T5

A Record of important things…

Ground Plane

IMG_1965

After having read Juan Rivera’s web site I decided that I would include a ground plane to improve the performance of the VHF communications antenna. The comm frequency range is 118 to 136 MHz.  Therefore the 1/4 wavelength range is 21 to 25 inches.  The sheet is 28 inches long.  The longest diagonal opening is about 6.5 inches.  No hole should be more than 1/10 wavelength (8.5 to 10 inches) so this should work well.

Cutting the sheet was a royal pain, but I didn’t want to just rivet strips together as the impedance across the joints would have adversely affected the RF performance of the ground plane.  Drawing for the ground plane sheet is GroundPlane_B_072012.pdf.