Just thought I'd provide an update for those who were kind enough to offer some advice.
I went up into the attic today to measure for the HBU55 that pamajestic recommended. While I was up there, I decided to hookup an old combo antenna that used to be on the roof (I really want this to work in the attic if possible). I pointed to DC (160 degrees) as suggested instead of Baltimore. Anyway, I ended up getting 3 of the 4 networks I'm targeting plus 7 or 8 other channels that I'll probably never watch. WJLA and WUSA are coming in pretty well (around 60%). I'm getting NBC only WHAG out of Hagerstown instead of DC. Not sure how that's happening since i'm not even pointing that direction. The DC NBC station was picked up by the TV I tested with in the attic but the signal was too weak to view. So I'm only missing FOX at this point and there is no sign of it whatsoever.
I have no idea what antenna this is. ...I think maybe a Channel Master but it was many years ago that I bought it. The boom is around 85" and it's nearly as wide. The UHF portion is 36" long. Right now I have it hooked up to an old Channel Master amp because there's a splitter in the attic going to the bedrooms. ...so a pre-amp won't really work. A second 10db amp is also hooked up on the first floor and at this point I'm receiving all channels on 8 different TV's in the house.
The problem now is that the HBU55 is going to be too big to fit because of the way it needs to be angled. I'm pretty sure it would hit into those trusses. Anyway, I've got around 126" in length to work with if I'm going to get Fox and complete this mission.
Any suggestions on an antenna that's better than this one that would fit up there? Max width needs to be somewhere around 80" but I can probably maneuver it around the trusses it it's slightly bigger than that. ...and I have no idea if that amp is the best for the job so I'll take any advice I can get on that as well.
Would the HD Stacker be a good option here? I've read the claims about it but I don't know enough to know if it's legit.
Thanks again to all for the help on this.