The Rowridge transmitting station is a facility for FM radio and television transmission at Rowridge on the Isle of Wight in southern England. It currently has a tall guyed mast, owned and operated by Arqiva (previously National Grid Wireless). There is a smaller tower on the site belonging to British Telecom. Prior to Digital Switchover (DSO) the station broadcast with a power of 250 kW (ERP) for FM radio, 500 kW for analogue television, and 20 kW for digital television. In July 2007, Ofcom confirmed that Rowridge would remain an A Group transmitter at Digital switchover; the digital television transmission signal was then boosted to 200 kW. From March 2018 MUXES 7 & 8 moved out of the A group to channels 55 & 56 (see graph), though these are due to be turned off between 2020 and 2022. Rowridge is one of only two main transmitters (the other is the rather smaller transmitter of Rosneath in Scotland) to broadcast its output on both horizontal and vertical polarities. Only the main 6 MUXES are transmitted in vertical polarity. The reason for this dual polarity transmission is to give a second option to those experiencing co-channel interference from transmitters on the continent. Analogue Channel 5 was not transmitted from Rowridge but was broadcast (at 10 kW) from Fawley Power Station, with the antenna located on the main chimney. Transmissions all fitted within the A group and were horizontally polarised. On 25 March 2009, Channel 5's analogue signal was turned off from Fawley Power Station, due to the digital switchover in the neighbouring Westcountry region. Population coverage for the main four analogue channels was about 1.75 million. History The station was first built to provide BBC 405-line television coverage for an area including Southampton, Portsmouth, Bournemouth, Chichester, Brighton, Winchester and Salisbury. Sites on the mainland and the Isle of Wight were considered, and three were tested by BBC Research Department. A temporary 200 ft lattice mast was built with a main antenna at 175 ft and a reserve antenna lower down. These aerials were directional to enhance the signal northwards and reduce unwanted coverage to the south. It was built by BICC, alongside Pontop Pike (also 500ft) and North Hessary Tor in Devon (a taller mast). The service opened on 12 November 1954, bringing television to the area for the first time. A programme feed was obtained via a Post Office radio