Power outage at BBC Wales

Yes, that was standard practice at all main sites (two diverse 11kV feeds). I know Bilsdale had a generator for BBC 1 and 2 because only one 11kV feed was (is still) available there.

Rowridge had diverse 11kV feeds, but not terribly diverse being on an island. The national FM transmitters there had a genny, but not Radio Solent (go figure !)

And of course during the 1994 World Cup final some wag switched off both 11kV feeds to Hannington

The Donald Heighway clip was on TV Ark (https://web.archive.org/web/20160317193726/http://www2.tv-ark.org.uk/bbc_southwest/news_1980s.html but the video doesn't work)

Yes, my statement was a little inaccurate. Definitely an 'IBA' thing. The same blue captions went out on Channel 4. Though I only witnessed a Channel 4 blue screen once. Nearly sure it was a power failure at Channel 4 HQ, on a Sunday evening in the early 1990s.

So, another small point that has lingered in my mind all these years: when I saw the apology caption on BBC Two, I remember thinking that BBC Two transmitters shouldn't even have been switched on at that point. Back then, the first transmitters were typically triggered c. 30 mins prior to the first advertised programme, which would've been Ceefax at 9am in this case. Test Card F would've been shown prior to 9am in normal circumstances, I'm assuming. So, in hindsight, if my recollection is correct - and I'd spotted that BBC Two caption shortly after 8am say - it'd suggest engineers may have keen to get some sort of signal going out on BBC Two, to perhaps assist during the efforts to restore impacted transmitter sites?

I don't think there was much damage to the transmitter network, most of the problems were loss of power, which was out of the BBC and IBA's control. I recall the following week's IBA eng info programme saying the only serious damage to the Tx network was the wooden pole at the Countisbury relay in Devon was snapped clean in two

http://tx.mb21.co.uk/gallery/gallerypage.php?txid=645&pageid=1238

Remember the BBC and IBA built their masts to a very high spec, what we had is Southern England, was not much worse than not so unusual contritions off the N Scotland coast.

I should've been clearer. So, I wasn't suggesting there was any serious damage to the transmitter network. What I was getting it is, that even in the case of a power loss to the site, I was led to believe in conversations with engineers many years ago, that transmitters don't always come back up cleanly when power is restored (I've seen evidence of this myself). To that end, it would have been helpful to have a signal coming through on BBC Two (which would otherwise have been closed down until c. 8.30am), to ensure that all channels were fully reinstated, when power had been reconnected at a site.

I can't recall exactly what BBC 2 used before the advertised on air time, but BBC 1 back then used Pulse & Bar test signals.
One morning at 05:30 I remember looking at it on the incoming feed from TC, and noticed that it didn't meet spec, although the ITS did. Reporting it to CAR I got the response that "Oh, that's going through the NC 1 mixer, so it won't be that great!".
Ah, OK.........

By the way, and heading back to the thread itself, does anyone know what the power failure at the soon to be decommisioned Llandaff site was due to in the end?

Fairly academic once it's been through a klystron (or two). IBA COP for Diff Phase post Tx output was something ludicrous like 12 degs ! A friend of mine who worked for Pye's TVT's studio systems dept always used to get a ribbing from his friends in the unit next door who built their transmitters !

I think BBC 2 carried Pulse and Bar until 09:00am, if there was no Net 2 available (which was the case 1979-82 between 10:30 and 16:00) then they'd sometimes spark up Hannington with a locally generated Pulse and Bar, or Linearity Staircase (both without any vertical sync, to avoid any RBS comedy moments ?)

So, there was some variation between the channels back in those days. BBC One generally came on air with Pulse & Bar, before giving way to a brief period of Test Card F, and then on to Ceefax. That was weekdays. Saturday and Sunday was P&B, then TCF - no Ceefax (not in 1987).

When closing down at night, NC1 would usually do 10 minutes of black and tone, Tone would then be faded out. Seconds later, they'd cut to Pulse & Bar (with a slight picture sync issue), before cutting the signal to the transmitters. Whatever test signal they cut to before withdrawing the signal to transmitters, that's what they opened up with in the morning. In the 90s, P&B disappeared, making TCF the only test signal radiated on BBC One/Two.

BBC Two was a little different. Most mornings, BBC Two had OU programmes. So, before closing down, NC2 switched network output to OU Con. For a period in the 80s, OU Con had its own 'test signal' - which was black & tone with 'OU' text in the corner of the screen. Later, this was replaced by TCF. And to the best of my knowledge, BBC Two then generally opened up on TCF + tone. In 1987, with no OU programmes in the morning, it's possible that BBC Two opened up with P&B (though I rarely ever saw P&B on BBC Two after the black/tone/OU signal was introduced). I recall as late as 1988, if there were OU programmes early morning on BBC Two, they'd typically finish up c. 7.20am. BBC Two would show then show the OU test signal (black + tone + OU text) until c. 8.30am/8.45am, when TCF would appear, followed by Ceefax + music from 9am.

Am I misremembering or did the OU test signal have OU in a different corner depending which network it was on? Presumably it was only intended to identify the two outputs from OU Con were getting routed to the right network? I wonder if that was introduced following a cock up?

I was so used to seeing the OU test signal on BBC Two, I can't recall if the 'OU' text position varied by channel.

It's a long time ago, but my recollection is that the OU test signal was introduced in 1985 and was discontinued c. 1989.

And here is an example of this rare pres item, from c. 1985 on BBC Two - recovered from a Betamax tape: