QTH locator calculator
Maidenhead QTH locator calculator — convert coordinates to a locator and back, up to 10 characters, with the cell’s centre, bounds and eight neighbouring squares.
Great-circle bearing and distance calculator
Bearing and distance calculator — great-circle distance between two Maidenhead locators or coordinates, short and long path, forward and reverse bearing.
Radio link budget calculator
Radio link budget calculator — EIRP, free-space path loss, received level and margin above receiver sensitivity: will the link work over your path?
Urban path loss calculator: Hata and COST-231
Okumura–Hata and COST-231 path loss calculator — urban, suburban and open terrain, with a check that your inputs are within the model’s range of validity.
Two-ray model and breakpoint calculator
Two-ray ground reflection model calculator — breakpoint distance, path loss beyond it, the path difference between the rays and a loss-versus-distance table.
MUF and hop length calculator
MUF calculator — maximum usable frequency from foF2, the secant factor, the working frequency, the number of hops and the longest single hop.
Satellite link parameters calculator
Satellite calculator — orbital velocity and period, slant range, footprint radius and Doppler shift across the amateur bands.
Sunrise, sunset and grey line calculator
Sunrise and sunset calculator for a Maidenhead locator or coordinates — UTC and local times, grey-line windows, solar declination and the equation of time.
Fresnel zone calculator
The Fresnel zone is the ellipsoid around a line-of-sight path that has to stay clear of obstacles. Work out its radius for your frequency and distance: Wi-Fi, LTE, VHF.
Line-of-sight range calculator
Radio horizon calculator — line-of-sight range between two antennas from their heights, with atmospheric refraction. How high your mast needs to be.
Point-to-point radio link calculator
Point-to-point Wi-Fi link calculator — maximum range from transmit power, antenna gain and receiver sensitivity. Will your bridge reach?