> > > What are the three colored lines supposed to represent
> in
> > > terms of a dbu contour? Is the innermost line 60?
> > >
> > In their FAQ, they say:
> >
> > 3. What criteria do you use to define the "local",
> "distant"
> > and "fringe" coverage areas?
> >
> > The "local", "distant" and "fringe" lines on the FM maps
> > correspond to the predicted 60, 50, and 40 dBu field
> > strength contours respectively.
> >
> > The "local", "distant" and "fringe" lines on the AM maps
> > corresponds to the predicted 2.5, 0.5, and 0.15 mV/m
> > contours respectively (of the horizontal groundwave
> > propogation only).
> >
> HOWEVER for FCC purposes, LOCAL or CITY Grade is 70dbu for
> FM and 5mV for AM which they DONT show...DISTANT is what
> RadioLocator calls Local....
> The FCC web site does show 70dbu for FMs...it does not show
> coverage for AMs (yet)
>
Not all FM stations run at 70dbu. According to the FCC site, they have WRZA (as an example running at 74dbu) with output power @ 50kw. Now WHFB is also a 50kw station, but the dbu is only 54. As for the FCC site and primary coverage, I think some maps are also including secondary coverage because where I live at in Gary, IN, WRZA gets lots of interference because it's a pre-1964 short-spaced station with WHFB Benton Harbor, and radio-locator.com shows my area as on the edge of primary & secondary contours. I think the radio-locator map is correct on that one (WRZA) since it's terrible to listen to in much of Gary Indiana. It's hard to really believe some sites on service contours, whether it would be radio-locator.com, or the FCC.
