History
Like its non-identical twin in London, what is now known as the "BT Tower" in central Birmingham was built in the 1960s. Both were close to main exchanges which had formed the ends of the 1949 television link. In Birmingham the tower is just along the road from Telephone House, where the Television Network Switching Centre remained. Whilst the tower at Birmingham housed radio equipment on the lower floors it was not directly connected to adjacent Post Office buildings. 1960s lists of trunk cables show several links between the tower and Telephone House. At Birmingham no public facilities were provided. The square main structure was a one-off design however the top section has circular "galleries" of the same style used in the "Chilterns" style of tower, topped with a built-in crane.
BT Archives has numerous images showing the tower under construction. Work on the foundations began during 1963 - the main structure had reached 100 ft by mid-1964 and 400 ft in August 1965. The gallery section appear to have been completed around the end of 1965 and images from October 1966 show horn antennas in place. By this stage the links at Telephone House included main routes to London (via Charwelton) and Manchester (via Pye Green) and the new tower provided for further expansion of their capacity with two ("large") horns each way. The local link to the ITA Lichfield transmitter was transferred to the new tower and the BBC televison link to Peterborough/Norwich was revised to run via the new site at Twycross - a single ("small") horn was provided for this secondary route.
During the early 1970s a new route was added towards Bristol (via Bredon Hill) - this had relatively low capacity until the intermediate sites were upgraded in the mid-1980s, at which stage a further route was added running west to Brown Clee Hill where new links ran to Bonnylands (probably serving the Madley satellite earth station) and towards Manchester and Liverpool. Significant numbers of television links for BBC, ITV (and later Channel 4) ran between London and Manchester via Birmingham together with trunk telephone traffic and it seems the section between London and Birmingham made full use of all available bands. (There were also multiple cable links between London and Birmingham.)
During the 1980s the SHF links migrated to digital systems, starting with new 11 GHz links and later displacing the analogue links in the lower frequency bands. Television links for the BBC remained largely analogue until transfer to another provider in 1995 but it is believed the ITV links were carried on digital SHF systems at one stage. Channel 4 transferred to an all-digital network in 1993, operated by BT, with limited use of SHF links.
The horn antennas survived until around 1987, by which they had been joined by a large number of dishes. According to a 2014 article Birmingham's Hidden Spaces: BT Tower the links at Birmingham were withdrawn from service around 2010. Photos confirm removal of the large dishes was complete by 2012. Currently still the tallest building in Birmingham, the site carries several local SHF links.