Amateur radio operators everywhere are using what is called “Ham radios”. With these, they can communicate with other radio hobbyists, and radio talk becomes easier.
In contrast to CB radios, only people with the right license can operate an amateur radio device, all the while adhering to the limitations and rules enforced by the Federal Communications Commission (FCC).
But those who already have a Ham radio device, and the right license to use their unit, might wonder how to utilize the radio to its maximum potential? The are multiple factors to consider and this article will go over the basics of radio technology, how radio range works, and ultimately what the range of a Ham radio is.
What is Ham Radio?
In many countries around the world, governments allocate a small portion of the radio spectrum for non-commercial use. This is mostly used by ordinary citizens who’ve demonstrated towards a government office the ability to use this spectrum properly.
In the United States, Amateur Radio regulations are enforced and administered by the FCC. Ham users are only authorized to use their devices and frequencies for non-commercial use.
Hundreds of thousands of ordinary people of all ages have completed the tests required for Ham radio usage. They are mostly hobbyists interested in the different aspects of radio from its technical workings to its social effects and everything in between.
An amateur radio operator typically uses his wide array of equipment at a station to engage in two-way radio communication with other Ham radio operators using the same radios on the assigned frequencies. Worldwide, these limitations and rules are assigned and enforced by the International Telecommunication Union. Most of the time, a Ham is a handheld two-way radio device that runs on one battery for about 18 months.
Ham devices are very commonly used in case of emergency. Occasionally, default communication systems either fail or become overloaded. This is when the Amateur Radio Service comes in handy as it can be used by everyone ranging from the military to the police and fire department.
Because of this, there are frequencies reserved for emergency use only, so that in case of unforeseen emergencies those never become overloaded. Most Ham radio devices are handheld but also include business radio (BRS), airband radio, walkie-talkies, and more.
What Are Radio Signals?
Radios transmit and receive electromagnetic waves. The radio’s signal is an electric current moving back and forth rapidly. The transmitter radiates this field via an antenna, then a receiver translates it to the audio heard through your device.
Radio waves transmit easily through the air, and also can be “bounced” or reflected to change direction. Bouncing entails shooting radio waves straight up into the sky, and they end up bouncing back from the earth’s ionosphere.
In contrast, reflecting means that an electromagnetic wave has encountered a change in medium, therefore some radio waves will be reflected. The part of the wave that enters the new medium is called the transmitted wave, while the other is called the reflected wave.
What Is A Repeater Station?
Even the best portable ham radios need a device called a “repeater station” is used to amplify radio signals. It increases the power of a signal and retransmits it, allowing it to travel even further. Amateur radio repeaters receive signals and retransmit them to a higher power. This is a sure-fire way to increase your communication range.
A repeater station extends your communication range if you key your microphone button to transmit through (or access) the repeater station. Most repeaters are open, therefore can be used by anyone who accesses them within range. But some repeaters have limited access, and some are restricted to exclusive groups or members of a club.
Ham Radio Range Basics
Ham radios are most commonly used in situations when the internet, phone lines, and other forms of communication are limited or non-existent. With the knowledge and application of radio range basic rules, you can theoretically talk all around the world on a Ham radio.
The maximum communication distance you can reach depends greatly on your device and location. The frequency you’re using, the transmitter’s output power, the type of your antenna, and propagation conditions all influence your true range.
Yet, the biggest factor is the frequency you’re transmitting on. Realistically, you can reach an about 2-18 mile range with handheld radios. However, this range is always circumstantial. If you manually enhance your radio’s strength or your base station, you can reach hundreds of miles.
An important factor to always consider regarding range is that all frequency ranges stated on any unit are considered to be its “theoretical range”. This is because we rarely, if ever, experience conditions that are absolutely perfect for radio transmission. Because anything, from buildings to terrain, can influence our range both in transmission and in reception. So when trying to figure out the true range of your unit, you should consider Frequency, Antenna, Interference, and Signal Strenght as the most important.
Signal Type & Frequency
In the US, Ham users can use 26 different radio bands or groups of frequencies with their devices. According to the National Association for Amateur Radio, this is everything above 1.8MHz to 275GHz. This range technically covers HF, UHF, VHF, SHF, and EHF frequencies.
Whether you’re able to reach a friend two houses over, or someone living in India also depends on the meter band that you use. Therefore, the frequency you use majorly influences your range.
Most Ham operators usually stick to UHF or VHF frequencies. EHF (extremely high frequency) is almost only used by satellite radios, and UHF radios (ultra-high frequency) are mostly used by hospitality, manufacturing, or the Family Radio Service (FRS).
FRS radios are used for private two-way communications for facilitation family or group activities, and since 2017, the FCC limits FRS channels to a specific communication range in order to moderate their use.
Simple HF is used by AM radio. FRS radios are able to communicate with Ham devices, but a Ham radio can only FRS if it has a wide enough receiver.
VHF frequency bands (very high frequency) work between 30-300MHz. These are commonly used by maritime, emergency, traffic control, and military systems. They’re also used by aviation radios and for broadcasting on FM radio.
VHF signals have longer wavelengths than UHF signals, meaning that they can travel further without less unwanted interference. So if you want to transmit as far as possible, the right choice for you would be the VHF band. However, the key downfall is that buildings and tall objects can make radio signals weaker. Having said this, it’s best to use VHF in long-distance communication and outdoors, where the receiving device is either in line of sight, or it’s deductible that there are no obstacles in the way of transmission.
In contrast, UHF radio technology (ultra-high frequency) and its bands are found somewhere between 300MHz and 3GHz. This means that they have shorter wavelengths and more energy compared to their VHF counterpart, translating to them being more reliable in areas with a lot of obstacles like trees, buildings, or hills.
But because UHF is less effective in long distances than a VHF signal, it’s used commonly for mobile radio, GPS, Wi-Fi, walkie-talkies, or Bluetooth devices. Mobile radios (also known as mobiles) are usually licensed land-based radios used for wireless communications which rely on radio frequencies and where the path of communication is movable on either end.
In conclusion, what this means for amateur radio users is to choose the right frequency band appropriate for your location, or your intentions. As someone who is just starting out, you should either choose a frequency for your location and stick with it or switch bands according to their specific intentions.
Not all radio signals are optimal for short-distance use either, which is why only sticking to the longer VHF frequency is not the best decision either.
The height and location of your antenna are very important for any radio operator. The higher your antenna, the better the range will be. Also, an antenna standing straight up can improve reception.
The antenna is most important at frequencies higher than 2MHz, as anything above this works on your line of sight, and can’t bend around the curvature of the Earth. Therefore, even when considering long-range communication, know that above this frequency, the maximum communication range will be from the location of your antenna to the distance of the horizon.
Theoretically, this means that if an antenna – or a handheld radio – is positioned at 5’ off the ground, you’ll have the “theoretical range” of 3.16 miles. But if your antenna or your device equipped with an internal antenna is located 20’ off the ground, it would have a range of 6.33 miles.
There are a lot of ways to calculate the distance of the horizon, including using apps or online calculators. The whip antenna is most commonly known by the average person. These are commonly seen on the top of cars, and the longer they are, the better the reception of the car radio will be.
Actually, the whip antenna can also be used by amateur radio operators. Although, whether you should or whether you can use a whip antenna mostly depends on your location and your device. There are different types of whip antennas, and some can be used with handheld Ham radios as well.
Taking this into consideration, a quick fix of range would be increasing the height of your antenna. But know that it’s not only up to your transmitting antenna, but also the location of the antenna you’re trying to reach. These calculations of knowing where the horizon is will always be theoretical, so don’t be surprised if you can’t manage to reach everything in that radius.
Radio waves generally travel best with the most optimal conditions, that’s why most people use their antenna and or their radio primarily outdoors. Not all antennas support various radio brands, so it’s important to get the right model.
Most Ham operators use handheld antennas for the easiest use, but for some, these are not effective enough. So before purchasing any type, make sure to do your research, and also be aware of where you’ll be using your device from, and for what purpose.
Ham radio users have what is called a “base station”. This base is used as a station for amateur radio operators, and today, they’re usually controlled and operated from a remote location. Most of these remote stations have similar features to any other amateur radio station, but can be controlled over a wired connection, the internet, or by radio.
Base station antennas are usually mounted antennas. These are most commonly antennas mounted on towers that make radio communications possible, serving as a hub of local wireless networks, sometimes even as the gateway between wired and wireless networks. In general, they consist of a low-power transmitter and a wireless router.
A radio signal can’t – or just barely can – travel through solid objects like mountains and buildings. Any obstacle will surely reduce your range. This is why radios can almost never reach the maximum of their theoretical range. Low-frequency signals and UHF signals “react” better in urban environments, as their higher energy wavelengths and strengths are better at traveling through buildings.
Electromagnetic interference (also known as radio frequency interference) is a disturbance generated by any external source that can affect radio transmissions. Apart from the widely known obstacles such as buildings, forests, and hills, interference can also be caused by equipment in your home.
While a radio signal passes walls easily, hairdryers, electric drills, light switches, smartphones, and their chargers, power supplies, and even lights can be seen as obstacles for your device. If you notice any interference when communicating with your unit, the first thing is to adjust your antenna, and by that, you can more easily determine the cause of the interference.
The transmission power of your unit is a key capacity that affects the radio’s range and is measured in watts. In telecommunications, specifically in radio frequency, radio signal strength (or field strength) refers to the transmitter radio’s power output received by an antenna at a distance from the transmitting antenna.
While commercial radio stations broadcast between 50 thousand and 100 thousand watts, handheld radios usually only have 0.5-5 watts of power. (For most unlicensed radios, this is the maximum wattage they can reach.) Apart from this, there are also laws that limit the signal strength of amateur radio. Commercial stations generally use strong commercial broadcast antennas (usually parabolic antennas) to reach a greater range.
Simply put, the higher the signal strength of a radio, the further it can travel. So if you only have a 2-watt handheld Ham radio, your antenna’s placement and height will not be able to increase your range by much. Still, it’s a universal rule, that the higher your antenna, the better the reception and radio transmissions will be.
Overall, the range of any radio device cannot be pinpointed to a single maximum. While someone can reach 30 miles without amplifying the signal, the same radio in a different location can be limited to just 5 or 10. This is why before investing in anything, you should consider your location and your intentions before starting to amplify your range.