The Long Mountain transmitting station is sited on a 400 metres (1,300 ft) ridge about 4 kilometres (2.5 mi) east of Welshpool in Powys, Mid Wales and has been broadcasting UHF terrestrial TV and VHF FM radio services since the late 1970s.

The site has a self-supporting 170' (52 metre) high lattice steel mast and was fed with an SHF link from Blaenplwyf via Llangurig.

[1] Long Mountain became re-classed as main transmitter in its own right (albeit a very low power one) with the advent of digital terrestrial TV from the site on 4 November 2009.

[3] All the analogue television services closed and the new digital multiplexes took over on parking-frequencies (until October 2011) with name-changes, power increases and a shift to 64-QAM.

[4] Unusually, for a digital TV site classed as a main transmitter, Long Mountain only radiates the three public service multiplexes of Freeview.