9 Element for 432 MHz
Building and optimizing a 9-element Yagi for 432 MHz, including stacking details
Description
Demonstrates the design and construction of a 9-element Yagi antenna for the 70 cm band (432 MHz), based on the DK7ZB concept. The resource details EZNEC+ calculations for a single antenna, providing gain, sidelobe suppression, and front-to-back ratio figures. It also presents a comprehensive analysis of stacking two such antennas, including optimal stacking distance (1000 mm) and the resulting performance enhancements for the stacked array, such as an increased gain of 17.03 dBi.
The article includes detailed drawings, wire file dimensions in millimeters, and azimuth/elevation plots for both single and stacked configurations. Practical construction steps are documented with original photographs, illustrating element mounting, the 28 Ohm matching system using two quarter-wave 75 Ohm transmission lines, and the critical N-connector wiring. It also covers the iterative process of fine-tuning the driven element length to achieve a return loss of 20 dB, validating the EZNEC+ simulation results with actual measurements.