Received are:

1) The common calling and distress maritime VHF frequency: 156.8 MHz (channel 16).
2) The frequency used by the US Coast Guard to broadcast safety related messages to all vessels: 157.1 MHz (channel 22a).
3) The aviation distress frequencies: 121.5 and 243.0 MHz. 121.5 MHz, commonly monitored by aircraft in flight and referred to by pilots as "guard", is also used for low power homing beacon transmissions by EPIRBs and ELT distress beacons, and occasional use for general calling by pilots. Brief voice tests of the "guard" frequencyies are usually received around 10 AM daily.
4) Coast Guard interagency liaison: 157.050 MHz (channel 21a). This channel is frequently used for interagency coordination of rescue activities.

The receiver is located on a sailboat in Pillar Point Harbor. The antenna is mounted at the masthead 40 feet above terrain. Maximum surface VHF reception range is normally 20 miles to the north, west, and south and covers the fishing grounds off Pillar Point Harbor, west to seaward, the southern traffic lane approaches to the San Francisco Harbor, and aircraft at altitude. Most San Francisco Bay radio traffic is blocked by intervening terrain. The location is well suited for receiving offshore transmissions because radio traffic on the same frequencies and general interference from the San Francisco Bay area are blocked by the Santa Cruz Mountains.

RF interference occasionally occurs from defective FM continuous wave radars. Since the sources of this interference are in motion, the interefernce usually abates in several minutes.The interference sounds like static that is pulsing several times per second. The affected channel is random and the interference blocks channel scanning while it is present.

The receiver and associated computer are provided with 96 hours of battery backup power and Internet connectivity via a Starlink station. It should continue to remain on line during a power outtage or collaspe of local internet service providers. 

Feed courtesy of Amateur Radio Station N8QH. Comments and questions should be sent to wdf2783@gmail.com.