What is the purpose of the notch filter found on many HF transceivers?
To restrict the transmitter voice bandwidth
To reduce interference from carriers in the receiver passband✓Correct answer
To eliminate receiver interference from impulse noise sources
To remove interfering splatter generated by signals on adjacent frequencies
Explanation
A notch filter is a very narrow band-reject response placed in the IF or audio chain, tuned onto the beat note produced by an unwanted carrier so that the carrier is nulled while the wanted signal continues through. Splatter is a wide, spread-out spectrum, so a narrow notch cannot remove it.