The Danville translator is on the air because it met all the requirements set by the Federal Communications Commission in order to be granted a license to operate by the FCC. This means it met all the rules and regulations including interference issues. In some instances, a frequency may allow a radio signal to be received beyond it's typical coverage area. More frequently, it is a person who enjoys listening to non-local signals (and frequently has invested in superior receivers to do so).
It is not the radio station that said I'm putting a station here, it was the FCC, the governing entity that said you meet all our requirements to put a station here. You might think of it this way, it's like moving in to a new neighborhood and you step out on the back porch for your morning coffee to enjoy the scene all the way to the next block because the lot behind you is vacant. One day you step out and they're putting up a house on that vacant lot. You can complain but the city or county said it was okay to build a house on that lot because all their requirements were met. And you were never guaranteed that view to the next block.
If you would like to see what I mean, you can go to radio locator (
Radio-Locator.com) or recnet (
REC Networks | a leading advocate for a diverse dial.) and check the 103.9 frequency in Danville and the location of the one you enjoy. I believe you will see the 60 dbu strength reception areas do not overlap. The 60 dbu is the red line. You can see the red lines are separated by quite a few miles. By the way, you can usually pick up a station with less than a 60 dbu signal in a vehicle, maybe down to 50 dbu. Even so, neither translator's 50 dbu signals would touch. The links are below.
Radio Station Search Engine
radio-locator.com
Radio Station Search Engine
radio-locator.com