To really have a lot of control over the RF, you'll want the MX-800, which comes with the MRF-200, a fully addressable RF base station. You can set what codes are sent IR, RF, and if RF, which emitter send the signal. It's incredibly versatile, but it's not nearly as affordable as one of the more common units, which often send out any and every code via RF, and anything within range of the emitter or blasters get the signal. Even these affordable units allow the use of IR-Blasters, which direct the signals right to the IR receivers of the devices, so other items aren't affected. For instance, you could attach an IR Blaster to the satellite receivers, and then only they would receive the codes sent by remotes around the house using remote extenders. The TV in the living room would be "immune". Let me know if you need further explanation!
David
www.BlueDo.com