Mechanical Disassembly/Assembly, Bezel Removal | Tektronix 1705A

Maintenance

Table 6- 7: Test Selectable Components

Circuit Number	Nominal Value	Range of Values	Selection Criteria

R50	5.62K	2.7K to 8.2K	To correct nonlin-
R74	3.40K	1K to 6.8K	earities of L--band
R73	18.2K	18K to 27K	tuners.

R53	115.0K	115K to 130K	To alter magnifier
			range when ad-
			justment range of
			A3R38 is insuffi-
			cient.

Mechanical Disassembly/Assembly

Use these instructions for disassembly and reverse them for reassembly, unless otherwise noted.

WARNING. Before attempting any disassembly/assembly of the instrument, be sure to disconnect the power cord.

CAUTION. Do not reinsert screws in the rear panel when the instrument is removed from the cabinet.

NOTE. All screws, unless otherwise noted, are TORX screws and can be removed with a T15 screwdriver tip (Tektronix part number 003-0966-00). The exception is #2 Pozidrive screws which can be removed with a #1 Pozidrive tip (003-0443-00).

Do not reinsert screws in the rear panel when the instrument is removed from the cabinet.

Bezel Removal

1.Remove the two bezel screws. See Figure 6-8.

2.Grasping the bottom of the bezel, pull out and upward. There are two hinges at the top of the bezel that hold it in place; once the bezel is at an approxi- mate 45° angle with the front panel, they will disengage.

1705A Spectrum Monitor

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Tektronix 1705A instruction manual Mechanical Disassembly/Assembly, Bezel Removal, Maintenance Test Selectable Components

Contents

1705A Spectrum Monitor SN B040000 and Above 070-8222-08 Table of Contents Installation Table of ContentsTheory of Operation Checks and Adjustments 1705A Spectrum Monitor Iii Maintenance Options Replaceable Electrical Parts Replaceable Electrical PartsReplaceable Mechanical Parts 10-1 List of Figures Simulation of a 1705A Full SPAN/DIV display Considerations for custom installation of an instrument 1705A Spectrum Monitor Vii List of Tables Viii General Safety Summary General Safety Summary Service Safety Summary Service Safety Summary Xii Installation PrefaceIntroduction Replaceable Mechanical Parts Contacting Tektronix PrefaceUSA Preface Xvi Introduction Page Typical Configurations Section Introduction Accessories OptionsIntroduction #73 Safety Information Optional Accessories Spectrum Display SPAN/DIVFull Power Source Introduction Spectrum DisplayCRT Display Introduction Environmental Characteristics Physical CharacteristicsCertifications and Compliances EMC Introduction Certifications and Compliances CAT Meters Applications SUN Satellite Earth Using the 1705A for Satellite Communication Band Input Signals Vancouver BC Seattle Portland Helena Boise SAN FranciscoLOS Angeles SAN Diego Zeroing in on a Satellite Tek 12.20 GHZ Horizontal Vertical Polarization Frequency and Number Down Link Transponder Looking at Exciters with the 70 MHz Input GHZ Miscellaneous Uses for the 1705A LNB OUT BandSplitter Input Operating Instructions Page Front-panel Controls and Indicators Section Operating Instructions Position Power Operating InstructionsFilter Input Display Variable control that adjusts the display brightness SPAN/DIV Rear- Panel Connectors Position Holder for the instrument’s mains fuse Spectrum Monitor Powering- up 1400 MHZ Measurement Graticule 1705A graticule scale Reading in dB Voltage Ratio Power Ratio Voltage Ratio Power RatioOperating Instructions DB Reference Reading in dB 75Ω 50Ω Operating Instructions DBm to v Conversion Reading in dBm Minimum Maximum Frequency MIDFrequency Scale = 10 Divisions Sweep Length = 12 Divisions Center Frequency Readout 70 MHZMHZ 1400 MHZ Point on Trace That Corresponds to Center Frequency Tuned AT this Point Customizing Frequency Readout Readout Mode Offset AdjustMain Menu Readout Position 12.00 GHZ Basic Operating Procedure Locating Ku- Band Satellites City Satcom K2 G-STAR 1705A Spectrum Monitor Operating Instructions Page Page Installation Page Section Installation Electrical Installation Mechanical Installation InstallationLNB Power Band Input OFF Cabinet Options 250 875105 130 1700F02 portable cabinet dimensions Cabinetizing Cabinet Securing Screws A WFM7F05 with a blank front panel 1700F06 1700F07 1705A Spectrum Monitor Theory of Operation Page Block Diagram Section Theory of OperationOverview Theory of Operation Front Panel Diagram RF Input Diagram If Amplifier Diagram Resolution Filter and Log Detector Sweep Generator Diagram Start Display Deflection Amplifiers Diagram Vertical Deflection Amplifier Microprocessor Diagram Front Panel Diagram LOW Load Average High Load Low Voltage Power Supply Diagram Pulse Width Modulator Theory of Operation High Voltage Power Supply Diagram Axis Amplifier CRT The pinout for the CRT is shown in Figure Pinout of the CRT Socket 1705A Spectrum Monitor Theory of Operation Checks and Adjustments Page Section Checks And Adjustments Recommended Equipment ListElectrical Instruments Auxiliary Equipment Short-Form Procedure Checks and Adjustments SMA Male-to-bnc Female AdapterPerformance Check 1705A Spectrum Monitor Long Form Procedure Checks and Adjustments Preliminary Control Settings Page Marker Here Marker is +/-- 1 Minor Division from Here Checks and Adjustments 1705A Spectrum Monitor Page Variable Autotransformer L-BAND Input Disregard Marker Here Graticule Line UHF Sine Wave Generator Page End of the Performance Check Procedure Adjustment Procedure Short- Form Procedure Preliminary Setup Video SPAN/DIV Full Center Frequency A3 Main BD FrontA1 PWR Sply BD Tek Remove the shorting strap 1705A Spectrum Monitor ShortingStrap 1705A Spectrum Monitor Page 1705A Spectrum Monitor Page 1705A Spectrum Monitor End of Adjustment Procedure Checks and Adjustments Maintenance Page Section Maintenance Cleaning Schottky Signal LOW Power SchottCmos ECL Troubleshooting Diagnostic Routines Nonvolatile 2444 RAM Test Reading Data Stored AT 60H to 7F in Processor Error Cannot Read or Write Press Input KEY to Exit Troubleshooting Aids Circuit board assembly locations Major Assembly Interconnection ROW B ROW a PIN Power Supply Troubleshooting Procedure Power Supply Fault Symptoms Maintenance Power Supply Fault Symptoms Low Volts Supply Maintenance Rectifier/Switcher Check High Volts Supply Maintenance High Volts Supply Fault Symptoms Focus Amplifier CheckAxis Amplifier Check Grid Drive Check High Voltage Oscillator Check CRT Voltage Check Corrective Maintenance Obtaining Replacement Parts Mechanical Disassembly/Assembly Maintenance Test Selectable ComponentsBezel Removal Graticule Light Removal and Replacement Removal of the CRT Replacing the CRT Removal of Front- Panel Assembly Removal of the Rear Panel Removing the L- Band Tuner Removal Replacement of the Main Board Removal Replacement of the Power Supply Board Removing the LNB Power Supply Board Front Repackaging 1705A Spectrum Monitor Options Page Field Upgrade Kits Power Cord OptionsPower Cord Options Description of power cord Section Options Ordering Replaceable Electrical Parts Page Using the Replaceable Electrical Parts List Section Replaceable Electrical PartsParts Ordering Information Column Descriptions Tektronix Part NoColumn Column 3 Spectrum Control INC Weight ST Cross Index MFR. Code Number to ManufacturerAMP INC Fulling Mill Harrisburg PA MSD INC Orange ST DARLINGTON, SC Zman & Associates Sobudai Zawa Kanagawa 228 JapanChrome Shibaura Tokyo Japan 2ND Floor NEW Kyoei MINATO-KU Wilhelm Westerman Circuit BD Assypower SUPPLY, 1705A Circuit BD ASSY18V Power SupplyCircuit BD Assyfront Panel Circuit BD Assymain Board ASSY,1705A IAL,MI CAP,FXD,PLSTC100PF,5%,1600VDC/500VACIN,BULK CAP,FXD,CER DI470PF,20%,100V TUBULAR,MI LAMP,GLOW135V MAX,1.9MA,C2A-T,WIRE Lead A1DS1A1DS2 A1DS3 SQ,TOP Adjustbulk SQ,SIDE ADJUSTT&RRES,FXD,CMPSN1.5M OHM,5%,1W RES,FXD,CMPSN2.2M OHM,5%,0.5W RES,FXD,FILM5K OHM,0.1%,0.2W,TC=T9 IAL,T&R,SMALL BodyREELED,SMALL Body RES,FXDMETAL FILM,100K OHM,1%,0.2W,TC=100 SQ,TOP ADJUST,T&R WIRED,1705ARES,THERMAL5 OHM,10%,7A/DEG C RES,FXD,CMPSN2.4K OHM,5%,2W LED ASSYDIR1 Part of A2DS313CA ASSY,SP,ELEC34,26 AWG,5.0 L RES,VAR,PNLCP,20K OHM,20%,0.5W,LINEAR,W BUS,CNDCT PLATE,ELEC Shldcircuit BoardSHIELD,ELECCIRCUIT Board SHIELD,ELEC1705A,BRS CAP,FXD,ELCTLT33UF,+50-20%,35WVDC UVX1H330MAACAP,VAR,CER DI9-45PF,200V CAP,VAR,PLSTC1-3.5PF,500V CAP,FXD,MICA DI98PF,5%,500V A3CR1A3CR2 DIO,SIGFAST RCVRY70V,200MA,100NS,COM A3FL1 FLTR,BANDPASSA3FL2 A3FL3 COIL,RFFIXED,45NH COIL,RFFIXED,15NHCOIL,RFFIXED,64UH COIL,RFFIXED,505NH ADJUSTT&R GF06UT 2KRES NTWK,FXD,FI10K OHM,20%,9RES GF06UT 5K RES,FXD,FILM115K OHM,1%,0.2W,TC=T0 RES,FXD,FILM237K OHM,1%,0.2W,TC=T0RES,FXD,FILM3.4K OHM,1%,0.2W,TC=T0 RES,FXD,FILM7.5K OHM,1%,0.2W,TC=T0 RES,VAR,NONWWTRMR,250 OHM,20%,0.5W LIN RES,FXD,FILM1M OHM.1%,0.2W,TC=T0 PercentCRB20FXE1K62 CRB20FXE9K35 RES,FXD,FILM2.1K OHM,1%,0.2W,TC=T0 RES,VAR,NONWWTRMR,100 OHM,20%,0.5W LINRES,FXD,WW6.3K OHM,1%,3W CRB20FXE210E GF06UT 1K RES,FXD,FILM187K OHM,1%,0.2W,TC=T0 Loss 10DB,PKG 7.2MM SQ,6.8MM HIIC,CONVCMOS,A/D8-BIT,32US,SAR,DIFF IN,SER MICROCKT,DGTLMICROCOMPUTER,8 BIT IC,MISCCMOS,ANALOG Swquad SPST,100 IC,LINBIPOLAR,AMPLRF AMP,20DBIC,DGTLTTL,BFR/DRVRHEX INV, OC, HI MIXER,FREQ1-500MHZ CONN,BOXSHUNT/SHORTINGFEM,STR,1 X 2,0.1 CTR,0.385 H,30 GLD,BLK,JUMPERTAIL,30 GLD IAL,MI,T&R RES,FXD,FILM267K OHM,1%,0.2W,TC=T0 RES,FXD,WW1 OHM,5%,2WOrder by Desc RES,FXD,CMPSN1K OHM,5%,0.50W CONN,HDRPCB/WIREWRAP,MALE,STR,1 X 7,0.15 CONN,HDRPCB/WIREWRAP,MALE,STR,1 X 4,0.150CORE,EMTOROID,FERRITE COIL,RFFIXED,150NH A10SKT1 Controlled 0LUA3CONN,RF Plug CA ASSY,SP Replaceable Electrical Parts Diagrams/Circuit Board Illustrations Page Diagrams/Circuit Board Illustrations SymbolsAssembly Numbers Component ValuesPage 1705A Spectrum Monitor With cross-references to schematic diagrams 1, 2, 3, 4, A3 Main Board Component Locator A3 Main Board A5 70 MHz Tuner Board Schematic Diagram 1 Component Locator Chart Local Oscillator 1705A Spectrum Monitor RF Input Schematic Diagram 2 Component Locator Chart Resolution Filter & LOG Detector 1705A Spectrum Monitor If Amplifier Schematic Diagram 3 Component Locator Chart Band Linearity Ramp GeneratorMarker Generator Schematic Diagram 4 Component Locator Chart Deflection AmplifierFilter Buffers Schematic Diagram 5 Component Locator Chart 1705A Spectrum Monitor MicroprocessorMicroprocessor Trace Schematic Diagram 6 Component Locator Chart 1705A Spectrum Monitor Front Panel & 18V Supply A2 Front Panel Board A1 Power Supply Board A1 Power Supply Board Component LocatorSee Parts List for Effective Serial Number Ranges Switcher ErrorLine Rectifier Output Filters Schematic Diagram 8 Component Locator Chart A10 CRT Socket Board Front of Board Error AMP 1705A Spectrum Monitor High Volts Power SupplyHV OSC Grid DrivePage Replaceable Mechanical Parts Page Using the Replaceable Mechanical Parts List Section Replaceable Mechanical Parts Qty Column Replaceable Mechanical PartsThis indicates the quantity of mechanical parts used Indicates actual manufacturer’s part number Panduit Corp Ridgeland RichcoCHICAGO, IL Nelson Name Plate CO Casitas Circuit BD Assypower Supply See A1 Repl Mounting Parts COVER,HOUSINGALUMINUMFRAME,CRTBEZEL SCREW,MACHINE6-32 X 0.875,PNH,SST HOUSING,CKT Bdaluminum FRAME,CHASSISSAFETY ControlledSCREW,MACHINE6-32 X 0.188,PNH,STL IN/OUT See A6 Repl Mounting Parts Standard Accessories CLAMP,LOOP0.375 ID,PLASTIC,SAFETY CON TrolledStandard only Optional Accessories CA ASSY,CRTDISCRETE,ANODE LEAD,CRT,1,22 A10