Ynys Pennal
Wales · TV
Position 52.566659, -3.937135 Grid reference SN68809830 Nation Wales Ground height 10 m Antenna height 16 m Aerial group Group K — C21–48, wideband across the post-clearance band Polarisation Vertical BBC region Wales ITV region Wales ITV news region Wales Parent transmitter Blaenplwyf Ofcom site number 13526 The position is our conversion of Ofcom's grid reference SN68809830 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
Ynys Pennal 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 .