London to Isle of Wight (1954 and subsequent development)

The planned BBC television transmitter at Rowridge on the Isle of Wight was expected to cover a significant population along the south coast between approximately Bournemouth and Brighton, extending inland towards Reading. It was not, however, possible to receive an adequate signal from Alexandra Palace at the transmitter site and the Post Office were contracted to provide a link. As would become a familiar pattern, this was achieved in stages. A site at Golden Pot was selected as being a suitable mid-point between London and the Isle of Wight and was initially used for a one-way link with off-air reception of the London BBC transmitter and a 4 GHz link to Rowridge. Also in a pattern which was to be repeated, some of the equipment used for the link had been recovered from an earlier link – originally experimental, but which was used during the first four months of the BBC Wenvoe transmitter. This “Stage 1” link as it is referenced in Post Office reports was available for the start of service in November 1954.

Subsequently an SHF link was provided from Museum Exchange and made two-way, allowing outside broadcasts to be injected either at Rowridge or Golden Pot. At this stage the BBC had no permanent presence in Southampton and therefore the return path seems to have spent most of its early life “looped” so that the Post Office control at Museum could monitor the end-to-end performance of both links. This “Stage 2” link was formally accepted by the BBC in January 1956.

This first-generation link was further expanded in “Stage 3” and “Stage 4” to meet the requirements of the newly appointed ITA contractor for the region. Southern Television launched in August 1958 from their transmitter at Chillerton Down (also on the Isle of Wight) and in January 1960 from Dover. The precise details of these two stages are yet to be confirmed but it seems most likely “Stage 3” was a further link from London and “Stage 4” was the return path. Southern’s main studios were built in Southampton. The “Southampton and back” routing to Dover remained a feature when the franchise was awarded to Southern’s successors – but it had the useful side-effect that Southern could contribute to “network” more readily than some of their contemporaries who were provided with one-way links.

The ITA requirements were accommodated by the provision of a cable link between the Rowridge (BBC) and Chillerton Down (ITA) transmitters and a 2 GHz link which ran from Chillerton Down to the main exchange in Southampton. From there a further cable ran to Southern’s studios to allow advertisements and locally produced material to be injected and the result was returned to Chillerton Down (and later onwards to Dover via London) using the same route in reverse.

The final configuration of the first-generation link, therefore, ran as follows:

Museum Exchange

Golden Pot

Rowridge (feeding BBC transmitter)

Chillerton Down (feeding ITA transmitter on return from Southampton

Southampton (Ogle Road TE) (feeding Southern and later BBC studios)

The BBC opened a Southampton studio in January 1961 – this was presumably connected via the exchange. Normal BBC practice would have required the feed from London to be routed to the studio and the transmitter then connected to the studio – presumably this would have been achieved by treating Rowridge in a similar way to Chillerton Down.

The Golden Pot link, with a guyed mast and timber buildings (albeit of a “permanent” nature as used for some local exchanges) gave the appearance of an interim measure and part of the 1960s expansion of the Post Office SHF network the site was duly bypassed by a new link. Despite this, however, the site remained in PO/BT ownership with the original mast (in truncated form) and buildings still present in 2016. Planning permission had already been granted for the mast and another later structure to be removed and a replacement tower had already been constructed. Although the site remained in use, Golden Pot did not form part of the core network and did not appear in PO/BT lists in the 1970s and 1980s. (The site at Turners Hill on the 1949 London to Birmingham television link similarly disappeared from the site lists.)

In the 1960s plans were made for the new Post Office Tower and links on four maiin routes away from London, one of which would split to provide a link to Southampton, carrying telephony and the expanding television traffic. By the late 1960s links were required for 625-line colour television and for three services. BBC2 launched from Rowridge in January 1966 but BBC1 and ITV were delayed until December 1969. It seems in part this was due to problems with the provision of the new links and was the subject of correspondence between the ITA and Post Office. It’s not clear how the BBC2 625-line programme feed reached the Rowridge transmitter in 1966 – perhaps it was somehow squeezed into the link via Golden Pot – but it seems not to have been feasible to use this route in the longer term or for the other services.

The “second generation” link ran from the Post Office Tower via Bagshot and Butser Hill to Thornhill, west of Southampton, from which local cable connections ran to the television studios. The Rowridge transmitter was fed via a spur from Thornhill and a telephony link between Thornhill and Ryde added subsequently. Unfortunately it seems there were planning or construction delays at all sites, with the possible exception of Thornhill, however there was then a problem with providing the cable from there to the Southern studios!

The VHF television services continued for many years but their original distribution arrangements would have been discontinued at an early stage. For ITA the “standards converters” producing 405-lines for the VHF service were normally installed at the transmitters – and were moved from the studios overnight on 8 September 1969. In the case of Chillerton Down it’s likely the direct Post Office feed would have given way to off-air reception of the UHF service from Rowridge. It seems unlikely the BBC would have retained a feed from Southampton for the 405-line service in the long term.

 

Including the telephony spur the second-generation links to Southampton and the Isle of Wight used the following sites:

London (BT Tower)

Bagshot

Butser Hill

Thornhill (cable links to Southampton studios and for telephony)

Rowridge (possible cable connection to Chillerton Down ITA transmitter)

Ryde (telephony)