<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html><head> <meta content="text/html; charset=ISO-8859-1" http-equiv="content-type"><title>Recognitions</title></head><body style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 204);" alink="#000099" link="#000099" vlink="#990099"> <div style="text-align: center;"> <h1>Recognitions</h1> <div style="text-align: left;">This software would not have been possible without the contribution of many programmers who have given their best to the open source community. The application is built upon the foundation of the Fast Light Tool Kit (http://www.fltk.org), a wonderfully fast and efficient graphical user interface design library. Many have asked what the Fast Light means. There are probably as many answers as there are programmers using the toolkit. I prefer to think of it as lightning fast and light on the code size. Take a look at the size of the executable for fldigi and then compare it with similar applications. I think you will be surprised by how small it is for what it does.<br> <br> The active current development team consists of:<br> <ul> <li>Dave Freese - W1HKJ</li> <li>Stelios Bounanos - M0GLD</li> <li>Leigh Klotz - WA5ZNU</li><li>Stephane Fillod - F8CFE</li> <li>John Douyere - VK2ETA</li> <li>Joe Veldhuis - N8FQ</li> <li>Chris Sylvain - KB3CS<br> </li> <li>Gary Robinson - WB8ROL<br> </li> </ul> Several authors have placed their digital modem code and signal processing code in the public domain and their source was either an inspiration or in some cases formed the backbone of the code used in <span style="font-style: italic;">Fldigi</span>.<br> <ul> <li>AE4JY - WinPsk - a windows application </li> <li>Takuya OOURA - a generic Fast Fourier Transform for real valued data streams - http://momonga.t.u-tokyo.ac.jp/~ooura/fft.html</li> <li>Tomi Manninen, OH2BNS - gmfsk - a great digital modem program for Linux</li> <li>Hamish Moffatt, VK3SB - dominoEX code originally for gmfsk</li><li>Dr. Steven W. Smith - author of "Digital Signal Processing", who has kindly placed an entire book on digital signal processing on the internet. (http://www.dspguide.com)</li> </ul> </div> <div style="text-align: left;">If you make a side-by-side comparison between gmfsk and fldigi source code you will see that they follow the same general structure. The primary difference is that gmfsk is written in the C language and uses the gnome/gtk libraries for the user interface. <span style="font-style: italic;">Fldigi</span> is a C++ application that uses the Fast Light Tool Kit (Fltk) gui library. The design of <span style="font-style: italic;">Fldigi</span> puts emphasis on separating the user interface from the sound card and transceiver input/output operations. Nearly all modern digital modem programs use a programming paradigm called "threads." Threads are light weight processes that share the same memory space, but each has its own stack. The use of threads makes the program look and feel responsive to the user while a lot of code is being executed in the background. <br> <br> Many of the modem source code files are C to C++ rewrites from the gmfsk application. They say that copying is the best form of flattery and gmfsk simply had the best explanations and the easiest source code to read and understand. The author had also spent several months creating improvements and fixing bugs in the original gmfsk application. That exercise was the impetus to create <span style="font-style: italic;">Fldigi</span>.<br> <br> The Fast Fourier Transform used by <span style="font-style: italic;">Fldigi </span> is a rewrite of Takuya Ooura's C code. The rewrite is in C++ but you will see the strong resemblence to Takuya's original if you study both. Takuya's FFT code was also used in the Winpsk program. Some of the signal processing algorithms used in <span style="font-style: italic;">Fldigi</span> are from Dr. Smith's book. His on-line publication is sufficient to allow you to become fluent in fft analysis and the creation of digital filters. I printed the relevant pdf files and then purchased the hard bound copy. Improvements to the original gmfsk signal processing algorithms can all be attributed to this excellent source.<br> <br> And last but certainly not least, I must thank the crew who perform alpha testing and on-line support of the application. These are stalwart amateurs who risk their operating system and radio equipment in testing, testing and more testing. Their only reward is in being able to influence the design of the application and the fun of seeing it work and the bugs disappear. Thank you to:<br><br><table style="text-align: left; width: 100%;" border="0" cellpadding="2" cellspacing="2"><tbody><tr><td style="text-align: left; font-weight: bold;">Call</td><td style="text-align: left; font-weight: bold;">Name</td><td style="font-weight: bold;"><br> </td><td style="text-align: left; font-weight: bold;">Call</td><td style="text-align: left; font-weight: bold;">Name</td><td style="font-weight: bold;"><br> </td><td style="font-weight: bold;">Call</td><td style="font-weight: bold;">Name</td><td style="font-weight: bold;"><br> </td><td style="font-weight: bold;">Call</td><td style="font-weight: bold;">Name</td></tr><tr><td><br> </td><td><br> </td><td><br> </td><td><br> </td><td><br> </td><td><br> </td><td><br> </td><td><br> </td><td><br> </td><td><br> </td><td><br> </td></tr><tr><td>4Z5ST</td><td>Boris</td><td><br> </td><td>K3GAU</td><td>David</td><td><br> </td><td>KU1T</td><td>Zibi</td><td><br> </td><td>VA3DB</td><td>Dianne</td></tr><tr><td>AA0HW</td><td>Chuck</td><td><br> </td><td>K4XTT</td><td>Victor</td><td><br> </td><td>KV9U</td><td>Rick</td><td><br> </td><td>VE3IXI</td><td>Dave</td></tr><tr><td>AC7JN</td><td>Dave</td><td><br> </td><td>K6KAR</td><td>Kirk</td><td><br> </td><td>N0NB</td><td>Nate</td><td><br> </td><td>VK2TMG</td><td>Brett</td></tr><tr><td>CT1DRB</td><td>David</td><td><br> </td><td>K7BRK</td><td>Chris</td><td><br> </td><td>N2AMG<br></td><td>Rick<br></td><td><br> </td><td>VK4BDJ</td><td>David</td></tr><tr><td>CX7BF</td><td>Walter</td><td><br> </td><td>K4RE</td><td>Brian</td><td><br> </td><td>N4UM</td><td>Tim</td><td><br> </td><td>W3NR</td><td>Ed</td></tr><tr><td>DF4OR</td><td>Ekki</td><td><br> </td><td>K9AO</td><td>Rick</td><td><br> </td><td>N4ZNV</td><td>Mike</td><td><br> </td><td>W4ROS</td><td>Ross</td></tr><tr><td>DK1JBE</td><td>Tom</td><td><br> </td><td>KB3FN</td><td>Lynn</td><td><br> </td><td>N6WFL</td><td>Jason</td><td><br> </td><td>W6JVE</td><td>Jim</td></tr><tr><td>DL6XAZ</td><td>Fred</td><td><br> </td><td>KD0AR</td><td>Mike</td><td><br> </td><td>N8FQ</td><td>Joe</td><td><br> </td><td>WA3VPZ</td><td>Marshal</td></tr><tr><td>DL8FCL</td><td>Walter</td><td><br> </td><td>KD4O</td><td>Phil</td><td><br> </td><td>NN8B</td><td>Don</td><td><br> </td><td>WA4SXZ</td><td>Rich</td></tr><tr><td>G0UZP</td><td>Paul</td><td><br> </td><td>KD8DKT</td><td>Mike</td><td><br> </td><td>NT1G</td><td>Skip</td><td><br> </td><td>WB8ROL</td><td>Gary</td></tr><tr><td>G3TDJ</td><td>Andy</td><td><br> </td><td>KE3Y</td><td>Travis</td><td><br> </td><td>OZ4KK</td><td>Erik</td><td><br> </td><td>WD4FDW</td><td>Steve</td></tr><tr><td>G6CKR</td><td>Roger</td><td><br> </td><td>KH6TY</td><td>Skip</td><td><br> </td><td>PA0R</td><td>Rein</td><td><br> </td><td>WD4FNY</td><td>Bill</td></tr><tr><td>G8SQH</td><td>David</td><td><br> </td><td>KL7NA</td><td>Rob</td><td><br> </td><td>PA3GWH</td><td>Richard</td><td><br> </td><td>WU9Q</td><td>Bob</td></tr></tbody></table> <br>and many others whose names are not listed, please accept my apology.<ul> </ul>The test team is representative of users on Windows, Linux, Free BSD and OS X operating systems. They have varying interests from very slow speed CW to high speed keyboard full break-in CW, from RTTY contesters to PSK rag chewers. They have insisted that fldigi perform well under all of those operations. I have been amazed by the global distribution of the testing team. It is easy to think that the internet will be the death of amateur radio. On the contrary it opens up so many additional ways for us to be cooperative.<br> <br> <div style="text-align: center;"><a style="font-weight: bold;" href="index.html">Contents</a></div> </div> </div> </body></html>
