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refers to an unlicensed radio
transmission system that transmits its signal via some type of
cable. There are four common types of cable radio:
- Leaky Cable FM
- For this type of radio station, a special type of "leaky" coaxial
cable is run through a building, usually down hallways or utility
shafts. The coax cable has intentionally poor sheilding, so a little
bit of FM signal leaks out. The range of this type of system is usually no more than a
few hundred feet from the cable. The radio station can be picked
up with an ordinary FM radio, usually anywhere within the building.
Because this system uses very low power, the FCC does not require
that these types of stations be licensed.
(see also: Carrier
Current AM Stations)
- Cablecast FM
- This is a system where a radio station's FM signal is injected
into a cable TV network at the head end of the system. The station
signal operates at a normal FM frequency within the coax cable. To
receive the station, a listener must connect the cable directly to the
antenna jack on his or her radio, in the same way that one hooks up a
television set to a cable TV system. An advantage of this system is
that if a building already has cable-TV installed, no new cables need
to be run. One drawback of this system is that many types of radios
do not have a way to hook up an external antenna. Another drawback is
that the radios that are attached to the cable are not portable.
- Cable TV Audio Channel
- This is a system where the audio signal of a radio station is
played on the audio portion of a cable TV channel. The station cannot be
picked up with an ordinary radio. It can only be heard if a
television or VCR is hooked up to the cable TV system. This system
is sometimes used on college campuses on "information" cable TV
- Cafeteria Radio
- This system simply sends an audio signal over wires to
loudspeakers in other rooms, or in other buildings. Technically,
this really isn't radio broadcasting, but some campus "radio stations"
use this type of system to deliver their programming to their listeners.