If an AM broadcast station is broadcasting 50,000 Watts, does that include sideband power as well? Or is it just carrier power? Thanks!

Hi Mark

Interesting question. In the case of amateurs rating is power to the output tube. Maybe commercial stations rate their transmitters this way?

Norm

:If an AM broadcast station is broadcasting 50,000 Watts, does that include sideband power as well? Or is it just carrier power? Thanks!

Guys,
The engineers where I work tell me the power is still measured the same ol' way. You can run 50kw input to the final stage, measured by the plate volts X amps. They allow you to also measure it with a watt meter at the output to the final amplifier, as long as you take into account the efficiency of the amp. Assuming 65% efficiency, your 50kw transmitter would be legal, measured at the output, at 50,000 x .65: 32,500 watts output to the antenna.
Jim

:If an AM broadcast station is broadcasting 50,000 Watts, does that include sideband power as well? Or is it just carrier power? Thanks!

Mark: The product of plate current times voltage is indeed the correct answer. Another facet of this thing is that the FCC limits the audio frequency that commercial AM stations can broadcast to 5KHz. This results in an overall 10KHz bandwidth which is the standard AM "channel" in the U.S. This is why there is no such thing as a "high fidelity" AM radio receiver.

:If an AM broadcast station is broadcasting 50,000 Watts, does that include sideband power as well? Or is it just carrier power? Thanks!

Broadcast stations are not controlled by the same rules as ham radio. Ham transmitter power is based on input to the final amplifier and depends on efficiency. Broadcasters, AM/FM/TV, are required by their FCC licence to provide the licensed output power of the transmitter into the antenna regardless of the efficiency of the transmitter. Licensed AM transmiter output power is measured as the unmodulated carrier power. RF power for 100% modulation, integrated over the modulating audio cycle is 50 % higher than the carrier, with 25% in each sideband. Hope this helps.