Transmitter power output

In radio transmission, transmitter power output (TPO) is the actual amount of power (in watts) of radio frequency (RF) energy that a transmitter produces at its output.

This is not the amount of power that a radio station reports as its power, as in "we're 100,000 watts of rock 'n' roll", which is usually the effective radiated power (ERP). The ERP for VHF/UHF transmitters is normally more than the TPO, for LF/MF transmitters it has nearly the same value, while for VLF transmitters it may be less.