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Land mobile curves
Distance and field strength for land mobile frequencies on the FCC curves.
Going from curves to a complete study
A curve yields the same distance on every bearing. RF Navigator calculates coverage over actual terrain, one radial at a time, and produces the maps. Or have Nexus Broadcast take on the engineering.
About these curves
- Results are the FCC's own curve calculation (geo.fcc.gov). For 150-174 MHz it applies the TV channel 7-13 curves of §73.699, and for 450-470 MHz it uses that section's TV channel 14-69 (UHF) curves. Those same charts underlie Tables 1 and 2 of 47 CFR §90.205.
- By default the field strength is set to the §90.205 service contour: 37 dBu at 150-174 MHz and 39 dBu at 450-470 MHz. Edit it to calculate a different contour.
- F(50,50) is the field strength exceeded 50% of the time at 50% of locations; F(50,10), exceeded 10% of the time, applies to interference. Every curve assumes 1 kW ERP, and each tenfold rise in ERP adds 10 dB of field strength.
- The curves cover 30 to 1,600 m HAAT: anything lower is treated as 30 m and anything higher as 1,600 m. Unsure what your HAAT is? Try our HAAT calculator.
- Planning a Part 90 application? Height and power caps by service area are listed in the §90.205 tables, and they permit less than the reach these curves show.
Intended for planning. Not an FCC product; confirm with the FCC's tools and an engineer prior to filing.