§73.807 and §73.825 of the FCC Rules specifies the minimum distance separation requirements between LPFM stations and other broadcast facilities.
The "vacant channels" search at Radio Locator is intended for people wishing to use small consumer grade FM transmitting devices such as those that plug into the lighter port of an automobile in order to place audio from a cell phone on an FM radio, pursuant to Part 15 of the FCC Rules. The Radio Locator "vacant channels" search does not take into consideration any of the FCC Rules for LPFM.
Therefore, you should never depend on Radio Locator in order to determine potentially available channels for LPFM applications.
LPFM enhancements and change applications
LPFM station planning and construction
LPFM during the filing window
