When you think of directional ham radio antennas, you probably think of a Yagi, cubical quad, or a log-periodic antenna. These antennas usually are in a horizontal configuration up on a high tower.

But what principles of the electromagnetic spectrum allow radio to work, and how do antenna design ... such as why a longer diploe is more directional than a shorter dipole.

The company’s new rubber duck antennas are small and lightweight, making them easy to carry, store and fit into tight spaces. Some are less than an inch tall. They are easy to install, typically ...