Why might the 100% power output level of your transmitter read 30 kilowatts instead of the specified 100 kilowatts?

The assertion that 30 kilowatts is the actual power output while 100 kilowatts represents the effective radiated power (ERP) accurately captures a key distinction in broadcasting technology.

Effective radiated power is a measure of the power that an antenna emits in a specific direction, accounting for the gain of the antenna and other system losses. The actual power output of the transmitter can differ from the ERP due to several factors, including efficiencies in the transmission line, losses within the transmission system, and the characteristics of the transmitting antenna itself. Therefore, when a transmitter shows a lower reading, such as 30 kilowatts, it may reflect the real power that is being fed into the antenna, while 100 kilowatts denotes the expected output in terms of ERP once the radiation characteristics are taken into account.

This distinction is vital for understanding how power levels in broadcasting are calculated and understood, as they can affect both compliance with regulations and the overall signal coverage achieved by the broadcast station. The explanation also highlights the importance of grasping the differences between different measurements in broadcasting to ensure effective transmission and operations.