CWStudio is fast, computationally efficient and portable generator of various CW signals for telegraphy training purposes. Besides efficiency and portability, it is designed to simulate as much as possible a real air listening.
It can generate signals of various complexity, from one sine signal without any noise, to AGC-like complex air signal mix with possible hum, chirp, detuning, hand irregularities and so on. It can also generate stereo and multichannel (surround) sound with surround panning.
The project was started in 2008 and after reaching any usability it was registered in April 2010 on SourceForge. From a simple command line tool, it has become a fully functional application with many features.
|Written in ANSI, pedantic C and C++. CLI is library independent, the other binaries depend only on ncurses or wxWidgets. Designed to be small and portable. Compiles and runs under DOS, Windows, Linux, FreeBSD, OpenBSD, NetBSD, Solaris and OpenSolaris.|
|One executable and portable file (with optional lame_enc.dll). No installer, simply download and run.|
|Optimized sound routines provide quick sound generation on slower machines. Well-considered memory management allows to use on vintage hardware.|
|Many parameters and switches. Simulation of a real AGC-like noise, QSB, chirp, hum, detuning, clicking etc.|
|Stereo sound support with phase setting, panning and panning drift. Dots and dahs can be panned separately!|
|Built-in database of real callsigns and most often used English words (inside executable!).|
|Both text and graphical user interfaces. Curses-compatible library is enough to compile and run. For GUI you need wxWidgets 2.8 or above.|
|Direct MP3 export through any external encoder compatible with lame_enc.dll.|
|The command line interface allows you to generate training texts in batch mode and pipe them to any external software (lame, ffmpeg etc.).|
|Used by increasing number of CW fans all over the world (currently more than 500 downloads per month).|
|Free as in freedom and free as in beer. Open source, GPL3.|
Retro TUI (text user interface) version. For description of parameters, see CWCLI manual.
|F2 (2)||save to WAV file|
|F3 (3)||reset parameters|
|F4 (4)||regenerate random|
|F5 (5), ENTER||play|
|F8 (8)||noise mode|
|F12 (=)||mode (chars/words/callsigns)|
|Ctrl-Ins / Ctrl-Del||paste and copy|
|L||load text file|
|LEFT/RIGHT (,/.)||char spaces|
|Shift-LEFT/RIGHT (>)||word spaces|
|Shift-HOME (:)||dash length|
|Shift-END (')||space length|
|M||MP3 export |
|`||DOS device change |
|(/) (Shift - 9/0)||Number of channels |
|%^ (Shift - 5/6)||Pandrift |
|#$ (Shift - 3/4)||Panning |
GUI version, made with wxWidgets. Editable text. For description of parameters, see CWCLI manual.
Currently, all sound functions are organized into internal libcwgen library, which is
compiled and then linked with the main program. Its use is very simple,
morsetext = cw_encode("VVV = CQ DE
CWSTUDIO PSE K");
They are all containing text "VVV
= CQ CQ DE CWSTUDIO PSE K"
(Concise CW Course made with CWStudio)
I have published a small Polish book about CW learning in 2011,
making a complete course (182 audio files in FLAC format) with
CWStudio. These files come in 10 parts (can be burn as 10 audio
CDs). Recordings are named number-letter-number, for example 04B3
is third recording from second (B) lesson on fourth CD. Below is
short description to make this course usable for English-speaking
- First three CDs are for letters learning - 600Hz, 3%
harmonics, 10% noise 300 - 2400 Hz. Tempo 20 wpm with additional
spaces. First file with 14 spaces (37 cpm resulting tempo), next
9(48), 6(58), 4(68) i 2(81) respectively. 13 lessons have
subsequently added new characters. Last lessons focus on similar
- CD 04 is analogous for learning of digits.
- CD 05 is for training mixed reception. Lesson A - digits with
larger and larger amounts of added letters. Lesson B is reverse
- adding more and more digits to letters. Parameters similar to
- CD06 - texts without additional spaces, with increasing tempo
100, 110, 120, 130, 140, 150, 180 i 200 (8 texts for each
lesson). Lesson A is with letters only, B - digits and special
characters, C - mixed texts.
- CD07 - training difficult signals. Three mixed signals: 600,
200 and 1000 Hz, tempo 1, 4/3 and 2/3 of original, respectively.
Different additional difficulties: click, hum, bug key, straight
key, sweep etc. Each signal transmits the same text in loop.
- CD08 - real callsigns from contest databases. Five mixed
signals: 1, 0.333, 1.666, 0.5, 1.5 of base frequency, 1, 1.333,
0.666, 1.25, 0.8 of base tempo, 1, 0.2, 0.2, 0.5, 0.5 base
amplitude. True pileup feeling. Last recording is very narrow
and all signals are very close to each other.
- CD09 and CD10 - training most common English words, to
recognize them as whole pattern, not focusing on letters. Words
without spaces, 35 additional dots between words. Tempo: 100,
110, 120, 130, 140, 150, 180 i 200 cpm.
Since January 2015 the complete course in video version is
available as Youtube Channel (reuploaded in December 2016 due to some problems).
All recordings are available under CC-BY-NC-ND license
(different than CWStudio software itself!)
When downloading any MP3 external encoder, be sure to download 32-bit or 64-bit DLL according to your binary.
Current release: 0.9.6 (2017-12-22, Winter Solstice Release).
- Stereo and multichannel (up to 7ch) support!
- Multichannel WAV export
- Multichannel Playback on supported systems
- Stereo and surround panning with out-of-phase possibility
- Several small memory management bugs fixed
- Two Windows versions, the "legacy" one is better for old systems
- Cygwin version fixes
- Unified configuration file format, stored in home directory (or user directory in Windows)
- Watcom compiler supported
Current release: 0.9.5 (2017-01-01, New Year Release).
- Small bug in 8-bit wav saving fixed
- Endless playing bug under OSS fixed
- SNDIO and AUDIOIO drivers implemented (BSD and Solaris)
- Retro fun! DOS Sound added (SB16, PC Speaker, Covox)
- Icons in better resolution, including SVG
- Clipboard support in Windows version of cwcurses
- Cwcurses contains buttons clickable by mouse
- Cwcurses allows to load text from file and enter it manually
- Small fixes for wxWidgets 3.0 compatibility
Previous release: 0.9.4
(2015-02-14, Valentine's Day Release).
- Added MP3 Support (via external encoder compatible with
lame_enc.dll). Be sure to download 32-bit
dll release according to your binaries, otherwise it will not
- Sound generation only if needed
- Compiles on systems without getopt_long_only()
If you are looking for
abandoned QedKey, the CWStudio predecessor written in Delphi,
the open-source version under MIT License can be downloaded here.
cwcli [--play] [--noplay] [--silent] [--verbose] [--groups]
[--words] [--calls] [--agc 0-100] [--bits bits] [--click 0-100]
[--chars nchars] [--charset charset] [--cspaces 0-100] [--dashlen
100-10000] [--detune 0-100] [--even 0-100] [--freq 50-4000]
[--number 1-100] [--hand 0-100] [--highcut 300-10000] [--hum 0-100]
[--lowcut 50-1000] [--noise 0-100] [--odd 0-100] [--output outfile]
[--qsb 0-100] [--samplerate samplerate] [--seed 1-32767] [--shape
-10 - 10] [--signals 1-5] [--spacelen 20-300] [--sweep -4000 - 4000]
[--sweepness 0 - 10000] [--tempo 5-500] [--window 0-1000] [--wordset
0-1000] [--wspaces 0-100]
Generates 1-5 mixed CW signals of various properties, adds optional
noise and saves it to a WAV file. If compiled on proper environment,
it can play the result. Command line parameters are also interpreted
in interactive mode!.
All text output is written to stderr; if stdout is redirected,
the created file is written here. If stdin is redirected, the
generated text is taken from it.
Optional CWPARAM environment variable can be set to hold some
parameters, for example CWPARAM="--even 10 --odd 10".
- --play --noplay
- Play the result (default), otherwise only save the WAV file.
- --silent --verbose
- Verbose mode gives full output (default), silent mode
presents only generated text.
- --groups --words --calls
- The "groups" mode generates random five-letter groups. The
"words" mode generates most common English words. The "calls"
mode generates real amateur callsigns.
- --agc 0-100
- Simulate AGC response of receiver by varying noise volume
along RMS of the signal. Default is 100.
- --bits bits
- Set bitrate. Default is 16.
- --click 0-100
- Simulate click by lowering sustain part of tone at given
level (in dB) below attack phase. Default is 1 dB.
- --channels nchannels
- Generate stereo or multichannel sound. Default is 1 (mono), 7 is max
- --chars nchars
- Take first "nchars" from default charset in "groups" mode.
- --charset charset
- Set customized charset for random group generation in
- --cspaces 0-100
- Set additional spaces (one space has a length of a dot)
between chars. Default is 0.
- --dashlen 100-1000
- Length of dash, in percentage of dot. Default is 300% (3:1).
- --detune 0-100
- Simulate frequency drift of the signal. Default is 0.
- --even 0-100
- Enhance the signal by given percent of even harmonics.
Default is 0. Values 0-5 are most valuable in practice.
- --freq 50-4000
- Use given frequency in Hz..
- --number 1-100
- Generate given number of groups/words/calls. Default is 20.
- --hand 0-100
- Simulate hand transmitting by introduce random errors in
- --highcut 300-10000
- Set high cutoff frequency (Hz) of generated noise. Default is
- --hum 0-100
- Add given percentage of 50 Hz mains hum. Default is 0.
- --lowcut 50-1000
- Set low cutoff frequency (Hz) of generated noise. Default is
- --noise 0-100
- Add given percentage of noise. Default is 100.
- --odd odd
- Enhance the signal by given percent of odd harmonics. Default
is 0. Values 0-5 are most valuable in practice.
- --output outfile
- Store the result in a WAV file of given name. Default is
- Stereo and multichannel panning. Possible values are -720 to 720,
default is 0 (center). Values greater than +-180 give some interesting
behavior (out of phase, separate dits and dahs - please try! this needs
- Change pan after each dit/dah (this allows drift of signals in stereo
pan or between surround speakers.
- --qsb 0-100
- Add given amount of signal QSB. Default is 0.
- --samplerate samplerate
- Set given samplerate. Default is 44100.
- --seed 0-32767
- Set explicitly the seed of random generator. If not set or
set to 0, seed is also random generated. Otherwise it is set to
given value, resulting in a possibility of repetitive random
- --shape -50 - +50
- Set the shape of random generated numbers. Positive value
increases the fraction of higher numbers (last letters, words,
calls). Negative values prefer first ones. Zero means flat
uniform distribution. Can be used to increase the number of
newly learned letters/words. In practice, values -10 to 10 are
- --signals 1-5
- Generate given number of mixed signals, each of hardcoded
frequency ratio, tempo ratio and amplitude ratio. Every signal
plays the same text in a loop. Default is 3.
- --spacelen 20-300
- Space length (between dots and dashes) in percentage of dot.
Default is 100% (1:1).
- --sweep -4000 - 4000
- Simulate sweep (chirp or filter ringing according to
parameters) by starting each tone from given frequency (can be
negative, which results in zero crossing). Frequency is then
changed exponentially to this given in --freq with a rate given
by --sweepness. Default is 0.
- --sweepness 0-10000
- The rate of exponential frequency change from --sweep to
--freq. Default is 0 (no sweep).
- --tempo 5-500
- Tempo of generated main signal in cpm (chars per minute)
according to PARIS group.
- --window 0-1000
- Raised cosine window width (used to avoid clicks in each
tone). Default is 100 samples.
- --wordset 0-1000
- Take only first given number of most common English words in
- --wspaces 0-100
- Set additional spaces between words/groups/calls. Default is
CWStudio returns 0 if everything is OK. In the case of error, return
value is different.