CDW is here!
The first beta release available
by SW3ORA

The CDW mode of communication

CDW is a ham radio digital mode designed with a single puspose in mind: To work in difficult (low s/n ratios) conditions. This applies on HF bands as well as on VHF/UHF/SHF, including EME, where signals are exceptionally weak. It is a new digital mode/program utility that allows low data rate radio communication under minimum bandwidth. CDW works pretty much like CW and has the same propagation and bandwidth properties, but it includes the next additional features:

• Minimum bandwidth required (like CW; minimum bandwidth is relative to the speed of transsmission and other factors).

• Data transmission (unlike CW that is used only for text).

• Data encryption.

• Data compression.

• Data loss detection and error discarding. (beta)

• Error correction by retransmission. (to be developed)

CDW is currently under development. The first version of the program includes a web utility for encoding/decoding and a pc utilities for bit sending/receiving. The web utility can also run locally from your computer and the installation package takes care all the web programs that are required in order to run the utility. The current beta release of CDW can be found here: CDW (6.89Mb .zip file. Last updated 30 May 2010)

* Since the utility uses javascript for it's operation it can be used only for small files efficiently (<20k). This release is out just to show the basic principles of CDW. The next version will have this "problem" solved.

How CDW sounds like?

Wav sample file CDW1.wav

You can find more information about this new mode, as well as installation instructions, in the official CDW website .