I have received a lot of questions about the contours shown on the Radio-Locator maps. For AM they are:
- Red – 3.0 mV/m – Generally the Sellable area of the station
- Purple – 0.5 mV/m – Rural protected service area, but nobody would buy ads.
- Blue – 0.1 mV/m – You might still get it on a car radio
For FM they are:
- Red – 60 db/uV or 1.0 mV/m – Protected service area for Class A and C stations
- Purple – 50 db/uv or 0.316 mV/m – A pretty weak Signal, nobody would buy ads.
- Blue – 40 db/uv or 0.1 mV/m – You won’t pick it up, except in rural areas
I determined this by comparing the plots of sample stations in Radiosoft’s Comstudy with their Radio-Locator maps. Hopefully this clears a few things up!