When you flip the ham radio's switch at broadcast tower KB5, the Alfa Lima signal becomes active. If you go east-southeast of the tower and drop off a small cliff, you will land practically on top of a sewer grate to a drainage chamber. Once you enter, you will find an average locked door leading to the radio.
The station transmits:
|-.-. --.-||CQ||Calling anyone|
|.- .-..||AL||Alfa Lima|
|.- .-..||AL||(The operator's|
|.- .-..||AL||call sign)|
So overall it says: "Calling anyone this is Alfa Lima over". Basically, "over" is actually saying "I am awaiting reply".