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Really interesting nations opts and network chatter.

Can you tell I really don't know what to call this topic. (January 2018)

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CO
commseng
I'm surprised that a system to inhibit unwanted RBR wasn't put into service.
There were means to stop Oxford which was usually RBL of Sutton Coldfield if the feed to SC failed.
(SC would take Oxford as its RBR - and not very well(!) - so Oxford had to be forced to RBR Crystal Palace instead, or a nasty howl round would entertain the Midlands folks).
That is just one example, so why could it not be introduced in NI to prevent Scotland being radiated?

One other example of stopping unwanted RBR is a radio one, London Control Room had a switch to turn off Radio Three in Scotland only. This was something to do with school's programmes and rights. I think it was that there were only so many times each programme could be transmitted, and Radio Scotland may already have played them out? This would have also inhibited the RBR from being taken.
Please feel free to correct that if you know better, as I never had to throw the switch myself!
Last edited by commseng on 2 January 2018 3:34pm
CO
commseng
..... but no circuit from London had been booked to provide a feed of CEEFAX. .

I am slightly confused by that - you still had CEEFAX data in Glasgow, as in opt out mode the data bridge lifted those lines from network and re-inserted them into your transmission feed.
So, did you not have access to a CEEFAX decoder that could generate a local feed the same as London did to generate the national CEEFAX in vision pages?
That really couldn't have been expensive to do?
MM
MMcG198
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!!!).


A couple of questions on this, if I may.

The practice of showing TCG on BBC One/Two Scotland after closedown and until network had closed down - any idea what period this procedure covered? I know that NI did something similar - but they used black + GLITS (the GLITS pattern was different from that of network) - I have a recording of this somewhere. I think it was played out by Belfast CTA - there was a very pronounced picture disturbance when it started (not just on VHS but live too). So, perhaps a similar scenario to Scotland, where the continuity desk is taken out of circuit and control passes to CTA to play out black + GLITS until they can rejoin network. My recollection is that NI generally only followed this procedure when they closed before network; I don't think they gave a stuff about closing before Scotland went off air - I recall many occasions where BBC Scotland was relayed on NI transmitters after NI close (and I have some recordings of this).

I read somewhere - quite a few years ago - that the BBC Scotland TCG generator eventually malfunctioned and was never repaired. However, I note a comment under one of those YouTube videos, where it's claimed the TCC has the generator? Actually, not even sure if there was one TCG generator or two (one for each channel)? London seemed to use one TCG generator for both channels?

Finally, do you happen to know if BBC Northern Ireland relayed BBC Scotland's TCG during the afternoon "programme transfers" on BBC Two? I'm almost certain it was Scotland's TCG that we saw over here. I seem to recall the Sunflower and Baby I'm A Want You tapes being broadcast with this non-network version of TCG. In the 70s/80s, BBC NI had no TCG generator that I can recall - well, none that was ever broadcast to viewers; and no TCF either.
CO
commseng
I can't see why Belfast would take a feed of test signals from Glasgow?
The network wasn't configured to do that, and I don't recall any vision circuits from Glasgow to Belfast - and renting them for test signals would not have happened.
Belfast must have had its own generator of some description surely?
There was no reason why it couldn't have been pulse and bar or colour bars as it wasn't an advertised programme.
MM
MMcG198
I can't see why Belfast would take a feed of test signals from Glasgow?
The network wasn't configured to do that, and I don't recall any vision circuits from Glasgow to Belfast - and renting them for test signals would not have happened.
Belfast must have had its own generator of some description surely?
There was no reason why it couldn't have been pulse and bar or colour bars as it wasn't an advertised programme.


Tony will know the technical specifics better than I but somehow, Belfast was relaying Glasgow's TCG during the programme transfer window on BBC Two. I'm pretty sure it was BBC Scotland's output. Some sort of temporary reconfiguration of feeds occurred here from what I can recall. It was as if the network distribution circuit for BBC Two, supplied to NI transmitters, was temporarily overridden with BBC Scotland's output. An alternative would've been that Belfast continuity went into circuit on BBC Two and relayed BBC Two Scotland's TCG - but I don't think that's what happened here. I think it was reconfiguration of feeds to Belfast.

And no, Belfast did not have a TCF or TCG generator back in those days, that I'm aware of. If they had any local downtime, they just filled it with black and tone - and in the 90s, black + GLITS.

If memory serves me right, BBC Birmingham also had TCG generators and during programme transfers, Birmingham's output was supplied to most if not all English region transmitters. I could be completely misremembering all this. But, as I say, I'm sure Tony will have all the answers.
CO
commseng
It is all a long time ago, and as the systems improved it became easier to get video feeds around.
My 1986 copies of Network Routings shows Belfast taking network feeds from Carlisle, as a spur from the feed that then headed north to Glasgow. (Other spurs went to Caldbeck and to Newcastle).
I don't think I have any notes of the contribution network, but I recall Belfast, Newcastle and Glasgow had one feed each back to Carlisle.
There was a remote switch there controlled by Manchester CTA, to feed the line to Manchester.
They must have also been able to switch the network feed to Caldbeck for local opt outs, as I can't see how else that would have carried BBC NW programmes. (I don't think that Manchester's local programmes would have gone on the network feeds north of them?)
Maybe they had switching to allow the Glasgow contribution feed to connect to the Belfast network feed - but it would have been a very dirty switch. I understand it was a basic, and not totally reliable beast the Carlisle switcher.
Birmingham certainly had means of putting local test signals out, and there was a dusty 1/4" machine with music on it in Comms Centre. Later Pebble Mill Comms had a basic VT machine and a cupboard of tapes for emergencies.
One of my colleagues grabbed a copy of Dad's Army the day that TVC lost power at the start of the Six O'Clock news, and only starting rolling it when he spotted that the network feed into him now had his own VT clock on it!
SP
Steve in Pudsey
There is a map showing the old analogue distribution routes at the start of this document showing that Birmingham is indeed in the path to most of the country.

http://www.bbceng.info/Install/comms_projects/mbn/mbn-rts-award-drr1.pdf

I guess the specifics of where the test card was inserted would depend on where the programme transfers were intended for on each day?
CO
commseng
That map is from the early 1990s, and slightly different to the time I was describing - you'll note that the dependence on Carlisle had been reduced - but I can't see on that any contribution circuit south from Glasgow - that has surprised me.
There had been one in the 1980s!
MM
MMcG198
Would you say this is a fair assessment of what happened during the 'programme transfer' process on BBC Two:

BBC Birmingham fed their version of Test Card G + music to all transmitter sites in England.
BBC Wales fed their version of Test Card G + music to all transmitter sites in Wales.
BBC Scotland fed their version of Test Card G + music to all transmitter sites in Scotland and Northern Ireland.

Presumably part of the reasoning behind this weird set-up is the fact that the SE of England was effectively served by the network feed 24x7. And if that feed was being used to send programme material, there needed to be some way of preventing viewers in the SE seeing that. Having Birmingham send their output to all transmitter sites got around that presumably? I'm assuming TVC couldn't send anything other than network feed to transmitters in the SE? If they could, I can't understand why each region couldn't just opt in to BBC Two, put out their own test card (assuming they had a generator and music - and perhaps this was also part of the problem), and record what was coming in on the network feed? Perhaps a lack of resourcing for BBC Two opts in regional centres also had a part to play - don't know. But it would be good to understand the rationale behind this.

And re your point about if a switch occurred at Carlisle, it would probably look messy. Well, I saw that switch at 4pm in 1983 in Northern Ireland on a number of occasions - and it was actually reasonably tidy. Just a slight picture hiccup. I kick myself now because if I had looked at the VBI at the time, that might've told me a bit more about where the Test Card was coming from.
CO
commseng
I'm slightly wary that we are not really discussing BBC Scotland in the BBC Scotland thread here.
But if we are talking about using the distribution for BBC 2 to send programmes to regional / national centres you have to be talking about as it was in the 1980s or beforehand.
There were 2 feeds of BBC 2 leaving TVC to LBH, and from there a feed to CP, one to Birmingham, one to Bristol and one to Rowridge / Southampton.
Any of these 4 could be switched to the main or reserve feed, or to another source.
If a programme was being sent to Glasgow (for example) then the Birmingham line would have had another feed switched to it, but
only once Birmingham and Manchester and Newcastle and Leeds and Norwich had also put local signals out.
Birmingham could not feed all the transmitters in England, they only had the network feed in and the lines to Manchester and Norwich out (plus of course their own transmitter feeds to SC / Waltham etc). They may have fed Norwich with their test signals, but couldn't feed Manchester as that was carrying the wanted material to Glasgow.

I'm not certain what the smaller regions could do on BBC 2, before there were advertised opt outs on that channel.

Your point about a using the network feed to CP to send programme material I don't understand - who would the material have been sent to? It was only a transmitter, there were no VT machines there! I don't recall ever having to operate the opt out on that, only to switch between main and reserve feeds.
SP
Steve in Pudsey
Glasgow (for example) then the Birmingham line would have had another feed switched to it, but
only once Birmingham and Manchester and Newcastle and Leeds and Norwich had also put local signals out.


Would Newcastle, Leeds and Norwich not have been switched to a test card originating in Manchester rather than having to opt out themselves?
CO
commseng
Norwich was fed from Birmingham, but bear in mind that Newcastle, Glasgow and Belfast were all fed from the same line to Carlisle from Manchester.
Therefore Manchester couldn't put its test signals out on that, as it would stop the material getting to Glasgow.
It had a separate feed to Leeds, so could look after that region.
Last edited by commseng on 3 January 2018 10:56am

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