Which component allows mobile radios to have a higher transmitter output power than portable radios?

The component that allows mobile radios to have a higher transmitter output power than portable radios is the power supply unit. Mobile radios typically have the advantage of a direct connection to a vehicle's electrical system, which provides a stable and sufficient power source to operate with higher output levels. This enables them to transmit over greater distances and penetrate more effectively through obstacles compared to portable radios, which rely on batteries that have limited capacity and provide lower power output.

While other components like antenna technology, signal boosters, and transceiver units play important roles in radio communications, their functions do not directly influence the maximum output power available. Antenna technology can improve the range and quality of the signal, signal boosters can amplify incoming or outgoing signals, and transceiver units are responsible for both transmitting and receiving signals. However, none of these components impact the fundamental limitation presented by the power source that the radio can draw from, which is why the power supply unit is crucial in allowing mobile radios to achieve higher transmitter output power.