plan9sinplace:

Communications with Big Mountain were often scarce. A place left truly to its own devices by the harsh desert, perhaps because it was more fearsome than even the Mojave, few dared enter. Those to wander in by mistake did not typically leave, and if they did, they did not do so with their organs…

Yes Man wasn’t sure where this signal was coming from, or what purpose it had, but he had decided to track it down. He had some down time in between the courier crashing in and leaving him to attend the city while they were out dragging themselves through the dirt and muck. He stumbled across the signal on accident, picking up it’s transmission to the pip-boy located on the courier, and finally he was making progress.

…and it seems he’s stumbled upon someones communication line. Boy, did he feel sheepish!

“Hi there!” Yes Man doesn’t let his mild embarrassment deter him or hinder the cheerfulness of his voice. “I’m sorry for harassing you out of the blue! Bit I found this mysterious broadcast, and I was curious where it was originating from!”