Dynamic carrier control (DCC) is a method of reducing power consumption in radio transmitters during periods of low audio activity or silence.
There are two types of Modulation-Dependent Carrier Level (MDCL) control methods: DCC, as discussed above, and Amplitude Modulation Companding (AMC), developed by the BBC.
It limits the peak voltages on transmitter and antenna circuits, possibly preventing damaging arcs.
With both methods, the main disadvantage is marginal loss of coverage, comparable to running slightly less power.
Also in lower signal strength parts of the coverage area, a station using Dynamic Carrier Control may be more likely to be skipped on digital-tuned radios during seek/scan tuning (if the frequency is passed during carrier reduction), an issue compounded by manual tuning (instead of seek/scan) selection not being easy on some receivers.