Q) Which of the following circuits combines a speech signal and an RF carrier?
What the heck is a modulator anyway? For the unintiated, the word modulation is somewhat strange. In field of music, the word modulation refers to the act or process of changing from one key to another. In the context of radio, modulation is the process of varying one or more parameters (amplitude, phase, frequency) of a waverform with a modulating signal. It is the modulation which imparts information to the signal being transmitted. The information can be in the form of an on/off tone as in CW, voice, music, or a stream of data.