Audio/Video Timing (Option 42); Vm700T Audio/Video Measurement Operating Instructions; Figure 2-19: The Audio Video Timing Display - Tektronix VM700T User Manual

Audio/Video Timing (Option 42)

VM700T Audio/Video
Measurement Operating
Instructions
VM700T Option 40/41/42 Audio Measurements User Manual
The Audio/Video Timing feature of the VM700T is part of a system that
measures the timing difference between audio and video portions of a program
that arrive from different transmission paths. Use this feature in conjunction with
the VITS 200 NTSC Generator and Inserter or the VITS 201 PAL Insertion
Generator and the ASG100 or ASG140 Audio Signal Generator that is also
equipped for the Audio/Video Timing measurement. Check the operators
manuals for your instruments to determine if they support the measurement. The
generators may be modified if they do not support the measurement. See your
local Tektronix representative for information either on obtaining modification
kits or having your equipment modified.
Figure 2–19: The Audio Video Timing display
The Audio/Video Timing measurement feature on the generators permits
synchronization of the video and audio test signals at the sending end of the
program. The VM700T, equipped with Option 40 or Option 41 and Option 42
(the Audio Video Timing measurement), receives both signals and measures the
timing difference to aid in retiming the signals. Figure 2–19 shows the VM700T
display for the Audio Video Timing measurement display. The error message
line above the graph provides information regarding the state of the triggers
needed to make a timing measurement. The line may say that it is waiting for
either or both triggers (audio and video) to arrive, or that one or the other has
arrived and it is waiting for the other. Upon receiving both triggers, the VM700T
makes the measurement and provides a delay time numerical readout and a
graphical display.
Option 41 and Option 42
2–33