To watch tv in this room, how can I switch easily from the DVDR in the
other room to the set-top box in this room? All but the last bit of
wiring is in place already!

1) My first plan was to use a splitter and set the DVDR to channel 3
and the set-top box to channel 4, and then just use the tv remote to
switch the tv to channel 3 or 4. That would have worked but the
signal from the DVDR, even though it gives a grainy picture and even
though it is set to output on channel 3, overwhelms the other signal
on channel 4. Are there filters that would stop this?

2) Then I found for only $3.50 a piece at an online surplus store,
RadioShack Automatic tv/game switches (#15-2367A), where just one tv
channel is used and the antenna plugs into A, and the video game plugs
into B, and C goes to the TV and the TV is supposed to use Antenna,
unless you turn the game on, and the signal that comes from the game
is supposed to switch off or overpower the signal from the antenna.
Sounded perfect but didn't work. Is that because the signal from my
DVDR is a lot stronger than the signal from an antenna would have
been?

I bought three of these switches, but I've only tried one of them. I
suppose I should try the others in case this one is defective. Likely?
Maybe they're all defective and that's why they are surplus??

3) Now I'm using an A/B Switch, and so I have to get up to switch back
or forth. The only better idea I have is a remote controlled A/B
switch, but that means another box, another power adapter, more
electricity, and another remote control. (And I've never seen an A/B
switch listed in a universal remote control instruction book.)

Maybe you guys have a fourth possibility??? Please.