BasicB-008-002-003
What sound is heard from a public address system if audio rectification of a nearby single-sideband transmission occurs?
A
Answer
Safety
Type
A
Distorted speech from the transmitter's signals
B
On-and-off humming or clicking
C
A steady hum
D
Clearly audible speech from the transmitter's signals
Answer Notes
Audio rectification occurs when strong radio frequency (RF) signals are picked up by the wiring of an audio device and converted (rectified) into audio signals by a non-linear component, like a transistor junction. Because Single-Sideband (SSB) does not transmit a carrier, the rectified audio lacks the reference frequency needed for proper demodulation.
As a result, the speech recovered by the PA system sounds like 'Donald Duck' or highly distorted voice rather than clear audio. Options suggesting steady hums or clear speech are incorrect because clear speech requires a carrier (like in AM) and hums or clicks are typical of continuous wave (CW) or unmodulated carriers.
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What sound is heard from a public address system if audio rectification of a nearby CW transmission occurs?