3MA triband mobile antenna
Building a 3-band mobile antenna with quick coil changes for 10m, 15m, and 20m.
Description
Demonstrates the construction of a 3MA triband mobile antenna designed by IZ7DJR, emphasizing a full-size quarter-wave whip for 10 meters. The design incorporates a rapid tilt-down mechanism to facilitate quick changes of loading coils for operation on 15 and 20 meters. This approach aims to minimize losses and enhance efficiency compared to conventional base-loaded mobile antennas.
The resource provides specific coil winding data: 22 turns for 15 meters and 37 turns for 20 meters, both using 1mm wire over an 80mm coil length. The 10-meter band operates without a loading coil, leveraging its full-size design. The author's design prioritizes ease of band switching and improved performance for mobile HF operations, offering a practical alternative to more lossy commercial options.