click to download YagiCAD is Freeware
Les Moxon, G6XN (sk) Moxon authored a July 1952 QST article, "Two-Element Driven Arrays." Several other of his articles appeared during the 1970s and 1980s in Ham Radio magazine.Moxon Antenna Generator from Dan Maguire, AC6LA cand is based on an algorithm developed by L. B. Cebik, W4RNL. If you see an error message about "COMDLG32.OCX" being missing or not correctly registered you should download the MoxGen with OCX package (315 KB)
click to download DX Atlas
Electronic World atlas for Radio Amateurs. Scrollable World map with smooth zoom, DXCC territories, province/state prefixes, Grid Squares, CQ and ITU Zones in the rectangular, azimuthal and Globe projections, 3D relief, Gray Line, city and island index, unique hierarchical prefix database, local time with DST for all cities, islands and call areas
DX Atlas (7.6 mb)
Minimum system requirements:
- CPU: Pentium 166 MHz
- RAM: 32 Mb
- OS: Win7 / Win8 / Win10
- Video card: 640x480, 256 colors
- Disk space: 65 Mb
Ionospheric maps in DX Atlas
DX Atlas includes a set of dynamic, interactive ionospheric maps. Each map displays the selected parameter, such as the F2 layer critical frequency, D layer peak electron density, etc. The parameter value under the mouse cursor is displayed on the status bar, and various levels of shadows show how the parameter is distributed across the Globe.
To use the ionospheric maps, one needs to understand how the ionosphere works. As you probably know, the F layer reflects radio waves, and the D layer is responsible for signal absorption. By checking the F layer's critical frequency along the path, you can tell if the high bands are open, and the D layer density gives you an idea how strong the signal is going to be. There is much more information that can be extracted from the maps. For example, chordal propagation is likely to occur in the areas where the F2 critical frequency (foF2) or height changes quickly along the path, and path bending can occur if there is a significant transverse foF2 gradient.