This page describes the antenna we realised for ATV transmission in the 23cm band from our club station. It consists of a simple 10 elements Yagi, completely built in copper, and with the element soldered directly to the central boom.
The dimensions of the antenna have been computed using a software based on the DL6WU
design. The software for DOS environment is simple to be used and quite intuitive,
therefore you can easily compute dimensions for other frequencies and for boom or
elements with different diameters.
In order to check the goodness of the design we did some simulations using the software 4NEC2 by Arie Voors. The main characteristics of the antenna obtained from the simulation are the followings.
The plots of the gain patterns on the horizontal plane, on the vertical plane and a 3D view are reported in the following three pictures. In the fourth picture it is reported the VSWR (and the return-loss) between 1200 and 1300 MHz.
Here below you can fine the assembly manual of the antenna, the software to compute
the dimensions and the NEC file used for the simulation.
WARNING! In the versione 1.0 of the assembly manual, the length of the balun was wrong. The length (equal to lambda/2) has to be measured from the point where you cut the cable shield, and not from the point where you cut the inner conductor. To have the correct measure, downloand the latest version!
23cm Yagi Assembly Manual - yagi23cm-ENG.pdf (~1,2MB)
Antenna Dimension Computation SW - dl6wu-2.zip (~80kbyte)
NEC file for the simulation - yagi23cm.nec (~1kbyte)
Here below we have collected some pictures taken during the assembly of one of our antennas, with some words of description. By clicking on each picture you can download it at higher resolution.
1) Drilling the boom and mounting the elements.
2) Building the dipole (bending and drilling the brass sheet).
3) Building the box for the balun and the balun.
4) Installing the dipole and the balun inside the box and connecting them.