Like many children of my generation, I was a regular viewer of ‘Play School’ on weekday mornings. As far as the Radio Times was concerned, BBC-2 would spring into life at 11am for 25 minutes, and then close down until the evening, the rest of the time being taken up with ‘trade test transmissions’.
However, I was quite a fan of the testcard and its music, so one morning, after Play School had ended at 11.25, I stayed watching.
As expected, I saw a BBC-2 closedown announcement over the clock, followed by a black screen. Nothing unusual there. What came next, however, was unexpected. A clock, in the usual BBC design (the early colour era one, in which the hour markers grew in thickness from 1 to 12 o’clock) but with the colour scheme reversed: dark on light instead of light on dark (chez Page was still black and white at the time). Underneath, instead of a simple BBC-2 logo, was a ‘BBCtv’ logo accompanied by the text: Service Information Follows At 11.30
This clock remained on screen for over two minutes, counting the seconds to 11.30 to the accompaniment of a very mysterious-sounding tune (which many years later I now know to be ‘Walk And Talk’ by Syd Dale), heightening the anticipation for a programme which wasn’t listed in any Radio Times or newspaper.
The appointed time came, and with it an on-screen image of a giant mast, over which the BBC-2 announcer read details of place names and comments that they might be ‘on reduced power’, or ‘liable to interruption’ (which I remember Dad translated for me as ‘it means it’s going to be switched off’). At the time, I didn’t fully understand what all this meant, but it sparked my curiosity: at the end, the announcer said that there would be ‘more service information at 2.30’.
And so, at around 2.25 I ensured that I was watching BBC-2: sure enough, the sequence continued as before. However, this time, instead of returning to a testcard, I was treated to a film - again, unlisted in Radio Times - about how ‘It’s The Tube That Makes The Colour’, with some very nice animation showing the combinations of red, green and blue light beams which make up the combinations of colour on screen.
Fascinated, I continued over the years to watch these hidden broadcasts at every opportunity (that’s what school holidays were for, wasn’t it?), gradually learning more about transmitter place names, especially when a new transmitter would be announced with a caption card giving the location of the transmitter, and UHF channel numbers for BBC-1 and BBC-2.
It was from these broadcasts that I learned how TV came from many different transmitters, something reinforced when the IBA introduced the ‘Transmitters In Service’ list during start-ups (and which would come in useful around 1975, when I received for my 11th birthday one of those portable TVs with a rotary tuning dial, marked in UHF channels). I never saw the ‘Tube’ film again, although I do remember a few other unannounced films, mostly of transport and scenery.
Naturally, I was curious as to whether ‘the other side’ did anything similar: one summer Tuesday morning, I was to find out. Instead of testcard or colour bars, a caption was on screen: ‘IBA Engineering Announcements commence at 9.15’ - accompanied, in line with what seemed to be ITV’s habit, by a piece of music far more dramatic than the one used by the BBC (I know now that this was Gilbert and Sullivan’s ‘Mikado Overture’).
Instead of the BBC’s daily broadcasts of 2 minutes or so, this was a full 10-minute programme, opening and closing with shots of the IBA building at Crawley Court, and differing from the BBC in that actual coverage maps of new transmitters were shown.
This was particularly fascinating in that I realised that this was a programme actually made by the IBA, existing independently of the ITV companies - emphasised by the fact that the all-important ITV start-up followed this broadcast rather than preceding it.
I must also mention one magnificent afternoon around Easter 1978, when at around 3.30pm on BBC-2, the colour bars which had been showing disappeared to be replaced by a view of a room with lots of wires around, occasionally focusing on testcards propped up on music type stands. The BBC were actually testing a camera live on screen!
Of course, as time went on and broadcasting hours increased, the opportunities to catch these hidden programmes decreased, eventually disappearing completely: transmitter information is now distributed over teletext, there being no place in the broadcast schedule for anything to be hidden anymore.
However, these broadcasts still hold a place in our memories as a reflection of a time when Television was something mysterious and exciting, reliant on technology and effort, not taken for granted as it so often is now.
