Hameg HM305 电路图.pdf

Instruments Oscilloscope HM 305 ENGLISH 4S-0305-00E0 01 SEP 1996 SERVICE-MANUALHM305 RadioFans.CN 收音机爱 好者资料库 nderungen vorbehalten / Subject to change without notice 1 Y- Input, Attenuator, Preamplifier CH1. 2 Y- Input, Attenuator, Preamplifier CHII. 3 Y- Intermediate Amplifier CHI + CHII, Channel Switch + Chopper Generator, . 4 Analog/ digital Switch, TRIG. and X- Signal Amplifier. 4 Trigger Amplifier, Trigger Coupling, TV Sync. Separator,. 5 Peak Value Detection, Trigger Comparator . 5 Timebase Sweep 8.3 YPA Board (Bottomside) nderungen vorbehalten / Subject to change without notice 20 Power Supply Board (Topside) nderungen vorbehalten / Subject to change without notice 21 P1002 P1003 P1004 LINE BLV FOCUS G1 -1950V HT1 HT14 P1005 P1006 LINE +5V P1007 P1008 P1009 GND +12V -12V +5V +5V GND +12V -12V BLV HT1 HT14 -2025V HVC +185V +141V GND +12V -12V GND GND +12V -12V 4. R1003 3. R1004 1. R1008 2. R1016 INT. max.CUT-Off LEVEL 4.1 INTENS. on max. 4.2 adjust for max. intensity 3.1 INTENS. on min. 3.2 adjust for dark screen +12V10mV at 0,95A load current +141V0,2V at 60mA load current Adjustment Plan : Power Supply Board nderungen vorbehalten / Subject to change without notice 22 Digital Board (Topside) nderungen vorbehalten / Subject to change without notice 23 Adjustment Plan: Digital Board nderungen vorbehalten / Subject to change without notice 24 Front Controlboard (Topside, Bottomside) nderungen vorbehalten / Subject to change without notice 25 CRT Board (Topside, Bottomside) nderungen vorbehalten / Subject to change without notice 26 XY Board (Topside) nderungen vorbehalten / Subject to change without notice 27 XY Board (Bottomside) nderungen vorbehalten / Subject to change without notice 28 TB Board (Topside) nderungen vorbehalten / Subject to change without notice 29 TB Board (Bottomside) nderungen vorbehalten / Subject to change without notice 30 CCT Board (Topside, Bottomside) nderungen vorbehalten / Subject to change without notice 31 Adjustment Procedure nderungen vorbehalten / Subject to change without notice 32 ADJUSTMENT PROCEDURE Digital Storage Scope HM305 WARNING The Instrument must be disconnected from the mains power supply whenever you open the case, repair or exchange parts. HIGH VOLTAGE WARNING! Hazardous High Voltage of up to 2,000 Volts is present inside this Instrument. The areas particularly affected by High Voltage are the high voltage circuit on the PS-board, the CRT-board and the CRT- socket. SERVICE AND ADJUSTMENT of this instrument should only be performed in accordance and in conjunction with the operating manual and the WARNINGS contained therein. should only be performed by suitable qualified and experienced service personnel, or should be referred to one of the HAMEG companies listed on the rear cover of the manual. Test Instruments required: 1)Scope Tester HZ60-2. 2)Constant amplitude sinewave generator, 20Hz - 250MHz, output 5mV - 5V into 50, preferably with 20dB attenuation (e.g. HM8133, TEK SG502 + TEK SG503). 3)Amplitude Calibrator with 1kHz squarewave output and 600 impedance, risetime faster than 150ns.Output voltage 2mV - 20Volts in 1-2-5 sequence for 4 divisions display amplitude (e.g. HZ62, TEK PG506). 4)Time mark generator from 5ns/div to 5s/div. Output min. 10mV into 50 (e.g. HZ62, TEK TG501). 5)Pre-attenuator 2:1 (1M , 12-48pF), e.g. HZ20. 6)50 BNC through termination, e.g. HZ22. 7)2 BNC-cables, 50, e.g. HZ34. 8)BNC-T-connector. 9)Oscilloscope probe 10:1, with exactly 9M series resistance and compensated for test oscilloscope mentioned under 10). 10) Oscilloscope 100MHz, 5mV/div to 5V/div, e.g. HM1005. 11) Trimming/adjusting tool. 12) Variable output safety insulation transformer. 13) Video signal generator with positive and negative signal output. 14) Yt-EPROM HM1007. This procedure covers all adjustments and the most important - but not all - performance checks. The correct sequence of all adjustment steps must be strictly followed. Exact adjustment is only possible when any influence of the earths magnetic field has been compensated with the trimmer marked TR (trace rotation). All adjustments should only be performed by qualified and experienced personnel. This is particularly important for adjustments in the high voltage section of the instrument. nderungen vorbehalten / Subject to change without notice 33 1) R1008: +141 Volt supply. 35 2) R1016: +12 Volt supply. 35 3) RV7000: Trace Rotation Check. . 35 4) R1004 : CRT minimum intensity. . 35 5) R1003 : CRT maximum intensity. . 35 6) R712: Mean Y-plate Potential Channel I. . 35 7) R714: Mean Y-plate Potential Channel II. . 37 8) RV6021 : Astigmatism correction. 37 9) R640: Y-Gain CH I. . 37 10) R122: FET operating point CH I. . 37 11) R203: Invert-Balance CH I. . 37 12) R177: Variable-Balance CH I. . 37 13) R139: 100Hz Squarewave 5mV/div CH I. . 38 14) R134: 100Hz Squarewave 1mV/div Adjustment CH I. . 39 15) R658: Y-Gain CH II. . 39 16) R422: FET operating point CH II. . 39 17) R503: Invert-Balance CH II. . 39 18) R477: Variable-Balance CH I. . 39 19) R439: 100Hz Squarewave 5mV/div CH II. . 39 20) R434: 100Hz Squarewave 1mV/div CH II. . 39 21) RV2005 (A), RV2006 (C), CV2000 (D) and CV2001 (B): . 41 22) Y-Amplifier Bandwidth Check. . 41 23) C111 (A)/113 (B)/102 (C)/105 (D):Attenuator Compensation CH I. . 41 24) C411 (A)/413 (B)/402 (C)/405 (D): Attenuator Compensation CH II. . 41 25) RV2501 (A): Storage Mode Y-Gain . 43 26) RV9101: Dot-Join Overshoot . 43 27) RV9700 (A), RV9701 (B): Digital Y-Gain/Offset CH I. 43 28) RV9800 (A), RV9801 (B): Digital Y-Gain/Offset CH II. 43 29) R663: Digital ADDition/Offset. 45 30) RV2417 (A), RV2418 (B): Overscan. . 45 31) RV3421 (A), RV2225 (B): Digital Time Base Adjustment. . 45 32) RV3519 (A)/3589 (B)/3591 (C), CV3511 (D): Analogue Time Base. . 45 33) RV2234: X-Magnification x10. . 47 34) RV2260: X-Amplifier Symmetry. 47 35) R624: XY-Gain . 47 36) RV3293: Trigger-Symmetry. 47 37) R612: DC-Triggering CH I. . 47 38) R603: DC-Triggering CH II. . 47 39) RV2301 (A), RV4322 (B): Component Tester Y-Position and Tilt. . 49 40) RV8940: Calibrator Output. 49 41) Trigger Filter Check. 49 42) Triggerbandwidth Check. . 49 43) External Trigger Check. 49 44) Video Trigger Check. . 50 45) Pretrigger Check. . 50 46) Interface Connector Check. 50 Writing data into memory. 51 NOTE The adjustment procedures assume that the instrument had once been properly adjusted in the factory and adjustments are required due to temperature drift or the replacement of defective components. Before starting each adjustment procedure, set the oscilloscope to the following basic settings: Press POWER pushbutton (in!). Release all other pushbuttons (out!) except AC/DC input coupling. Rotate the three variable controls (TIME/DIV. and VOLTS/DIV.) to their (calibrated) detent positions. Set TIME/DIV. switch to 50s/div. Set both VOLTS/DIV switches to 5mV/div. Rotate the HOLD OFF knob fully counterclockwise. Trigger coupling set to AC. Set all other controls to their midrange positions. If different settings are required, they are mentioned particularly for each subject. Table of Contents nderungen vorbehalten / Subject to change without notice 34 3 21 PS-BoardFront panel 6 7 YPA-Board 458Pin 2 Pin 4 XY-BoardPS-Board nderungen vorbehalten / Subject to change without notice 35 (1)R1008: +141 Volt supply. WARNING:To avoid damage use a fully insulated screwdriver! Locate and identify R1008 (1) on PS-Board (screened section). Locate 8 pole checkpoint socket on XY-Board and identify pin 2. Adjust R1008 (1) for exactly +141 Volts ( 0.1 Volt) in respect to ground. (2)R1016: +12 Volt supply. Locate and identify R1016 (2) on PS-Board. Locate 8 pole checkpoint socket on XY-Board and identify pin 4. Adjust R1016 (2) for exactly +12Volts ( 10mV) in respect to ground. All other voltages +185V (pin 1), -12V (pin 5) and -1950V on cathode of CRT depend on the correct +12Volt adjustment. All these voltages must be checked and verified. (3)RV7000: Trace Rotation Check. Locate and identify RV7000 (3) TR“ on front panel. Using Y-Pos.I and X-Pos. controls, move baseline to the center of the graticule. Press channel I GD pushbutton (in!). When turning RV7000 (3), check that the range of inclination of the baseline is at least 1mm at both horizontal limits of the graticule. Readjust baseline exactly parallel to the horizontal center line of the graticule. (4)R1004 : CRT minimum intensity. Locate and identify R1004 (4) on PS-Board. Set INTENS. control to fully left position. Press XY pushbutton (in!). Adjust R1004 (4) so that the dot just disappears. Release XY pushbutton. (5)R1003 : CRT maximum intensity. Locate and identify R1003 (5) on PS-Board. Set INTENS. control to fully right position. Set FOCUS control for optimum sharpness. Adjust R1003 (5) so that the beam diameter is 1.5mm. Repeat adjustment (4) and (5) until optimum is obtained! (6)R712: Mean Y-plate Potential Channel I. Locate and identify R712 (6) on YPA-Board. Press DUAL pushbutton (in!). Set both beams to the horizontal center of the graticule by using Y-POS. I and Y-POS. This settings must not be changed during until item 6) and 7) are finished. Release DUAL pushbutton (out!) - channel I mode -. Switch the oscilloscope OFF. Locate and identify both lines from the Y-final amplifier to the Y-plates of the CRT. Connect both lines galvanically (short). Switch the oscilloscope ON. Measure the DC voltage at the Y-plates in respect to ground. Adjust R712 (6) for +85Volt Y-plate voltage. Note: Do not remove the short at the Y-plates until item 7) is finished. nderungen vorbehalten / Subject to change without notice 36 10 127119 8 YPA-Board PS-Board nderungen vorbehalten / Subject to change without notice 37 (7)R714: Mean Y-plate Potential Channel II. Locate and identify R714 (7) on YPA-Board. Press CH I/II pushbutton (in!) for channel II mode. Measure the DC voltage at the Y-plates in respect to ground. Adjust R714 (7) for +85Volt Y-plate voltage. Switch the instrument OFF. Remove the connection between both Y-plates. Switch instrument ON. (8)RV6021 : Astigmatism correction. Locate and identify RV6021 (8) on CRT-Board. Connect a 1MHz squarewave signal with 25mVpp at 50 (HZ22) to input CHI. Set time base to 1s/div. Adjust FOCUS control for optimum sharpness. Adjust RV6021 (8) until leading edge and top of signal have equal sharpness. Recheck range of FOCUS control. Adjust FOCUS control for optimum sharpness. (9)R640: Y-Gain CH I. Locate and identify R640 (9) on YPA-Board. Connect a 25mV/1kHz squarewave signal via 50 cable and 50 through terminator to input channel I. Set time base to 1ms/div. Adjust R640 (9) for 5 division signal height. (10) R122: FET operating point CH I. Locate and identify R122 (10) in CH I section of the YPA-Board. Release all pushbuttons (out!) for channel I mode. Press Y x5 channel I (in!) for 1mV/div. Press GD pushbutton channel I (in!). Switch the attenuator channel I constantly between 5mV/div (1mV) and 10mV/div (2mV). Adjust R122 (10) until no Y-