Question 6A313

A full-wave rectifier operating from a 500 Hz AC supply will produce a pulsating DC output at twice the input frequency, which is 1000 Hz. Since the circuit is unfiltered, this significant 1000 Hz ripple will be present on the plate supply of the amplifier. * **B) A modulated continuous wave of 1000 Hz:** The dominant ripple frequency on the plate voltage will be 1000 Hz, amplitude modulating the carrier wave produced by the transmitter. * **A) A modulated continuous wave of 500 Hz:** While full-wave rectification ideally removes the fundamental, an *unfiltered* and imperfect circuit can still have residual components at the original 500 Hz frequency due to imbalances, adding a 500 Hz modulation component. * **C) A-2:** This emission designator refers to "Telegraphy, on-off keying of an amplitude-modulated audio-frequency (or audio-frequency modulated continuous wave)." The 500 Hz and 1000 Hz ripples are audible frequencies that are amplitude-modulating the carrier, effectively creating an A-2 type emission, even if not intentionally keyed for telegraphy. Therefore, all descriptions accurately characterize the emission from such an unfiltered power supply.