Sync HD unstable with video reference (SD)

[babyseal]

Hello everyone,

We have recently upgraded from Sync I/O to Sync HD. We are currently feeding SD black (29.97) from a generator. Before, we never had any problems with Sync I/O unlocking while seeing the black. But with Sync HD, it loses lock with the same SD black. The Sync HD is the first device that's getting the video reference, then it hits DP570/571 where it's terminated.

At least once a day, it loses sync and an error message shows up in PT. Then it goes back and forth locking and unlocking for about 5~10min. At the end, it seems to find the black again and it's happy. I don't know what's causing this.

Whenever it's having problems locking to black, I look at the DP570/571 and they are happily locked to the same signal looping thru Sync HD. Originally we had to send back one Sync HD because it just was not detecting the video reference. So I'm wondering if there's any hardware problems or problems with the black itself. Would Sync HD be more sensitive whereas Sync I/O was more robust and wasn't having problems with the black??? Any ideas?

PT HD3, 7.4.2cs1 on Mac Pro w/ 2 x 2.8GHz Quad-core intel Xeon, 10 GB RAM w/ 3 x 192 i/o

Thanks!

[Chief Technician]

Originally Posted by babyseal

The Sync HD is the first device that's getting the video reference, then it hits DP570/571 where it's terminated.

This may not be your problem, but looping something through more than one device is not the best thing to do. Consider using a distribution amplifier to achieve the same goal.

At least once a day, it loses sync and an error message shows up in PT. Then it goes back and forth locking and unlocking for about 5~10min. At the end, it seems to find the black again and it's happy. I don't know what's causing this.

I had this intermittent problem with a SYNC I/O. Something went bad with the SYNC I/O. I replaced it with a SYNC HD and have not had the problem occur once in over two (2) weeks.

Whenever it's having problems locking to black, I look at the DP570/571 and they are happily locked to the same signal looping thru Sync HD.

The SYNC HD could be more sensitive to changes in voltage or frequency drift. The sync pulse is supposed to be from -20 to +20 IRE on a waveform monitor. If the SYNC HD has a tight tolerance to that, and your signal is on that edge, it might explain the loss of sync. This can be compensated for with an equalizing DA or a DA with variable gain. The same could be said for the frequency, but if the frequency is drifting enough to cause that problem, you would want to get another sync generator.

Originally we had to send back one Sync HD because it just was not detecting the video reference. So I'm wondering if there's any hardware problems or problems with the black itself.

How many SYNC HDs do you have? If you loop the video ref from one SYNC HD to another, and watch both of them, does one lose video ref and the other keep it? If so, its a SYNC HD problem. If they both lose ref, change the order they are in the loop. If they both still lose ref, I would say that's enough evidence to suggest the video ref generator is the problem.

[DigiTechSupt]

Does the unit lock properly if set to internal?

I think you should probably contact tech support by phone for further troubleshooting as well as updating your contact info in your profile - we tried to have someone contact you directly, but the email got bounced back.