Build a 9 dB, 70cm Collinear Antenna from Coax

This article provides instructions for building a 9 dB gain, 70cm collinear antenna using RG58/U coaxial cable and encased in PVC pipe. The design is suitable for average use and offers a cost-effective homebrew solution. It details the construction of an 8-element collinear array, including calculations for half-wavelength sections of RG58/U coax, accounting for a velocity factor of 0.66 at 444 MHz. The article also covers the addition of a quarter-wave wire element at the top and a quarter-wave aluminum or copper tube at the bottom, with specific length calculations for each. It includes step-by-step instructions for cutting and soldering the coax elements, exposing the center conductor and braid, and tinning the braid. The feed point connection to RG58/U coax is also described. This project is aimed at amateur radio operators interested in constructing their own UHF antennas.