Reduced-carrier transmission
AM signal with a low-power or suppressed carrier
Reduced-carrier transmission is an amplitude modulation (AM) transmission in which the carrier signal level is reduced to reduce wasted electrical power. Suppressed-carrier transmission is a special case in which the carrier level is reduced below that required for demodulation by a normal receiver.
Reduction of the carrier level permits higher power levels in the sidebands than would be possible with conventional AM transmission. Carrier power must be restored by the receiving station to permit demodulation, usually by means of a beat frequency oscillator (BFO). Failure of the BFO to match the original carrier frequency when receiving such a signal will cause a heterodyne.
Suppressed carriers are often used for single sideband (SSB) transmissions, such as for amateur radio on shortwave. That system is referred to in full as SSB suppressed carrier (SSBSC) or (SSB-SC). International broadcasters agreed in 1985 to also use SSBSC entirely by 2015, although the anticipated widespread adoption of IBOC and IBAC digital radio (specifically Digital Radio Mondiale) would seem likely to make this irrelevant.
FM stereo transmissions use a double-sideband suppressed carrier (DSBSC) signal from a stereo generator, together with a pilot tone of exactly half the original carrier frequency. This allows reconstitution of the original stereo carrier, and hence the stereo signal.
Begin with the source’s own compact description: “Reduced-carrier transmission” is aM signal with a low-power or suppressed carrier. The dossier treats that line as a proposition to test through Reduced-carrier, transmission and signal, not as a finished interpretation.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Mar 14, 2026. The linked authority identifier is Q7306319. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1985 and 2015.
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