5B4AZ Website

My dog Aris

Neoklis Kyriazis ("Nick")
Ham Radio Station 5B4AZ

Hello and Welcome to my Website.
This is my Contribution to Ham Radio:
Software for the Linux Operating System

His friend Pico

Digital Communications	NORAD SDP4/SGP4 in C	QRA Grid Locator & QSO Logging
Morse Code Decoders	Space Communications	Firewire Video & Object Tracking
NEC2 Translation to C	APT Image Decoders	Egyptian Hieroglyphs

Introduction:
The main purpose of this web site is to provide the end result of several years of work in the field of software development (for the GNU/Linux Operating System), e.g the source code (and related material) of various applications for Ham Radio communication as well as other purposes. These source packages should be able to compile on other POSIX/UNIX compatible platforms (*BSD distributions, Solaris and perhaps Mac OS X), possibly after some modification.

Some "caveats" are in order here: I don't have any formal training in Information Technology or Computer Programing, although I have a B.Sc. Degree from London University in Electronic Engineering (graduated in 1973, I am of 1948 vintage and retired early!). I am basically a teach-your-self C/Linux programmer, learning from books as well as the Internet, of course. As such it should be expected that there will be mistakes and/or bad/incorrect programming practices evident in my source code, even if the applications themselves appear to work well.

I try my best to test and bug fix my software, but on my own it is difficult to make sure that I have exercised my applications in every possible way, to bring up hidden bugs. I use some tools (gdb, efence and valgrind especially) to check for memory violations/leaks etc, but even so these will only detect bugs if the program is used in such a way as to put the execution flow through faulty code. Also, spare time is at a premium now, since I have to deal with serious illness in the family and at best I can only just deal with bug reports, if at all. Therefore my software is offered here "as is" and under the GPL license model, including the standard disclaimers of the GPL.

Since I use the Arch Linux distribution, which is basically a fast-moving "bleeding edge" distribution, I have had reports of compilation or run-time difficulties by users who tried to compile and use some of my software on there own systems. This is particularly true of my apps for X/GTK2 since I use the latest GTK2 releases and there are occasional backward compatibility problems with distros using older versions. There are also problems with sound card compatibilities and I try to modify my source code as I receive bug reports. Be warned!

Software Description:
My software is generally related to my Ham Radio hobby, for which I acquired a license and a call sign (5B4AZ) in 1973 and operated in various modes and frequency bands since. I was probably the first radio amateur in Cyprus to operate on the early OSCAR satellites, using mostly home brew gear, including antenna rotors controlled by a computer I built from Wireless World magazine's kit, running my own tracking software. And it was based on a 2 (two) MHz Z80 cpu with an MM57109 fpu running at 800 kHz (0.8 MHz)!! It had all of 4 KB (four kilobytes) of RAM and 8 KB of ROM containing BURP (Basic Using Reverse Polish notation) - of course no disks at all, just a 300 baud interface to a domestic tape recorder!!

My current computer is a 2.4 GHz AMD Athlon-64 X2 on an ASUS A8N SLI motherboard with 1Gb RAM, two 120 Gb SATA-2 hard disks, a Radeon X300 video card and an EIZO 18-inch LCD monitor. I used various Linux distributions over the years, but with a 64-bit processor I also need a 64-bit Linux distribution if I am to enjoy the full performance of my computer. I chose Arch Linux for this purpose since its a lean O/S with good package management and an active AMD64 developer community. Arch Linux is a little harder to install than other User/Desktop-oriented distros but I still thought I should give it a try.

The software I have developed follow the UNIX approach to an application, e.g to do one job and do it well. For this reason I have on this site for Ham Radio, separate software for PSK31 and Hellschreiber digital communication modes, Morse code decoding, satellite tracking and space communications, QRA grid Locator calculators and a logging application. I also have nec2c, a translation to the C programing language of the well-known NEC2 FORTRAN antenna analysis tool and, still under development, a graphical interactive version of nec2c. This can visualize antenna structures and much of NEC2's output (current/charge distribution, radiation and near field pattern, input impedance/vswr/gain etc) in real time, e.g. as results become available and without producing an output file.

Not related to Ham Radio directly, I have experimental software for web cam image capture via the video-for-linux API, a translation from FORTRAN to C of NORAD's SGP4/SDP4 and SGP8/SDP8 satellite ephemeris routines and a translation from PASCAL to C of Dr. Kelso's sgp4-plb26a library. This I have built into a complete source code package which can and has been used, by me and others, to build satellite/sun/moon tracking programs. Finally I also have an old ncurses-based application that interfaces with a Rockwell Microtracker LP(tm) GPS module and provides control and data read-out from this interesting device.

My Ham Radio Station:
My base station is an FT847 transceiver which I use for both HF and VHF/UHF operation, including satellite communications. I have an AT-200Pro auto tuner for my WIMO 160m G5RV and a 10-30 MHz broadband vertical, which I designed using xnec2c and then built from locally available materials. For satellite communications I have a Yaesu G-5500 Az-El rotor system, controlled via a GS-232 interface connected to my computer. I use my xsatcom satellite tracking application to control both the rotors and the transceiver, including Doppler shift correction and frequency tracking of Tx and Rx, satellite pass predictions and much more. My satellite antenna system includes a WIMO 7-turn helix for 70cm, an X-Quad for 2m and an 80 cm barbecue grill dish + DB6NT down converter for 2.4 GHz. For the 6m band I have a home brew 4 element Yagi, and for the 137 MHz APT weather satellite band I have a home brew RH polarized turnstile feeding an R139 receiver.