Query on Test Pattern Generator

[cbenham]

Originally Posted by W.B.

Or more specifically, 14.31818182 . . . MHz. In this case, the bars in question would have been 104 in width (except the first which in some applications stood at 106). However, with very few exceptions, the screencaps that are out there are not even done in this sample rate. Nor in the 17.734475 MHz (4 x 4.43361875) that was the composite sample rate for PAL standard. But with picture width at 754 pixels in the 14.31818182 . . . MHz sample clock, the horizontal timing of the top of the bars in this layout as on that WTVS screencap (and on those YouTube clips) would have been:
106 + 104 + 104 + 104 + 104 + 104 + 104 + 24 (black)
The lower portion would have been, with PLUGE added:
130 + 132 + 130 + 52 + 52 + 78 + 52 + 128
The vertical timing, unless I'm mistaken, would've been 21-200 and 263-442 for the top part, and 201-263 and 443-525 for the bottom.

The pics in this thread look like standard SMPTE BARS to me. Of course I may be missing your point entirely on the timing issue. The Tek TSG-100 portable test pattern generator includes SMPTE BARS and 1KHz tone, although I'm sure the oscillator frequency could be lowered. Hope this helps.
Cliff