47 CFR §80.874

1. (a)The receiver used for providing the watch for navaigational safety required by § 80.313 must be certificated by the Commission and capable of effective reception of G3E emission on the frequencies required by § 80.871(d) when connected to the antenna specified in § 80.876.
2. (b)The receiver must have a usable sensitivity of 0.5 microvolts.
3. (c)The receiver must deliver adequate audio output power to be heard in the ambient noise level likely to be expected on board ships with a loudspeaker and/or a telephone handset.
4. (d)In the simplex mode when the transmitter is activated the receiver output must be muted.