With over 700,000 licenses issued to citizens in the U.S. in 2018, ham radio is certainly not new to a majority of people. Ham radio is still one of the most robust means of communications we have today.
While knowing how to operate a ham radio is important, knowing how it works is a far bigger bonus. Apart from making it easy for you to build your own ham radio from scratch, it also makes fixing a broken ham radio quite easy as well.
You do not have to be a prepper to understand how ham radios work. Since they can come in handy in almost any kind of emergency situation, everyone should at least have an idea about how the radios work.
To better understand how ham radios work, it would be almost impossible to not talk about the electromagnetic wave spectrum. Of interest, however, will be the radio waves that range from 3MHz to 300MHz. High Frequencies (HF), Very High Frequencies (VHF) and Ultra High Frequencies (UHF) frequencies lie in this range.
Ham radios can communicate to each other in one of two ways:
Short Range Communication
Short-range communication involves two ham radios that may be in one line of sight. Many of the low-powered ham radios with small antennas are usually only capable of short-range communication. In the U.S., ham radios that are capable of short-range communication use the 144MHz – 148MHz band.
Ideally, the maximum distance between two ham radios is supposed to be 6 miles. However, with the help of repeaters, ham radios can be capable of broadcasting signals well over 50 miles.
Repeaters work by receiving signals from several ham radios, amplifying the signals and then re-transmitting them. They are publicly available to licensed ham operators who prefer placing them on high places such as on hills for better signal reception.
Without repeaters, the overall quality of a signal from a ham radio will be limited to the strengths and weaknesses of VHF. One popular weakness is atmospheric noise. If there are many obstructions between two ham radios, the maximum range can reduce to 1-2 miles.
Long Range Communication
Unlike short range transmission, long range transmission uses the 3MHz to 30MHz band. It also does not necessarily rely on repeaters. This is because the signals from the ham radio bounce off the ionosphere and can travel farther. The only downside is that the equipment you will need for such long-range communication will be expensive.
At times, some ham radios that are capable of long-range transmission also come with special features such as cross band repeat. This feature allows you to have your own repeater without requiring too much. You may only need to buy a slightly taller and better antenna in case your current one cannot do the job.
Factors That Affect Ham Radio Operation
It is also a good idea to know a few of the things that can affect how ham radios work. This can help you know exactly what you need to adjust to make it work.
The type of antenna you use has a significant impact on range. An omnidirectional antenna placed on a high point will be far more efficient than a directional antenna surrounded by tall trees. In such cases, you will be restricted to short-range communication only unless there are repeaters in your area.
The range will be significantly better if you are in an area where the terrain is flat. Obstructions such as trees and buildings will reduce range. However, if there are repeaters in your neighborhood and you have a powerful antenna, you need not worry.
Time of Day
During daylight, you will find that the 15MHz to 27MHz band is ideal for long distance communication. At night, you can use the 3MHz to 15MHz band. Unlike with terrain, the time of day is not too much of a big deal since you can always use a lower frequency to get a clearer signal.
Before you can legally operate a ham radio, you need to have the necessary licenses to do so. To get the license, you would have to learn electronics theory and be familiar with amateur radio rules and regulations.
In the U.S., each individual license class allows operations within specific bands and specific modes. Of course, the higher the license class, the more allowable bands are available for your use.
Going after the highest license class will enable you understand how ham radios work much better. The general class license, for instance, allows you to setup your own repeater and help the network to grow.
In addition, once you become an elmer, you can choose to be a volunteer examiner. Nowadays, they are responsible for administering examinations. In this way, you will get to learn even more about ham radios.
In summary, knowing how ham radio works is a great skill to have, whether you are a ham radio enthusiast or not. Ham radios have come in handy in many emergency situations where other communication channels failed.
Their working is also simple especially if you understand a few things about the electromagnetic wave spectrum. They can either provide short-range communication or long-range communication depending on the frequencies in use.
Short-range communication is when two ham radios are either in one line of sight or when there are repeaters in the vicinity. Long-range communication, on the other hand, uses a much lower frequency. A signal is thus capable of bouncing off the ionosphere without necessarily needing a repeater.
There are a few things that also affect how a ham radio operates. These include the time of day, the terrain, and the antenna being used. Other than that, you would also need a license to operate a ham radio. While getting the highest license class may be a difficult task, it also doubles as a great way of understanding how ham radios really work.