Tektronix 5440 oscilloscope

Tektronix 5440 oscilloscope

Overview of Instrument Core

(1) Hardware structure

Plugin compartment: There are a total of 3 compartments that can accommodate 5000 series plugins (without N suffix plugins supporting display readings), 2 vertical compartments (left and middle) for amplifier plugins, and 1 horizontal compartment (right) for time base plugins. The combination of plugins determines the functionality of the measurement system.

Key controls:

Display related: INTENSITY adjusts the brightness of the trajectory, READOUT INTENS only adjusts the brightness of the reading part (the reading system fails when counterclockwise to the bottom), FOCUS controls for clear display, and BEAM FINDER compresses the trajectory to the scale range.

Power supply and calibration: The power switch (POWER) controls the power on/off, and the internal calibrator (CALIBRATOR LOOP) provides a square wave signal with a voltage of 400mV (± 1%) and a current of 4mA (± 1%), with a frequency of twice the power supply frequency, for calibration and probe compensation.

External interface: EXT INTENSITY INPUT interface receives Z-axis modulation signals (DC coupling,+5V enhanced brightness, -5V reduced brightness, maximum safe input ± 50V, frequency range DC to 2MHz).

(2) Core functions

Display mode:

Alternate mode: The time base plugin display switch pops up and switches between the activated plugin/channel with each CRT scan, suitable for high-frequency signals.

Chop mode: When the time base plugin display switch is pressed, it electronically switches between channels at a rate of 100kHz, suitable for displaying low-frequency signals or single event phenomena.

X-Y operation: Install 5A series amplifiers or 5B series time base plugins with amplifier channels in the horizontal cabin to receive X signals, and 5A series amplifiers in the vertical cabin to receive Y signals, achieving signal comparison display.

Grating display: Both the left vertical cabin and the horizontal cabin are equipped with 5B series time base plugins. The scanning speed of the vertical cabin is slower than that of the horizontal cabin, and brightness modulation is achieved through EXT INTENSITY INPUT, which can simulate TV display.

Reading System: Only supports 5400 series plugins, displaying alphanumeric information in real-time with analog waveforms on CRT. Each plugin's reading occupies a fixed position (channel 1 is indexed at the top, channel 2 is indexed at the bottom), displaying up to 6 readings (option 3 can select 8 readings). The reading interruption waveform display is only about 20 microseconds/character.

Operation Guide

(1) First operation process (19 steps in total, with the following key steps)

Plug in preparation: Install 5A series amplifier plugs in the left/middle vertical cabin and 5B series time base plugs in the horizontal cabin.

Power connection: After confirming the operating voltage, turn off the power switch and connect a power source that meets the voltage/frequency requirements.

Initial setup:

Amplifier plugin: Display on, center position, CH1 Volts/Div set as needed, CH1 Variable Volts/Div clockwise to the end (Cal), CH1 Input Coupling set to DC, mode set to CH1.

Time base plugin: Display alternately (button pops up), center position, Main Sec/Div set to 5ms, Variable Seconds/Div clockwise to the end (Cal), Swp Mag turned off (button pops up), Main Trig Level counterclockwise to the end, trigger source selected to the left (or center, if the amplifier is in the middle compartment), coupled with Auto Trig, AC Couple,+Slope, mode set to Main Sweep.

Calibration check: Connect the probe/test line to the calibrator, adjust the trigger level to obtain stable display, check the waveform amplitude (4 divisions) and cycle (6 complete cycles, 5 cycles for 50Hz power supply), and recalibrate if abnormal.

(2) Basic measurement methods

Calculation formula/explanation for key steps of measurement type

AC peak to peak voltage: 1. The vertical plug-in input coupling is set to Gnd, and AC is set after receiving the signal; 2. Volts/Div is set to display 5-6 vertical divisions, and Variable Volts/Div is set to Cal; 3. Adjust the trigger to obtain stable display, and measure the vertical division of peak values; 4. Result=Division value × Volts/Div × Probe attenuation ratio (if any) Example: 4.6 Division value × 5V/Div=23V

DC instantaneous voltage: 1. The vertical plug-in input coupling is set to Gnd, and the trajectory is positioned to the reference line (such as the bottom part degree, negative voltage is used at the top); 2. After receiving the signal, set the DC and measure the vertical division between the reference line and the measurement point; 3. Result=division value x Volts/Div x probe attenuation ratio (if any), polarity determined by waveform position (+input and waveform is positive on the reference line) Example: 4.6 division x 2V/Div=+9.2V

Time cycle 1. Connect the signal, select AC/DC coupling, set Volts/Div to display 4 divisions; 2. Adjust the trigger to obtain stable display, set Sec/Div to 1 cycle display<8 divisions; 3. Measure the horizontal division of two points (Variable Sec/Div at Cal); 4. Result=Division value x Sec/Div Example: 5 divisions x 0.1ms/Div=0.5ms