by: John Rivers

Most people have a television set these days, but very few actually understand the process by which their favourite programmes are transmitted. Of course, you don’t have to know how to enjoy it, but it may help you appreciate the amount of effort that goes in to a transmission.

There are three basic steps involved in the transmission of a television programme. These are:

• Material – this is the programme itself
• Master control – this selects the programme to be transmitted
• Effects – this includes the network identifier

The programme itself can be in a number of different formats. A live transmission is where the material is coming directly from a live feed, such as a sports or news event. A second source of material is from a digital video server. This is basically a huge computer hard drive that has various pieces of material recorded on it that can be played at any time. The final type of material is from tape. This tape tends to be digital video, but analogue tapes can still be played too using a special analogue-to-digital converter.

The master control operator, or transmission operator, is responsible for selecting the correct programme to air at the right time. This can be done manually, usually in a live programme, or automated using a transmission program. During a live event, the operator is responsible for selecting commercials at the ad breaks, and then going back to the live feed at the end of each commercial break.

If the material is pre-recorded, either on tape or server, the operator is responsible for starting the material playing, as well as ensuring that the feed is being transmitted. Most television networks use an automated system, and the operator simply loads in the day’s schedule. The rest of their time is spent monitoring the transmission, and ensuring that the material for the day is loaded into the VCRs or digital video servers as appropriate.

The effects that we see on many television programmes have become so common that we often don’t notice them. But everything that is superimposed on the actual programme has to be controlled by a transmission operator, or automated transmission system. These include station identifiers, scoreboards, and ‘tickers’ with information scrolling across the screen.