Foundations Of Amateur Radio

Foundations of Amateur Radio In our hobby we regularly invoke line of sight when we discuss the VHF and higher bands. It's a simple concept to help describe when two transceivers can hear each other. The process evokes an image of a beam of light travelling unobstructed between the antennas at either end. Some might picture a laser, others a flashlight, both are useful to become familiar with some of the concepts. If there's a pole between the two, a laser beam, unless it's particularly powerful, won't go through to the other side. A flashlight beam on the other hand might fit around the pole and still be visible at the destination. That illustrates that objects can get in the way of a signal, reducing strength and sometimes blocking it entirely, but it's not the only effect at play. Imagine a building with a mirror glued to its side. If you shine a laser at an angle at the mirror, you can reflect the light off the mirror and essentially still land on target. This is useful if you want to avoid an obstacle