Channel 4 pre-1993 regional opt outs

In 1982?

I distinctly remember seeing Geoff Druett presenting an advert for YTV itself about how cheap advertising could be which mentioned Belmont splits on C4

Yes. TVS were using a pair of Questech frame syncs from about Easter 1982 on ITV. They also used a frame sync on C4 ( you could see a fine mesh appear when they switched themselves into circuit during the black and silence ‘buffer’ between the test card and the start of programmes) Frame syncs were a mixed blessing back then ! However there wasn’t much of a splat at that switch point, because presumably they were slave locked to C4 incoming ? Just like a BBC region ?

I think I know the effect you mean. It depended sometimes on the make and model of the TV. We had a Philips telly for a while. If there was a horizontal timing error, and the switch was made during 'black', what you'd see would be the 'colour burst' dart across the screen (this was a band of subcarrier that when (because it could be viewed) viewed on professional monitors was a muddy brown vertical stripe in the blanking on the left side of the picture.

If there was a timing error (only needed to be 10 or 20 microseconds) on some TVs the burst would dart onto the screen, and as the TV corrected itself, it would dart back off again. Hard to describe, it would all happen within a frame time period, and you could often hear the line output transformer in the telly 'chirp' as it missed a beat.
As the phase was random while this happened, it could end up as any colour too.

Ron Miller (LWT's Sales Manager) appeared in ads in London, pushing the idea of local ads on C4. (This was because national advertisers were hampered by an Equity dispute over repeat fees for actors in ads on C4 (and TV-am))

Westcountry (not TSW) had the four way news split. I'm pretty sure it didn't extend to ads. The ads were played out to the whole region from HTV Cardiff, that was only a single feed. The news regions were remotely opted from Plympton, (but locally fed their transmitters (in other words, unlike today, the sub regional transmitters were not centrally fed). That's not to say other regions of that era did the same. Central Abington was routed to the Oxford and Ridge Hill transmitters via Broad St Brum (so that region could and did have split ads) Same for Meridian Newbury, that fed Hannington, via Southampton.

How did the regional ads split work for the Channel Islands? I presume that local ads on C4 during this period would be from TVS, for viewers in the Channel Islands, and thus all local advertising, specific to the Islands, was restricted to ITV only.

I don't know whether Channel inserted any ads at all on C4, but rather passed through the off air feed of C4 from the mainland. I do recall some ads on TVS and C4 having 'CI disclaimers'. I assume, just as with national ads on ITV, TVS simply sold the ads on Channel's behalf, and paid them a percentage ?

However, in the mid 80s Friday mornings at 09:30 C4 Rowridge would opt out of the test card, and show a block of ads, then opt back to the test card. I can only assume they were for Channel to record ?

Channel 4 themselves used an unsynced source for overnight teletext in-vision for years (and for the test card before that I believe).

In these examples, you'll see the slight picture glitch when they cut to teletext in-vision:





However, sometimes they would disguise the sync issue by cutting to the source during black and then fading up the teletext source. If you look very carefully at this clip, you'll see two vertical bars appear on the left side of the screen, at 42 seconds in. This is where the switch to the teletext source occurs. This enables a smooth fade up of the teletext source, at 1 minute 25 seconds in:



Channel 4 Pres didn't always do this. It seemed to depend on which director was on duty - some were obviously more fussy than others, and tried to avoid a visible picture glitch.

The first two might just be station router cuts, to take the pres mixer out of circuit. The third one is interesting, because the Teletext pages are still faded up, but the glitch we see might have been the ITV company taking their ad insertion gallery out of circuit.

It wouldn't have been, because it's from 1996, nearly 4 years after the ITV companies stopped providing the adverts.

Would have been one of the final closedowns and showings of 4-tel as well, as they went 24 hours the following month.

Used to love 4-Tel on views and all those animations, so much more interesting than Ceefax.

I'm not sure it was anything as interesting as that, as I say there was no loss of sync and nine times out of ten the transition was completely clean.

I got the impression they were switching without using a mixer (but the two sources were still synched/locked). YTV's initial provision of TT pres was similar; they'd send TT a mixture of a dirty feed, clean network feed, and TT-specific items up the line and TT would opt out for continuity at the appropriate points. In order to prevent TT crashing into YTV continuity/idents at the start of programmes they'd switch to a clean network feed a few seconds before a programme started then back to the YTV dirty feed a few seconds into the programme. At that point you would see a slight picture tear (more noticeable than the Bilsdale opt, but that may have been because the two sources were carrying the same material in the YTV case), coupled with a minor change in picture hue/saturation.

In fact thinking about it some older TV programmes made in the 1970s exhibited the same atrefact when cutting between cameras. Just an unclean cut.