St Helier
England · TV
Position 49.175375, -2.109772 Grid reference XD92001950 Nation England Ground height 8 m Antenna height 67 m Aerial group Group K — C21–48, wideband across the post-clearance band Polarisation Vertical BBC region South West/Channel ITV region Channel ITV news region Channel Parent transmitter Fremont Point Ofcom site number 12801 The position is our conversion of Ofcom's grid reference XD92001950 from OSGB36 to WGS84 [V] . Ofcom publish no latitude and longitude for television sites. The transform is verified rather than assumed: on the 3,403 radio records that carry both, it reproduces Ofcom's own coordinates to within 0.1 m.
On the map
St Helier is not the strongest signal anywhere the model predicts — it is shown here in place. That is normal for a relay, which fills in inside a main station's area.
Television This site carries the three public-service multiplexes and none of the three commercial ones, which is the normal arrangement at a relay — 1,059 of 1,169 sites are like this. Channels on SDN, ARQ A and ARQ B are simply not transmitted here, and no aerial will recover them; they need a main station. PSB3 (BBC B) is the UK's only DVB-T2 multiplex and carries every HD channel. Losing the HD channels while keeping the rest is therefore a single-multiplex fault rather than an aerial problem.
Transmitter data is Ofcom's; every dataset and the terms it is used under are listed under sources . Coverage figures are modelled, not measured, and are systematically optimistic .