Radio Tower 3SM-U81

Extending the satellite dishes in this antenna will allow you to hear the following signals:

Greenbriar Radio Signal

Head east of the radio tower and look for an abandoned camp site with a cooking station. Look for a bunker's entrance on the ground underneath some bushes behind a barrel and a crate. Inside the bunker, you'll find the ham radio where the signal is coming from. Turn it off and loot the containers there. There are also a good number of Aluminum cans here for the taking.

Nautical Radio Signal

This is coming from a beached boat NW of Breakheart Banks. Enter the boat cabin to find the ham radio and turn it off. There are no special loot inside.

Automated Radio Alarm

This is originating from the Mass Fusion Containment Shed's sub-level. You have to reach it and trigger the circuit breaker to stop the broadcast.