I can probably be a bit higher but I think 30 is the limit and still be in the attic.As for number of TVs 3 initially, but I have 10 coax runs spread throughout the house.
Here is some more info that I had typed in, but was lost when I initially tried to post. I had to be somewhere so I just put the basic stuff out there before I lost that.
I had an antenna at about 12-15agl at our previous home(east about 7miles and a little south) in the garage attic and was able to receive all the metro stations really well, and saint cloud(ION) on most days. That home was at a lower elevation than our new house.
I bought a Lava HD2605
http://antennadeals.com/HD2605.html thinking I didn't need much here, but I'm only able to get a couple of stations of pixelated garbage.
As for the combiner(and two antennas) I think that would be a great solution to get the stations that are SW of me. I would prefer not to rotate because of tivo. I have plenty of room in the attic for two large antennas(12/12 roof pitch), so I am open to suggestions as to which antennas to buy and which combiner.
We did some antenna stuff in A&P school but I don't remember much.
Thanks for responding
Paul Hastings