Ham Radio General Class Practice Test 2026 – Complete Exam Prep

In a typical single-sideband (SSB) phone transmitter, a balanced modulator plays a crucial role in combining the signals from the carrier oscillator and the speech amplifier. The balanced modulator takes the audio signal (from the speech amplifier) and the carrier wave (from the carrier oscillator) and combines them to produce a modulated output. This process effectively shifts the audio signal into the radio frequency (RF) spectrum for transmission.

The balanced modulator works by ensuring that the carrier signal is suppressed while the information (audio) is modulated onto the signal. This is key to SSB transmission, as it only transmits one sideband (either upper or lower) of the modulated signal, significantly improving bandwidth efficiency and reducing power usage compared to traditional amplitude modulation (AM).

Other circuit types serve different functions. For instance, a discriminator is typically used in the receiver's process of demodulating frequency-modulated signals, while a detector is similarly used for demodulating AM signals. The IF amplifier amplifies intermediate frequency signals in superheterodyne receivers but does not combine the carrier and audio signals. Hence, the balanced modulator is the appropriate circuit for this application in SSB transmission.