Anik is basicallly just a relay station. It receives a signal from Earth, amplifies it, and retransmits it in the form of a television signal, a telephone signal or any other communications signal. The instrument aboard Anik, which is also found aboard many other satellites, is called a transponder. It receives a signal from a station on Earth at one frequency, say 6 GHz. The transponder then amplifies the signal and shifts it to a new frequency, say 4 GHz. A transmitter within the transponder amplifies the shifted signal using a travelling wave tube. There are actually 12 five-watt travelling wave tubes aboard Anik A that boost the signals so that they can be easily received on Earth. Each of these tubes could carry one television program or 960 voice channels. After the signal is amplified, it is then transmitted back to Earth at its new frequency.