Original Broadcast Network

This was the original Distribution Network installed by the University in the late 1960s and early 1970s to provide comprehensive video links around the campus.

An equipment room LTC (adjacent to Central Hall) acted as the transmission hub. For transmission, the video was modulated onto a carrier at 4.5MHz (405-line B+W channels) or 10.7MHz (625-line colour-capable channels) and the audio (at baseband) amplified. Audio-only channels were fed via power amplifiers so that outlets could use passive loudspeakers without further amplification, on the same basis as 100V-line PA systems. The transmission equipment and televisions were supplied by Rediffusion VisionUnverified or incomplete information. This method of cable based AV distribution was used in a number of towns in the UK, however it had reached the end of it's technological lifetime by the end of the 1980's. The system installed at the University of York was originally black and white (with a mixture of 405-line (BBC1) and 625-line (BBC2) channels and was upgraded to support colour in the 1980s.

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  Rediffusion racks in LTC

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  Cable entry and exit in LTC

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  Video modulators in LTC

Installed alongside the distribution network was an AV Contribution Network. The contribution/distribution system was quite advanced in it's day since it would have been possible to do point to multi-point lectures and video conference across campus. However, it is not known if it every was ever utilised beyond retransmission of BBC1/BBC2/ITV and contribution/distribution of YSTV.

The passing of the years had taken its toll on the system. By 1994, various colleges/buildings had been remodelled, leading to removal of the AV racks or cutting of contribution/distribution cables. At the time YSTV moved into G/046, the contribution cable from Goodricke back to LTC had suffered a break. This lead to the contribution point in P/X/002 being pressed back into service. From here it fed back to the AV rack in P/S/016 before being sent to LTC. At the time, YSTV could be seen in Derwent, Langwith, Alcuin, Vanbrugh and Goodricke. Wentworth distribution had been lost sometime between 1993-94. The distribution system suffered from having to use televisions that could receive the Rediffusion signal. This made replacing them difficult, since Rediffusion had pretty much disappeared and the transmission system was technologically obsolete. The proximity of the Goodricke snack bar to G/046, allowed audio and video to be fed at baseband to a normal television via a SCART socket. The remaining televisions soldiered on, and when required were repaired by using parts from any spares that could cannibalised from the spares from the garage in Wentworth. Despite best efforts, picture quality was suffering, colour would turn to black and white and then back or various interference patterns could be seen on the screen.