Main Page | See live article | Alphabetical index Transmitter power output (TPO) is the actual amount of power (in watts) of RF energy that a transmitter produces. This is not the amount of power that a station reports as its ERP, such as "we're 100,000 watts of rock 'n' roll", but is in fact many times less for the high-power stations. The antenna's design "magnifies" the signal toward the horizon, creating gain. TPO x gain = ERP This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.