UK Broadcast Transmission
Main indexMain GalleryFeaturesInfo
Send in your photosMailing listsFAQsContact
The LibraryTeletextMHPTBS


Looking back at the days when more than half the weekday output from an IBA transmitter might be generated at the transmitter itself.

A selection of the 35mm slides which could usually be found lurking in the slide scanners:

Thanks to Colin Dalziel for contributing the slides for this page:

"They were all used in the period 1969 to 1980 during the era of the IBA "colour control room" of which there were 22. Each of these control rooms were located at a main IBA site (though not always a UHF TV site), and were loaded into the slide carriage of the Cintel slide scanner to be used when required, though mostly during the "Trade" sequence which was a pre-programmed morning sequence involving periods of colour bars and tone, pictures with taped classical music, plus black and silence.

Engineering tests

In most cases these would usually be generated electronically.

This grey-scale slide was probably used to line up the slide scanner itself but this test pattern may have gone to air. Does anyone remember seeing it?

"I particularly loved playing the "Trade" sequence in the morning, though my seniors would try and cook up excuses not to, as there was a greater chance of things going wrong with the automatic sequencing unit, the tape machine, or the slide machine - colour bars and tone was so much more trouble-free!"

Monday's Newcomers

This was a regular feature of the ITV network. Each Monday morning at 0905 new commercials would be transmitted across the network from London. This gave the ad agencies a chance to see their ads on air and gave regional playout facilities a chance to video record the commercials locally.

Of course, something had to be held in stand-by in case it didn't happen for some reason.

"Monday's Newcomers had all but gone by 1975 when I joined up, there seemed to be any excuse not to show them, and the ITCA never seemed to have a feed to line on a Monday morning!"

Colour Test Slides

These colour slides were shown as a regular part of the morning trade test transmissions on ITV.


The pretty colour slides were always a favourite, it is said (though it could be rumour) that the parrot was the family pet of the (then) IBA Chief of Transmitters, Harry Boutall!


Can anyone remember what time they were shown? I think they were shown as a sequence for 30 minutes per day but I can't recall when exactly. Was it at 0930, with the testcard from 1000?

Test Card F

Of the test card itself, each region transmitted its own. Usually the top row of blue castellations was almost completely obscured by the injection into the first 20 lines or so picture lines, of pure, electronically generated colour bars, but here the slide is shown in its entirety, including areas beyond the points of the arrowheads, which would not have been included in the transmitted picture.

This images were scanned from what appeared, at first sight, to have been completly normal 35mm transparency slides which were mounted between glass in standard plastic mounts. Dissecting the slide revealed, on closer inspection, that the slide actually contained two pices of film, one containing the colour elements of the image, while they other held the monochrome components.


"Trade" was used less and less as the 1970's wore on, as programme encroached more and more into the daytime schedule.

The "colour control rooms" were phased out in about 1980/81 to be replaced by 4 Regional Operations Centres (ROC's) Croydon, St.Hilary, Emley Moor and Black Hill, and the slide scanners were gone to be replaced by a horrible electronic test card generator, but there was little "Trade" by this time anyway.

More about Test Cards in The Test Card Gallery
on the Meldrum Home Page


Five minutes or so before programmes were due to start on ITV the test card and music would be faded out and after a minute of silence the ITV start-of-day sequence would begin. This generally ran for 4-6 minutes and consisted of two pieces of music, and three visual elements..

First the ITA Picasso card would be shown...

Later the Picasso was replaced by a list of the transmitters and their channel numbers.

Here we find the IBA terminally confused about whether or not Blackhill is in fact one word or two.

The final part of the start-of-day sequence was a short animated section introducing the television contractor themselves.

More about ITV Start-of-Day sequences
at the Transdiffusion site

Adverse Weather

Now, just as we think things are going to get somewhere we find the afternoon's racing is cancelled. Seems the horses may have drowned.


Here is the caption the IBA engineers put up if they fancied an early night - but "reasons outside our control" sounded so much better!

Finally, here are the captions the IBA Engineers put up if their control room was invaded by little green men from the planet Snarg or they just fancied a quiet night in with a cup of cocoa listening to the wireless.

The decade of the colour control rooms was, I believe, one of the most successful periods in the history of the IBA. It spanned the period of enormous development and growth in the ITA (became IBA), the phenomenal growth of the UHF network, and the building of Crawley Court, vast staff level increases, and technical innovation under the dynamic technical leadership of Howard Steel.


PMC Bitstream Sounds On
HHG HTW ITW Irish TV mb21
sub-TV Transdiffusion TodayEMCRMCTMCPMC


mb21 by Mike Brown
Hosted by Astrohosts