Welcome to QUISK

May 2010

NOTE: Quisk now requires that PortAudio be installed on your computer. You probably have PortAudio, but you also need the development files in package portaudio19-dev (or newer). PortAudio enables you to use other audio devices, and to link Quisk to other software.

This is QUISK, a Software Defined Radio (SDR). QUISK is the software that controls my receiver and transmitter. QUISK rhymes with "brisk", and is QSK plus a few letters to make it easier to pronounce. QSK is a Q signal meaning full breakin CW, and QUISK has been designed for low latency CW operation. It works fine for SSB and AM too. QUISK is written in Python and C, and all source is included so you can change it yourself.

It currently runs only under Linux using ALSA sound drivers or PortAudio and offers these capabilities:

As a receiver it can use the SDR-IQ by RfSpace as a sample source. There are several decimation rates available. The screen shots below were taken using the SDR-IQ. The QUISK receiver will read the sample data, tune it, filter it, demodulate it, and send the audio to the sound card for output to external headphones or speakers.
As a receiver it can use your soundcard as a sample source. You supply a complex (I/Q) mixer to convert radio spectrum to a low IF, and send that IF to the left and right inputs of the sound card in your computer. The demodulated audio goes to the same soundcard for output.
As a transmitter it can control my SSB/CW exciter and my transceiver using Ethernet.
As a transmitter it can accept microphone input and send that to your transmitter for SSB operation. For CW, QUISK can mute the audio and substitute a side tone. Quisk can send transmit data to your sound card for use with SoftRock or similar. If you are not using SoftRock hardware and not using Ethernet, then you can modify the C code in microphone.c to connect to your hardware.

If you have the SDR-IQ or the Softrock-40 hardware, then QUISK is ready for you to use as a receiver. If you have other receive hardware, then you will need to change the file quisk_hardware.py to connect your receiver to QUISK. For example, if you change your VFO frequency with a serial port, then you need to change quisk_hardware.py to send characters to the serial port. The file quisk_hardware.py is written in the Python programming language, a very easy language to learn and use.

I have tried to make QUISK easy to modify so it can be used for hardware other than my own. See the packages by Leigh L. Klotz, Jr. WA5ZNU on http://pypi.python.org.

To install QUISK, download it from http://pypi.python.org (search for quisk). Then read the README file and the help.html file for further instructions. Quisk can be installed with distutils, easy_install, or you can just use the tarball. The list of recent changes is in CHANGELOG.txt.

Here are some screen shots of QUISK. The usual graph and waterfall display are available. I dislike radios that look like computer programs so I designed QUISK without menus and with lots of buttons (a personality quirk of mine I guess). Hopefully QUISK looks like a radio and it is obvious how to use it. The red/yellow/blue bars at the bottom of the graph are the band plan. They mark the CW/SSB parts of the band, and show the ARRL additions. The yellow is the data part of the CW segment. The band plan and colors are in the configuration file quisk_conf.py so you can change it.

Here are some screen shots of QUISK:

Scrrenshot of graph display

Screenshot of waterfall display

Screenshot of configuration display