Question T7A04
From subelement T7 - T7A
Which term describes the ability of a receiver to discriminate between multiple signals?
Why is this correct?
Selectivity is the receiver's ability to discriminate between multiple signals that are close together in frequency. It allows you to focus on your desired station while rejecting interference from nearby frequencies. Sensitivity (option B) measures ability to detect weak signals, not separate them. Discrimination ratio and harmonic distortion are not standard receiver specifications for signal separation.
Memory tip
Remember the distinction: sensitivity is about 'how weak' (detecting faint signals), while selectivity is about 'how narrow' (separating crowded signals). Think of sensitivity as volume control and selectivity as tuning precision. This pattern appears throughout receiver specifications.
Learn more
In practical operation, selectivity becomes critical in contest environments or busy band conditions where strong adjacent signals can cause interference. Modern transceivers often include adjustable IF bandwidth controls and digital signal processing filters to enhance selectivity. Poor selectivity manifests as 'bleedover' from nearby stations, while poor sensitivity simply means you can't hear weak stations at all.
Think about it
Why do you think selectivity becomes more important during band contests or in urban areas with many active stations?