Sync HD losing dropping lock

[kkfaudio]

Sync HD using Video REF.

Ref Present light staying lit, but Speed Cal and Locked lights fluctuate quite a bit, and will often disappear long enough and I get:

"The SYNC Clock Reference is not locked. Although the system will still play, it will not properly resolve until the clock is restored. Check your cables or change the Clock Reference or Clock Source."

It usually resolves itself quickly. The reference and loop sync cables seem fine - although I have not swapped the serial cable as yet, as it's hard to get to on the Mac. Is it possibly that cable, or is my Sync HD being faulty?

Thanks!

[dr sound]

Check your reference. Make sure your reference and your session are the same.
23.98 reference and 23.98 session
24 reference and 24 session.

They may lock if it's different but it won't be right.
MAKE SURE WHAT YOUR REFERENCE IS!

[dr sound]

What is your Video Reference? What is the origin of it?
Check the devise and verify it's the same as your session..
23.98 or 24 frame.

[Ray JB]

A quick question, do you have a 75 Ohm video terminator on the loop thru BNC socket of the sync ref input on your Sync HD? Mine used to do that even with the correct reference signal if un-terminated

[Frank Kruse]

Originally Posted by Ray JB

A quick question, do you have a 75 Ohm video terminator on the loop thru BNC socket of the sync ref input on your Sync HD? Mine used to do that even with the correct reference signal if un-terminated

Yes, what Ray said. The video ref out is a passive through and needs to be terminated.

[kkfaudio]

Thanks for the replies..

I forgot to mention the video ref continues on to the Aja Kona 3 breakout box.

I will have to check that it is terminated properly there. Any reason to swap the order? ie ref to Kona and then sync HD? I don’t see any blips in Aja control panel.

Yes, I definitely check that the correct reference is setup according to frame rate in the session.

I’ll follow up next week after I get back to that room.

[Ray JB]

Just put a 75 ohm terminator at the end of the video ref chain. The Sync HD is finicky with the feed it gets. The manual states that you need to terminate the end of the chain properly for correct operation. Believe me, it's generally needed.

[kkfaudio]

Copy that - I'm 99% sure it is terminated, but I'll take the Aja out of the loop and terminate on the Sync HD for testing and go from there...

Thanks..

[mgoorevich]

You might want to check if your Sync HD is well cooled as its very sensitive to higher temperature.
Does this happens at the morning when the unit is cold?
I had the same problem with my Sync HD in conditionered machine room until I made some room above and beneath of Sync HD in order to be well ventilated.

[Ray JB]

Kevin, did you sort your problem? If so what caused it?