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Land mobile propagation curves calculator
Two-way radio on 150-174 MHz and 450-470 MHz: how far your service contour reaches, how strong the signal is at a distance, or how much power you need to cover the area you want.
From curves to a full study
A curve gives one distance in every direction. RF Navigator works coverage on real terrain, radial by radial, and builds the maps. Or let Nexus Broadcast do the engineering for you.
About the curves
- Numbers come straight from the FCC's own curves calculation (geo.fcc.gov). 150-174 MHz uses the TV channel 7-13 curves and 450-470 MHz the TV channel 14-69 (UHF) curves of §73.699, the same charts 47 CFR §90.205 Tables 1 and 2 are based on.
- The field strength starts at the service contour §90.205 uses: 37 dBu for 150-174 MHz and 39 dBu for 450-470 MHz. Change it to work any other contour.
- F(50,50) is the field exceeded at 50% of locations 50% of the time; F(50,10) is exceeded 10% of the time, for interference. The curves are drawn for 1 kW ERP: field strength rises 10 dB for every tenfold increase in ERP.
- The curves run from 30 to 1,600 m HAAT: lower heights use 30 m and higher heights 1,600 m. Not sure of your HAAT? Use our HAAT calculator.
- Applying for a Part 90 station? The power and height limits for your service area are in the tables of §90.205, which allow less than these curves reach.
For planning. Not a product of the FCC; check the FCC's own tools and an engineer before you file.