Do TV Signals Travel In a Straight Line?
In short, yes, TV signals travel in a straight line – but they may not always travel directly to their target destination, as they can also refract or bounce off obstacles in their way.
You’ve probably heard of a popular term, line of sight (LOS), which refers to the direct path of free space that exists between two points (the TV transmitter and your home). However, a direct LOS cannot always be achieved.
If this is the case, then your TV installer will use a signal strength meter to determine whether a bounce/reflective signal can be achieved. Bounce signals are made possible by the fact that when a TV signal hits an obstacle, it changes direction. For example, if there is a mountain blocking a direct LOS between a house and a transmission tower, the TV signal may have to refract over the top of the mountain to reach the antenna. Whether or not a bounce signal is achievable will depend on the location between your home and an obstacle. Generally speaking, the closer you are to an obstacle, the harder it is for the signal to refract.
The frequency of a channel also determines the degree to which a signal will refract. The higher the frequency the less flexible a signal is. In rural areas, TV signals are delivered through the UHF band, a higher frequency – meaning that they refract less compared to lower frequencies (VHF). This is sometimes an issue due to obstacles such as mountains and dense terrain. In city areas signals are able to ‘bounce’ more easily off obstacles such as buildings or nearby homes, due to being delivered through a lower frequency (VHF). That said, higher frequencies in rural areas have a relatively low entry requirement for the signal to be amplified – if using the right tools, good reception can be achieved.
To truly ‘see’ and understand how to achieve the best reception possible, signal meters and experienced professionals who can read the results and know what the next steps require, are needed.
