O
But the OPs problem is (and this is probably common) he wants to pull
in signals from different transmitters at different compass points.
He wants one antenna 'pointed' at one transmitter, and another antenna
'pointed' at another transmitter. If you can't combine two separate
antennas in this way without their interfering with one another, maybe
a rotor really is the only way to do it. -- H

Honestly...putting dual antennas up will only give you a 3db gain if
everything goes well. A 3db gain is not much when you are talking
about a DTV signal.

If he is looking for a antenna structure that needs to be
multidirectional that is located in the attic then he is basically
entering into a non predictable situation. It would be a trial
and error situation.

As you have suggested one antenna, one amplifier mounted at
the antenna, and a rotor would be his best bet in the attic.
Better yet would be to get the antenna outside. I suspect that
one omni directional antenna without a rotor or amplifier would
do just as good or better.