Don_M

Not by itself, though you are onto something. Here's what to do: Unplug the cable, and then attach a coax terminator to the wall plate. Terminators resemble little caps; they're available at Radio Shack and some of the big-box hardware stores for a buck or so apiece.

Even better: Try to locate the splitter -- the contractor should be able to remember where he put it. (My money's on the attic, basement or a centrally-located closet.) Unscrew the cable leading to that room, and attach the terminator there. This prevents signals from "leaking" out of unused connectors, thereby degrading reception at the other two tuners. For the same reason, attach a terminator to any other unused splitter connection as well. Doing this might be just enough to bring back KCBS.

It might help, or it might not. Give yourself plenty of time; arm yourself and your spouse with cordless/cell phones so she can report results at both tuners; and don't hesitate to take a break if you start feeling frustrated during the process. Drive a nail or screw into a rafter or truss and use that as a temporary "mount" at each location if you can. At each trial location, remember to step several feet away from the antenna, and to avoid standing between it and the stations; this will prevent interference of any kind with antenna function.

Just in case this doesn't do you any good, leave your current antenna mount and mast in place, and move the antenna by itself around. This way, you can re-mount the antenna where it was without having lost anything more than time spent. If you find a better location, it's definitely the time to move the mount to take advantage of that spot.