Free for the amateur community

Ham radio tools

Practical calculators and references, built by a broadcast engineer. They work on your phone, have no ads or logins, and cite where every number comes from.

Station & safety

RF exposure calculatorSafe distances for your household and neighbors under FCC §1.1310, plus the §1.1307 exemption check. Antenna lengthsDipole, vertical and radials, J-pole, end-fed half-wave and loop dimensions for any frequency. Feedline loss & SWRCoax loss from manufacturer data, extra loss from SWR, and return-loss conversions. Antenna pattern over groundHow height and ground shape your elevation pattern and takeoff angle, with ITU-R ground types. Tower height & FAA noticeDoes your tower need FAA notice? 14 CFR 77.9 screen against every nearby airport and heliport. Need a tool that isn't here?Tell me what would help at your station. Good ideas get built and added here, free like the rest.

Operating

US band planCan I transmit here? Privileges, modes and power by license class, cited to Part 97. Band conditionsLive solar flux, K and A index, flares and NOAA scales, explained for hams. Grid square & beam headingYour Maidenhead locator, plus distance and short- and long-path headings, with a map. Best band right nowLive MUF estimate from ionosondes to any target, and which bands it leaves under the MUF. Greyline & beam mapLive day/night map, your sunrise and greyline times, and a great-circle map centred on you. Where am I heard?Who copied your signal, from PSKReporter and WSPR spots, on a map. Satellite passesUpcoming amateur satellite and ISS passes over you, with sky plot and Doppler. VHF/UHF path profileTerrain, line of sight and Fresnel clearance between two stations (US).

Call signs

Callsign lookupLicense class, grid and expiration for any US call, from FCC data. Is this call sign available?Who holds it, when an expired or canceled call frees up, which classes may request it, and pending vanity requests.

License paperwork

Renew your licenseWhen you can file, the $35 fee, paying in CORES, the 2-year grace period, and your own renewal dates. Change your FCC addressUpdate your mailing address or email in ULS. Free, and required by Part 97.

License alerts

FCC license alerts by emailAn email the day the FCC acts on your license: new call, vanity call, upgrade or renewal. Plus reminders before it expires. Daily FCC amateur actionsEvery day's new licenses, vanity calls, upgrades and renewals from the FCC's license database.

Learning

Morse, Q-codes & phoneticsTranslator with audio, a Koch trainer with Farnsworth timing, and quick references. Schumann resonanceThe Earth's 7.8 Hz lightning-driven resonances: live spectrogram, measured modes, and the real science.

Accuracy

The regulatory tools are built from the current eCFR text, and the engineering tools from FCC bulletins and manufacturer datasheets. Each page cites its sources. They're references, not legal advice.

Found something wrong, or have an idea for a tool? Send me a message.