Ham Radio Links
Fldigi, a digital modem program for Linux, Free-BSD, Mac OS X, and Microsoft Windows XP, W2K, and Vista. Supports modes CW, Domino, Hell, MFSK, MT=63, PSK, OLIVIA, RTTY, Thor, and Throb.
WSJT-X weak signal software from Joe Taylor, K1JT. This software supports WSPR, FT-8, FT-4, JT-65, JT9, and other MF/HF/VHF/UHF modes. Open source with GPL license, and uses the Qt multi-platform GUI kit. Source code can be compiled for Windows, Linux, FreeBSD, Macintosh OS X, and most other UNIX-like operating systems; binary installation packages available for Windows and some Linux variants. I have no problem compiling these for Fedora Core Linux.
VOACAP Online. Web site based on VOACAP, but with new "frequency-time wheel" presentation in addition to coverage maps. Also handles direct or long path predictions.
Gpredict. A real-time satellite tracking and orbit prediction application. Integrates with hamlib to control radios and point antennas.
GRIG. Simple ham radio control program based on Hamlib. Integrates with other Hamlib logging and digital modes applications.
Ham Radio Control Libraries (Hamlib)
SDR-J - Jan van Katwijk's multi-platform (Qt toolkit) SDR software for SDRPlay and many others...
CuteSDR - multi-platform software that can talk to the RFSpace SDR-IP and NetSDR and the AFEDRI SDR-Net. software defined radios.
HDSDR - Formerly called Winrad. Nice SDR software, works well with CWSL, HDSDR, and Fldigi. Windows only
CWSL - CW Skimmer Listener - Great utility that "breaks out" the up to 7 QS1R CW Skimmer Server channels so that you can process them via HDSDR and other digital decoding software. From Peter, OK1FFU via OL5Q Club. WIndows only.
CW Skimmer and CW Skimmer Server by Alex, VE3NEA. Commercial, Windows only
Virtual Audio Cable by Eugene Muzychenko. Commercial, WIndows only
Modern receiver reviews/stats/photos from www.dxing.com. The older tube radios are here
Circuit, Antenna Simulation, and General Scientific Software
Ngspice mixed-level circuit simulator, multi-platform. Update - release 24, 2012-01-31.
gplEDA GPL's suite of Electronic Design Automation tools. gEDA has been selected as a Google Summer of Code 2008 project!
Mithat F. Konar's paper describing how to model vacuum tubes with Spice.
Radau5's Tube Spice Fit Technique
XCircuit -- an X11 circuit drawing and netlist program.
Numerical Electromagnetics Code NEC2 Page
GAEL -- GNOME Assisted Electronics. The successor and assign of Oregano....