Name: Karlos S.
What dose "XM" radio mean?
The "XM" does not mean anything. XM is a company that provides satellite
radio at a frequency around 2.333 GHz. Other companies offering satellite
radio include Sirius, near 2.325 GHZ, and and WorldSpace in the 1.5 GHz
The signals come from satellites orbiting in space. Urban areas, where
buildings might block the signal, are helped by antennas put on towers.
Conventional radios use a radio wave that is either modulated in amplitude
(AM radio) or modulated in frequency (FM radio). These signals come from
antennas put on towers. The satellite radio broadcasts are all digital.
XM is the trademark of one of the companies that provide satellite radios.
The other main company is Sirius, which I have installed in my car. Each
provides 120 or more channels covering a wide range of material (popular
music, classical music, talk radio, news programs, country music, etc. )
The programs are generated on earth (naturally) and then beamed up to
satellites which then rebroadcast them towards earth. I find the system
works quite well except when one is under some cover. For example going
through a tunnel or under a very wide bridge will interrupt the signal. The
radio stores about 5 seconds of program, so the radio continues to play for
about 5 seconds after the signal is interrupted. Conversely, the program
remains interrupted for some 5 seconds after the satellite radio antenna has
a clear view of the satellite. I am quite pleased with my system.
Best, Dick Plano
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Update: June 2012