Installing a residential audio/video modulator is not difficult. Start by connecting the audio/video device(s) that you wish to modulate to the modulator with RCA-type patch cables with phono connectors on both ends. Then connect both your local off-air antenna and the output of the modulator to a backward 2-way signal splitter. When used in reverse, the splitter becomes a combiner. Then finally connect the output of the splitter to your TV distribtution system.
Selecting a Channel
Once you have the modulator connected it's time to set the modulator to an unused channel that is not adjacent to any of the already used local off-air channels. Preferably, it is best to choose an unused channel that is at least 2-3 channels away from an already used channel.
Here is an example of how to determine which channel to use for a UHF modulator:
You have an outdoor TV antenna and would like to be able to watch the satellite receiver located in your living room in any room of your house. The local off-air channels in your area are 2, 4, 5, 8, 17, 28, 30, 39, 58, and 66. These channels are being passed from your TV antenna on to the TV distribution system, and therefore cannot be used (you can't modulate channels on top of existing channels).
Keeping in mind that it's best to use a channel that is at least two channels away from an already used channel, we could use any of the following channels to put our "new" modulated channel on to: 19-26, 32-37, 41-56, 60-64, 68 or 69.
Troubleshooting Signal Problems
There's always a possibility that the channel that you choose will not produce a good picture quality. There are a number of reasons for this, but the main causes are due to:
(1.) Unequal signal levels between your modulator and the over-the-air or cable TV signal. To solve this problem, install a 20dB fixed attenuator between the modulator and the backwards 2-way splitter (acting as a combiner). The attenuator reduces the amount of signal coming from the modulator by 20 dB so that the two combined signals are more balanced and one signal doesn't interfere with the other signal.
(2.) A distant analog TV station or a local digital TV station in your area is broadcasting on the same channel that your modulator is set to. If this happens, simply tune your modulator to a different channel until the picture quality is better. Maintaining at least 2 open channels between a local over-the-air channel and your "in-house" modulated channel will also greatly reduce interference on your TV system.