Maidenhead grid squares, path loss, link budgets, Fresnel zones, antenna length, SWR, dBm conversion, Morse and phonetic spelling.
payments ON MAINNET (real money) · 9 live endpoints
| Endpoint | Price | What it answers |
|---|---|---|
GET /dbm-convert | $0.02 | Convert power between dBm, dBW, mW and W, and the RMS and peak voltage across 50 ohms (or your impedance). |
GET /dipole-length | $0.02 | Wavelength and half-wave dipole, quarter-wave vertical and full-wave loop lengths for a frequency, with velocity factor. |
GET /fresnel-zone | $0.02 | Fresnel zone radius for a radio path from distance and frequency, with the 60% clearance needed for a clear link. |
GET /fspl | $0.02 | Free-space path loss in dB from distance and frequency, plus wavelength; or the range that produces a given loss. |
GET /link-budget | $0.02 | Link budget: received power, fade margin and maximum free-space range from TX power, antenna gains, losses and sensitivity. |
GET /maidenhead | $0.02 | Convert latitude/longitude to a Maidenhead grid locator (4, 6 or 8 characters) or a locator to its centre and bounds. |
GET /morse | $0.02 | Encode text to International Morse or decode dots and dashes, with duration at your words-per-minute (PARIS standard). |
GET /phonetic-spell | $0.02 | Spell a callsign, code or name with the ICAO/NATO phonetic alphabet, digits included, flagging unspellable symbols. |
GET /swr | $0.02 | SWR, reflection coefficient, return loss, mismatch loss and reflected power from SWR, a resistive load, or two power readings. |
GET /catalog returns this list as JSON. Activity hub · uptime.
Radio-frequency arithmetic computed locally from the numbers given, using standard textbook formulas, provided as is. Free-space path loss ignores terrain, buildings, weather and antenna patterns, so real links differ. Not engineering certification, and not legal advice about transmitter power, licensing or band use in your country. Every paid response carries a disclaimer field.