gb387 said:
I know it depends... but you can do that?
To do as rcdallas suggested, look at this link
http://www.satelliteguys.us/attachment.php?attachmentid=11789&d=1158064663 which is a picture posted by "bertbarndoor" on (Page 3) of another thread -
http://www.satelliteguys.us/showthread.php?t=76031. This picture is kind of what you want to do, except he is using it for a different result.
In the upper left hand corner of the diagram, you would subsitute the "UHF Remote Antenna" with a "VHF/UHF TV/DTV Antenna" and replace the "SDTV" with a "Cable TV Connection". The satellite splitter is a normal TV/Cable splitter that operates between 50 - 1000 MHz.
In the bottom center of the picture, this satellite splitter is also a normal TV/Cable splitter that operates between 50 - 1000 MHz. However, the two outputs would go to where ever you needed the two outputs, or skip this splitter and go directly from the Diplexer VHF/UHF connector to the Ant/Cable connector on a receiver.
The only problem with this setup is: If you are not using a cable box, or a TV that can receive "digital cable" then you probably are using an analog cable system in which the frequencies for Cable Channels 2 - 13 are the same as TV Channels 2 - 13. Just like when you are in the country, you can not receive Channel 5 from 2 different cities when you are half-way between the two cities. You may be able to compensate for this by using modulators, cable boxes, or other techniques, but this may be more trouble or costs than its worth.
In case you do not know, diplexers are different than splitters (which usually can be used as a combiner). I think you can find 2 diplexers for <$10.
This is one site with many documents:
http://www.solidsignal.tv/dishpro_installation.asp
Including this one:
http://www.solidsignal.tv/dishnetwork/Installation_Documents/The_Ins_and_Outs_of_Diplexers.pdf which is everything you wanted to know about diplexers.