Finally got around to following up on the Lost Patrol quest. Tuned the radio in on a signal and discovered that it originated right in Sanctuary Hill. Homed in until I got the signal stength up to 99.88% -- where there is NOTHING. But it also happens to be on the empty house foundation between the workbench house and the cooking campfire house where I do all my scrapping. Saw somewhere that someone theorized that if you scrap a distress beacon -- which I did, twice -- it does NOT kill the signal. Which henceforth emanates from the beacon's last location, that being on the house foundation where I scrap things.

Anyone else know anything more on this subject? I kept figuring that if I could get the signal up 100%, a trap door would open, or something of that sort.

Most likely you picked up some distress beacon and put it in your workshop. The lost patrol quest brings you nowhere near sanctuary hills.

Go back to where you started the quest, read in the quest log, listen to the holoraqes and follow the clues and signals. You have to go to various locations and track down several distress beacons and pick up several holotapes along the way.