Chapter 23 Television and Video Display Units 405
Satellite transmission
Once a signal is made by a communication station
on earth, it is beamed up to the satellite. The satellite
picks up the signal on its receiving antenna, amplifies
the signal, and then sends it back down to earth. See
Figure 23-29. The signal sent up from the studio to the
satellite is a narrow, targeted signal. The signal sent back
down from the satellite is a wide signal designed to cover
a large area of the earth.
Telemetry
and command
bicone antenna
Dual
polarized
reflector
Fixed forward
solar panel
Solid-state
power amplifier
TWTA
Battery pack
Antenna
feed assembly
Thermal
radiator
Propellant
tanks
Apogee
kick motor
Extendable
aft solar
panel
Equator
Figure 23-26. Looking inside a communications satel-
lite. (Hughes Communications, Inc.)
Figure 23-27. Parts of the Telstar III satellite.
(Hughes Communications, Inc.)
Figure 23-28. Geostationary communication satellites in
orbit over North America.
Figure 23-25. A communications satellite used for com-
munication in Australia. (Hughes Communications, Inc.)