I just picked up a Sencore TVA92 that's looks barely used. I also have a VG91 and had heard that you need to connect them together.
That is definitely true. The TVA92 is a brick without it. You can't even turn it on!

Does anyone have the specs for the synchronizing cable that connects these two? If it's just wired straight through, I'm sure I could throw one together.

https://live.staticflickr.com/65535/51914536426_8fb60723e3_c.jpg (https://flic.kr/p/2n6vz1f)

https://live.staticflickr.com/65535/51914536456_cecf1603b5_c.jpg (https://flic.kr/p/2n6vz1L)

I don't have the specs, but I do have the cable. I just checked and it is just wired straight through.

I have schematics for the VG91 if that would be of any use to you.

Sorry for the late reply.

Thanks. I did figure it out a while ago. Just a standard cable as you said.