Really interesting nations opts and network chatter.

Not sure if this has been raised before on TVF...

...two BBC Scotland closedowns appeared on a YouTube channel a few years back: one for BBC One Scotland and one for BBC Two Scotland:





The rather odd thing about these clips is that closedown is quickly followed by the appearance of Testcard G - and even more bizarrely for the time of day, is accompanied by music. There's a slightly odd transition to testcard in each clip too.

I can only assume the Scotland had its own programmes on each channel that evening and that Network was potentially still on air and that the testcard was being shown until BBC Scotland could rejoin Network (after it had completed its closedown routine).

Question is - is the testcard element of these clips legitimate? It does look like the TCG generator that BBC Scotland used. Black and tone would've been the norm in that era for late night closedown.

BBC2 Scotland sometimes went to TCJ with music when their Learning Zone schedule finished earlier than the network too.

Almost certainly to do with either network or Northern Ireland still being on the air when they closed down, which would have caused transmitters to switch over to their output via RBS if Glasgow just switched off and went home.

I may be wrong here, but was the black and tone used to shut down the transmitters? Something to do with taking away the field syncs, and after an amount of time the transmitters would switch to RBS if available or shut down. The music might simply have been that a bored engineer in Glasgow CTA fancied dusting off the reel of tape?

The blip on audio when switching to the test card is curious though.

Have we ever used on-air tones to turn transmitters off?

Not sure I understand why Northern Ireland still being on air would be a problem? If Scotland had their own schedule and network was still on air, I can understand why Scotland wouldn't necessarily want to join network until network closes - and they'd put out TCG whilst they wait on network to call it a night. However, what's the issue with NI? I can't understand why Scotland would have to stay on air if NI was still on air.



The black and tone had no particular significance for transmitters.

When the new TV Room is sorted, I'll have an updated feature about test cards and teletext in-vision. For now, there's some information about tones in the bottom section of this page (which was written quite a few years ago):

http://www.thetvroom.com/features/spotlight-bbc-testcards-part-1.html

And the second part of that feature is here - and includes info on teletext in-vision and other test signals:

http://www.thetvroom.com/features/spotlight-bbc-testcards-part-2.html

There are some dates and other bits on those pages that need revisited but the majority of info should be correct.



Agreed. Very odd.

Didn't some of the transmitters in Scotland RBS those in Northern Ireland?

I'm not sure they did, only Cambret Hill being an RBS source for Divis. I'll check my records later.

The TCGs on 1 and 2 in Scotland may well have been connected with overnight engineering work or path tests on the tx chains within Scotland, and the simplest way to keep the two networks alive was to inject TCG 'locally' in Glasgow.

I can recall a breakdown on BBC One Northern Ireland and we got BBC One Scotland and oddly I recall Channel 5 popping up out of nowhere for a few moments on BBC One NI when we couldn't even get a Channel 5 signal.

Parts of NI certainly took Scotland as an RBS source, but I think it could work both ways.

On the shutting down point, I thought that putting out a signal with no syncs would cause a shutdown, and that was what the black level was (because if you tried a real picture with no syncs it would be rolling all over the place)?

It was absence of line syncs (but not field syncs) that caused a shut down for both BBC and IBA transmitters.
The BBC had a further measure involving a 23 kHz audio tone, as an anti-hijacking measure for RBL/RBS.

1) The clips are real; once the Announcer-Director had put the test card on air, the suite was often taken out of circuit and the test card emanated from CTA, hence the small sync disturbance (made larger by the failings of VHS recorders). test Card and music were radiated to keep transmitters and lines open until the network closed down. Likewise in later years, if closing before the network, BBC ONE or TWO Scotland would go to CEEFAX and music until they caught up. In the cases where I played out Test Card J and music after the Learning Zone on BBC TWO Scotland (it was always me on duty for these opts) it was because there was a gap before we caught up, but no circuit from London had been booked to provide a feed of CEEFAX. Test Card J was simply played out from a still store (and therefore didn't animate - but none of you ever spotted that!!!)

2) Actually, the NI problem was that if NI closed down before Scotland, and Divis remained on air, then when the feed from Ormeau Avenue was pulled, Divis went to RBL and rebroadcast BBC ONE Scotland (via Sandale then Cambret Hill).

Thanks for that Tony. Glad I asked about this. We've unearthed a few little factoids about BBC Scotland pres.

And re point 2) above - that's my understanding. BBC NI going off air before BBC Scotland is what caused the issues, with NI transmitters rebroadcasting BBC Scotland when BBC NI's signal was switched off. I couldn't understand the scenario described above where BBC Scotland had to stay on air because BBC NI was still on air - just didn't make sense to me.

Markymark and I had a discussion on NI/Scotland RBS/RBL in the recent past - a few pages back in this very thread actually.