Thanks for the feedback. Agreed that having MyNetwork and thisTV would be preferable. Both of those (along with KVBO) seem to be problem channels for the locals due to their low power output, even for those as close at 8 miles and in direct sight of the antennas (
http://www.avsforum.com/t/336964/aus...#post_22059636). But they may also not be set up well.
I believe I have exclusively blown-in insulation, but I'll need to check. The attic has very little human-serviceable area and is a little precarious with a 2-story drop in much of it, so an exterior antenna is pretty much the only (and probably preferred) choice.
The reason I mentioned a pre-amp from the start is I'll be looking at up to 100 feet of cable, depending on final location (whole-house patch panel has multiple runs to the cable demarc, and I'd prefer to continue using that).
Thanks again.