Harmonic radiation from electrical power transmission lines is known to trigger strong emissions in the magnetosphere in the range of a few kilohertz. To study this phenomenon on a controlled basis, an experiment was conducted using a very-low-frequency transmitter at Siple, Antarctica (L?4) and a receiver at its conjugate station, Roberval, Quebec, Canada. Many important features of power-line-induced emissions including their frequency dependence, rapid amplitude variations, and spectral forms could be simulated by transmitting waveforms containing sidebands with 50 and 100 Hz frequency separations. It is found that power line effects can be simulated by radiating as little as 0.5 W at a given frequency. The results also demonstrate that the magnetosphere can generate sidebands at frequencies up to 25 Hz from the transmitter frequency. This explains why power-line-induced emissions sometimes show frequency components 20--30 Hz from exact multiples of the fundamental power frequency.