490 MHz 4-Element Yagi Triad Array, a TRUE-OMNI-Directional Antenna with Horizontal Polarization was analyzed with 4nec2 after determining Dimensions using nikiml's Python Optimization Scripts. BTW: TRUE-OMNI has SAME Gain in ALL Directions (+/- 1 dB).
Raw Gain = 2.7 to 3.3 dBi at 490 MHz and SWR (50-ohms) Under 1.2.
That's a lot of complexity for just slighly more than the Gain of simple Dipole. Gain in one direction must be working AGAINST Gain in the opposite direction, bearing in mind that each 4-El Yagi generates Gain of about 8-10 dBi each.
enlarge 313KB, 1024x1024 7 490 MHz 4El Yagi Triad H-POL True-OMNI Azimuthal Gain = 2.7 to 3.2 dBi at 486 MHz
enlarge 314KB, 1024x1024 8 490 MHz 4El Yagi Triad H-POL True-OMNI Azimuthal Gain = 2.7 to 3.3 dBi at 490 MHz
enlarge 318KB, 1024x1024 9 490 MHz 4El Yagi Triad H-POL True-OMNI Azimuthal Gain = 2.7 to 3.5 dBi at 494 MHz
enlarge 331KB, 962x1024 10 490 MHz 4El Yagi Triad H-POL True-OMNI Elevation Pattern at 490 MHz Null at 48-deg Look-Down Angle isn't Deep Enough to be much of a Problem
enlarge 114KB, 1152x363 11 490 MHz 4El Yagi Triad H-POL True-OMNI Side View [1 large square = 5-inches]
enlarge 33KB, 791x1024 12 490 MHz 4El Yagi Triad H-POL True-OMNI 4nec2 File includes Summary of Dimensions
