On Sunday, September 17, 2017 at 7:46:25 PM UTC-4, badgolferman wrote:
I'm thinking of installing an HD antenna either in the attic or on the roof
to be rid of cable video. However I'm wondering if I can hook up the
antenna to the existing coax in the attic that runs to the various rooms in
my house. Will one antenna work on 2+ TVs at the same time?

The national network stations are at least 30 miles away, but they're all
in the same general direction so I'm thinking a directional antenna would
work. I do have a large maple tree in the direct line of sight though. Not
sure if that will be a problem.

You can try it. The more cable runs, the more splits and things sharing the signal from the antenna, the weaker it will be. But it only has to be good enough to work, extra doesn't get you anything more. There are amplifiers available to boost the signal if you need to split it and that may work too. Used to be a website antennaweb.org I think where you could put your location in and it would show what you could receive,what direction and what kind of antenna is recommended.