30 September 1988
Video time base error
Figure 3-5. Sync to subcarrier
time base error
f. If sync to subcarrier time base error occurs either on the reference
pulses to a tape machine, or exists on the recorded video tape, color frame
lock will be difficult.
In the normal playback mode, excessive sync to
subcarrier time base error will cause the tape machine to shift horizontal
lines by 279 ns (subcarrier cycle) increments. This phenomenon is seen as a
tearing of the picture.
Learning Event 3:
DESCRIBE COMPONENTS USED TO BUILD AND MEASURE AN SC/H-PHASED PLANT
The heart of every system is the synchronizing generator.
requirements for the sync generator should include the following:
a. Less than 1 ns sync to subcarrier time base error.
b. Less than 10 ns long term SC/H phase stability.
c. Consistent SC/H phase regardless of operational mode or initial
d. Compatibility with other equipment.
Many studios use multiple sync generators to provide advanced drive
pulses and subcarriers to various source equipment.
synchronizing generator must meet these requirements, and be able to color-
frame lock precisely to the master reference-synchronizing generator.