Diplexers fix everything

At the park here in Hollister, we have cable TV included in the rent. The cable offerings are rather basic, but it does include the local ABC, CBS, NBC and FOX stations.  WE also have a portable satellite dish which gives us a much better selection (at least 123 shopping networks and 57 religious ones!) but we can't get local stations.  So, we want the best of both worlds--cable plus satellite.  However, our trailer is wired with only one cable running from the outside to the TV inside.  How do we get both without having to go outside to rewire every time or add new wire? 

After researching the problem on the Internet including on several RV forums, the answer was two diplexers.  A diplexer is used to combine cable and satellite signals on the same cable.  Actually two are required.  One is used on the outside the RV to combine the satellite and cable inputs and another is used to separate the signals into cable and satellite at the TV.  A diplexer looks like a cable signal splitter, but it is a different device.  Here is the hook up outside the RV:

The top cable plugs into the trailer cable inlet outside.  The bottom left is the cable coming from the satellite and the bottom right is the park  TV cable.  Inside, at the television, is the identical setup.  Another diplexer is connected to the trailer cable wiring.  The satellite out cable is wired directly to the satellite receiver box and the cable TV line goes directly to the television.  Now to switch between cable and satellite, we only need to change the antenna source on the television menu. 

This setup sure saves a lot of stress not having to send Donna outside to rewire the hookup every time we want to watch one system or the other.  But there is still nothing on worth watching.