Robert Neville wrote:

[....]

I'm not an RF engineer, but
[....]

if the broadcasters of free over the air digital TV signals
really wanted to make this work well and ensure an exacting
coverage of a specific area with standardized signal strength
they'd take a lesson from the cell phone signal providers with
their tower placements.

with a few more well placed towers and by making use of repeater
technology the people living 25 miles from the central station
could receive the same level of service as the people living 10
miles from said location.

but, that's not going to happen as a result of realistic cost
considerations.