in phase as 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° of the L=–R axis indicates the channels are out of phase. Energy Distribution The 760A’s pattern display provides a graphic representation of the stereo signal’s overall energy distribution.
Operating Instructions Figure 2–7: Well balanced stereo Monaural Compatibility Transmitting a mono–compatible stereo television signal is, and will remain, critical for broadcasters since most viewers have monaural receivers. The 760A pattern display and the L+R bar indicate the fitness of your audio for monaural reception.
Operating Instructions wave into both channels of the system and checking outputs stage by stage, the source of the phase reversal can be quickly identified. Clipping Another problem illustrated clearly by the 760A is clipping. Regardless of its source, clipping manifests itself on the 760A pattern display as a ”squaring off” of the pattern edges. Figure 2–9 illustrates a severe case of clipping.
WARNING The following servicing instructions are for use only by qualified personnel. To avoid injury, do not perform any servicing other than that stated in the operating instructions unless you are qualified to do so. Refer to all Safety Summaries before performing any service.
Installation
Section 3 Installation Unpacking At installation time, save the shipping carton and packaging materials for repackaging in case shipment becomes necessary. See Repackaging for Shipment in SECTION 6, MAINTENANCE, for repackaging instructions. Electrical Installation Power Source This instrument is intended to operate from a single–phase power source having one of its current–carrying conductors at or near earth–ground (the neutral conductor). Only the Line conductor is fused for over–current protection.
Installation 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 (AUXILIARY) to the desired sensitivity, which is marked on the Main circuit board (Assembly A3) at each jumper location. Figure 3–3 shows all jumper locations on the Main board and what each jumper position represents. NOTE. The specified level is that of a sine wave which reads 0 dB peak program level, not the line–up level.
Installation graticule supplied with the instrument. Detailed instructions for removing the bezel 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 (pins 2 & 3) in Figure 3–1. Also for X–Y display orientation, rotate P886 (on back of A3, Main board) so pins 1 and 2 of the connector mate with pins 2 and 1 of J886 (connect backward). Repeat with P862/J862.
Installation 3–4 760A / 760D / 760N
Maintenance
Section 4 Maintenance Introduction This section discusses preventive maintenance, general troubleshooting information, and corrective maintenance. If the instrument does not function properly, troubleshooting and other corrective measures should be taken immediately to prevent any additional problems. Preventive Maintenance Preventive maintenance consists of cleaning, visual inspection, a performance check, and, if needed, readjustment.
Maintenance CAUTION. Do not allow water to get inside any enclosed assembly or component. Do not clean any plastic materials with organic cleaning solvents, such as benzene, toluene, xylene, acetone, or similar compounds, because they may damage the plastic. Visual Inspection After cleaning, carefully check the instrument for defective connections, damaged parts, and improperly seated transistors and integrated circuits.
Maintenance PARTS LOCATING CHART CIRCUIT BOARD ILLUSTRATIONS SCHEMATIC THEORY OF OPERATION OR ADJUSTMENT PROCEDURE SCHEMATIC Figure 4–1: Using the foldout pages Diagrams. Block and circuit diagrams are the most often used aids to troubleshooting. The circuit number and electrical value of each component is shown on the diagram (see the first page in the Diagrams section for a definition of the reference symbology used to identify components in each circuit.
Maintenance Replaceable Electrical Parts List. The Replaceable Electrical Parts List is arranged in assembly–by–assembly order, as designated by ANSI Standard Y32.16–1975. The circuit number in the parts list is made up by combining the assembly number and the circuit number. EXAMPLE: R117 on A4 would be listed in the Replaceable Electrical Parts List as A4R117. In the Replaceable Electrical Parts List, assemblies are listed first, followed by circuit board mounted parts in alpha numeric order.
Maintenance NOTE. The parts lists in this manual should be used when ordering replacement parts. Obtaining Replacement Parts Replacement parts are available from or through the local Tektronix, Inc., field office or representative. Changes to Tektronix instruments are sometimes made to accommodate improved components as they become available, and to give you the benefit of the latest circuit improvements developed in our Engineering Department.
Maintenance 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 until one–quarter scale where three successive bits are used for position markers. Since maximum glitch occurs at half scale, the MSB transition is exhibited three times (the only times the scale goes down). The eight bits surrounding the MSB transition are displayed. The upper addresses nearly mirror the lower 50.
Maintenance PIN 18 DELAY makes a low–to–high transition when the current signal value is ≥ 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 following pins are internal nodes without external connection. PIN 13 LCMP is a delayed and inverted CMP signal. PIN 14 PEAK goes high when the first peak segment should be turned on.
Maintenance 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), or High Voltage Oscillator Check (High Volts) Does not power up Control Circuit Check (Low Volts) 5 V not regulating Error Amplifier Check (Low Volts) Improper CRT display High Volts Supply Low Volts Supply NOTE. A 20W, 2-watt resistor should be used as a load for the Low Volts Supply.
Maintenance 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) of Q9. Be sure the voltage is near 0 V before proceeding. b. Unsolder and lift one end of R102. c.
Maintenance 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 0V U5, pin 4 80 kHz triangle wave, 2 Vp-p U5, pin 6 80 kHz square wave, 18 Vp-p U3, pin 1 80 kHz square wave, 5 Vp-p U3, pin 2 2.1 VDC U3, pin 6 2.
Maintenance 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-panel control Focus Amplifier Check Unable to adjust CRT intensity using the front-panel control Z-Axis Amplifier Check Grid Drive Check No CRT display High Voltage Oscillator Check CRT Voltage Check Focus Amplifier Check H Unsolder and lift one end of R24.
Maintenance H Using the digital multimeter, measure the voltage between TP1 and the cathode of CR5. It should vary between approximately +75 and +200 V as R58 (CRT Bias) is adjusted. H Connect the oscilloscope probe to the anode of CR5 and the probe ground to TP1. The signal should be a clipped sine wave of +75 to +200 Vp-p. High Voltage Oscillator Check H Connect the oscilloscope probe to T1 pin 3 (Q6 collector) and the probe ground to TP1. Turn on the power supply.
Maintenance MECHANICAL DISASSEMBLY AND ASSEMBLY Before removing parts from the 760A, disconnect the power cord and then remove the instrument from its cabinet. Reassembly is performed by reversing the steps used to disassemble the instrument. WARNING. For your protection and to avoid damage to the instrument, when removing or replacing any of the circuit boards, shut the instrument off. CAUTION. Do not reinsert screws in the rear panel when removed from the cabinet. NOTE.
Maintenance 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. Graticule Light Removal and Replacement 1. Remove the bezel, following the preceding procedure. 2. Using a pair of needle nose pliers, gently grasp the graticule light and carefully pull straight out. 3. The light is replaced by carefully lining up the holders with the round pins that they are to be inserted into.
Maintenance 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 touch your body or any circuitry. 3. Use a screwdriver to ground the anode connector on the CRT to the chassis. 4. Slide the CRT into the instrument, guiding the rubber manchet on the end of the shield into the rear CRT support. 5.
Maintenance b. Remove the four screws from the rear. c. The board may now be separated from the front panel and the components should be accessible. 5. To reassemble, reverse the procedure. NOTE. When remounting the Front Panel board to the front panel, carefully line up the LED bars so they fit inside the cut–outs in the front panel. LED Bar and Socket Removal and Replacement 1. Disassemble the front–panel assembly using the procedure just given, and remove the LED bar. 2.
Maintenance Ground strap J1 J3 ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉ A1 Power Supply board retaining screws J2 J4 FRONT REAR A3 Main board retaining screws Figure 4–4: Retaining screw locations 5. To remove the board, slide it toward the rear panel until the potentiometer shafts clear the front and then lift it out. 6. To replace the Main board, lay the board flat and slide it back into place (there are grooves in the front molding for the board to slide into).
Maintenance 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 or repair, attach a tag to the instrument showing: 1. Owner (with complete address) and the name of the person at your firm that can be contacted. 2. Instrument serial number and a description of the service required.
Maintenance For best results, save and reuse the package in which your instrument was shipped. If the original package is unfit for use or not available, repackage the instrument as follows: 1. Obtain a carton of corrugated cardboard having inside dimensions of six inches, or more, greater than the dimensions of the instrument. This will allow for cushioning. Use a shipping carton that has a test strength of at least 275 pounds. 2. Surround the instrument with polyethylene sheeting to protect the finish.
Maintenance 4–20 760A / 760D / 760N
Performance Check and Calibration
Section 5 Performance Check and Calibration Procedures Introduction This section of the manual consists of two procedures. The Performance Check procedure is a guide to verifying warranted specifications of the 760A, while the Adjustment procedure, when properly performed, will result in a 760A that performs as warranted in SECTION 1, INTRODUCTION AND SPECIFICATION. Throughout both procedures, all 760A front– and rear–panel nomenclature is fully capitalized, (e.g., DISPLAY GAIN).
Performance Check and Calibration Procedures 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 “Sound Stage” graticule, if your 760A is not set up in this way. See Figure 5–1 for jumper locations.
Performance Check and Calibration Procedures b. Connect the 760–series AC power cord to the variable autotransformer. Turn power on and set the autotransformer to the local nominal mains voltage (either 110 or 220 volts). Set the GRATICULE illumination so the graticule markings are clearly visible. c. With no inputs to the LEFT or RIGHT AUDIO INPUTS, set the INTENSITY control for an easily visible dot. d. Set the VERTICAL and HORIZONTAL POSITION controls so the illuminated dot is centered on the graticule.
Performance Check and Calibration Procedures c. Return the autotransformer to the local nominal mains voltage. 3. Check Input Termination a. Disconnect the input from the LEFT AUDIO INPUT. b. CHECK – that the resistance across pins 2 and 3 of each rear–panel XLR input is greater than 10k Ω. c. Set the Input Termination for each AUDIO INPUT to the 600 Ω position (see Figure 5–1). d. CHECK – that the resistance across pins 2 and 3 of each input is 600 Ω "50 Ω. e.
Performance Check and Calibration Procedures Check the RIGHT and AUXILIARY bars in the same manner, connecting 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 segments or less from 0 dB) with the combinations of 760A INPUT SENSITIVITY jumper settings and audio signal generator output levels given in Table 5–1. h. (760A only) Set S340 to position 0.
Performance Check and Calibration Procedures 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 the DISPLAY GAIN control to AUTO. b. Align the trace with the “R” graticule line. c.
Performance Check and Calibration Procedures d. Move the leveled audio signal generator output from the RIGHT to the LEFT AUDIO INPUT and repeat part c of this step. 10. MANual Gain, CAL Gain and PEAK HOLD a. Connect the leveled audio signal generator output to the LEFT and RIGHT AUDIO INPUTs. b. CHECK – that when the DISPLAY GAIN is varied in its MANual gain range (between detents), the CRT display size varies with no rotation of the trace. c.
Performance Check and Calibration Procedures 760N: "5 bar segments d. Set S340 to Position 7 (expanded scale with offset). e. Set the leveled audio signal generator output level so the LEFT bar indicates: 760A: 0 dB 760D : 0 dB on white scale 760N : 0 dB on blue scale f. CHECK – that when the audio signal generator frequency is varied from 20 Hz to 20 kHz each bar amplitude changes less than 0.5 dB.
Performance Check and Calibration Procedures 14. Check Bar Crosstalk a. Connect the leveled audio signal generator output to the LEFT AUDIO INPUT and set SELECT to AUX. b. Set the leveled audio signal generator for the following output: Output Sine Wave Frequency 1 kHz Output Level 760A 4.2 Vrms 760D 5.5 Vrms 760N 9.8 Vrms c. CHECK – that none of the RIGHT or AUXILIARY bar segments are lit. d. Move the input from the LEFT to the RIGHT AUDIO INPUT. e.
Performance Check and Calibration Procedures 16. Check Dynamic Response (760A only) Attack Time a. 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 10 kHz, and set the output level for a bar reading of 0 dB (top green LED on). c. Set S340 to position 2, and turn on the PEAK HOLD control. d.
Performance Check and Calibration Procedures 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 mVrms 760D 550 mVrms 760N 777 mVrms a. Set the display orientation to X–Y (on A3 Main board, J273 & J373 to pins 1 & 2). Use the “sound stage” graticule even though the X–Y orientation is in use.
Performance Check and Calibration Procedures TOP S340 R347 R155 R252 R253 R351 R352 R553 R262 R463 R580 R556 R546 R776 R759 FOCUS R11 R789 R786 R758 FRONT R782 A3 MAIN BOARD ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ CAUTION MAINS VOLTAGE GEOM R45 ASTIG R49 CRT BIAS R58 W4 –15V W1 +5V W3 +15V +5V ADJ * R99 A1 PWR SPLY BD Figure 5–2:
Performance Check and Calibration Procedures f. CHECK – that the crt is blanked out while there is no signal applied. 5. Adjust Geometry, Focus, and Astigmatism a. ADJUST – R45 (GEOM) for 35V "1V at pin 1 of J3. a. Reconnect the signal from the leveled audio signal generator to the LEFT AUDIO INPUT. b. Set the FOCUS control on the front panel so that it is approximately at the center of its range. c. ADJUST – R11 (CTR FOCUS) and R49 (ASTIG) for the most clearly defined display. 6.
Performance Check and Calibration Procedures c. ADJUST – R463 (Orthogonality) on the A3 Main board, to align the trace with the dotted horizontal line. 9. Adjust Vertical Dynamic Stability a. ADJUST – R782 to eliminate updown motion of the horizontal trace as the audio generator is turned on and off. NOTE. If the audio generator is capable of tone burst operation, such as the TEKTRONIX SG5010, it may be set for one second on one second off tone burst operation, instead of turning the generator on and off.
Performance Check and Calibration Procedures 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 leveled audio signal generator to the output level shown in Table 5–2. Table 5–2: LED Bar Gain Adjustment Inst Signal Level Left Right Aux R351 R352 R553 760A 7.75 mVrms Adjust for 5 segments lit. 760D 15.
Performance Check and Calibration Procedures 5–16 760A / 760D / 760N
Theory of Operation
Section 6 Theory 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 provided to show the relationships between major functional blocks of circuitry. Each block directly relates to a portion of circuitry on a schematic that is described in detail in this section.
Theory of Operation MATRIX & AGC CONTROL LOGIC <4> 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° diagonal and Right signals along the right 45° diagonal. A vertical line indicates Left and Right signals are equal and in phase (mono). This orientation makes pattern interpretation more natural.
Theory of Operation 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 determine the largest signal. The comparator output is combined with AUTO and CAL in U153, a one of eight decoder.
Theory of Operation Input Signal Filter & Rectifier DAC Ramp – Comparator + Decoder / Driver LED Bar DAC ROM Lookup Table Clock Counter Figure 6–2: Simplified Level Indicator block diagram The LED segments of a 100–segment bar are scanned from top to bottom about 300 times per second by a down–counter and decoder. The counter simultaneously addresses a ROM lookup table which contains the amplitudes represented by each segment of the bar.
Theory of Operation Peak Hold Circuit. The Peak Hold circuit is entirely digital. It stores peak values as follows. On each scan of the bar (300 times per second) the Comparator (described above) provides a CMP signal to PAL U438. The PAL then asserts BAR ENABLE, which allows the Bar Anode Driver to operate. The PAL also asserts DELAY to clock the counter state corresponding to the signal level into the latch, U428.
Theory of Operation BAR SCANNER/DRIVER & DAC <3> Master Clock U818 provides approximately 30 kHz clocking for the counter. Its output is a square wave whose rising edge defines clock phase 1. An inverter U825 provides clock phase 2, whose rising edge is delayed from phase 1 by one–half the clock period. Down Counter U828 and U623 form a two–digit BCD down–counter. The counter output is delayed half a clock period by latch U424 which in turn drives the bar decoders.
Theory of Operation The Low Voltage Power Supply is called a Flyback Switcher. When switcher mosfet Q9 is turned on, its drain voltage drops to approximately 0 V. The current through the 350 mH primary winding of T3 begins ramping up. The voltages present at all secondaries is such that the rectifier diodes are reverse biased. Energy is being stored in the magnetic field of T3. When Q9 turns off, the drain voltage “flies back” in a positive direction.
Theory of Operation U5 pin 2 is the inverting input of an internal op-amp. The noninverting input is set to 2.5 V by an internal voltage reference. Current from the peak detector flows through R83 and R79. R84 provides a 100 mA offset. The voltage at U5 pin 1 will vary in order to maintain U5 pin 2 at 2.5 V. The voltage at U5 pin 1 is modified by an internal circuit and sets the trip point of the internal comparator. U5 pin 3 is the external input to the comparator.
Theory of Operation within 50 ms of power up, U3B will shut down the switcher. The power supply will then cycle on and off every couple of seconds. HIGH VOLTAGE POWER SUPPLY <7> The High Voltage Power Supply generates the heater, cathode, control grid, focus anode, and post accelerating potentials required to display the outputs of the Vertical and Horizontal Output Amplifiers. HV Osc and Error Amp The High Voltage Power Supply is generated by a sine wave oscillator and step-up transformer.
Theory of Operation Power Supply Outputs Focus Amplifier Grid Drive Circuit CR4 is the high voltage rectifier. Filter capacitors C3, C4, and C8 work with CR4 to provide –2530 V to the CRT cathode. U1 is a four-times multiplier providing +11 kV to the CRT anode. Q1 and Q2 form an operational amplifier that sets the voltage at the bottom of the focus divider. The front-panel FOCUS pot determines the voltage at the bottom of the focus divider.
Theory of Operation pull-down transistor. C6 speeds up the amplifier by coupling AC signals to the base of Q3. CR2 and R41 protect the amplifier during CRT arcing. CRT The pinout for the CRT is shown in Figure 6–3.
Theory of Operation 6–12 760A / 760D / 760N
Options
Section 7 Options Introduction This section describes instrument options available for the 760–Series. CRT 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) phosphor CRT installed. The CRT part numbers are given at the end of the Replaceable Electrical Parts List. Power Cord Options Any of the power cord options shown in Table 7–1 can be ordered for the 760–Series.
Options 7–2 760A / 760D / 760N
Replaceable Electrical Parts
Section 8 Replaceable Electrical Parts This section contains a list of the electrical components for the 760A, 760D, and 760N. Use this list to identify and order replacement parts. Parts Ordering Information Replacement parts are available through your local Tektronix field office or representative. Changes to Tektronix products are sometimes made to accommodate improved components as they become available and to give you the benefit of the latest improvements.
Replaceable Electrical Parts Parts List Column Descriptions Column Column Name Description 1 Component number The component number appears on diagrams and circuit board illustrations, located in the diagrams section. Assembly numbers are clearly marked on each diagram and circuit board illustration in the Diagrams section, and on the mechanical exploded views in the Replaceable Mechanical Parts list section.
Replaceable Electrical Parts Manufacturers Cross Index Mfr.
Replaceable Electrical Parts Manufacturers Cross Index (Cont.) Mfr.
Replaceable Electrical Parts Manufacturers Cross Index (Cont.) Mfr.
Replaceable Electrical Parts Replaceable Electrical Parts List Component Number Tektronix Part Number A1 Serial no. effective Serial No. Discont’d Name & Description Mfr. Code Mfr.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A1C22 281–0563–00 A1C23 285–1328–00 A1C24 Mfr. Code Mfr. Part Number CAP,FXD,CERAMIC:MLC;0.47UF,20%,50V,0.150 X0.290 04222 SA305E474MAA CAP,FXD,PLSTC:MTLZD FILM;0.01UF,5%,2000V,POLYPROPYLENE,1.25X.95 TK1913 FKP1 .01/2000/5 290–1310–00 CAP,FXD,ALUM:10UF,20%,160V,ESR=24.9 OHM (120HZ,20C),LS=0.200 INCH,13X20MM,105C,5000HRS 0H1N5 CEJSM2C100M A1C25 281–0775–01 CAP,FXD,CERAMIC:MCL;0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A1C65 281–1301–01 A1C66 290–1311–00 A1CR1 A1CR2 Serial no. effective Serial No. Discont’d Mfr. Code Mfr. Part Number CAP,FXD,CERAMIC:MCL;0.47UF,10%,50V 37942 185/0.47/K/50/AB/B CAP,FXD,ALUM:10UF,20%,50V,ESR=1.4 OHM (100KHZ,20C),5X11MM,105C,5000HRS 55680 UPL1H100MDH1TD 152–0061–00 DIODE,SIG:200V,0.1A,700NS,4.0PF 12969 PV122 152–0061–00 DIODE,SIG:200V,0.1A,700NS,4.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A1J1 131–5338–00 A1J2 Serial no. effective Serial No. Discont’d Mfr. Code Mfr. Part Number CONN,HDR:PCB/WIREWRAP;MALE,STR,1 X 7,0.15CTR, 0.230 MLG X 0.285 TAIL,30 GOLD,SIDE BYSIDE STACKABLE 22526 65561–107 131–4794–00 CONN,HDR:PCB;MALE,STR,1 X 2,0.1 CTR,0.235MLG X 0.112 TAIL,30GOLD,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A1R12 A1R13 Name & Description Mfr. Code Mfr. Part Number 315–0471–03 RES,FXD,CMPSN:470 OHM,5%,0.25W 50139 CB4715 322–3097–00 RES,FXD:METAL FILM;100 OHM,1%,0.2W,TC=100 PPM 91637 CCF501G100R0F A1R14 322–3001–00 RES,FXD:METAL FILM;10 OHM,1%,0.2W,TC=100 PPM 91637 CCF501G10R00F A1R20 322–3248–00 RES,FXD,FILM:3.74K OHM,1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A1R59 A1R60 Name & Description Mfr. Code Mfr. Part Number 322–3485–07 RES,FXD,FILM:5K OHM,0.1%,0.2W,TC=T9,SMALL BODY 91637 CCF501C50000B 322–3268–00 RES,FXD,FILM:6.04K OHM,1%,0.2W,TC=T0MI,SMALL BODY 91637 CCF501G60400F A1R61 322–3034–00 RES,FXD:METAL FILM;22.1 OHM,1%,0.2W,TC=100 PPM 91637 CCF50–2–G22R10F A1R62 322–3097–00 RES,FXD:METAL FILM;100 OHM,1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A1R99 A1R101 Name & Description Mfr. Code 311–2239–00 RES,VAR,TRMR:CERMET;100K OHM,20%,0.5W,0.197 TK2073 GF06UT2 104 M L 322–3068–00 RES,FXD:METAL FILM;49.9 OHM,1%,0.2W,TC=100 PPM 91637 CCF501G49R90F A1R102 308–0290–00 RES,FXD,WW:8 OHM,5%,5W 91637 CW52–8R000J T/R A1R103 322–3452–00 RES,FXD,FILM:499K OHM,1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A2DS432 A2DS434 Serial no. effective Serial No. Discont’d Name & Description Mfr. Code Mfr. Part Number 150–1286–00 DIODE,OPTO:LED;ASSEMBLY,GRN,150–1109–00 IN TK1155 150–1286–00 ––––––––––– (PART OF A2DS432) A2R423 315–0121–00 RES,FXD,FILM:120 OHM,5%,0.25W TK1727 SFR25 2322–181– A2R424 315–0121–00 RES,FXD,FILM:120 OHM,5%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3C132 A3C145 Name & Description Mfr. Code Mfr. Part Number 281–0775–00 CAP,FXD,CERAMIC:MLC;0.1UF,20%,50V,Z5U,0.170 04222 SA105E104MAA 281–0775–00 CAP,FXD,CERAMIC:MLC;0.1UF,20%,50V,Z5U,0.170 04222 SA105E104MAA A3C148 281–0775–00 CAP,FXD,CERAMIC:MLC;0.1UF,20%,50V,Z5U,0.170 04222 SA105E104MAA A3C149 283–0220–00 CAP,FXD,CERAMIC:MLC;0.01UF,20%,50V,X7R,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3C379 A3C387 Name & Description Mfr. Code Mfr. Part Number 281–0775–00 CAP,FXD,CERAMIC:MLC;0.1UF,20%,50V,Z5U,0.170 04222 SA105E104MAA 281–0765–00 CAP,FXD,CER DI:100PF,5%,100V 04222 SA102A101JAA A3C390 290–0990–01 CAP,FXD,ELCTLT:10UF,20%,50VTAPE & REEL 62643 511D296 A3C406 281–0775–00 CAP,FXD,CERAMIC:MLC;0.1UF,20%,50V,Z5U,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3C562 A3C570 Name & Description Mfr. Code Mfr. Part Number 281–0775–00 CAP,FXD,CERAMIC:MLC;0.1UF,20%,50V,Z5U,0.170 04222 SA105E104MAA 290–0782–00 CAP,FXD,ALUM:4.7UF,20%,35V,ESR=42.33 OHM (120HZ,20C) 55680 UVX1V4R7MAA A3C571 281–0775–00 CAP,FXD,CERAMIC:MLC;0.1UF,20%,50V,Z5U,0.170 04222 SA105E104MAA A3C573 290–0488–00 CAP,FXD,ELCTLT:2.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3C753 A3C754 Name & Description Mfr. Code Mfr. Part Number 281–0775–00 CAP,FXD,CERAMIC:MLC;0.1UF,20%,50V,Z5U,0.170 04222 SA105E104MAA 281–0775–00 CAP,FXD,CERAMIC:MLC;0.1UF,20%,50V,Z5U,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number Serial no. effective Serial No. Discont’d Name & Description Mfr. Code Mfr. Part Number A3CR356 152–0066–00 DIODE,RECT:400V,1A,IFSM=30A,1.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3CR853 A3CR854 Name & Description Mfr. Code Mfr.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3P192 131–3199–00 A3P273 Mfr. Code Mfr. Part Number CONN,SHUNT:SHUNT;FEMALE,STR,1 X 2,0.1 CTR, 0.2 H,LOW PROFILE,JUMPER 22526 68786–202 131–3199–00 CONN,SHUNT:SHUNT;FEMALE,STR,1 X 2,0.1 CTR, 0.2 H,LOW PROFILE,JUMPER 22526 68786–202 A3P373 131–3199–00 CONN,SHUNT:SHUNT;FEMALE,STR,1 X 2,0.1 CTR, 0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number Serial no. effective Serial No. Discont’d A3R155 311–2230–00 B030000 B030209 A3R155 311–2231–00 B030210 A3R156 A3R157 Name & Description Mfr. Code Mfr. Part Number RES,VAR,TRMR:CERMET;500 OHM,20%,0.5W,0.197 SQ,TOP ADJUST (760N ONLY) TK2073 GF06UT2 501 M L RES,VAR,TRMR:CERMET,1K OHM,20%,0.5W,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3R280 A3R281 Name & Description Mfr. Code Mfr. Part Number 322–3289–07 RES,FXD,FILM:10K OHM,0.1%,0.2W,TC=T9,T&R,SM BODY 91637 CCF501C10001B 322–3318–00 RES,FXD,FILM:MET FILM;20K OHM,1%,0.2W,TC=100 PPM 91637 CCF501G20001F A3R282 322–3373–00 RES,FXD,FILM:75K OHM,1%,0.2W,TC=T0MI,SMALL BODY 91637 CCF501G75001F A3R287 321–1612–07 RES,FXD,FILM:4.455K OHM,0.1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3R383 322–3254–00 A3R383 Mfr. Code Mfr. Part Number RES,FXD,FILM:4.32K OHM,1%,0.2W,TC=T0MI,SMALL BODY (760D ONLY) 91637 CCF502G4321FT 322–3286–00 RES,FXD,FILM:9.31K OHM,1%,0.2W,TC=T0MI,SMALL BODY (760N ONLY) 91637 CCF501G93100F A3R387 321–1612–07 RES,FXD,FILM:4.455K OHM,0.1%,0.125W,TC=T9 19701 5033RE4K455B A3R388 321–0603–07 RES,FXD,FILM:15K OHM,0.1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number Serial no. effective Serial No. Discont’d A3R546 311–2230–00 RES,VAR,TRMR:CERMET;500 OHM,20%,0.5W,0.197 SQ,TOP ADJUST A3R547 322–3282–00 RES,FXD,FILM:8.45K OHM,1%,0.2W,TC=T0MI,SMALL BODY 91637 CCF501G84500F A3R548 322–3314–00 RES,FXD:METAL FILM;18.2K OHM,1%,0.2W,TC=100 (760A ONLY) 91637 CCF501G18201F A3R550 322–3350–00 RES,FXD,FILM:43.2K OHM,1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3R602 A3R603 Name & Description Mfr. Code Mfr. Part Number 322–3097–00 RES,FXD:METAL FILM;100 OHM,1%,0.2W,TC=100 PPM 91637 CCF501G100R0F 322–3097–00 RES,FXD:METAL FILM;100 OHM,1%,0.2W,TC=100 PPM 91637 CCF501G100R0F A3R604 301–0101–00 RES,FXD,FILM:100 OHM,5%,0.5W TK1727 SFR30 2322–182– A3R605 322–3193–00 RES,FXD:METAL FILM;1K OHM,1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3R683 A3R684 Name & Description Mfr. Code Mfr. Part Number 322–3450–00 RES,FXD,FILM:475K OHM,1%,0.2W,TC=T0MI,SMALL 91637 CCF50–2G47502F 322–3193–00 RES,FXD:METAL FILM;1K OHM,1%,0.2W,TC=100 PPM 91637 CCF501G10000F A3R685 322–3385–00 RES,FXD:METAL FILM;100K OHM,1%,0.2W,TC=100 PPM 91637 CCF501G10002F A3R686 322–3481–00 RES,FXD,FILM:1M OHM.1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3R772 A3R773 Name & Description Mfr. Code Mfr. Part Number 322–3177–00 RES,FXD:METAL FILM;681 OHM,1%,0.2W,TC=100 PPM 91637 CCF50–2G681R0F 322–3097–00 RES,FXD:METAL FILM;100 OHM,1%,0.2W,TC=100 PPM 91637 CCF501G100R0F A3R774 322–3267–00 RES,FXD,FILM:5.9K OHM,1%,0.2W,TC=T0MI,SMALL 56845 CCF50–2–G5901FT A3R775 322–3097–00 RES,FXD:METAL FILM;100 OHM,1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3R855 A3R856 A3R858 A3R861 Name & Description Mfr. Code Mfr. Part Number 322–3282–00 RES,FXD,FILM:8.45K OHM,1%,0.2W,TC=T0MI,SMALL BODY 91637 CCF501G84500F 322–3481–00 RES,FXD,FILM:1M OHM.1%,0.2W,TC=T0MI,SMALL BODY 91637 CCF501G10003F 308–0549–00 RES,FXD,WW:6.3K OHM,1%,3W 91637 RS2B–B63000F 322–3097–00 RES,FXD:METAL FILM;100 OHM,1%,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3TP568 214–4085–00 A3TP621 Serial no. effective Serial No. Discont’d Mfr. Code Mfr. Part Number TERM,TEST POINT:0.070 ID,0.220 H,0.063 DIAP CB,0.015 X 0.032 BRASS,W/RED NYLON COLLAR 26364 104–01–02 214–4085–00 TERM,TEST POINT:0.070 ID,0.220 H,0.063 DIAP CB,0.015 X 0.032 BRASS,W/RED NYLON COLLAR 26364 104–01–02 A3TP672 214–4085–00 TERM,TEST POINT:0.070 ID,0.220 H,0.063 DIAP CB,0.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number A3U213 A3U217 Serial no. effective Serial No. Discont’d Name & Description Mfr. Code Mfr.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number Serial no. effective Serial No.
Replaceable Electrical Parts Replaceable Electrical Parts List (Cont.) Component Number Tektronix Part Number J200 131–3208–00 Serial no. effective Serial No. Discont’d Name & Description Mfr. Code Mfr. Part Number CONN,CIRC:XLR,FEMALE,3 POS,SAFTEY CONTROLLED 82389 D3F *MOUNTING PARTS* 211–0097–00 SCREW,MACHINE:4–40 X 0.
Diagrams/Circuit Board Illustrations
Section 9 Diagrams/Circuit Board Illustrations Symbols Graphic symbols and class designation letters are based on ANSI Standard Y32.2–1975. Logic symbology is based on ANSI Y32.14–1973 in terms of positive logic. Logic symbols depict the logic function performed and may differ from the manufacturer’s data. Overline, parenthesis, or leading slash indicate a low asserting state. Example: ID CONTROL, (ID CONTROL), or /ID CONTROL. Abbreviations are based on ANSI Y1.1–1972.
Diagrams/Circuit Board Illustrations 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), circuit board illustration title, and lookup table for the schematic diagram. The Replaceable Electrical Parts List is arranged by assembly number in numerical sequence; the components are listed by component number.
A3 Main Board Diagram Component Locator C125 C127 C132 C145 C148 C149 1 1 1 1 1 3 G3 G3 G3 H3 G2 G4 C165 C172 C179 C187 C190 4 1 1 1 1 G3 G2 G2 C2 B2 C206 C211 C215 C251 C254 2 1 3 3 1 H1 H3 H1 G5 F5 C255 C258 C261 C262 C263 1 1 1 1 1 F5 F5 H3 G3 H2 C267 C268 C279 C287 C290 C324 C328 C332 C333 C338 C343 C344 C349 C361 C368 C369 C379 C387 C390 C406 C411 C415 C436 C445 C448 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1
A3 Main Board Static Sensitive Devices See Maintenance Section Assembly A3 Schematic Diagram <1> Component Locator Chart C125 C127 C132 C145 C148 G3 G3 G3 H3 G2 C261 C262 H3 G3 C338 C343 C344 C361 C368 H3 G3 G4 H4 H4
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Schematic Diagram <2> Component Locator Chart Assembly A3 760A / 760D / 760N C206 C349 C448 C536 C543 H1 A1 C1 D4 D1 Q507 C3 R632 R637 D4 D1 R122 R123 R124 R255 R306 H3 H2 H1 C1 H1 U436A U436B U438 D2 D4 F1 R641 R643 R646 R647 R648 B3 A4 B4 C4 C4 R311 R319 R320 R321 R347 H4 H3 H3 H3 A1 U445A U445B U445C U445D U453A A1 A1
R441 10.0K 2 3 -LEFT C349 10UF R347 500 4 +5V 1 U445A 1 MC34084 1 U445C MC34084 CR442 10 -12V CHANNEL MATCH +12V R543 10.0K R547 8.45K CR546 8 9 U453A MC34084 C448 .33UF C546 5.6PF 7 5 U445B MC34084 CR545 CR542 R446 4.75K 12 14 3 1 4 R255 43.2K -12V 1 U453C MC34084 10 LEFT DYNAMIC RESPONSE CONTROL (PPM) 2 C X R X Q C L B 5 J CK Q A[0..7] PEAK HOLD ON/OFF DAC 3 A0 A1 A2 A3 A4 A5 A6 A7 U823B 7473 +5V +5V R617 1.00K 1 PEAKHOLD B4 4 R821 10.
Schematic Diagram <3> Component Locator Chart Assembly A3.
R849 10.0K R851 10.0K 2 4 C755 10UF SELECT_BAR 1 1 R758 500 CR851 1 3 U853A MC34084 10 CHANNEL MATCH 8 9 R852 10.0K H1 4 U853C MC34084 CR850 -12V +12V NOTE: R857 +12V 760A 3.24M 3 760D 2.00M 2 760N 2.00M U453D MC34084 12 C858 .33UF C854 5.6PF 13 R857 3.24M 7 5 CR852 U853B MC34084 R854 4.75K R846 100 12 R853 18.2K 13 R356 43.2K 1 2 AUX DYNAMIC RESPONSE CONTROL (PPM) 9 Q A C L B Q C3 2 A Q C L B Q ADELAY C718 2700PF 5 C819 .
Schematic Diagram <4> Component Locator Chart Assembly A3.
B1 E1 5 1 VAGC AUX_ENABLE 1 SUM_ENABLE 16 SUM(L+R) 15 2 AUX AGCV 10 DIFF_ENABLE 8 DIFF(R-L) +12V -12V ORTHOGONALITY CORRECTION J273 2 - 3 L+R -RIGHT 4 2 J273 1 3 E4 1 2 1 R371 10.0K 2 1 3 11 7 6 13 4 5 U462B MC34084 CR558 R458 10.0K 7 R460 10.0K 6 5 R364 10.0K A1 GAIN CONTROL LOGIC 7 5 3 -12V R174 10.00K -LEFT 3 14 AUX BAR SELECT CR559 6 +12V U179A MC34084 1 1 R558 10.0K R370 10.0K +12V R175 10.00K SELECT_BAR R856 1.00M R560 10.
Schematic Diagram <5> Component Locator Chart Assembly A1.
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A1 Power Supply Board Static Sensitive Devices See Maintenance Section A1 Board and Diagram <6> Component Locator Comp No C1 C2 C3 C4 C5 Diag No 7 7 7 7 7 Diag Loc C4 D3 D3 D3 D4 Bd Loc A4 D1 A2 A2 B3 Comp No Diag No C27 C28 C29 C30 C31 7 7 6 6 6 Diag Loc B1 B1 F2 F2 F3 Bd Loc E3 E3 F1 F2 F3 C6 C7 C8 C9 C10 7 7 7 7 7 C4 F3 D3 E2 C5 B4 B1 B2 B2 B4 C32 C33 C34 C35 C36 6 6 7 6 6 F2 G2 D1 F3 G2 F3 F4 F4 G3 G3 C11 C12 C13 C14 C15 7 7 7
J5 1 1 2 CAUTION: 2 3 ALL CIRCUITRY TO THE LEFT OF THE ISOLATION BOUNDARY IS AT POWER LINE POTENTIAL AND REQUIRES AN ISOLATION TRANSFORMER TO SERVICE. 3 4 ISOLATION BOUNDARY 4 5 5 6 6 7 7 8 8 9 LINE RECTIFIER AND FILTER C62 9 10 CR10 NOT INSTALLED 10 11 11 C63 OUTPUT FILTERS MOUNTING L4 1MH C56 .022UF CLAMP R102 8 L3 4.7UH CR11 +15V J6 R89 5 F1 2A 90-250V CR23 C44 .47UF C54 330UF CR22 J10 REAR PANEL R91 100K C57 .
Assembly A1. Partial Assembly A1 also shown on Schematic 6.
R61 22.1 HV OSC & ERROR AMP C28 0.1UF +100V C19 10UF R66 499K U2 741 +15A CR31 5.5KV P-P R59 5.000K 2 P320 1 2 IN +11KV 3 OUT C21 .015UF R60 6.04K 2 CR30 C22 0.47 UF C20 .015UF R64 100K T1 +100V GRID DRIVE CR7 C66 10UF 5 CR5 R58 100K 8 CRT BIAS C16 10UF 13 GEOMETRY C12 .015UF R48 3.01K C14 .015UF 3 H Q6 R57 22.1 6 C11 .001UF R44 470 9 2 CR1 CR4 FIL1 VR5 R30 10K VR6 R39 470 R29 47 C4 .01UF C3 .01UF DS1 DS3 FIL2 WIRE COLOR CODES 3 R56 10.0 R51 4.
Static Sensitive Devices See Maintenance Section A2 Front Panel Board Schematic Diagram <8> Component Locator Chart Assembly A2.
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Replaceable Mechanical Parts
Section 10 Replaceable Mechanical Parts This section contains a list of the replaceable mechanical components for the 760A, 760D, and 760N. Use this list to identify and order replacement parts. Parts Ordering Information Replacement parts are available through your local Tektronix field office or representative. Changes to Tektronix products are sometimes made to accommodate improved components as they become available and to give you the benefit of the latest improvements.
Replaceable Mechanical Parts 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 view illustrations that follow. 2 Tektronix part number Use this part number when ordering replacement parts from Tektronix. 3 and 4 Serial number Column three indicates the serial number at which the part was first effective. Column four indicates the serial number at which the part was discontinued.
Replaceable Mechanical Parts Manufacturers Cross Index Mfr. Code Manufacturer Address City, State, Zip Code S3109 FELLER U.S.
Replaceable Mechanical Parts Replaceable mechanical parts list Fig. & Index Number Tektronix Part Number 1–1 426–2174–02 1 –2 211–0690–02 –3 Mfr. Code Mfr. Part Number FRAME,CRT:BEZEL *MOUNTING PARTS* 80009 426217402 2 SCREW,MACHINE:6–32 X 0.875,PNH,SST *END MOUNTING PARTS* 93907 B20–70430 361–1515–00 1 SPACER,RING:4.9 X3.
Replaceable Mechanical Parts Replaceable mechanical parts list (Cont.) Fig. & Index Number Tektronix Part Number Serial No. Effective Serial No. Discont’d Qt y Mfr. Code 211–0721–00 B030000 B030208 7 Mfr. Part Number SCREW,MACH:6–32 X 0.375,PNH,STL,CDPL,T–15 TORX DR (760N ONLY) 0KB01 ORDER BY DESC 211–0721–00 B030209 6 SCREW,MACH:6–32 X 0.375,PNH,STL,CDPL,T–15 TORX DR (760N ONLY) 0KB01 ORDER BY DESC TK0435 ORDER BY DESC Name & Description –22 211–0014–00 2 SCREW,MACHINE:4–40 X 0.
Replaceable Mechanical Parts Replaceable mechanical parts list (Cont.) Fig. & Index Number Tektronix Part Number –45 161–0066–10 1 –46 161–0066–11 1 ––––––––––– ––––––––––– ––––––––––– ––––––––––– ––––––––––– 1 1 1 1 1 –47 –48 –49 10–6 Serial No. Effective Serial No. Discont’d Qt y Mfr. Code Mfr. Part Number CA ASSY,PWR:3,0.1MM SQ,250V/10A,2.
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