Question 3-55G1

A single-sideband (SSB) signal is a complex, amplitude-modulated waveform with a continuously varying envelope. To accurately transmit the information encoded in this varying amplitude, the amplifier must be *linear*. A linear amplifier produces an output that is a faithful, scaled replica of its input. When an SSB signal is fed into a non-linear amplifier, the amplifier cannot accurately reproduce the complex amplitude variations. Instead, the non-linearity causes the different frequency components within the SSB signal to mix with each other, generating new, unwanted frequencies called intermodulation distortion (IMD) products. These spurious emissions broaden the signal's bandwidth, cause "splatter" into adjacent channels, and corrupt the original voice information, resulting in severe distortion and reduced intelligibility for the receiving station. * **A) Reduced amplifier efficiency:** While linearity can impact efficiency (linear amplifiers like Class A or AB are less efficient than non-linear Class C), the primary issue here is signal corruption, not a direct reduction in the non-linear amplifier's inherent efficiency. * **B) Increased intelligibility:** The opposite is true; distortion decreases intelligibility. * **C) Sideband inversion:** This occurs due to incorrect mixing or filtering processes during modulation/demodulation, not amplifier non-linearity.