This collinear antenna works perfectly after the installation. The antenna is basically two dipoles excited in-phase and theoritically exhibits 3 dB of gain when compared to a dipole. 3/8" aluminum tubing was used here but i suggest 1/2" will do the job even better. The quarterwave stub is made of #12awg stranded wire and is grounded at the center(null). When properly tune, this antenna should have SWR value of 1:1.1 to 1:1.2. 73 de hevir
