xnec2c is a GUI wrapper on the popular NEC2 antenna modeling program. The application allows the design of an arbitrary antenna, and displays gain, impedance and other useful results.
xnec2c displays its output in up to three windows. The first window shows the model the user has provided:
The user may rotate the view with the two numeric controls. The
X,
Y and
Z buttons permit views along the three axes, and the curved arrow button returns to the default isometric view.
Selecting from the menu opens the radiation pattern window (
Figure 32, “Radiation Pattern Display”). The view may be rotated in the same manner as the structure window. Buttons at the top allow for selection of the radiation pattern or the field pattern display.
The
dB /
MHz controls allow for specifying the precise frequency at which the gain is to be displayed.
Selecting from the menu opens the frequency data plots window (
Figure 33, “Frequency Data Plots Display”). Buttons along the top permit display of SWR, impedance, phase, etc.
Clicking on the graph causes the gain, SWR and impedance to be displayed immediately above the graphs for the selected frequency.
5.2.1. Improving calculation performance
When a complex antenna with many segments and many frequency steps is required, the calculation can take some time.
xnec2c is able to take advantage of modern, multicore processors by specifying
-j <n>, where <n> is the number of subprocesses to spawn. Many multicore processors can create two threads per core, so a command line entry of
xnec2c -j 8 &
can improve performance by almost a factor of eight on a quad core processor.
