An RF
modulator is a handy little
gadget that's necessary for most people's
home theater systems, especially if this system has an older
television. It converts the
component signal (usually carried by three
RCA cables), into a signal that is "patched in" over either
channel 3 or 4 on your
cable or
antenna cord.
This is because while your cable or antenna cord carries multiple channels on several
frequencies, your
A/V component (your
Playstations and
DVD players and such) outputs three individual signals--
- yellow: Video
- red: Right-speaker audio
- white: Left-speaker audio
The RF modulator combines these three
signals and substitutes them as a pseudo-channel on your cable/antenna line--usually channel 3 or channel 4. Newer
models will auto-detect a signal and substitute when the A/V component is turned on, while older models may require some sort of manual switching.
You can buy them at your friendly local
Radio Shack for about $30.
There are also specialized, less-
expensive versions of RF modulators made for
gaming systems that bypass the
A/V cables altogether. These vary in price from $10-$20.