To Analyze Video Waveforms - HP 54616B User And Service Manual

Operating Your Oscilloscope

To analyze video waveforms

To analyze video waveforms
Enhanced TV/Video Trigger
This section discusses basic TV video triggering. If you have Option 005
Enhanced TV/Video Trigger installed in your oscilloscope, refer to Chapter 3
"Using Option 005 Enhanced TV/Video Trigger."
The TV sync separator in the oscilloscope has an internal clamp circuit. This
removes the need for external clamping when you are viewing unclamped
video signals. TV triggering requires two vertical divisions of display, either
channel 1 or channel 2 as the trigger source, and the selection of internal
trigger. Turning the trigger level knob in TV trigger does not change the
trigger level because the trigger level is automatically set to the sync pulse
tips.
For this exercise connect the oscilloscope to the video output terminals on a
television. Then set up the oscilloscope to trigger on the start of Field 2. Use
the delayed sweep to window in on the vertical interval test signals (VITS),
which are in Line 18 for most video standards (NTSC, PAL, SECAM).
Connect a TV signal to channel 1, then press
1
Press , then press the
2
Display
Press , then press the
3
Mode
Press
4
Slope/Coupling
Polarity Selects either positive or negative sync pulses.
Field 1 Triggers on the field 1 portion of the video signal.
Field 2
Triggers on the field 2 portion of the video signal.
Line Triggers on all the TV line sync pulses.
HF Rej Controls a 500 kHz low pass filter in the trigger path.
2–40
Peak Det softkey.
softkey.
TV
, then press the
Field 2
.
Autoscale
softkey.