Based on Ofcom data, we've prepared maps of the UK DTT tranmsitters. Below are maps for PSB1, the main BBC multiplex (group of channels broadcast together), and for COM4, the commercial mux operated by SDN, a subsidiary of ITV.
Commercial muxes have about 90% population coverage, the PSB (Public Service Broadcasting) muxes have 98.5% coverage, but need many more transmitters as a result. These are generally lower power, used to fill in areas that are 'in the shadows' as far as the main transmitters (shown in red and yellow) go. For instance, these areas may be in valleys, and so shielded. You can see many low-power (green) PSB1 transmitters in Wales, for example, to ensure the Welsh get value for money from their BBC licence fee. By contrast, the flat fenlands of East Anglia can get by on very few transmitters.
Click on an icon to see information on which muxes transmit from that location and the power and height of the approved transmission. These parameters are set by Ofcom.
Scroll in on any transmitter and switch to satellite view to see the actual mast. (The Crystal Palace mast is at the bottom of the page, by way of example).
The icons indicate the power of transmission in kW:
Green: < 1kW
Mux: PSB1 (BBC)
Mux: COM4 (SDN)
The Crystal Palace mast