Why does the UK Free Freeview predictions differ from other sites?
I have adjusted the model that uk free uses based on feedback
The predictions often do not match the "official" value because feedback from ukfree.tv users have indicated the differences.
The original ONdigital boxes required a much stronger signal. The switch of four multiplexes to 16QAM mode, and the introduction of the Class I digital aerial brings better coverage.
Also, I found that many people in "poor coverage" aerials are happy to get a new aerial to get Freeview because in these areas Freeview pictures are noticeably better than analogue signal provides.
What I also found was that where it was necessary to change the aerial from pointing at a local analogue only transmitter to a remote Freeview transmitter, people would do this rather than wait another six years.
I also found that in some coastal areas it was common for people to use very long poles to get a good signal.
The original ONdigital predictions were before the introduction of 16QAM mode for four of the multiplexes (1, B, C and D) and the increase in power at some transmitters, so you expect some slight changes to the database.
The predictions by ukfree.tv take into account the line-of-sight to the transmitter, the power of the signals and the aerial height required to get a signal.