It is a common perception that it requires sophisticated equipment and large circularly polarised antenna arrays to work amateur satellites. While this may be true for using some of the high altitude 'birds' or on the higher bands such as 23cm, it isn't the case for all satellites. There are several low Earth orbiting satellites which can be worked with relatively simple transceivers and antennas. This article will concentrate on voice operation, as I have no experience at all with digital satellite operation. Amateur voice satellites can be divided broadly into two groups.
Linear transponders are capable of relaying several different signals simultaneously.
More recently, some satellites have been carrying crossband FM repeaters instead of linear transponders. These repeaters are similar to their familiar terrestrial cousins in that they receive an FM signal on a specific channel, demodulate the signal and retransmit the signal on a new frequency. Unlike linear transponders, but like conventional FM repeaters, these satellites can only carry one QSO at a time. To successfully work an amateur satellite, you need to have transceivers suitable for the satellites you wish to work. For linear transponders, SSB and CW transceivers on the bands of interest are required.