[James2001]

I never understood why ETP-1 was ditched though

Presumably it was somehow tied into the pre-1992 way of doing things and they were unable to use it after.

[Neil Jones]

Wasn't ETP-1 generated by the transmitter?
It used to appear during downtime/off air, and as channels went 24hrs, it sort of became irrelevant. Might have lasted on Channel 4 for a bit longer than it did on ITV.

Channel 4 apparently aired ETP-1 as the last thing shown from Crystal Palace at the point of digital switchover in London in 2012, but that was probably a recreation of some sort rather than a genuine "from the transmitter" (there is a video on YouTube but but its been filmed on a mobile phone pointing at a telly)

[James2001]

It was generated from Charlotte Street too- the way you could tell which you were getting was that the Charlotte Street version had a line above and below the text (and 1KHz tone, if there was tone), and the transmitter version didn't (and had a 440Hz tone).

From what I heard, the version broadcast from Crystal Palace at DSO was genuine, from an original generator (albeit modified to remove the caption). There's certainly been proper off-air recordings of it rather than just filmed off a TV, even if none of them are online right now.

[Larry the Loafer]

Can someone tell me why the switches were so clean whenever BBC One had a regional opt-in/out back in the day? I've never seen a clip where there are any sync issues on the tape, unlike the ITV regions.

[Stooky Bill]

That's a good point - presumably the ITN programme got to the network via Central or another of the big regions rather than Thames on that occasion?

No reason why it couldn't have gone to air via Thames, the previous programme came from them, so it makes sense to. All that was turned off at midnight was their output to the transmitter - none of the network were taking that

In fact thanks to announcer Mark Lipscomb who took a camcorder into Thames that evening, here is video footage of Thames's transmission controller checking the on-air time of that bulletin with the PA at ITN. No out-time of course, I assume the regions just ducked out of Big Ben whenever they had had enough

twitter.com 

Admin edit: to fix Twitter URL.

[Steve in Pudsey]

Can someone tell me why the switches were so clean whenever BBC One had a regional opt-in/out back in the day? I've never seen a clip where there are any sync issues on the tape, unlike the ITV regions.

The BBC regional centre would genlock so it was in sync with the incoming network feed, much like ITV regions did before each network programme.

Where ITV had glitches was when BT did line switches

[James2001]

I've heard some people claim the non sync cuts ended with GMTV, but I'm sure we still had them for a few years afterwards. Maybe it depended on the region.

But even after that, there were still often split
It second glitches at switch time, often showing things like video from other regions, test cards or feed slates- there's a few on the MHP Private Parts, like a split second shot of the Grampian ident showing up in a different region and an empty Anglia News studio.

[Steve in Pudsey]

I believe there was a potential for 9.25 splats as GMTV finished as the distribution was reconfigured at the London end to take the extra facilities for macro regional ads out of circuit.

[Stooky Bill]

I believe there was a potential for 9.25 splats as GMTV finished as the distribution was reconfigured at the London end to take the extra facilities for macro regional ads out of circuit.

It wasn't the macro regions being taken out of circuit, it was the ITV companies presentation suites being taken out/put back into line. 

GMTV still passed through the regional centres as they did the news bulletins, but my understanding but via the news studios who essentially opted out. 

Presumably the circuits carrying GMTV to the regions was then replaced with the first network programme. The macro ad regions were irrelevant, each station would have just got one

[robertclark125]

I believe there was a potential for 9.25 splats as GMTV finished as the distribution was reconfigured at the London end to take the extra facilities for macro regional ads out of circuit.

It wasn't the macro regions being taken out of circuit, it was the ITV companies presentation suites being taken out/put back into line. 

GMTV still passed through the regional centres as they did the news bulletins, but my understanding but via the news studios who essentially opted out. 

Presumably the circuits carrying GMTV to the regions was then replaced with the first network programme. The macro ad regions were irrelevant, each station would have just got one

In other words, all they were doing was switching the output from the regional companies news studios to the main suites. What would've happened at weekends, when GMTV didn't have regional news?

This leads to another question; had Oracle retained the teletext franchise beyond 1992, would this have meant their regional sections being available during GMTV? On the flipside, had TV-am remained on air after 1992, and Teletext UK had the teletext service, I guess the regional teletext sections wouldn't have been available during TV-am?