I have done a number of antennas in Southern Maine, and know the pitfalls. I am strongly against using an omnidirectional antenna, as they have no gain of their own, relying solely on an amplifier for gain, and they have no ability to reject multipath, which is a digital signal killer.
I have a very different take on what you need, and it has proven itself in a number of Southern Maine installations.
I would use a 2-antenna installation: an AntennasDirect DB4 UHF antenna along with an Winegard YA-6713 6-element VHF high-band antenna mounted on the same mast, separated by at least 4'. Combine the 2 antennas into one coaxial cable using a Pico-Macom UVSJ antenna joiner. If you follow these directions, you will see all the major networks including FOX, PBS and CW.
Aim the DB4 at 30 degrees, as measured by your compass, and aim the YA-6713 at 0 degrees: you'll see far more stations with this solution that you ever will with an omni-directional antenna, and your reception will be far more reliable in bad weather.
Please see the attached link for the results of a similar installation in Southern Maine
http://www.hdtvantennalabs.com/forum...it=Maine#p2409