E4C12 - Amateur Extra Class

E4C12 : How does a narrow-band roofing filter affect receiver performance?
A It improves sensitivity by reducing front-end noise
B It improves intelligibility by using low Q circuitry to reduce ringing
C It improves blocking dynamic range by attenuating strong signals near the receive frequency
D All these choices are correct
Correct Answer: It improves blocking dynamic range by attenuating strong signals near the receive frequency