# What is QRSS?

QRSS is a type of continuous wave (CW) radio signal which uses frequency-shift keying (FSK). QRSS is ultra-narrowband (5Hz bandwidth) and ultra slow speed (about 3 letters per minute). The abbreviation QRSS is [Morse code slang](https://en.wikipedia.org/wiki/Q_code) for "transmit a lot slower".

### Introduction to QRSS
  * [What is QRSS?](https://www.qsl.net/m0ayf/What-is-QRSS.html) by m0ayf
  * [QRSS and you](http://www.ka7oei.com/qrss1.html) by ka7oei
  * [QRSS (slow CW)](https://sites.google.com/site/qrssinfo/QRSS-Slow-CW) by AA6DY

### Technical Pages
  * [Simulation of QRSS Signals](https://www.qsl.net/pa2ohh/12qrsssim1.htm) by pa2ohh

### Other QRSS Software

* Argo ([website](http://digilander.libero.it/i2phd/argo/)) - closed-source QRSS viewer for Windows
* SpectrumLab ([website](http://www.qsl.net/dl4yhf/spectra1.html)) - closed-source spectrum analyzer for Windows 
* QrssPIG ([gitlab](https://gitlab.com/hb9fxx/qrsspig)) - open-source spectrograph for Raspberry Pi (C++)
* Lopora ([website](http://www.qsl.net/pa2ohh/11lop.htm)) - open-source spectrograph (Python 3) 
* QRSS VD ([github](https://github.com/swharden/QRSS-VD)) - open source spectrograph (Python 2)

### QRSS Hardware
This repository is exclusively devoted to software. I run a separate repository dedicated to theory, design, construction, and testing of QRSS transmission and reception hardware: https://github.com/swharden/QRSS-hardware