CH1
"Red Guard"(NLYL)
It seems that the main DTV transmitters such as Crystal Palace are belting out high power signals, and adjacent transmitting stations have frequencies which are staggered to avoid interference.In short - different technologies. DTT evolves slowly over time compared to GSM/UMTS. Mobile phone handsets are involved in two-way adaptive communications with cell tower base stations. Freeview box sets are receiving a one-way signal from the broadcast antenna which is invariably further away. A handset and base station have wiggle room to negotiate their way around interference, as it were. DVT-B signals are also susceptible to being interfered with by LTE to varying degrees. A properly fitted and setup outdoor antenna (for DTT reception) will almost always win over an indoor one.
On the other hand the high frequency lower power transmitters for more obscure HD networks are I think supposed to be synchronised, so all transmissions all over the country - where they are carried, which is by no means on all transmitters - are all on channel 55 and 56 at low power.
All I can say is it doesn't work for me in the heavily built up area of Brixton. I have seen planning applications in Southwark where shadowing of TV signal is a recognised issue.
On one occasion when Freeview went on the blip I rang them up and the person in the Freeview call centre said Can't you use Sky?