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Propagation curves
Distance to any contour, field strength at any distance, or the ERP to reach a contour, on the FCC curves.
You can also enter the details by hand below.
Going from curves to a complete study
A single contour is only the beginning. RF Navigator plots each contour over actual terrain, one radial at a time, tests spacing and interference against all stations in the FCC database, and produces the exhibits. Or have Nexus Broadcast take on the engineering.
About these curves
- Results are the FCC's own curve calculation (geo.fcc.gov), based on the FM charts in §73.333 and the TV charts in §73.699 covering UHF, high VHF (7-13) and low VHF (2-6) channels.
- F(50,50) is the field strength exceeded 50% of the time at 50% of locations, and defines FM service contours. F(50,10), exceeded 10% of the time, defines interfering contours. The TV service curve is F(50,90) = F(50,50) - [F(50,10) - F(50,50)] (§73.619(b)(1)).
- Every curve assumes 1 kW ERP. Each tenfold rise in ERP adds 10 dB of field strength, and that relationship produces the ERP result, which is then verified against the FCC calculation.
- HAAT means antenna height above average terrain toward the direction of interest. The curves cover 30 to 1,600 m: anything lower is treated as 30 m and anything higher as 1,600 m. Unsure what your HAAT is? Try our HAAT calculator.
Intended for planning. Not an FCC product; confirm with the FCC's tools and an engineer prior to filing.