WSPR Code Generator
An online resource for generating encoded WSPR messages
WSPR (Weak Signal Propagation Reporter) is a protocol for weak-signal radio communication. Transmissions encode a station’s callsign, location (grid square), and transmitter power into a frequency-shift-keyed (FSK) signal that hops between 4 frequencies to send 162 tones in just under two minutes. Signals can be decoded with S/N as low as −34 dB! WSJT-X, the most commonly-used decoding software, reports decoded signals to wsprnet.org so propagation can be assessed all over the world.
WsprSharp is a WSPR encoding library implemented in C#. I created this library learn more about the WSPR protocol. I also made a web application (using Blazor WebAssembly) to make it easy to generate WSPR transmissions online: WSPR Code Generator
WSPR Transmission Information
- One packet is 110.6 sec continuous wave
- Frequency shifts between 4 tones
- Each tone keys for 0.683 sec
- Tones are separated by 1.4648 Hz
- Total bandwidth is about 6 Hz
- 50 bits of information are packaged into a 162 bit message with FEC
- Transmissions always begin 1 sec after even minutes (UTC)
Resources
- WSPR Code Generator - encode WSPR messages from your browser
- WsprSharp - a .NET library for encoding and decoding WSPR transmissions using C#
- FSKview - spectrogram for viewing frequency-shift keyed (FSK) signals in real time
- Anatomy of a WSPR transmission
- WSPR on Wikipedia
- K1JT Program
- Grid square lookup
- WSJT on SourceForge
- WSPR Mode in WSJT-X