As I recently blogged, I’ve set up a Bell ExpressVu receiver to receive NASA TV. Soon after installing the system, I ran in to a TV ‘scheduling’ issue with the rest of the family (who aren’t nearly as interested in watching images of astronauts brushing their teeth in zero-g). Instead of moving the entire setup to a second television set, I decided to move the receiver to my server room, and build a distribution system to distribute the channel to all of the televisions in the house.
I don’t use any antenna inputs on any of my televisions, because all of the devices I use (satellite receivers, XBOX consoles, etc) have composite, component, or S-video outputs. This means that every set has an unused antenna input that would be an ideal input to view the NASA TV. Unfortunately, I would have to run a second coax cable to each set just for this. Instead of that, I discovered a way to ‘multiplex’ the Bell ExpressVu LNB signal and the channel 3 signal from the NASA TV receiver.
The trick is to use some satellite/UHF/VHF combiners (a fuzzy picture here). I put one of these in the server room on the output of the NASA TV receiver to multiplex the channel 3 signal on the LNB feed back upstairs to the TV. On the TV end, I put another one of these to de-multiplex the LNB signal and the channel 3 signal, which goes straight to the antenna input of the TV. This worked beautifully, so I then split the channel 3 signal into 3, ran this in to 3 separate combiners, and multiplexed the signal on 3 separate LNB feeds to separate TVs around the house.
This now gives me the ability to watch NASA TV at three separate locations in the house.