The process of transmission involves the modulation of the carrier with the programme output of the radio station. The carrier can be either a radio wave or carried on cables or other material - fibre is become more widespread and will become THE standard method of distribution within our lifetime. Where fibre isn't feasible, radio waves will continue to be used.
Common Carrier routes
LW, AM, SW, FM
Satellite & WWW (Internet)
This section is concerned with the programme origination, at the studio part of the transmission chain. From there it is processed to match the method of distribution.
Less than a generation ago, radio and TV studios would use very expensive equipment; a typical radio studio would cost between £20,000 and £150,000 to build. This can now be achieved for a couple of thousand pounds and the resulting studio will provide much better audio quality than previously. It will also be much easier to operate!
Digitisation has revolutionised radio studios and programme origination. Until very recently all sound sources in radio studios were analogue, which means they sent a contant stream of varying audio information to the user. Sound sources were traditionally quite large and they used separate cables for each source, until the point of mixing. Digital has decimated the size and cost of almost every item (except human beings; we are probably next!).
Digital audio has had some really profound effects in four distinct areas of the operation of radio stations. These are seen most in controllability, miniaturisation and especially in cost.
Audio production Many sources have changed beyond all recognition, especially in size. The adaption of digital techniques, in particular the use of compression, renders files much smaller and make it possible to record on very small (physically) media.
Controllability of equipment has become easier, with remote operation of sources being simple to achieve.
Administration. These are vital in tracking royalty liabilities. Now all logging of music played can be done automaticaly.
Transmission: the process of sending the finished programme to listeners.
Playout equipment has become far more efficient, smaller and thus very much cheaper. The kit is also much more easily controlled, smaller, faster and cheaper too. Control is a key aspect of digital's improvements: instead of having to be adept at equipment operation or the technical parameters radio presenters are free to concentrate on programme content.
The key source of equipment for most radio stations is the item with which it all began - the microphone. In the early days of radio this was a huge contraption mounted on a trolley. To add music, the microphone would be wheeled over to an ensemble of live musicians, or placed next to a gramophone - electric pickups for turntables only came in ten years after broadcasting started.