In a single-sideband transmitter, which stage transposes the voice message from the audio spectrum to the radio spectrum?

The balanced modulator is the specific stage in an SSB transmitter that mixes the audio signal (from the microphone and speech amplifier) with a fixed radio frequency (RF) carrier signal. This process transposes the voice frequencies into the radio frequency spectrum, creating a Double Sideband Suppressed Carrier (DSB-SC) signal. While a standard mixer simply combines two signals and leaves the carrier intact, the 'balanced' modulator is designed specifically to cancel out (suppress) the original carrier frequency. This leaves only the upper and lower sidebands containing the audio information, which is the necessary first step in generating a Single Sideband (SSB) signal.