Knutsford was not a core site in the BT Network but a television facility used by TV-am. Although some aspects are known in detail there are also significant gaps. BT diagrams of the television circuits in the Manchester area show the addition of two pairs of vision circuits in 1983. One pair is shown as routed via Heaton Park then "Radio Channels to Sutton Common" and the other is shown running directly from the TV Network Switching Centre as "Radio Channels to Knutsford". The purpose appears to have been to allow the Knutsford site the option of access to two "network" feeds and the option to return two (different) local outputs back to the network. In contrast, local "contribution" studios normally had a single outgoing circuit only.
Much of the detail of TV-am's operation is forgotten, however it is known that during their contracted hours the TVNSCs disconnected the local ITV contractors normal circuits and effectively connected the TV-am studio output directly to the transmitters. This required TV-am to be responsible for advertising, which was organised on a regional basis. It appears at least five variants were originated at the London studio, however the Knutsford site was required to substitute the advertising on one or two feeds before they reached their destination.
The former TV-am site is shown as "Television Studios" on a 1987 OS Plan but appears to have started as a video production facility for the Distributive Industry Training Board, known as the Knutsford Video Centre. The Board was abolished in 1982 and the site offered for disposal. Planning applications were made in 1983 to 1985 for microwave dishes however the details are no longer available.
There is clear line of sight to Sutton Common however the path to the TVNSC (at what was originally Telephone House, Salford) appears more difficult. It may have required an intermediate site (not yet identified). Curiously the circuit numbers on the BT diagram are sequential, suggesting both links were provided at the same time - so it's diffiult to understand why two different paths were used. Perhaps there was insufficient capacity via Sutton Common, but the direct path was not thought suitable for both pairs of circuits?
After TV-am the site was used for a time by Signal Vision (a video production company associated with Factory Records) and then by IFE Services Ltd - Google Street View shows satellite dishes branded IFE in April 2009 - it seems the company's main business was in-flight entertainment. The company announced a refurbishment of its studio complex in 2012 and was acquired by Global Eagle Entertainment in 2013.