Getting 2 colour 

25 July 2014 tbs.pm/5204

When the BBC started to open UHF 625-line transmitters for its new BBC-2 service, it noticed something unpleasant.

VHF transmission turned out to be very forgiving. A mis-aligned aerial or a poorly tuned TV set left enough of the picture for most people to still be able to watch in comfort. The BBC also discovered that most people didn’t actually care that their set was imperfectly tuned.

But UHF was a lot less robust. The power to each transmitter was, initially, quite low compared to what it turned out UHF television required. The service area of each main transmitter was far smaller. And poor UHF signals were far less watchable than poor VHF had been.

The net effect was to put people off from investing in an expensive new 625-line set. When colour was introduced to BBC-2, people didn’t rush to it in the way the BBC had expected – not least because colour reception was even less robust than black and white UHF. Why pay for a colour set – and a double-the-price colour licence – only to have the colour flick in and out variably? Why go to all that trouble only to have to have a new, huge aerial erected in order to get what you had paid for?

The BBC began a long publicity campaign, not just for BBC-2 but also for 625, UHF and colour, attempting to convince the population that it was worth upgrading. More than that, they fought against the bad reputation the new system had gained by stressing that it worked perfectly if you set it up perfectly at home. People who didn’t do that got poor pictures. It was their fault for skimping, not the BBC or UHF’s. Also, if your picture was bad and it wasn’t your fault (it probably was your fault, but still) then it was worth you sitting tight as the BBC would be along to build you a UHF relay shortly.

In the meantime, get a decent aerial and learn how to tune your set correctly. Then you too can enjoy heavyweight highbrow arts programming in full colour.

You Say

3 responses to this article

Andrew 25 July 2014 at 3:58 pm

This is probably a silly question, but why didn’t they just do colour on VHF?

In Australia (where we probably waited a bit too long to go to colour: 1975) the existing channels (all VHF) converted their existing frequencies across to colour transmission. So there was no need for viewers to have to update to UHF until many years later when the VHF band became full.

Russ J Graham 25 July 2014 at 4:08 pm

We switched line-standard at the same time, from 405-lines to 625 and they didn’t want to “break” existing sets.

Also, in Europe the VHF bands, especially Band-I, used by the BBC, were full to bursting and the large state broadcasters often suffered mutual signal interference from neighbouring countries.

A switch to UHF, with more space to avoid interference and a shorter reach than VHF, plus a 10+ year changeover period, was meant to solve all these problems.

Andrew 26 July 2014 at 3:42 pm

I guess that was one benefit in getting TV so late (1956) we would have gone straight to 625-lines from day one.

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