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Outside broadcasting

Presenters and camera operator of Sky Sports F1 on an outside broadcast

Outside broadcasting (OB) is the electronic field production (EFP) of television or radio programmes (typically to cover television news and sports television events) from a mobile remote broadcast television studio. Professional video camera and microphone signals come into the production truck for processing, recording and possibly transmission.

Some outside broadcasts use a mobile production control room (PCR), which is known as a "production truck", "scanner" (a BBC term), "mobile unit", "remote truck", "live truck", "OB van", "OB Truck" or "live eye". In the United States a "live truck" is smaller in size than a production truck and generally requires fewer people in the field to manage.


Dumont Telecruiser, one of the earliest television production trucks which allowed remote TV broadcasts, built in 1949 by the Dumont Television Network. The microwave dish antenna on the roof beamed the live feed back to a dish at the studio.
Television South (TVS) OB Unit 1 as seen in 1991

The BBC's first Outside Broadcast truck MCR 1, short for mobile control room, was built by the joint Marconi-EMI company and delivered to the BBC just in time to televise the Coronation of George VI and Elizabeth in May 1937. MCR 2 was identical to MCR 1 and was delivered in the summer of 1938. The MCRs could handle three cameras. Initially they were standard Emitrons, but were later supplemented by Super Emitrons, which performed much better than the standard ones in low light. The MCRs were built on the chassis of an AEC Regal single decker bus.

After the Second World War, the joint company Marconi-EMI ended. The BBC ordered two 3-camera MCRs from EMI. The cameras were equipped with CPS tubes, had electronic viewfinders and a 3 lens turret. MCR 4 was delivered in time to be used on the 1948 Olympics.[1]

After developing colour television in the mid 1960s, the BBC began to develop a fleet of colour OB units, known as CMCRs. These trucks were known as Type 2 scanners and were, at the time, completely state of the art. Type 2 scanners first came equipped with Pye PC80 cameras but these were soon superseded by EMI 2001 colour cameras. These trucks would remain in service through the 1970s and into the mid 1980s. Throughout this time, they would see use on some of the BBC's most prestigious programmes, including Royal Events, Doctor Who, Wimbledon Tennis, and Question Time.

Although made from converted HGVs, inside these trucks were incredibly cramped as a result of housing an entire mobile television studio. These were normally made up of three sections:

  • A section to house the camera control units, or CCUs, and camera monitoring equipment. Being so large and complex, these cameras required a team of skilled engineers to keep them functioning. During a production, the camera operator would control the pan and the focus but it was the engineer who controlled the exposure and the colour balance.
  • A section for the production crew, led by the director, who would orchestrate the over all production.
  • A section for the sound crew which housed their mixing desk and other sound equipment. From here the sound crew controlled not only the sound of the programme but all the production communications which allowed the whole crew to communicate to one another. Without which the production would undoubtedly grind to a halt.[2]

Modern applicationsEdit

Modern outside broadcasts now use specially designed OB vehicles, many of which are now built based around IP technology rather than relying on coaxial cable.[3]

There has been an increasing rise in the use of flyaway or flypack Portable Production Units, which allow for an increased level of customisation and can be rigged in a larger variety of venues.[4]

In the past many outside broadcasting applications have relied on using satellite uplinks to broadcast live audio and video back to the studio. While this has its advantages such as the ability to set up anywhere covered by the respective geostationary satellite, satellite uplinking is relatively expensive and the round trip latency is in the range of 240 to 280 milliseconds.[5]

As more venues install fiber optic cable, this is increasingly used.[6] For news gathering, contribution over public internet is also now used. Modern applications such as hardware and software IP codecs have allowed the use of public 3G/4G networks to broadcast video and audio. The latency of 3G is around 100–500 ms, while 4G is less than 100 ms.[7]


See alsoEdit


  1. ^ "TV OUTSIDE BROADCAST HISTORY". TV Outside Broadcast History. Retrieved 2018-05-28.
  2. ^ John, Ellis,; Nick, Hall, (2017-11-09). "ADAPT". figshare. doi:10.17637/rh.c.3925603.v1.CS1 maint: extra punctuation (link)
  3. ^ Bickerton, Jake (19 June 2018). "Arena reveals OBZ, its fourth UHD-HDR IP truck". Broadcast. Retrieved 24 June 2019.
  4. ^ Dams, Tim (19 June 2018). "Trickbox TV unveils 12-camera 4K flypack". Broadcast. Retrieved 24 June 2019.
  5. ^ "Geostationary satellite latency and time delay 240ms - 279ms".
  6. ^ "SIS LIVE expands Anylive network". TVBEurope. 11 September 2016. Retrieved 24 June 2019.
  7. ^ "O'Reilly Media - Technology and Business Training".

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