If running legally - range won't extend much past your backward! Legally, without a license, you're only allowed to produce a field strength of 250 uV/m at 3 meters - it takes about 8 to 10 mW (milliWatts) of TPO (transmitter power output) into a 0 dBi antenna (like a 1/4 wave groundplane) to get in the ballpark of 250 uV/m at 3 meters ...
LPFM (Low Power FM) is another thing entirely; currently limited to non-commercial community groups, churches and the like ...
Excerpt:
Myths and Our Rebuttal:Few LPFM stations are on the air and LPFM will remain rare - First, the statistics quoted are out of date. As of today more than 600 construction permits has been issued and 150+ LPFM stations are on the air. By the end of this year, we predict nearly one thousand CPs - this is the amount predicted by former FCC Chairman Bill Kennard.
Excerpt:
1. WHAT IS LOW POWER RADIO (LPFM) SERVICE? Low power FM radio (LPFM) refers to the over one thousand 10 watt or 100 watt stations the FCC expects to license in the coming year and a half.The 10 watt stations will reach a 1-2 mile radius, and the 100 watt stations should reach a radius of at least 3.5 miles.
By comparison, full power FM stations usually have between 6,000 to 100,000 watts of power, and broadcast over an 18-60 mile radius. LPFM stations would be located throughout the FM band. Initially, they will be licensed only to local, community-based and nonprofit entities.