Actually, they are all close together. But that troublesome one broadcasts in the VHF band, while the others are up in the UHF band. I just don't think the antenna is good enough to get good reception in the VHF band. I have a brick house too. Don't know if that affects signal strength more than other materials.
I think my indoor antenna options are: huge, in the window, or amplified. The only tolerable one will be amplified. I'm hesitant to go with an attic/slash outdoor antenna right now, until/unless the wife decides she's ready to cut the cable.
Wow, just listen to me - I've been reading up on this stuff for a couple of days, and now I'm pretending to know what I'm talking about.