Philip de Cadenet wrote:

TV TX power is not cheap.

It's all in the antenna and HAAT.

Back in the 70's a London AM pirate station dabbled with TV and played
with a couple of watts and a simple colour bar generator to feed it.
Using a simple yagi antenna atop a local hill they were received around
15 miles away albeit line of sight.

You've forgotten the early 80s "Thameside TV" broadcasts over one Christmas.
They were at quite high power (erp of a few kilowatts) from Crystal Palace.
CP was chosen because it's very high, and there are already other TV
transmitters up there - so all the rooftop yagis point at that area! It
was possible to get a P5 picture over much of west London!

--
BIAS COMMS

Everything gets easier with practice, except getting up in the morning!