Rich & Barb,
Is your antenna amp on? If it is, turn it off. (It’s probably not, because you say cable works fine.)
Here’s a diagram of Monty wiring. It should bear a close resemblance to yours.
http://pic3.picturetrail.com/VOL19/1.../111212066.jpg
It does say that you’d have to have a switch in there. But in a little while, others will be along to let you in on how they’ve gotten theirs to work.
But I was wondering if you can put the receiver in the back, with the big TV. You could back-feed the bedroom TV to show whatever the receiver’s putting out.
Steve