AMRT — Ham Radio Toolkit

The field-ready toolkit for amateur radio operators. Build antennas, tune feedlines, and look up the references you need — fast, accurate, and fully offline. AMRT puts the math you actually use in the shack and in the field into one clean, dark-mode app. Every calculator shows its formula and assumptions, so you always know exactly what it computed and why. ANTENNA & FEEDLINE CALCULATORS • Dipole, inverted-V, vertical, and end-fed half-wave lengths • Yagi, cubical quad, J-pole, and magnetic loop designs • Wavelength ↔ frequency, with quarter- and half-wave taps • VSWR, return loss, mismatch loss, and reflection coefficient • Coax velocity factor, electrical length, and loss • Resistor color codes and series/parallel networks • Maidenhead grid square from coordinates or GPS PRACTICAL BUILDER FEATURES • Results in meters, feet-and-inches, or fractional inches (to 1/8, 1/16, 1/32) • Save any calculation and reopen it later — values restored exactly • Pin your favorite tools and jump back to recent ones from Home • Home screen widget for your callsign, grid square, and UTC clock QUICK REFERENCES, ALWAYS OFFLINE • Q codes, the NATO phonetic alphabet, and Morse code • Band plans and coax cable specifications BUILT FOR THE FIELD • Works with no signal — calculators, references, saved work, and projects are all offline • Permanently dark, easy on the eyes at the operating position • Accessibility: adjustable text size, high-contrast mode, and VoiceOver support A one-time PRO unlock opens the full tool library. No subscriptions, no ads in the calculators, and Restore Purchase is always available. 73 and good DX!