What is the common method for determining the exact sensitivity specification of a receiver?

• A. Measure the recovered audio for 10 dB of quieting.
• B. Measure the recovered audio for 25 dB of quieting.
• C. Measure the recovered audio for 12 dB of SINAD
• D. Measure the recovered audio for 10 dB of SINAD

Answer: (C)

The measurement is based on how clearly you can hear a weak signal, not just whether it can be detected. Sensitivity is defined by the input signal level that gives a specific quality in the recovered audio, and that quality is quantified as SINAD—the ratio of the desired signal to the sum of noise and distortion in the output. Using 12 dB SINAD as the threshold provides a practical, widely accepted standard for intelligible reception. In testing, you feed a calibrated RF signal into the receiver, gradually reduce the input level, and determine the input level at which the recovered audio reaches 12 dB SINAD. That input level is the sensitivity specification. Other thresholds based on quieting or different SINAD values don’t align with this established standard for meaningful sensitivity.