In order to reflect what the software actually does, the name "HDSSTV" has been changed to "RDFT". RDFT stands for Redundant Digital File Transfer.
Below is a Robot 36 second image received by W9NTP, from a transmission by VK3LM, on 20 Meters.
A few minutes before, the following image was sent in a 30.5 second transmission from VK3LM to W9NTP, using the same radios via SSB on the same 20 meter frequency.
A new method of digital communication was used to transfer an exact copy of the original digital file. The links below lead you through a presentation of this method of digital communication made at the 2001 Dayton Hamvention.
The RDFT presentation made at the 2002 Dayton Hamvention concentrated on how to use it.
The two main topics of KB9VAK's 2003 Dayton Hamvention Presentation were
Links to the initial version of one paper, and to incomplete drafts of two other papers are provided in the list below.
The software available via the link just below is released under the terms of the GNU General Public License. This license states the terms under which the software may be legally: copied, modified, and distributed.
See the file "ChangeLog", in each distribution, for a detailed list of changes.
The Wyman1x mode of RDFT is tailored for use over High Frequency (HF) radio channels.
This version introduces Frequency Change Compensation.
This version primarily fixes errors.
This version of the software is a 'Win32 Console Application'. It can be run by the DOS_Prompt program with the processor in 32 bit mode. It will not work if the processor is in 16 bit mode.
The software available via the link just below is released under the terms of the GNU General Public License. This license states the terms under which the software may be legally: copied, modified, and distributed.
Version 2.02 incorporates relevant changes introduced with the previous release of Linux version 1.3.0.
Additionally, a maximum of 5 unsuccessfully decoded blocks is used to allow decoding to continue. Subsequent decoding is aborted just after the 6th unsuccessfully decoded block is finished decoding.
Software with the improvements listed in the 2001 Dayton Hamvention Presentation and released under the GNU General Public License, has been superseded.
A new feature has been added to version 1.2.0. This new feature is the saving of completely corrected code blocks in individual files, and the deletion of these individual code block files if all code blocks are completely corrected. This facilitates the recovery of a file from multiple receptions, where only some of the code blocks were completely corrected in each of the receptions.
In this version, 50% of the inner code symbols are redundant. Four different levels of redundancy in the outer code are provided. These different levels of redundancy use about: 10%, 20%, 40%, and 70%, of the outer code symbols, respectively, to implement the redundancy. This version has been used to successfully transfer files from Australia to the United States using single sideband transmissions in the 20 meter band.
Two files ("Makefile", and "README") were mistakenly left out of version 1.1.0, so it has been removed.
This version of the software is a 'Win32 Console Application'. It can be run by the DOS_Prompt program with the processor in 32 bit mode. It will not work if the processor is in 16 bit mode.
The README.TXT file from the "WEXE20E.ZIP" distribution file has been changed. This is the reason for the "WEXE20F.ZIP" distribution file. The utility "split.exe" has been removed, the other executable files are the same in both distribution files.
Some documentation files were mistakenly left out of the "WSRC20D.ZIP" file. They have been added to the "WSRC20E.ZIP" distribution file.
The software available via the links just below is released under the terms of the GNU General Public License. This license states the terms under which the software may be legally: copied, modified, and distributed.
The "Win32 Console Application Executable files distribution" contains all that is necessary to run the software under the DOS_Prompt program. The installation instructions from the documentation that is part of the Win32 Console Application Executable files distribution, have been extracted as a separate file, for those who want to read them before unzipping the Executable distribution.
Barry Sanderson, KB9VAK, 13 October, 2003