M
Michael A. Terrell
Guest
radams2000@gmail.com wrote:
NTSC color calls for +/- 10 Hz for the 3,579,545 burst frequency.
Long ago I learned a painful lesson about video frequency accuracy. I assumed that getting a crystal within 100ppm of tbe ideal frequency should be just fine. But when we tried to send that signal through a satellite, it wouldn't go because the frequency accuracy was too poor.
I think the issue is that VCXO's are often used for clock recovery and they can't be pulled very far. Or maybe they just rely on absolute accuracy, and when things drift between the source and the sync, you just drop or repeat a frame. Not sure.
NTSC color calls for +/- 10 Hz for the 3,579,545 burst frequency.