The network switch "glitch"

[digidan]

Having just read a wonderful thread on the improvement of network audio in the late 70's, it reminded me of a common occurrence in early TV, the rolling or jumping picture when stations switched to the network. I grew up watching TV in the Philly market in the 70's, and all 3 affiliates had that issue. KYW (NBC) and WPVI (ABC) at some point in the 70's were able to eliminate the jump, but WCAU (CBS O&O) was most noticeable to me and it continued into the 80's. Knowing nothing about TBC/Frame Syncs (or the lack of) as a kid, I never cared why it happened, but always told me when the station joined or left the network. I've watched a lot of vintage tape, and those glitches caused more havoc on the recordings than the live switch. Does anyone else have memories of those "glitchy"days? And how long did it take for your station to make the "smooth" transition to network?

 

[newsmark]

The first station I worked at ALWAYS had the glitch. The second one had a way we could avoid it, but it tied up a lot of resources, so we didn't do it often. Finally, at my third station, it was about 1984 when we got a dedicated frame sync for our main network feed.

 

[danderson4411]

ive seen that sometimes like when cbs switches to another nba game in 1978

 

[newsmark]

Heck, at my first station, we'd even get the glitch when we switched to a live camera at our bureau or our own radar. Both were physically away from the main studio, so for all practical purposes, they were outside sources.

 

[Mediafrog+]

Years ago, the networks, being an external video source, would of course have sync that didn't match up with the local stations. It was possible to "genlock" the station to the network in order to smoothly transition in and out of programming, or to super an ID. However you didn't want to stay genlocked outside of network programming, as the network feed might not be stable due to line switches, rerouting, maintenance, signal loss, etc. which would cause your local video to go nuts.

If you recorded various unsynchronized sources to video tape, the playback would tear up at the switch point as the VTR would have to relock on the video.

Frame syncs at local stations eliminated that problem, as they could digitally slightly delay the analog network video to match the station's own sync. Frame syncs eventually got integrated into everything, which kept all the video sources in line. With all digital video feeds these days, the network is just one of many sources to go in and out of routing equipment--all digitally mixed and synchronized.

Sync generator war story: Years ago I was switching Master Control on a Saturday afternoon during a long stretch of video taped local programming, and the main sync generator for the station died. Of course, every internal video source in the station went nuts, including our on-air programming. I quickly went back to the racks and switched over to the backup sync generator...which I discovered was also dead. By repatching some cables, I was able to sync the station to the network feed which had color bars up. That settled down the station video issues, but I was sweating bullets hoping that AT&T or the network didn't do anything to the feed, or I would be complete toast until the network had programming later in the day. Fortunately, the network feed remained stable during the rest of local programming, and when we hit the network later that afternoon an engineer made it to the station, found another sync generator in storage, and got our station sync back before we had more local programming.

 

[newsmark]

I had something similar happen. Everything list sync. I had the chief engineer on the phone and he talked me through syncing everything to a studio camera.

 

[danderson4411]

i have seen it where cbs switches to another regional nba game you see audio come in before the video this was in 1978