Philips PM3208 - User Manual

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Summary

1 Safety Instruction

1.1 Introduction

Provides general information and guidelines for safe operation of the instrument.

1.2 Safety Precautions

Essential procedures for correct and safe use by operating and servicing personnel.

1.3 Caution and Warning Statements

Defines the meaning of CAUTION and WARNING labels used in the manual.

1.4 Symbols

Illustrates and explains common safety symbols used in the manual.

1.5 Impaired Safety-Protection

Procedures for handling instruments where safety features may be compromised.

1.6 General Clauses

General warnings and clauses regarding instrument safety and component replacement.

2 Characteristics

2.1 Display Characteristics

Details the specifications of the oscilloscope's display screen and associated features.

2.2 Vertical Deflection or Y Axis

Describes the deflection sources, modes, and signal output for the vertical axis.

2.3 Channels A and B

Details input connectors, impedance, capacitance, and coupling for input channels.

2.4 External Input

Specifies input connector, impedance, and voltage limits for external signals.

2.5 Horizontal Deflection or X Axis

Outlines deflection sources and modes for the horizontal axis of the oscilloscope.

2.6 Main Time Base

Details modes, deflection coefficients, error limits, and variable gain for the time base.

2.7 External Horizontal Deflection

Describes deflection sources, coefficients, and frequency response for external horizontal input.

2.8 Trigger MTB

Specifies trigger sources, modes, and channel coupling for the main time-base trigger.

2.9 Blanking or Z Axis

Details input coupling and voltage limits for the Z-axis blanking signal.

2.10 Calibrator

Specifies waveform shape, output voltage, and frequency for the built-in calibrator.

2.11 Power Supply

Provides details on AC input voltage, frequency, and power consumption of the instrument.

2.12 Environmental

Lists environmental requirements for temperature, humidity, altitude, and vibration.

2.13 Safety

States the safety standards and certifications the instrument meets.

3 Block Diagram Description

3.1 Vertical Deflection

Explains the signal path and circuitry for the vertical deflection system.

3.2 Horizontal Deflection

Describes the trigger generator, sweep generator, and output stages for horizontal deflection.

3.3 Power Supply

Details the operational amplifiers, regulator circuits, and DC-DC converter for high voltage.

4 Circuit Description

4.1 Vertical Deflection

Details the attenuator, preamplifier, intermediate, switching, and output amplifiers for vertical signals.

4.2 Horizontal Deflection

Explains the trigger amplifier, trigger generator, sweep generator, and output stages for horizontal signals.

4.3 CRT Circuit

Describes the Z-axis amplifier, CRT control, and high voltage supply for the cathode ray tube.

4.4 Calibrator

Explains the circuit that produces a square-wave voltage for calibration purposes.

4.5 Power Supply

Details the line-transformer, rectifiers, and stabilizing circuits for the instrument's power.

5 Performance Check and Adjustment Procedure

5.1 General Information

Provides general guidance, warming-up times, and safety notes for performance checks.

5.2 Recommended Test and Calibration Equipment

Lists the necessary test equipment and their required specifications for calibration.

5.3.1 Power Supply Low Voltage

Procedure to check and adjust the low voltage outputs of the instrument's power supply.

5.3.2 Power Supply High Voltage

Procedure to check the high voltage output of the instrument's power supply.

5.3.3 Power Consumption

Procedure to check the maximum input power consumption of the instrument.

5.3.4 CRT Intensity Adjustment

Procedure to adjust the intensity control for the CRT display.

5.3.5 CRT Focus Adjustment

Procedure to adjust the focus control for optimal spot brightness on the CRT.

5.3.6 CRT Astigmatism Adjustment

Procedure to adjust astigmatism for a perfectly round spot on the CRT.

5.3.7 Vertical Step Balance Adjustment

Adjusts trace jump when switching AMPL/DIV for vertical channels.

5.3.8 Vertical x5 MAG Balance Adjustment

Adjusts trace jump when pulling/pushing the variable MAG control.

5.3.9 Vertical Variable Gain Balance Adjustment

Adjusts vertical movement when turning the variable gain control.

5.3.10 Vertical Gain

Procedure to set the vertical gain for channel A and B using a square-wave signal.

5.3.11 Vertical x5 MAG Gain

Procedure to set the vertical gain when using the x5 magnification.

5.3.12 Channel B Invert Adjustment

Adjusts the position control to ensure trace B does not move when INVERT is switched.

5.3.13 ADD Balance Adjustment

Ensures the ADD trace coincides with the X-axis of the graticule.

5.3.14 Low Frequency Response Adjustment

Adjusts the MF circuit for a flat response from rising edge to 0.2 µs.

5.3.15 High Frequency Response Adjustment

Adjusts ringing and overshoot for flat frequency response at high frequencies.

5.3.16 1 kHz Square-Wave Response Adjustment

Adjusts for minimum over/undershoot in response to a 1 kHz square-wave signal.

5.3.17 Input Impedance Adjustment

Adjusts probe trimmer for optimum waveform and checks pulse aberrations.

5.3.18 Dual A and B, Polarity Inversion Channel B

Checks if A and B display same polarity and if inversion reverses waveform B.

5.3.19 ADD Facility

Checks ADD function displaying one waveform and INVERT function displaying a straight line.

5.3.20 Vertical Bandwidth

Checks trace height at 50 kHz and 20 MHz to verify vertical bandwidth.

5.3.21 Trigger DC Balance Adjustment

Adjusts minimum movement of trigger point when switching trigger coupling.

5.3.22 Y-out DC Balance Adjustment

Adjusts output voltage at YA-OUT terminal to 0 V at 50 Ω.

5.3.23 Y-out Gain Adjustment

Calibrates channel B using YA-OUT signal for 8 divisions display.

5.3.24 X-gain Adjustment

Adjusts the X-gain control for a 5 division amplitude with a 0.5V signal.

5.3.25 Triggering Adjustment

Adjusts trigger level and slope for minimum starting point movement.

5.3.26 Trace Starting Point Adjustment

Adjusts the trace starting point to the beginning of the X-axis.

5.3.27 X-Y Centering Adjustment

Positions the spot at the centre of the X-axis in X-Y mode.

5.3.28 Horizontal Bandwidth

Checks trace amplitude at 50 kHz and 1 MHz to verify horizontal bandwidth.

5.3.29 Z Input

Procedure for adjusting Z input for normal brightness and checking blanking.

5.3.30 MTB Deflection Coefficients

Adjusts marker pulses for coincidence with graticule lines for various TIME/DIV settings.

5.3.31 Sweep Length Adjustment

Adjusts VR614 for a sweep length of 11.5 divisions with a 0.1 ms marker pulse.

5.3.32 x10 MAG Time Adjustment

Adjusts VR807 for coincidence of marker pulses with graticule lines in x10 MAG mode.

5.3.33 x10 MAG Centre Balance Adjustment

Adjusts VR806 for minimum movement of the trailing edge in x10 MAG mode.

6 Dismantling the Instrument

6.1 General Information

Provides general safety and handling notes for dismantling procedures.

6.2 Removing the Top- and Bottom Covers

Detailed steps for removing the instrument's top and bottom covers.

6.3 Access to Parts for Checking and Adjusting Procedure

Describes accessibility of adjusting elements after cover removal.

7 Corrective Maintenance

7.1 Replacements

Guidance on obtaining and replacing standard, special, and semiconductor components.

7.2 Removing and Remounting the Units

Procedures for removing and remounting various PCB assemblies and the CRT.

8 Safety Inspection and Test After Repair in the Primary Circuit

8.1 General Directives

General guidelines for wiring, soldering, and replacing guards during repairs.

8.2 Safety Components

Notes on using Philips-selected components for safety in the primary circuit.

8.3 Checking the Protective Earth Connection

Procedure to verify the integrity of the protective earth connection resistance.

8.4 Checking the Insulation Resistance

Procedure to measure insulation resistance between mains connections and accessible parts.

8.5 Checking the Leakage Current

Procedure to measure leakage current between supply poles and accessible parts.

8.6 Voltage Test

Procedure to test the instrument's withstand voltage capability without breakdown.

9 Partslist

9.1 Mechanical Parts

Lists all mechanical parts of the instrument with their ordering codes and descriptions.

9.2 Units

Lists the main PCB assemblies (units) with their ordering codes and descriptions.

9.3 Cables and Connectors

Lists all cables and connectors used in the instrument with their part numbers.

9.4 Electrical Parts

Lists various electrical components like capacitors, resistors, diodes, transistors, and ICs.

10 Circuit Diagrams + PCB Lay Outs

Figure 10.1 Vertical PCB Lay Out

Shows the component layout for the vertical printed circuit board.

Figure 10.2 Circuit Diagram of Vertical Input

Illustrates the circuit diagram for the vertical input stage and attenuator.

Figure 10.3 Vertical PCB Lay Out

Provides a component layout view for the vertical printed circuit board.

Figure 10.4 Circuit Diagram of Vertical Amplifier

Shows the circuit diagram for the vertical amplifier stages.

Figure 10.5 Vertical PCB Lay Out

Component layout diagram for the vertical printed circuit board.

Figure 10.6 Circuit Diagram of Vertical Output Amplifier

Illustrates the circuit diagram for the vertical output amplifier.

Figure 10.7 Horizontal PCB Lay Out

Shows the component layout for the horizontal printed circuit board.

Figure 10.8 Circuit Diagram of Trigger Generator

Details the circuit diagram for the trigger generator section.

Figure 10.9 Horizontal PCB Lay Out

Component layout diagram for the horizontal printed circuit board.

Figure 10.12 Circuit Diagram of Horizontal Output Amplifier

Illustrates the circuit diagram for the horizontal output amplifier.

Figure 10.13 Vertical PCB Lay Out Showing Parts of Power Supply

Vertical PCB layout highlighting components of the power supply section.

Figure 10.14 Cal and Control PCB Lay Out

Component layout for the calibration and control printed circuit board.

Figure 10.15 Circuit Diagram of Power Supply + Miscellaneous

Shows the circuit diagram for the power supply and related miscellaneous components.

Figure 10.16 Horizontal PCB Lay Out