OPERATING INSTRUCTIONS
Contents
1. SWEEP control can be set to display the exact number of waveforms desired When the TV V mode is selected vertical sync pulses are selected as triggers to permit viewing of vertical fields and frames of video A sweep time of 2 ms div 1s appropriate for viewing fields of video and 5 ms div for complete frames two interlaced fields of video At most points of measurement a composite video signal is of the polarity that is the sync pulses are negative and the video is positive In this case use SLOPE If the waveform is taken at a circuit point where the video waveform is inverted the sync pulses are positive and the video 1s negative In this case use SLOPE zd2. This control is usually set to the MIN position fully counterclockwise because no additional holdoff period is necessary The HOLDOFF control is useful when a complex series of pulses appear periodically such as in Fig 4B Improper sync may produce a double image as in Fig 4A Such a display could be synchronized with the VAR SWEEP control but this is impractical because time measurementsare then uncalibrated An alternate method of synchronizing the display is with the HOLDOFF control The sweep speed remains the same but the triggering of the next sweep is held off for the duration selected by the HOLDOFF control Turn the HOLDOFF control clockwise from the MIN position until the sweep starts at the same point of the waveform each time MAGNIFIED SWEEP OPERATION Since merely shortening the sweep time to magnify aportion of an observed waveform can result in the desired portion disappearing off the screen magnified display should be performed using magnified sweep Using the POSition control move the desired portion of waveform to the center of the CRT Pull out the PULL X10 knob to magnify the display ten times For this type of display the sweep time is the Main Time Base TIME DIV control setting divided by 10 Rotation of the POSition control can then be used to select the desired portion of the waveforms X Y OPERATION X Y operation permits the oscilloscope to perform many measurements not possible with conventional sweep op
3. eration The CRT display becomes an electronic graph of two instantaneous voltages The display may be a direct comparison of the two voltages such as stereoscope display of stereo signal outputs However the X Y mode can be used to graph almost any dynamic characteristic if a transducer is used to change the characteristic frequency temperature velocity etc into a voltage One common application is frequency response measurements where the Yaxis corresponds to signal amplitude and the X axis corresponds to frequency OPERATING INSTRUCTIONS 1 depress the X Y switch Set the Trigger Source and VERTical MODE switches to X Y 2 In this mode channel 1 becomes the X axis input and channel 2 becomes the Y axis input The X and Y positions are now adjusted using the POSition and the channel 2 POSition controls respectively 3 Adjust the amount of vertical Y axis deflection with the CH 2 VOLTS DIV and VARIABLE controls 4 Adjust the amount of horizontal X axis deflection with the CH 1 VOLTS DIV and VARIABLE controls VIDEO SIGNAL OBSERVATION Setting the COUPLING switch to the TV H or TV Vposition permits selection of horizontal or vertical sync pulses for sweep triggering when viewing composite video waveforms When the TV H mode is selected horizontal sync pulses are selected as triggers to permit viewing of horizontal lines of video A sweep time of about 10 ms div is appropriate for displaying lines of video The VAR
Download Pdf Manuals
Related Search