Radio stations can be accessed with the Pip-Boy 3000 in the Capital Wasteland. Other radio signals can be found that are related to quests. While the sounds of the radio resonate with the local environment, it does not affect the Sneak skill.
One is set up as part of the public-address system in the Super-Duper Mart. Raiders using the store as a base use the PA system to alert others in the building.
Morse code signals
The "Morse code signals" all can be decoded to decipher a message, and they must be turned on at the towers they are being broadcast from. These radio signals will become clearer the nearer one gets to the ham radio, not the tower that broadcasts the signal. Translated, they follow almost the same pattern without variation: CQ CQ CQ DE ## K. This translates as follows:
CQ - A general non-emergency call, indicating that the station is looking for a reply from any station that can hear it. CQ is a two-letter code that shortens, and is pronounced as, "seek-you."
DE - DE is Morse shorthand for "this is," and is followed by the station's ID or callsign repeated two or three times.
## - This is where the station's ID is broadcast. In the wasteland stations, these codes are always two letters long and correspond to the signal name as identified in the Pip-Boy radio list. Signal Alpha Lima uses ID code AL, while Signal Kilo Bravo uses ID code KB.
K - A terminal code. K is Morse shorthand for "over," meaning the transmitter will pause and wait for a reply from another station.
Only Galaxy News Radio and Enclave Radio can be accessed right away from coming out the vault. All other signals (like the signals obtained from various power stations all over the map) must be discovered or the appropriate quest completed.
Galaxy News Radio, Enclave Radio and Agatha's Station are broadcast across the entire Capital Wasteland; for all others, one must be in a certain range or the Pip-Boy 3000 won't pick them up. At the beginning of the game, Galaxy News Radio is only available in some regions around Washington D.C. One must complete the Galaxy News Radio quest for it to broadcast across the entire Capital Wasteland. Also, Agatha's Station radio signal is unable to be picked up until the quest Agatha's Song is completed.
During the quest Tranquility Lane, when entering a house, sometimes a message in the top-left corner will say, "(Radio station) signal found", but one is unable to look at or listen to this station because they can't access the Pip-Boy 3000 in the simulation.
If Raven Rock is destroyed, Enclave Radio will be lost. If Broken Steel is downloaded, the loss of the aforementioned radio station is unavoidable, as Raven Rock will be destroyed by the Brotherhood of Steel if the Lone Wanderer has not done so already.