HP-120B-Manual 电路图.pdf

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1、RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 Table of Contents TABLE OF CONTENTS Model 120B Section Page Section Page I GENERAL INFORMATION . 1-1 V MAINTENANCE . 5-1 . 1- 1 . Introduction 1- 1 . 1.4 . Description 1-1 1.14 . Cathode Ray Tube Warranty . 1-2 1.16 . Options .

2、1-2 . 1 1 INSTALLATION 2-1 . . 2.1 Incoming Inspection 2- 1 . 2.7 . Power Requirements 2-1 . 2.10 . Installation 2-2 . 2.13 . Repackaging for Shipment 2-2 3.1 . Introduction . 3-1 3.3 . Controls and Indicators . 3-1 3.5 . General Operating Suggestions . 3-1 IV PRINCIPLES OF OPERATION . 4.1 4.1 . Ove

3、rall Block-Diagram Description . 4-1 4.9 . Circuit Analysis . 4-2 4- 10 . Vertical Amplifier . 4-2 4.16 : Sweep Generator . 4-3 4.30 . Horizontal Amplifier . 4-4 4.34 . Low-Voltage Power Supply . 4-5 . 4.41 . High-Voltage Power Supply 4-6 . Introduction 5-1 . Test Equipment 5-1 . Troubleshooting 5-1

4、 . System Troubleshooting 5-1 Sectional Troubleshooting . 5-2 High-Voltage Power Supply . 5-2 . Repair 5-5 Replacement of Semiconductors . 5-5 Servicing Etched Circuit Boards . 5-5 Crt Replacement . 5-5 . Adjustments 5-6 5.24 . Adjustments Following Repair . . 5-6 . . 5.27 Low-Voltage Power Supply 5

5、-6 . . 5.33 High-Voltage Power Supply 5-6 5.35 . Vertical Amplifier . 5-9 . . 5.42 Horizontal Amplifier 5-10 . . 5.48 Sweep Generator 5-11 . . 5.52 Performance Check 5-11 . . 5.67 Diagrams 5-14 VI REPLACEABLE PARTS . -6-1 . . 6.1 Introduction 6-1 . . 6.3 Ordering Information 6-1 Model 120B LlST O F

6、ILLUSTRATIONS List of Illustrations and Tables Number Title Page Number Title Page . Model 120B Oscilloscope 1-1 Primary-Power Connections . 2- 1 . Rack Mounting. ; . 2-2 Model 120B Oscilloscope, Front View . . 3-2 Operation Using Internal Horizontal . Sweep or Single Sweep 3-3 Operation Using Exter

7、nal Horizontal . Input .3-4 Operation Using Balanced Vertical . Input .3-5 Vertical Deflection Calibration and . Balance Adjustment 3-6 . Overall Block Diagram 4- 1 . Sweep Generator, Block Diagram 4-2 . Sweep Generator Waveforms 4-3 . Typical Schmitt Trigger 4-3 Low-Voltage Power Supply, Block Diag

8、ram. . .4-5 High-Voltage Power Supply, Block . Diagram. .4-6 Top View, Location of Parts and . Adjustments 5-3 High-Voltage Power Supply, Location . of Parts. 5-4 Vertical Sensitivity (A21 and Trigger Source (A201) Switches, Location of Parts and Adjustments . 5-5 Right-Side View, Side Panel Removed

9、, . Location of Parts and Adjustments 5-6 Servicing Etched Circuit Boards. . 5-7 Vertical Amplifier, Schematic . Diagram 5 - 15 Horizontal Amplifier, Schematic . Diagram 5- 17 Sweep Generator, Schematic Diagram . . 5-19 Low-Voltage Power Supply, Schematic . Diagram 5 - 2 1 High-Voltage Power Supply,

10、 Schematic . Diagram 5- 23 Horizontal Display Switch, Schematic . Diagram. 5-25 LlST O F TABLES Number Title Page . 1-1. Specifications 1-0 Recommended Test Equipment . 5- 1 . System Troubleshooting. 5-4 Adjustments Following Tube, Transistor, and Diode Replacement. . 5-8 Low-Voltage Power Supply Vo

11、ltages . 5-9 Horizontal Sweep-Time Adjustment. . 5-12 . Horizontal Sweep Time 5-14 Reference Designation Index . 6- 2 . Replaceable Parts 6- 14 Code List of Manufacturers . 6-17 Section I Table 1- 1 Model 120B Table 1- 1. Specifications SWEEP Phase Shift: Vertical and horizontal amplifiers have same

12、 Sweep Range: phase characteristics within +ZO to 100 kc when One p3ec/cm to at least 0.5 sec/cm. Fifteen verniers are in CAL. calibrated sweeps accurate to within *5%, in a 1,2,5,10. . sequence, from 5 psec/cm to 200 millisec/cm. Vernier control permits contin- HORIZONTAL AMPLIFIER uous adjustment

13、of sweep time between calibra- ted steps, and extends the 200 millisec/cm to at Bandwidth: least 0.5 sec/cm. DC coupled: dc to 300 kc. AC coupled: 2 cps to 300 kc. Bandwidth is at least 300 kc regard- Sweep Expand: less of attenuator setting. X5 sweep expansion may be used on all ranges and expands

14、fastest sweep to 1 psec/cm. Ex- Sensitivity: panded sweep accuracy is *lo%. 0.1 volt/cm to 100 volts/cm. Three calibrated steps, accurate within and from line voltage. Input Impedance : 1 megohm nominal, shunted by approximately External: from signal 50 cps to 450 kc, 1.5 v 100 pf. peak-to-peak. Tri

15、gger Point: Phase Shift: Horizontal and vertical amplifiers have same Zero-crossing negative slope of external sync phase characteristics within k2O to 100 kc when signals; or zero-crossing positive or negative verniers are in CAL. slope of vertical deflection signals. Front-panel control overrides

16、automatic and permits the trigger point to be set between -7 to +7 volts. GENERAL Turning control fully counterclockwise restores automatic operation. Cathode Ray Tube: VERTICAL AMPLIFIER P31 phosphor, mono-accelerator with internal graticule normally supplied; 2700-volt acceler- Bandwidth: ating po

17、tential. Face plate eliminates glare and DC coupled: dc to 450 kc. AC coupled: 2 cps reduces hazard of implosion. P2, P7, and PI1 to 450 kc. Bandwidth is at least 450 kc regard- phosphors also available. less of sensitivity setting. Internal Graticule: 10 cm x 10 cm marked in cm squares. Major Sensi

18、tivity: horizontal and vertical axes have 2-mm sub- 10 millivolts/cm to 100 volts/cm. Four cali- divisions. Eliminates parallax error. brated steps with attenuator accuracy of *3%, 10 mv/cm, 100 mv/cm, 1 v/cm, and 10 v/cm. Intensity Modulation: Vernier permits continuous adjustment of sensi- Termina

19、ls on front panel. Plus 20 volt pulse tivity between steps, and extends 10 v/cm step required to blank trace of normal intensity. to at least 100 v/cm. Dimensions: Internal Calibrator: 16-3/4 in. wide, 7-1/2 in. high, 18-3/8 in. Calibrating signal automatically connected to deep, overall; hardware f

20、urnished for quick con- vertical amplifier for standardizing of gain, ac- version to 7 in. x 19 in. rack mount. curacy +2%. Weight: Input Impedance : Net: 32 lbs; shipping 45 lbs. 1 megohm, shunted by approximately 50 pf. Power: Balanced Input: 115 or 230 volts *lo%, 50 to 1000 cps, approlci- On 10

21、mv/cm range only; input impedance is 2 mately 95 watts. megohms shunted by approximately 25 pf. Options : 05. External graticule crt with P31 phosphor. Common-Mode Rejection: 06. Rear terminals in parallel with front. Rejection at least 40 db. Common mode signal 10. Provision for single sweep operat

22、ion. must not exceed +3 volts peak. 13. Special front panel for rack mounting only. Model 120B Section I Paragraphs 1-1 to 1-8 SECTION I GENERAL INFORMATION 1-1. INTRODUCTION. 1-2. This manual provides complete instructions on the installation, operation, theory of operation, and maintenance of the

23、Hewlett-Packard Model 120B Os- cilloscope. 1-3. The Hewlett-Packard Company uses a two- section, eight-digit serial number (e. g. 000-00000). If the serial prefix (first three digits) on your instru- ment does not agree with the prefix shown on the title page of this manual, refer to either the sepa

24、rate change sheet included or Appendix I, which contain changes required to adapt this manual to the listed prefixes. The separate change sheet also contains corrections required for all known errata (errors). Contact your Hewlett-Packard Sales/Service Office if additionalinformation or clarificatio

25、n is required. 1-4. DESCRIPTION. 1-5. The Model 120B is a general-purpose oscillo- scope whose bandwidth extends from dc to 450 kc. It combines the precision characteristics of calibrated horizontal sweeps, calibrated vertical sensitivity, and a crt that eliminates parallax error; in addition, its c

26、onstruction provides easy circuit accessibility and quick convertibility from a rack-mounting to a bench-model configuration. Specifications are listed in table 1-1. 1-6. The internal graticule of the Model 120B is in the same plane as the phosphor and crt trace; conse- quently, crt parallax error i

27、s avoided, allowing easier, quicker, and more accurate measurements. 1-7. The Model 120B can be used with either internal or external sweeps, which can be either internally or externally synchronized. Because of its high sensi- tivity and balanced input, the Model 120B can be used to view complex wa

28、veforms and monitor transducer outputs. 1-8. Computations are avoided and possibilities of error are reduced by direct-reading calibrated sweeps. A single control selects 1 of 15 calibrated sweeps between the ranges of 5 microseconds/cm and 200 Figure 1- 1. Model 120B Oscilloscope 1-1 Section I Para

29、graphs 1 - 9 to 1 - 18 Model 120B milliseconds/cm or determines the calibrated sensi- tivity of the horizontal amplifier. Continuous control of sweep time and horizontal sensitivity between cali- brated steps is provided by a vernier control; the vernier control extends the 200 milliseconds/cm sweep

30、 time to at least 0.5 seconds/cm, and reduces the horizontal amplifier sensitivity to at least 100 volts/cm. 1-9. Accurate direct-reading sweeps are obtained from a feedback type (Miller) integrator, which en- sures high linearity and stability of the horizontal sweep. This type of sweep generator i

31、s reliable and relatively independent of vacuum-tube characteristics. 1- 10. Observation and analysis of transients are sim- plifiedby the expanded-sweep control. This X5 sweep expander may be used on all sweep time settings, and expands the fastest sweep time to 1 microsecond/cm. 1- 11. An automati

32、c trigger capability facilitates es- tablishinga base line on the crt when a synchronizing signal is not present. The automatic baseline pro- vision can be easily locked-out and an adjustable trig- ger level established. 1- 12. Accurate voltage measurements of waveforms are quickly made with the Mod

33、el 120B. A built-in calibrator that is accurate to within *2 percent per- mits rapid verification and standardization of vertical amplifier sensitivity. 1-13. Phase-shift measurements can be made ac- curately over a wide range of input frequencies. Rel- ative phase shift between the vertical and hor

34、izontal amplifiers is less than 2 degrees up to 100 kc. 1-14. CATHODE RAY TUBE WARRANTY. 1-15. The cathode ray tube supplied with the Model 120B and replacement crts purchased from Hewlett- Packard Company are guaranteed against electrical failurefor one year from the date of sale by Hewlett- Packar

35、d. The Cathode Ray Tube Warranty and Claim sheet is included at the rear of this manual. 1-16. OPTIONS. 1- 17. The Model 120B is available with four options, as listed in table 1- 1. Replaceable parts for alloptions are listedunder MISCELLANEOUS at the end of table 6-1. 1-18. OPTION 05. This optionp

36、rovides a crt without internal graticule. An external graticule with adjust- able illumination is installed over the face of the crt. Refer to figure 5- 9 for a schematic of the added circuit. CRTs without internal graticule are available with types P7, P11, andP3l phosphor. Afilter is also sup- pli

37、ed with each crt; amber for P7 type, blue for PI1 type, and green for P31 type. 1-19. OPTION 06. This option provides rear panel connectors in parallel with the front panel input con- nectors. One connector is wired in parallel with the VERTICAL input terminals on the front panel, and one connector

38、is wiredin parallel with the HORIZON- TAL input terminals as shown in figures 5-6 and 5- 7. Mating connectors and cable clamps are also supplied. The additional circuitry changes the vertical input capacitance to approximately 75pf, and the horizontal input capacitance to approximately 135 pf. 1-20.

39、 OPTION 10. Thisoptionprovides circuitry for single sweep operation. Operation procedures are contained in figure 3-2 and a schematic for the added circuit is shown in figure 5-8. 1-21. OPTION 13. This option provides a plain 7 x 9 x 3/16 inch front panel for rack mounting only. The panel is suitabl

40、efor installing special handles to match existing equipment in system or console configuration. 1-22. AMBER FILTER. A special amber filter is supplied with oscilloscopes having an internal graticule crt with P7 phosphor. This filter may be installed for improved visual observation of displays such a

41、s single-shot phenomena or very low frequency applica- tions. The filter will improve the long persistency characteristics desired for visualobservations of this type display. To install the filter proceed as follows: a. Remove front panel crt bezel. b. Set filter into bezel, aligning larger rectang

42、ular slots in the edge of filter with metal guide posts of the bezel casting. c. Remove oscilloscope top cover for access to rear of crt. d. Carefully move crt towardrear of instrument enough to provide clearance for thickness of installed filter (about 1/8 inch). e. Loosen clamp at socket of crt. f

43、. Replace bezel with filter and tighten bezel screws. g. Slide crt forward until light mask on front of crt just lightly touches filter. h. Tighten clamp just enough to keep crt from turn- ing. Do not over-tighten the clamp or tube damage may result. i. Check alignment of trace with graticule accord

44、- ing to theprocedure given in Section V of this manual. Model 120B Section I1 Paragraphs 2-1 to 2-9 SECTION II INSTALLATION 2-1. I N C O M I N G INSPECTION. 2-2. MECHANICAL INSPECTION. Unpack and in- spect the Model 120B in the presence of the carrier. Be careful when unpacking the instrument, for

45、all electron tubes including the cathode ray tube remain installed during shipment. Save all packing materials until inspection is complete. These materials may be required for reshipment in the event shipping dam- age is discovered. 2-3. Inspect the instrument for signs of possible dam- age in ship

46、ment such as scratched panel, broken knobs, etc. If possible, energize the equipment and check it operationally (see paragraph 2- 5). 2-4. I f there are any indications of damage, file a claim with the carrier. Refer to the Hewlett-Packard Warranty sheet at the front of this manual. 2-5. PERFORMANCE CHECK. Paragraph 5-52 con- tains performance check procedures for verifying operation within listed specifications. The perform- ance check is recommended for inclusion in receiv- ing quality-control inspection. The following proce- dure is offer