AP mast (2K)

DIRECT TELEVISION from ALEXANDRA PALACE

by Arthur Dungate

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The Flying (spot) Mechau

(and more about telerecording)


While I was in Telecine at Lime Grove the BBC Designs Department had developed an improved Mechau telecine system using, instead of a studio camera, a flying spot scanning system with standard BBC amplifier units. This was known, logically enough, as the Flying Spot Mechau, and it was in a room across the corridor from the EMI telecine machines.

Flying Spot mechau at Lime Grove (7K)

One day I'd been detailed to Flying Spot Mechau to look after the film insert for a play, but all the studio wanted was a "The End" title from me.

End title (3K)

So this bit of film was in the gate of the Mechau all day and being fed to the studio, with me just sitting beside it..... Come transmission, and the play was the last programme of the evening, and there I still was, waiting for my "The End" to be used.

As the play drew to its climax, the rest of the telecine staff next door in the EMI room, got up to go home and, forgetting all about me, still waiting, went along the corridor and threw the master switches, so just as the studio came to my "The End", it all disappeared.....

That really was "the end" as all the phones started ringing..... ("Where's the picture? What happened to telecine? Studio gallery wants to know!")

The INTERVAI?

 
Interval (2K)

On another occasion the drama studio wanted just an Interval slide. On transmission, about 10 minutes before the play's interval I surreptitiously slid a piece of card into the Mechau gate, obscuring the end of the letter L, and waited for the reaction.....

Eventually someone in the Gallery noticed..... "Aaargh, What's happened to our Interval?" I smartly removed the card, and there was a mild titter of relief from "upstairs".

'modified' Interval (2K)

Telerecording, and the Mechau

 
Mechau telefilm system at AP (9K)

Even before the Suppressed Frame Telerecording system, first used for the Coronation, in 1953, there was a tv recording system at AP. It was housed in a basement room, just along a corridor from Central Telecine, and comprised a pair of Mechau machines looking at good quality monitors.

The Mechau was a German film projector, originally made for showing silent films, which used a rotating drum of mirrors which by a complex system of gears and cams, angled themselves as they went round, and produced a continuous image from the film, one film frame dissolving into the next, thus the film didn't move intermittently but in continuous motion.

Mechau projector (8K)

The original Emitron cameras as developed in the mid-1930s needed a continuous image and so the Mechau projector was a convenient and practical way of making an early telecine machine for the studio.

Although the Mechau telecines were used extensively in television in those days, we never realised that they had been designed by a man whose name was Mechau! On the base of each one was a name plate with Mechau AEG which we took to be just the name of the manufacturing company.

However a short biography of Emil Mechau the inventor of this ingenious equipment has been researched by Helmut Krueger and is published here with permission.

Mechau telecine at AP (11K)

This is the pair of Mechau telecines used to show feature films from AP before the flying spot Cintel and EMI machines were developed. A 500w lamp illuminated the film and the continuous image looked into a standard Emitron camera.

To record television, the system was reversed and unexposed film run through the Mechau. I seem to remember that the system wasn't light-tight so we had to work almost in darkness, with just a dim red lamp.....

A complication was that it was a variable speed machine, it could be run fast, or slowed right down. But for recording a tv programme we had to keep it running at exactly 25fps, and we did this with a long joystick control (on the right of the picture, just above the motor) which we used while watching a strobe lamp..... Sound was recorded on the same film as the picture by a glow lamp. This produced a variable density soundtrack and was a simpler (and cheaper) method than building onto it a variable area unit, which would have had to be leased from RCA.

Mechau telefilm recorder (9K)

The resulting recording was known as a Telefilm, the term "telerecording" not coming into use until the advent of the Suppressed Frame system.

In the News (8K)

But nevertheless, this primitive system was used to record and repeat programmes such as "In The News", a topical discussion programme.

From left to right are -
W.J.Brown, Lady Tweedsmuir MP, Edgar Lustgarten (Chairman), Barbara Castle MP, Jim Callaghan MP.

The earliest known surviving example of a BBC Television drama series is Robin Hood dating from March 1953, and was recorded on this system.

Cintel back again, and switching units
When the Cintel flying spot scanners, after being removed from CTR at AP had been refurbished by the manufacturers, they were installed in Telecine Lime Grove, together with a third scanner as a standby. During the installation there was an unfortunate delay when it was discovered that one of the large cable looms was just a bit too short, so the cable loom had to be removed and a new one made, much to the frustration of the installation guys.

About this time there was some requirement to have additional labelling on part of this equipment, but Cinema-Television quoted a price of 400 (a lot of money in the early 1950s) for this, which seemed like a "we don't want to do it" price, so the BBC had it done internally.

The Cintels were in a room just up a few stairs from the main telecine rooms and just beside those stairs, in the room next to the Flying Spot Mechau someone had had the bright idea to install a complex switiching unit whereby it was possible to automatically switch all inputs, outputs and talkback lines etc to any studio in the building. However, the main switching mechanism was achieved by uniselectors, whose contacts often became dirty, so a rather tedious procedure was instituted in that every morning every possible combination was selected and run through in the belief that this would clean the contacts. It was not completely successful....

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Telerecording at Lime Grove