Tektronix 1705A - Manuals

Table of Contents iv 1705A Spectrum Monitor Short-- Form Procedure 5-- 17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Long Form Procedure 5-- 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mainten...

Table of Contents 1705A Spectrum Monitor v Replaceable Electrical Parts Section 8 Replaceable Electrical Parts 8--1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Parts Ordering Information 8-- 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

Table of Contents vi 1705A Spectrum Monitor List of Figures Figure 1-1: 1705A used to locate satellites and determine maximum signal level 1--2 . . . . . . . . . Figure 1-2: Relationship of a communications satellite to earth 1--9 . . . . . . . . . . . . . . . . . . . . . . . Figure 1-3: Angle A (th...

Table of Contents 1705A Spectrum Monitor vii Figure 3-8: Considerations for custom installation of an instrument 3--8 . . . . . . . . . . . . . . . . . . . . Figure 4-1: 1705A L--Band comb display showing the areas each of the six sweep shaper variable resistors adjust 4--8 . . . . . . . . . . . . ....

Table of Contents viii 1705A Spectrum Monitor List of Tables Table 1--1: Spectrum Display 1--4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1--2: CRT Display 1--5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

1705A Spectrum Monitor ix 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. While...

General Safety Summary x 1705A Spectrum Monitor Provide Proper Ventilation. Refer to the manual’s installation instructions for details on installing the product so it has proper ventilation. Terms in this Manual. These terms may appear in this manual: WARNING. Warning statements identify conditions...

1705A Spectrum Monitor xi 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 ...

1705A Spectrum Monitor xiii Preface The information in this manual is intended for instrument operators and servicetechnicians. Operators are assumed to befamiliar with basic television terms andmeasurements. Qualified service technicians are also assumed to be familiar withtelevision terms and meas...

Preface xiv 1705A Spectrum Monitor Section 7, Options, documents instrument options. The information in thissection summarizes the options. Additional details are included in appro-priateplaces throughout the manual. Section 8, Replaceable Electrical Parts, includes order information and partnumbers...

Preface 1705A Spectrum Monitor xv Contacting Tektronix Phone 1-800-833-9200 * Address Tektronix, Inc.Department or name (if known)14200 SW Karl Braun DriveP.O. Box 500Beaverton, OR 97077USA Web site www.tektronix.com Sales support 1-800-833-9200, select option 1 * Service support 1-800-833-9200, sel...

1705A Spectrum Monitor 1- 1 Section 1Introduction The TEKTRONIX 1705A Spectrum Monitor is an 8 ½ ” wide by 5 ¼ ” high special purpose spectrum analyzer. It weighs approximately 8 ½ pounds and is powered from an ac source. The crt occupies approximately two-thirds of thefront-panel area, with the con...

Introduction 1- 2 1705A Spectrum Monitor LOW-NOISE AMPLIFIER/ BLOCK DOWN CONVERTER 1705A SPECTRUM MONITOR RECEIVER Figure 1-1: 1705A used to locate satellites and determine maximum signal level Options The only options currently available for the 1705A Spectrum Monitor are thepower plug options desc...

Introduction 1705A Spectrum Monitor 1- 3 Camera, C9 (Option 20) Viewing Hood (016-0475-00) Front Panel Cover (200-3897-01) 1700F00, Plain Cabinet (painted silver grey) 1700F02, Portable Cabinet (painted silver grey with handle, feet, and frontcover) 1700F05, Side-by-Side Rack Adapter 1700F06, Blank ...

Introduction 1- 4 1705A Spectrum Monitor ELECTRICAL SPECIFICATION Table 1- 1: Spectrum Display Characteristic Performance Requirements Supplemental Information Check Step Frequency Range L --- Band70 MHz 950 to 1800 MHz45 to 100 MHz F --- type connectorBnc connector Frequency Span L --- Band Full10 ...

Introduction 1- 6 1705A Spectrum Monitor Table 1- 4: Environmental Characteristics Characteristic Supplemental Information Temperature Non - Operating Operating --- 55˚C to +75˚C. 0˚C to +50˚C. Altitude Non - Operating Operating To 50,000 feet (15,000 meters).To 15,000 feet (4,800 meters). Vibration...

Introduction 1705A Spectrum Monitor 1- 9 APPLICATIONS The principal application for the TEKTRONIX 1705A Spectrum Monitor is toprovide a convenient method to locate and identify Ku-Band satellites, find thecorrect transponder and check on its availability, and optimize antenna position-ing and polari...

Introduction 1- 10 1705A Spectrum Monitor orbit of the satellite. If the orbit of an equatorial orbiting satellite were roughlyequal to the distance from earth to the sun, ordinary latitude could be used todetermine the elevation of the antenna, which is, of necessity, very finelyfocused. However si...

Introduction 1705A Spectrum Monitor 1- 11 NEW YORK CITY CHICAGO LOS ANGELES HONOLULU ANCHORAGE GREENWICH ENGLAND NORTH POLE PRIME MERIDIAN 000 ° INTERNATIONAL DATELINE 180 ° 45 ° W 45 ° E 90 ° E 135 ° E 135 ° W SPACENET 2 69 ° RCA K2 81 ° RCA K1 85 ° SBS 3 97 ° GSTAR A2 103 ° GSTAR A1 105 ° ANIK B 1...

Introduction 1- 12 1705A Spectrum Monitor L - Band Input Signals At the present time there are numerous satellites in geostationary orbit. Thetransponders on each have specific assigned functions, which makes it essentialto accomplish at least four things before illuminating a particular transponder...

Introduction 1705A Spectrum Monitor 1- 13 Zeroing in on a Satellite In almost all cases a set procedure for Locating, Identifying, Finding (transpond-ers), and Optimizing will be followed. The 1705A Spectrum Monitor is a toolthat greatly simplifies the individual steps so the correct satellite trans...

Introduction 1- 14 1705A Spectrum Monitor Tek REF -- 10 -- 20 -- 30 -- 40 -- 50 -- 60 -- 70 L O G + f 12.20 GHZ Figure 1-6: A computer representation of the 1705A display showing the 12.198 GHzhorizontally polarized telemetry beacon on the SATCOM K2 satellite (Span/Div setto 100 kHz with a 10 kHz Re...

Introduction 1705A Spectrum Monitor 1- 15 11.729GHz 11.788GHz 11.847GHz 11.906GHz 11.965GHz 12.024GHz 12.083GHz 12.142GHz 11.7585GHz 11.8175GHz 11.8765GHz 11.9355GHz 11.9945GHz 12.0535GHz 12.1125GHz 12.1715GHz 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 HORIZONTAL POLARIZATION VERTICAL POLARIZATION DOWN ...

Introduction 1- 16 1705A Spectrum Monitor Tek REF -- 10 -- 20 -- 30 -- 40 -- 50 -- 60 -- 70 L O G + f 11.73 GHZ 1 3 5 7 9 11 13 15 Figure 1-8: Simulation of a 1705A FULL SPAN/DIV display showing six transpondersilluminated The 70 MHz Input to the spectrum monitor is a bnc connector. It is designed f...

Introduction 1705A Spectrum Monitor 1- 17 1705A SPECTRUM MONITOR IN RF OUT HPA OUT IN UP CONVERTER OUT VIDEO EXCITER 70 MHZINPUT DIRECTIONAL COUPLER Figure 1-9: Up link Video Exciter, Up converter, and High Power Amplifier (HPA)showing how to hook up a 1705A Spectrum Monitor to look at the Video Exc...

1705A Spectrum Monitor 2- 1 Section 2Operating Instructions These instructions provide information about the front-panel controls andindicators, rear-panel connectors and switch, powering-up, and the measurementgraticule and alphanumeric readout. Front - panel Controls and Indicators The front--pane...

Operating Instructions 2- 2 1705A Spectrum Monitor Tektronix INPUT DISPLAY 1705A VIDEO ON SPECTRUM MONITOR POSITION = HOLD FOR FUNCTION FOCUS SCALE INTENS ON 300 KHz10 KHz LBAND70 MHz POWER 1 2 3 4 5 6 7 8 9 10 11 12 13 HORIZONTAL VERTICAL RESOLUTION FILTER SWEEP SPEED CENTER FREQUENCY TRACE ROTATIO...

Operating Instructions 1705A Spectrum Monitor 2- 3 6. SPAN/DIV Two push-button switches (left and right) that select the calibrated span perdivision. Each span is indicated by a front-panel LED. FULL -- Provides a span of 50 MHz per division for the L--Band (900 -- 2000MHz) input, and 5 MHz per divi...

Operating Instructions 2- 4 1705A Spectrum Monitor 11. HORIZONTAL A variable control that positions the trace horizontally (X axis). 12. VERTICAL A variable control that positions the display vertically (Y axis). 13. POWER Switches the instrument between a powered up state and standby. Portionsof th...

Operating Instructions 1705A Spectrum Monitor 2- 5 70 MHz SPECTRUM MONITOR 333 --3990 --01 INPUT BESCHLEUNIGUNGSSPANNUNG KLEINER ALS 20kV DIE IN DIESEM GERAT ENTSTEHENDE RONTGENSTRAHLUNG IST AUSREICHEND ABGESCHIRMT 1 2 3 4 6 5 WARNING TO AVOID ELECTRICAL SHOCK, THE POWER CORD PROTECTIVE GROUNDING CO...

Operating Instructions 1705A Spectrum Monitor 2- 7 Measurement Graticule The 1705A is equipped with an internal graticule crt. The graticule has an 8 X10 division scale that is lighted. Scale brilliance is controlled by the front-panelSCALE control. Figure 2-4 shows the 1705A graticule. Refer to thi...

Operating Instructions 1705A Spectrum Monitor 2- 9 Table 2- 2: dBm to v Conversion Reading in dBm v (75 Ω ) v (50 Ω ) Reading in dBm v (75 Ω ) v (50 Ω ) --- 30 8660 7071 --- 105 1.540 1.257 --- 35 4870 3976 --- 110 0.866 0.707 --- 40 2739 2236 --- 115 0.487 0.398 --- 45 1540 1257 --- 120 0.274 0.224...

Operating Instructions 1705A Spectrum Monitor 2- 11 Tek REF -- 10 -- 20 -- 30 -- 40 -- 50 -- 60 -- 70 L O G + f 45 MHZ 95 MHZ 1900 MHZ 900 MHZ 50 55 60 65 70 75 80 85 90 1000 1100 1200 1300 1400 1500 1600 1700 1800 70 MHZ L-BAND Figure 2-6: Frequency relationship to horizontal graticule scale; cente...

Operating Instructions 2- 14 1705A Spectrum Monitor Customizing Frequency Readout The type and location of the readout for the TEKTRONIX 1705A SpectrumMonitor can be changed from the front panel. The options available are: 1. Thechoice of having readout or turning it off. 2. The position on the crt ...

Operating Instructions 1705A Spectrum Monitor 2- 15 . SPECTRUM DISPLAY READOUT MODE ON OFF L-BAND OFFSET L.O. HIGH >EXIT USE SPAN KEYS TO MOVE CURSOR, PRESS INPUT KEY TO SELECT. MAIN MENU READOUT MODE READOUT POSITION TEST >EXIT USE SPAN KEYS TO MOVE CURSOR, PRESS INPUT KEY TO SELECT. READOUT ...

Operating Instructions 1705A Spectrum Monitor 2- 17 ments the frequency readout (low to high) and moves the brightened portion ofthe sweep from left to right. When L.O. Low is selected the readout decrements(high to low) and the brightened portion of the sweep moves from left to right,with clockwise...

Operating Instructions 2- 18 1705A Spectrum Monitor 2. Stabilize the vehicle in a location where there will be a clear path betweenthe antenna and the satellite. The vehicle should be reasonably level tofacilitate antenna and polarization adjustment. 3. Point the antenna in the expected direction of...

Operating Instructions 1705A Spectrum Monitor 2- 19 Table 2- 3: Azimuth / Elevation Table for 21 CONUS Cities (Cont.) Salt Lake City 137˚ 34˚ 169˚ 42˚ 155˚ 39˚ San Francisco 125˚ 28˚ 154˚ 42˚ 140˚ 38˚ Seattle 131˚ 22˚ 158˚ 32˚ 146˚ 29˚ St. Louis 166˚ 44˚ 204˚ 42˚ 188˚ 45˚ Washington DC 186˚ 45˚ 221˚...

1705A Spectrum Monitor 3- 1 Section 3Installation The shipping carton and pads provide protection for the instrument duringtransit, and should be retained in case subsequent shipment becomes necessary.Repackaging instructions can be found in Section 6 (Maintenance) of thismanual. Electrical Installa...

Installation 3- 2 1705A Spectrum Monitor L BAND INPUT LNB POWER ON LNB POWER OFF +18 VDC @ 250 mA ON Figure 3-1: L-BAND INPUT connector and controls Under extreme LNB load conditions it is possible for the +18 V supply to loadthe main 1705A power supply enough to change the low line regulation. Unde...

Installation 1705A Spectrum Monitor 3- 3 All qualification testing for the 1705A was performed with a 1700F00 cabinetinstalled. See Figure 3-2. To guarantee compliance with specifications, theinstrument must be operated in a cabinet. The portable cabinet, 1700F02, has ahandle, four feet, a flip-up s...

Installation 3- 4 1705A Spectrum Monitor Top 410.97 mm (16.180 in) 126.49 mm (4.980 in) Rear 209.55 mm (8.250 in)174.63 mm (6.875 in) 17.48 mm (0.688 in) 14.00 mm (0.551 in) Side 209.55 mm (8.250 in) Figure 3-3: 1700F02 portable cabinet dimensions WARNING. Do not attempt to carry a cabinetized instr...

Installation 1705A Spectrum Monitor 3- 5 LNB POWER 70 MHz SPECTRUM MONITOR 333 --3990 --01 INPUT BESCHLEUNIGUNGSSPANNUNG KLEINER ALS 20kV DIE IN DIESEM GERAT ENTSTEHENDE RONTGENSTRAHLUNG IST AUSREICHEND ABGESCHIRMT WARNING TO AVOID ELECTRICAL SHOCK, THE POWER CORD PROTECTIVE GROUNDING CONDUCTOR MUST...

Installation 3- 8 1705A Spectrum Monitor For applications such as consoles, shown in Figure 3-8, the instrument can bemounted with front molding flush or protruding from the console. In both cases,allow approximately 3 inches of rear clearance for bnc and power cord connec-tions. Requires four 0.156...

1705A Spectrum Monitor 4- 1 Section 4Theory of Operation The material in this section is subdivided into a general description (which issupported by the main block diagram) and detailed circuit descriptions that usethe schematic diagrams as illustrations. A thorough understanding of theinstrument st...

Theory of Operation 4- 2 1705A Spectrum Monitor driven with a pre-corrected sweep ramp. Pre-correction is required to make upfor the inherent VCO nonlinearity. A +18 V supply is connected to the L--BAND input connector so that it can beused to power a Block Down Converter (usually at the antenna). T...

Theory of Operation 1705A Spectrum Monitor 4- 3 bright-up signal, centered around the center frequency, is generated for theZ--Axis Control circuit by the Marker Generator. The Z--Axis Control circuit provides the driving signal for the Z--Axis Amplifier(Diagram 8). Included in these unblanking sign...

Theory of Operation 4- 4 1705A Spectrum Monitor regulated to become the + and --11.8 V supplies on the Main circuit board(regulator circuits are on Diagram 4). The Power Supply schematic also contains the 11.8 V Post Regulators, whoseoutputs are used by most of the circuits on the Main circuit board...

Theory of Operation 1705A Spectrum Monitor 4- 5 by a 7-pole, 120 MHz, low-pass filter that rejects out-of-band frequencies. TheMixer, U190, with input frequencies of 45 -- 100 MHz, and the Local Oscillatoroperating at [F i + 130 MHz] provide a 130 MHz 1 st IF. The signal output from the Mixer is ter...

Theory of Operation 1705A Spectrum Monitor 4- 7 Sweep GeneratorDiagram 3 This schematic contains the free--running Ramp Generator, Switchable GainControl (SPAN/DIV), Sweep Shapers, Marker Generator, and the Z--Axis(Brightness) control. U24 is the Ramp Generator; U24B is configured as an integrator a...

Theory of Operation 4- 8 1705A Spectrum Monitor START OF DISPLAY R727 R729 R737 R733 R731 R735 Figure 4-1: 1705A L- Band comb display showing the areas each of the six sweepshaper variable resistors adjust The Marker Generator is U14. The front-panel CENTER FREQUENCY controlprovides the voltage from...

Theory of Operation 1705A Spectrum Monitor 4- 9 conditions the output goes toward the positive supply. If the input is between +and --0.7 V, neither diode conducts and the amplifier has no input and, conse-quently, an output of 0 V. When the output of U14D is near 0 V, a pulse thatproduces the crt b...

Theory of Operation 4- 10 1705A Spectrum Monitor control into the summing junction of U27 (pin 2). The Vertical Position controlis attenuated by resistors R152 and R140 (2 dB POS RANGE). This positionsthe video signal at pin 6 of U27, providing greater positioning range while inHigh Gain mode. The h...

Theory of Operation 1705A Spectrum Monitor 4- 11 MicroprocessorDiagram 5 The 1705A is a microprocessor-controlled instrument. Circuitry on Diagram 5shows the microprocessor, the front-panel LED drive, the crt readout drive, thegraticule light circuit, and the trace rotation circuit. The processor (U...

Theory of Operation 4- 12 1705A Spectrum Monitor U6 is an 8-bit D-type data latch that drives all the front-panel LEDs and most ofthe internal control lines. Chip select for U6 is /WR (U2, pin 16) inverted (U7C)and ANDed with Address 14 (U2, pin 27) by U7A. U10 is a dual 8-bit DAC (Digital-to-Analog...

Theory of Operation 1705A Spectrum Monitor 4- 15 The input line voltage is filtered by the rear-panel connector to reduce theelectrical noise conducted into or out of the instrument. R89 limits the initialcharging current through the rectifier diodes and C54. CR21, CR22, CR23, and CR24 form a bridge...

Theory of Operation 4- 16 1705A Spectrum Monitor increases, causing the voltage across R96 to increase. This voltage is divided byR87 and R101, and is applied to the comparator (pin 3). When the voltage at U5pin 3 reaches the comparator trip point, the latch toggles and the switcher mosfetis turned ...

Theory of Operation 1705A Spectrum Monitor 4- 17 High Voltage Power SupplyDiagram 8 The High Voltage Power Supply generates the heater, cathode, control grid, focusanode, and post accelerating potentials required to display the outputs of theVertical and Horizontal Output Amplifiers. The High Voltag...

Theory of Operation 4- 18 1705A Spectrum Monitor 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 t...

Theory of Operation 1705A Spectrum Monitor 4- 19 Q5 is a current amplifier feeding the output stage. Q3 and Q4 form a push-pulloutput stage. Q3 acts as a 2.7 mA constant current pull-up, while Q4 is thepull-down transistor. C6 speeds up the amplifier by coupling ac signals to thebase of Q3. CR2 and ...

1705A Spectrum Monitor 5- 1 Section 5Checks And Adjustments This section consists of two separate procedures. The first, a PerformanceCheck, is used to determine compliance with the Performance Requirements inthe Specification. The second is the Adjustment Procedure, that provides theinstructions on...

Checks and Adjustments 5- 2 1705A Spectrum Monitor 2. Leveled Sine Wave Generator , at least 250 kHz to 95 MHz. For example: A TEKTRONIX SG503 Leveled Sine Wave Generatorinstalled in a TEKTRONIX TM500 Series Power Module. 3. Voltmeter Range, 0 to greater than 100 Vdc; accuracy, ± 0.1%. For example: ...

Checks and Adjustments 1705A Spectrum Monitor 5- 3 11. SMA Male-to-bnc Female Adapter Two required (supplied with the Tektronix Comb Generator). For example: Tektronix Part No. 015-1018-00. 12. SMB Female-to-bnc Female Adapter For example: Coaxial Components Corporation Part No. 2525-4. Performance ...

Checks and Adjustments 1705A Spectrum Monitor 5- 5 s. CHECK -- that the readout still reads 1000, ± 10. u. CHECK -- that the marker is on screen. v. CHECK -- that the readout still reads 1000, ± 10. x. CHECK -- that the marker is on screen. 12. Check L--Band Gain and Flatness e. CHECK -- that the ma...

Checks and Adjustments 5- 6 1705A Spectrum Monitor Table 5- 1: Preliminary Control Settings POWER ON INTENSITY Set to Preference FOCUS SCALE VERTICAL POSITION Set later HORIZONTAL POSITION INPUT 70 MHz RESOLUTION 300 kHz VIDEO off SPAN/DIV FULL CENTER FREQUENCY anywhere SWEEP SPEED y ! ! SG503 CombG...

Checks and Adjustments 5- 8 1705A Spectrum Monitor a. Adjust FOCUS, INTENSITY, SCALE, and SWEEP SPEED for auseable display. b. Place the 2 nd marker on the left edge of the graticule. See Figure 5-2. ALIGN 2ndMARKER HERE CHECK THAT 3rdMARKER IS +/-- 1 MINORDIVISION FROM HERE Left edge of graticule 3...

Checks and Adjustments 5- 12 1705A Spectrum Monitor 10. Check L--Band Linearity REQUIREMENT -- One marker per Division ± 1 minor Division. a. Connect the output of the leveled sine wave generator, through the combgenerator, to the 1705A L--BAND INPUT. See Figure 5-4. SG503 CombGenerator VARIABLEAUTO...

Checks and Adjustments 1705A Spectrum Monitor 5- 13 ALIGN 2ndMARKER HERE DISREGARD #1 GRATICULE LINE #2 GRATICULE LINE Figure 5-5: Aligning L- Band time markers with the graticule lines. The graticulebegins with 0 while the time markers are counted 1, 2, 3, etc. The first and lastdivisions of sweep ...

Checks and Adjustments 5- 14 1705A Spectrum Monitor h. Change the leveled sine wave generator Frequency to 5 MHz, AmplitudeMultiplier to X1, and the Amplitude to 3.0 (14 dBm). i. CHECK -- for 1 marker every 5 Divisions, ± 1 Division (adjust CENTER FREQUENCY, if necessary). j. Repeat parts f. through...

Checks and Adjustments 5- 16 1705A Spectrum Monitor a. Set the UHF signal generator Frequency to 1400 MHz, and Amplitude to --60 dBm. b. CHECK -- that the tip can be positioned 2 Divisions left and right of center. c. Set the UHF signal generator Amplitude to --30 dBm. d. Position baseline on the --...

Checks and Adjustments 1705A Spectrum Monitor 5- 17 Adjustment Procedure The Adjustment Procedure covers only adjustments. Checks, other than thosethat must be made to ensure a step is completed, are in the Performance CheckProcedure. There are actually two Adjustment Procedures, the short-form vers...

Checks and Adjustments 1705A Spectrum Monitor 5- 19 2. Adjust CRT Bias a. Turn the INTENSITY control fully counterclockwise. b. ADJUST -- R58 (CRT BIAS) so that the display is just extinguished. c. Set INTENSITY control for a useable display. CAUTION MAINS VOLTAGE A1 PWR SPLY BD R11 R45 R49 R58 W1 +...

Checks and Adjustments 5- 20 1705A Spectrum Monitor 3. Adjust Geometry, Focus, and Astigmatism Display the DAC test pattern by completing parts a. through c. a. Press both the 1705A SPAN/DIV buttons simultaneously to display theMain Menu. b. Press either SPAN/DIV button to move the cursor to TEST, t...

Checks and Adjustments 1705A Spectrum Monitor 5- 21 b. Exit the DAC test pattern by first pressing the INPUT button to displaythe TEST menu. c. Press either SPAN/DIV button to move the cursor to EXIT, then pressthe INPUT button twice to return to a normal display. A3 MAIN BOARD (Refer to Figure 5-7 ...

Checks and Adjustments 1705A Spectrum Monitor 5- 27 e. ADJUST -- R239 (IF AGC) for maximum signal amplitude. f. ADJUST -- R240 (RF AGC) so the signal is one major Division ( ± 0.5 major Divisions) down from the top graticule line. g. ADJUST -- R232 to its midpoint. 18. Adjust 2 dB/Div Position a. Di...

1705A Spectrum Monitor 6- 1 Section 6Maintenance This section contains instructions for preventive maintenance, diagnostics,general troubleshooting, and corrective maintenance. If the instrument does notfunction properly, troubleshooting and corrective measures should be takenimmediately to circumve...

Maintenance 6- 2 1705A Spectrum Monitor detergent and water. Abrasive cleaners should not be used. If the circuit boardassemblies must be removed for cleaning, follow the instructions for removal/re-placement under the heading of Corrective Maintenance. After cleaning, allow the interior to thorough...

Maintenance 1705A Spectrum Monitor 6- 3 Observe the following precautions to avoid damage: 1. Minimize handling of static-sensitive components. 2. Transport and store static-sensitive components or assemblies in theiroriginal containers, on a metal rail, or on conductive foam. Label anypackage that ...

Maintenance 6- 4 1705A Spectrum Monitor . SPECTRUM DISPLAY READOUT MODE ONOFFL-BANDOFFSET L.O. HIGH >EXITUSE SPAN KEYS TO MOVE CURSOR,PRESS INPUT KEY TO SELECT. MAIN MENU READOUT MODEREADOUT POSITION TEST >EXITUSE SPAN KEYS TO MOVE CURSOR,PRESS INPUT KEY TO SELECT. READOUT POSITION OFFSET ADJU...

Maintenance 1705A Spectrum Monitor 6- 5 selected by moving the cursor to a point adjacent to the test name and pushingthe INPUT push button. USE SPAN KEYS TO MOVE CURSOR, PRESS INPUT KEY TO SELECT TEST MEMORY >DAC LEDKEYEXIT Figure 6-2: 1705A Test menu, displayed when Test is the Main menu select...

Maintenance 1705A Spectrum Monitor 6- 7 PRESS [INPUT] KEY TO EXIT ERROR : CANNOT READ OR WRITE TO 2444 Figure 6-4: 1705A power up error message When this message is displayed, any subsequent measurements (if possible)must be considered suspect. The DAC test is used to test the readout capability, cr...

Maintenance 6- 8 1705A Spectrum Monitor Tek REF -- 10 -- 20 -- 30 -- 40 -- 50 -- 60 -- 70 L O G + f Figure 6-5: DAC check waveform used to check Focus, Astigmatism, Geometry, andTrace rotation setting There are two additional diagnostic tests that can be made. The LED testalternates high and low lev...

Maintenance 1705A Spectrum Monitor 6- 9 Refer to the Replaceable Electrical Parts list for a complete description of eachcomponent. NOTE . Check the Change Information section at the rear of the manual for corrections and modifications to the instrument and the manual. Look up Charts . Each schemati...

Maintenance 6- 10 1705A Spectrum Monitor The circuit numbers of the individual components in the parts list is made up bycombining the assembly number with the individual circuit number. EXAM-PLE: R117 on Assembly (circuit board) A3 is listed in the ReplaceableElectrical Parts list as A3R117. NOTE ....

Maintenance 6- 12 1705A Spectrum Monitor all obvious defects. In the case of overheated components, determine andcorrect the cause of overheating before re-applying power. 5. Use successive electrical checks to locate the source of the problem. Theprimary tool for problem isolation is the oscillosco...

Maintenance 1705A Spectrum Monitor 6- 13 Table 6- 2: Power Supply Fault Symptoms (Cont.) 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...

Maintenance 6- 14 1705A Spectrum Monitor CAUTION. Do not proceed until 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 thetab (drain) ...

Maintenance 1705A Spectrum Monitor 6- 15 b. Table 6--4 lists the signal present in a properly functioning controlcircuit. Table 6- 4: 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 ...

Maintenance 6- 16 1705A Spectrum Monitor Table 6- 5: 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 thefront-panel control Z-- Axis Amplifier CheckGrid Drive Check No crt display High Vol...

Maintenance 1705A Spectrum Monitor 6- 17 Connect the oscilloscope probe to the anode of CR5 and the probe ground toTP1. The signal should be a clipped sine wave of +75 to +200 V p-p. High Voltage Oscillator Check Connect the oscilloscope probe to T1 pin 3 (Q6 collector) and the probe groundto TP1. P...

Maintenance 6- 18 1705A Spectrum Monitor CORRECTIVE MAINTENANCE CAUTION. A 2% RMA flux content solder is recommended for making repairs in this instrument. Cleaning of rosin residue is not recommended. Most cleaningsolvents tend to reactivate the rosin and spread it under components where itmay caus...

Maintenance 1705A Spectrum Monitor 6- 19 Table 6- 7: Test Selectable Components Circuit Number Nominal Value Range of Values Selection Criteria R50R74R73 5.62K3.40K18.2K 2.7K to 8.2K 1K to 6.8K 18K to 27K To correct nonlin- earities of L-- band tuners. R53 115.0K 115K to 130K To alter magnifier rang...

Maintenance 6- 20 1705A Spectrum Monitor Remove these screws in order to remove the bezel Figure 6-8: Bezel securing screws For graticule light removal and replacement, tweezers with curved, serrated tipsare recommended. For example: Miltex PL312, 6--100 (equivalent to PL312) orPL317 (longer than PL...

Maintenance 1705A Spectrum Monitor 6- 21 1. Remove the bezel. WARNING. The crt may retain a dangerous charge. Ground the conductor of the anode to discharge the crt. Do not allow the conductor to touch your body orany circuitry. 2. Remove the anode connector and discharge it to ground. 3. Disconnect...

Maintenance 6- 22 1705A Spectrum Monitor BESCHLEUNIGUNGSSPANNUNG KLEINER ALS 20kV DIE IN DIESEM GERAT ENTSTEHENDE RONTGENSTRAHLUNG IST AUSREICHEND ABGESCHIRMT TO AVOID ELECTRICAL SHOCK, THE POWER CORD PROTECTIVE GROUNDING CONDUCTOR MUST BE CONNECTED TO EARTH GROUND. SPECTRUM MONITOR 70 MHz INPUT L-B...

Maintenance 1705A Spectrum Monitor 6- 23 TO REMOVE FRONT PANEL ASSEMBLY TO REMOVE FRONT PANEL ASSEMBLY TO SEPARATE BOARD FROM THE FRONT PANEL Figure 6-10: Screws securing the front panel board (A2) in place 3. Remove the board by slipping it through the front--panel opening. 4. To access the Front-P...

Maintenance 6- 24 1705A Spectrum Monitor FRONT J1 Remove these screwsto remove A3 Main bd. Remove these screws to remove 70MHZ Turner. Remove this nut to remove L-Band Turner. Figure 6-11: Screws holding the Main board (A3) and the Tuners (A5 and A6) inplace 4. Remove the six screws that hold the co...

Maintenance 1705A Spectrum Monitor 6- 25 2. Remove the plugs from the following connectors: J1 to the Front-Panelboard, J4 on the Power Supply board, and J2 on the Main board (TraceRotation). 3. Unsolder the leads that go to the rear-panel bnc connector and ground thetwo horizontal crt leads (red an...

Maintenance 6- 26 1705A Spectrum Monitor FRONT J1 J3 J2 J4 Ground strap Remove these screws to remove this board Figure 6-12: Removing the Power Supply board 1. Unplug the interconnecting plug from the right side of the LNB powersupply. 2. Remove the two Torx screws securing the circuit board to the...

Maintenance 1705A Spectrum Monitor 6- 27 REPACKAGING If the instrument is to be shipped to a Tektronix Service Center for service orrepair, attach a tag to the instrument showing the following information: 1. Owner (with complete address) and the name of the person at your firm thatcan be contacted....

1705A Spectrum Monitor 7- 1 Section 7 Options This section describes instrument options and customer-installable field upgradekits available for the 1705A Spectrum Monitor. Options The standard instrument is shipped with a P31 (green) phosphor crt installed. IfOption 74 is ordered, the instrument is...

Options 7- 2 1705A Spectrum Monitor Plain Cabinet (1700F00) This plain, silver-grey cabinet is designed for permanent mounting. The ventilating holes in the top, bottom, and sides of the cabinetallow heat generated within the instrument to dissipate. When mounting, allowair to circulate freely throu...

1705A Spectrum Monitor 8- 1 Section 8 Replaceable Electrical Parts This section contains a list of the components that are replaceable for the 1705A.Use this list to identify and order replacement parts. There is a separateReplaceable Electrical Parts list for each instrument. Parts Ordering Informa...

Replaceable Electrical Parts 8- 2 1705A Spectrum Monitor Column Descriptions The component circuit number appears on the diagrams and circuit boardillustrations, located in the diagrams section. Assembly numbers are also markedon each diagram and circuit board illustration, in the Diagram section an...

9- 1 1705A 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. Logicsymbols depict the logic function performed and may differ from the manufactu...

A3 Main Board Component Locator (with cross-references to schematic diagrams 1, 2, 3, 4, and 5). Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc 1705A C1 5 ...

Static Sensitive Devices See Maintenance Section A3 Main Board A5 70 MHz Tuner Board See parts list for earier values and serial number ranges.

A3 C80 C4 L1 C89 C5 M1 C91 F4 P5 CR31 C4 M2 J9 F2 K3 J11 G5 M1 Q20 C5 M1 Q21 C4 M2 Q30 D5 O6 Q31 D5 O6 Q32 F4 O5 Q101 G5 P6 R205 C4 M2 R214 C4 M2 R215 B4 M2 R216 C4 M2 R217 C5 M1 R233 C5 O6 R234 D5 O5 R235 D5 O6 R236 D5 O6 R237 D4 O6 R238 G5 O6 R239 G5 P6 R240 G5 P6 R305 G5 P6 R306 H5 P6 R307 H5 O6 ...

C31 G1 H2 C32 H1 H2 C33 G1 H3 C34 H1 H3 C35 H1 H4 C36 E3 I2 C37 B5 I3 C39 F2 I1 C41 E2 I1 C42 E2 J1 C43 F2 J2 C44 C5 J3 C45 C5 J3 C46 B4 J4 C47 B4 J4 C48 D4 J4 C50 D2 J2 C51 F3 J2 C52 C5 J3 C53 D4 J4 C54 E2 J1 C55 D2 J1 C56 D4 J4 C57 D4 J4 C58 D4 J4 C59 D2 K1 C60 D2 K1 C61 E3 K2 C62 D5 K3 C63 C2 K1 ...

C4 F5 A4 C6 F5 B3 C7 B3 C2 C10 F5 C3 C11 F5 C4 C14 G5 D2 C15 G5 D4 C18 G5 D3 C19 F5 D3 C20 B3 E6 C21 D5 F3 C25 H3 G3 C29 H1 G3 C30 H3 G3 C40 B1 I6 C49 A1 J5 C77 G5 L6 C79 F5 L6 C90 H1 N5 C92 G1 G4 CR2 F2 E2 CR3 E4 E3 CR4 G3 E4 CR5 G1 E4 CR6 E4 E3 CR7 F3 F4 CR8 E4 F6 CR11 B4 F3 CR12 E3 F5 CR13 G2 G4 ...

C22 C5 G2 C23 C5 G2 C24 D5 G2 C26 B5 G2 C27 B5 G2 C28 A5 G2 C65 G4 K6 C78 D2 L6 C84 D2 M6 C93 C1 K5 C102 B4 I2 CR9 D5 F2 CR10 D5 F2 CR17 B5 G2 CR18 B5 G2 J4 A3 H1 J7 H4 J6 J8 H4 J6 J12 H2 N6 J13 H2 N6 J21 A4 H1 J22 A4 I1 J23 A4 I1 L19 B4 H2 Q14 F4 K6 Q15 G4 J6 Q16 G4 K6 Q17 F4 K6 Q18 F4 L6 Q19 F4 L6...

A3 C1 D1 A4 C2 D1 A4 C3 D1 A4 C5 C3 A5 C8 G5 C2 C9 G5 C2 C12 B4 C6 C13 C4 C6 C16 C3 D6 C17 A5 D2 CR1 C3 B6 J1 A2 A2 J2 B5 D2 J300 C2 A6 J414 D5 A3 P300 C2 Q1 B5 D1 Q2 B5 E1 Q3 D5 D1 Q100 C4 D1 R1 C3 A4 R2 C2 A4 R3 C3 A3 R4 C3 B4 R5 G1 B3 R6 H2 B2 R7 H2 B2 R8 H2 B2 R9 H2 B2 R10 H2 B2 R11 H2 B2 R12 H3...

A2 DS112 A1 DS112A B1 DS112B A3 DS112C B3 DS129 B1 DS129A B1 DS129B B3 DS129C B1 DS130 B1 DS144 C1 DS144A C1 DS144B B3 DS144C C1 DS145 C1 DS319 A2 DS319A A2 DS319B B3 DS319C B2 DS319D B3 DS319E C2 DS319F B3 DS319G D2 DS325 B2 DS330 B2 DS337 B2 J303 H1 A2 R211 E2 A1 R235 F3 B2 R343 D2 C3 R411 F3 A3 R...

A1 Power Supply Board Component Locator (with cross-references to schematic diagrams 7 and 8). Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc Comp No Diag No Diag Loc Bd Loc 1705A C1 8 C4...

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...

1705A Spectrum Monitor 10 --1 Section 10 Replaceable Mechanical Parts This section contains a list of the components that are replaceable for the 1705A.Use this list to identify and order replacement parts. There is a separateReplaceable Mechanical Parts list for each instrument. Parts Ordering Info...

Replaceable Mechanical Parts 10- 2 1705A Spectrum Monitor Column Descriptions Items in this section are referenced by figure and index numbers to the illustra-tions. Indicates part number to be used when ordering replacement part fromTektronix. Column three (3) indicates the serial number at which t...