Question: The horizontal position of the picture from monitor outputs of the WFM601 and WFM601i seems to be slightly out of time with other digital equipment monitoring outputs. What is happening?
Answer: The position of the picture on a picture monitor, connected to the outputs of a WFM601 series monitor is established by the reinserted sync on the Y or G channel. In current models, the WFM601A, WFM601E, and WFM601M, we have optimized the timing of the reinserted sync. In the earlier WFM601 and WFM601i these values were not exact, but should not change from picture to picture. The only time you see any movement is when signals are switched at the monitor from the WFM601 or WFM601i to another direct component source.
Here are the typical positions of H sync 50% leading edge vs. TSG422 video framing signal for older instruments (WFM601 and WFM601i):
T1 is the last Y sample (word 1439) before EAV to the sample coincident with the 50% point of sync (word 1473 in 525/60, word 1465 in 625/50)
T2 is the time from the sample coincident with the 50% point to the first Y sample of the active line (word 001 in both standards)
| 525/60 standard | t1 | t2 | total |
| Nominal | 1.259 µs | 9.037 µs | 10.276 µs |
| WFM601/i | 1.255 µs | 9.035 µs | 10.290 µs |
| 625/50 standard | t1 | t2 | total |
| Nominal | 0.963 µs | 9.777 µs | 10.740 µs |
| WFM601/i | 0.665 µs | 10.075 µs | 10.740 µs |
The WFM601M is output timing is nominal. The WFM601A and WFM601E outputs are not calibrated, but these instruments are built on WFM601M hardware and are very close to nominal.