Editing Shortwave radio (section)

====SSB====
[[Single-sideband modulation|Single-sideband]] transmission is a form of amplitude modulation but in effect filters the result of modulation. An amplitude-modulated signal has frequency components both above and below the [[carrier frequency]]. If one set of these components is eliminated as well as the residual carrier, only the remaining set is transmitted. This reduces power in the transmission, as roughly {{frac|2|3}} of the energy sent by an AM signal is in the carrier, which is not needed to recover the information contained in the signal. It also reduces signal [[Bandwidth (signal processing)|bandwidth]], enabling less than one-half the AM signal bandwidth to be used.<ref name=RohdeWhitaker2000/>

The drawback is the receiver is more complicated, since it must re-create the carrier to recover the signal. Small errors in the detection process greatly affect the pitch of the received signal. As a result, single sideband is not used for music or general broadcast. Single sideband is used for long-range voice communications by ships and aircraft, [[citizen's band]], and amateur radio operators. In amateur radio operation lower sideband (LSB) is customarily used below 10&nbsp;MHz and USB (upper sideband) above 10&nbsp;MHz, non-amateur services use USB regardless of frequency.