The process of radio programme transmission involves the modulation a radio carrier wave, with the programme output of the radio station. There are now TWO main kinds of broadcast transmission - on traditional radio signals, as has been done for over a hundred years, or 'online', down wires which pre-dates radio, but has only become economically feasible since the advent of cheap digital methods. The use of fibre as a wire has made this even more practical and cost-effective; it is becoming so widespread that fibre become THE standard method of distribution within the next decade. Where fibre isn't feasible, some radio waves will continue to be used. Around 90% of all internet traffic is now carried on fibre cables, on power pylons, or just laid on the sea bed.
LW | MW | SW | FM | DAB
Satellite | WWW (online)
BROADCAST STUDIOS
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!
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 (FM and AM processors each have different circuitry).
DIGITISATION
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 humans; but perhaps we are 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.
The control of equipment has become easier, with remote operation of sources being simple to achieve.
ADMINISTRATION
These parts of a radio station are vital in tracking royalty liabilities and commercial loading, plus other revenue streams. Now all logging of music played can be done automatically, (it was previously a manual chore).
AUDIO SOURCES
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.
MIXING CONSOLES
It has a different name in different markets and types of stations - the consol, the board, the mixer and the desk are the most often used. Whatever you call it, the mixing panel is the heart of the studio, where all audio is switched and controlled. See some of the options on this page.
RECORDING
The process of preparing audio material in advance and then broadcasting it later has been revolutionsed in recent years with the plummeting cot of solid state recording. Digital editing and immediate playback was a different world a generation ago - but now?
INTERCONNECT
Previously all interconnection of audio, and often of switching circuitry too, had to be in screened audio quality cable. Dozens of cables can now be replaced by a simple network of ethernet cables, sometimes (wrongly) referred to as “Cat 5”. These have four pairs of conductors, twisted to give a constant impedance. They are colour-coded so different pairs can be used to add power and signalling as well as the programme feeds, multiplexed digitally so one pair can be used for many channels of audio.
An ethernet cable is simply four pairs of twisted cable in one encapsulation, with a small modular 'RJ' connector at each end. It can carry multiple signals, but take care to select the correct one as there are some variations and its important to have the right cable correctly terminated in the right connector.
MICROPHONES
Microphones have improved enormously and their size and cost has plummeted recently. For many years, large broadcasters have insisted on using high-end microphones, ones with huge diaphragms, but these are not really required for most radio broadcasting.
A decent quality microphone will cost between £75 and £400, but pay a little more and your listeners may be hard-pushed to tell the difference in sound between a much cheaper dynamic mic and the top of the range condensor or ribbon mic.
BROADCAST STUDIOS
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!
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 (FM and AM processors each have different circuitry).
AUDIO SOURCES
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.
MIXING CONSOLES
It has a different name in different markets and types of stations - the consol, the board, the mixer and the desk are the most often used. Whatever you call it, the mixing panel is the heart of the studio, where all audio is switched and controlled. See some of the options on this page.
MICROPHONES
Microphones have improved enormously and their size and cost has plummeted recently. For many years, large broadcasters have insisted on using high-end microphones, ones with huge diaphragms, but these are not really required for most radio broadcasting.
A decent quality microphone will still cost between £75 and £400, but pay much more and your listeners may be hard-pushed to tell the difference in sound between a much cheaper dynamic mic and the top of the range condensor or ribbon mic.
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.
Controlability of equipment has become easier, with remote operation of sources being simple to achieve.
ADMINISTRATION
These parts of a radio station are vital in tracking royalty liabilities and commercial loading, plus other revenue streams. Now all logging of music played can be done automatically, (it was previuously a manual chore).
PLAYOUT
This 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.
RECORDING
The process of preparing audio material in advance and then broadcasting it later has been revolutionsed in recent years with the plummeting cot of solid state recording. Digital editing and immediate playback was a different world a generation ago - but now?
INTERCONNECT
Previously all interconnection of audio, and often of switching circuitry too, had to be in screened audio quality cable. Dozens of cables can now be replaced by a simple network of Ethernet cables, sometimes (wrongly) referred to as “Cat 5”. These have four pairs of conductors, twisted at a set rate to give a constant impedance. They're colour-coded so different pairs can be used to add power and signalling as well as the programme, multiplexed digitally so one pair can be used for many channels of audio.
An Ethernet cable is simply four pairs of twisted cable in one encapsulation, with a small modular 'RJ' connector at each end. It can carry multiple signals, but take care to select the correct one as there are some variations and its important to have the right cable correctly terminated in the right connector.
DIGITISATION
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.
