QSO Central

QSO Central is the all-in-one companion for amateur radio operators and anyone studying for their license. No account, no sign-in, no ads, no tracking. The study and station tools work completely offline — perfect for the field, a contest site, or a basement shack with no signal. A set of optional Live Data features add real-time information when you're connected. LICENSE EXAM PREP (offline) • Full official NCVEC question pools: Technician, General, and Amateur Extra • Flashcards, browsable/searchable questions, and a realistic timed practice exam with instant grading • Missed-question review and per-subelement progress, saved on your device • Diagrams included for the questions that need them STATION TOOLKIT (offline) • U.S. Band Plan — slide across any band to see mode, common use, and exactly what your license class may transmit, color-coded by privilege • Antenna calculators — dipole, vertical, wavelength, plus SWR, coax loss, feedline impedance, and balun • Electrical calculators — Ohm's Law (voltage/current/resistance/power) and battery runtime & capacity • Grid Square tools — your Maidenhead grid from GPS, plus distance and bearing between grids on a map • Morse Code trainer — characters, random groups, callsign practice, and head-copy with adjustable speed and Farnsworth timing • Logbook — log your contacts and export standard ADIF and CSV files • Contest clock — a live UTC clock over a reference of major recurring contests • Emergency Comms — ICS forms reference, your own frequency plans, local repeaters, and contacts REFERENCE LIBRARY (offline) • The full text of 47 CFR Part 97 (the FCC amateur rules), plus plain-language summaries of common topics — Q-codes, phonetics, repeaters, operating procedures, and more • Everything searchable, everything offline LIVE DATA (optional, needs internet) • Callsign Lookup — U.S. lookups via the FCC database, no account required; optionally add your own QRZ.com or HamQTH account for worldwide results • Propagation — current solar indices and day/night band conditions • Repeater Directory — find and sort nearby repeaters with offset, tone, mode, and a map • On the Air — a live feed of current POTA (Parks on the Air). Each Live Data screen credits its public source and caches its last result so you can still see it offline. PRIVACY BY DESIGN QSO Central runs no servers and has no accounts, ads, trackers, or analytics. Your data stays on your device. Your location is used only on your device — to show your grid and sort nearby repeaters — and is never transmitted; you can skip it and type your grid by hand. The Live Data features send only what's needed to answer your request (for example, the callsign you look up) directly to the public service that provides it. Set your license class and home grid once in Settings, and the whole app tailors itself to you.