This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== WSPR ====== **WSPR**, pronounced “whisper”, stands for **Weak Signal Propagation Reporter**. It is a digital beacon protocol associated with Joe Taylor, K1JT, and the WSJT project. Stations transmit brief identification and location information so reception reports can reveal radio propagation paths. ===== Standard message ===== A conventional Type 1 message contains a callsign, a four-character Maidenhead locator and a transmitter power level in [[decibel|dBm]]. These fields are packed into 50 information bits. Other message formats support cases that do not fit this basic layout. For example, a power field of 30 dBm means 1 W. The stated transmitter power is not a measurement of antenna gain or radiated power in a particular direction. ===== WSPR-2 waveform ===== The widely used two-minute form uses four-frequency shift keying, error correction and a known synchronisation pattern. It sends 162 symbols with tone spacing and symbol rate of approximately 1.4648 Hz and 1.4648 baud respectively. <code> Symbol duration = 8192 / 12000 ≈ 0.6827 s Transmission time = 162 × 8192 / 12000 ≈ 110.6 s </code> The occupied bandwidth is about 6 Hz. Transmissions are arranged in two-minute UTC slots; accurate timing and frequency stability help receivers find and decode them. WSPR is a beacon/reporting system, not a normal two-way conversational QSO mode. ===== Interpreting reports ===== Reports may contain received SNR, frequency and drift. Reception depends on the transmitting and receiving antennas, noise, propagation and whether a receiver was listening at that time. A missing report alone does not prove that a band was closed or that an antenna failed. A fair antenna comparison keeps power, schedule and receiving conditions as consistent as possible and uses many observations. Uploaded reports can be viewed through WSPRnet and related tools; receiving a signal does not require every transmitter to have an Internet connection. ===== References ===== * [[https://www.arrl.org/wspr|ARRL: WSPR protocol and message structure]]. * [[https://wsjt.sourceforge.io/wsjtx.html|WSJT-X project and WSPR documentation]]. * [[https://www.wsprnet.org/|WSPRnet reception database]].
