Question T2B13
From subelement T2 - T2B
What is the purpose of a squelch function?
Why is this correct?
The squelch function mutes receiver audio when no signal is present, eliminating constant background noise. Without squelch, you'd hear continuous static and noise between transmissions. Choice A relates to CW transmission cleanup, not receiver audio control. Choice C addresses amplifier oscillation issues, unrelated to receiver squelch. Choice D concerns impulse noise reduction, which is a different receiver function entirely.
Memory tip
Think 'threshold gatekeeper' — squelch sets a signal strength threshold below which audio is muted. This pattern appears in many receiver controls: they either pass signals above a certain level or block everything below it. The key insight is distinguishing receiver audio management from transmission quality or RF amplifier issues.
Learn more
In practical operation, proper squelch adjustment is crucial for comfortable monitoring. Set too low and you'll hear constant noise; too high and you'll miss weak stations trying to reach you. The squelch threshold should be adjusted so background noise just disappears while still allowing legitimate signals through. This control works with CTCSS and DCS systems on repeaters, where sub-audible tones can override squelch settings to ensure authorized users can access the system regardless of signal strength variations.
Think about it
Why do you think repeater systems often use CTCSS tones to bypass normal squelch operation, and what operational advantage does this provide over relying solely on signal strength?