Key Figures in Radio Technology History

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Key Figures in Radio Technology History

Radio History FiguresThere were many key influences that helped the radio evolve into what it is today. We’ve already talked about how originally the radio was used only in simplex mode, and messages were simply transmitted via Morse Code, to recipients. There was no two-way communication going on, and even speaking was not yet possible via radio waves. But the idea that a form of electrical waves could be sent wirelessly to others across vast distances to send messages was innovative. Once these waves were more thoroughly understood, the advancement of their use happened exponentially.

Radios were first used in large ships out on the ocean, were before carrier pigeons were the only means of far away communication. In Australia, two-way radios were put into police cars by Senior Constable Frederick William Downie, and in World War II two-way radios were used by men on the ground and in the air, and by both Allies and the Nazis.

Before delving deeper into the historical timeline of the evolution of the radio (and subsequently the two-way), we would like to first start with the influential people who made that progress possible.

Heinrich Hertz

Although James Clerk Maxwell had already theorized that electromagnetic waves existed, Heinrich Hertz was the first to actually prove it. In 1886 and 1887 Hertz developed an apparatus to prove that electromagnetic waves could be sent and received wirelessly, using scientific methods to weed out all other possible variables that could have affected his results. In addition to his research on electromagnetic waves, he also began studying the photoelectric effect, which would later be built on and proven by Albert Einstein. Sadly, Hertz did not realize the importance of his findings. When asked of its importance, his response was that it had little value in the real world and was not significantly important. In 1894 Hertz passed away from Wegener’s granulomatosis, a form of vascular inflammation that affects the small and medium blood vessels. The hertz (Hz) is a unit of measurement named after Heinrich, defined as one cycle per second (Hertz History).

Samuel Morse

Before voice waves were able to be transmitted via radio waves, a system of dots and dashes was used to send messages. Samuel Morse, Alfred Vail and Joseph Henry invented the American telegraph back in 1836. Morse created the “language” used to send messages, beginning with only numbers being translated at each message end. Soon Vail took that system one step further and included letters. Before voice waves were sent over the air, Morse Code was the only way to get messages out quickly, and in many facets of the government there were jobs solely dedicated to learning and typing out of this code (Learn more on Morse).

Nikola Tesla

Nikola Tesla, a scientist originally from Serbia who came to the United States to work for Thomas Edison, is best known for his work with alternating current machinery. He was an electrical and mechanical engineer, and soon after coming to America, struck out on his own creating new inventions. He sold the patent rights to his AC machines to George Westinghouse in 1884, and with financial backing kept researching in New York City for many years. He was known as a bit of an eccentric, or mad scientist, as his ideas were extremely futuristic and ahead of his time. One of his inventions, the Tesla coil, was used in the progression of radios. Today his popularity has made a come-back, with the Tesla car company basing many of its principles on his work (Learn More about Tesla).

Reginald Fessenden

Reginald Fessenden, a Canadian mathematician, moved to New York City in 1886 hoping to get a job working with Thomas Edison. He knew little about science or electricity, but told Edison he was a quick learner. After being put off a number of times, Fessenden finally got a job with Edison Machine Works  and quickly moved up in ranks. In 1892 he became a professor for the electrical engineering department at Purdue University (after Edison Machine Works lost funding and had to lay off many workers, including Fessenden). And in 1893 George Westinghouse himself recruited Fessenden as chair of the electrical engineering department at the Western University of Pennsylvania (now the University of Pittsburgh). Fessenden’s main research was in the use of voice/sound transmission via radio waves. He began working for the United States Weather Bureau to prove that weather information could be sent using a better developed apparatus and forgo the need for telegraph systems. In December of 1900, using funding from the weather bureau and his own inventions, Fessenden transmitted a sound wave about a mile away. This is thought to have been the first sound wave ever sent using radio waves. After Fessenden’s stint with the weather bureau ended in 1902 due to patent disagreements, two wealthy businessmen from Pennsylvania created NESCO (National Electric Signaling Company) to carry on with Fessenden’s research. The base for the research was in Massachusetts, where Ernst Alexanderson comes in. Fessenden believed that a high frequency alternator-transmitter was needed to send sound waves across far distances, and the gentleman put up to that task at GE was Ernst Alexanderson (More on Reginald Fessenden).

Ernst Alexanderson

Taking the research and work of Hertz and putting it into practical use, Alexanderson created a radio transmitter that was used in the early 1900s to send radio waves over great distances, called the Alexanderson alternator. Originally from Sweden, Alexanderson worked for GE in Massachusetts and using his transmitter, was the first to send out music over the radio. Under the order of Reginald Fessenden, Alexanderson created a 75 kHz alternator and played Christmas music over it that was heard by Navy ships and shore stations all along the East coast. The first television broadcast was also to his home in Schenectady, NY. Alexanderson kept working well into his later years, consulting for GE and RCA. He passed away in 1975 and is buried in Schenectady (More on Alexanderson).

Edwin Armstrong

Like many of his counterparts, Edwin Armstrong was a prolific inventor. Over the course of his life he held over 40 patents, and many of his inventions for the radio were used in both World Wars in which he also served. He invented the regenerative circuit, the superheterodyne receiver and the modern frequency modulation (FM) radio transmission (Read More). Unlike many of his radio inventor predecessors, Armstrong was very withdrawn and quiet. He did his research on his own, having never worked for or been funded by a company or government entity. He questioned his professors and colleagues, and kept his patents as his own. Many of his inventions were created in his parents’ attic in Yonkers, and it wasn’t until the death of the professor of electrical engineering at Columbia did Armstrong take a scholarly position (31 years after graduation from Columbia himself). Many of the inventions that Armstrong created are still in use today, including regeneration, heterodyne radio and FM radio. Sadly, after years of litigation over FM patents with RCA and new FCC laws pushed in place by RCA (who was a strong proponent of AM rather than FM radio) Armstrong committed suicide in 1954. He left a letter to his wife, apologizing for fighting with her, and jumped out of his 13th floor apartment. His wife carried on with his court dealings, and many lawsuits were eventually settled in his favor.

There are many other influential figures in the history of radio, and countless inventions that have not only set the stage for radio, but also TV and telephones. Many of the theories established or inventions created for radio made their way into many other areas of technology, such as transmitter towers, ships, cars, and the list goes on. Battles have been lost and won on the basis of radio, and it has been said that a large part in why there were any survivors from the Titanic were because of the use of radios. Since the late 1800s we have been using radio waves to send messages, and we still do today. From our firefighters saving our lives to our government keeping our land safe, radios are in our past, present and future. Keeping us connected and informed, radio technology has been and will keep doing for us what no other form of communication has yet to do.

UHF VS VHF

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UHF VS VHF

UHF vs VHFWhen using two-way radios, signals are typically transmitted via VHF (30 MHz to 300 MHz) or UHF (300 MHz to 3,000 MHz) waves on the radio spectrum. There are pros and cons to each. In some instances it is better to use radios set to the VHF frequencies, and in others the UHF frequencies. In addition to two-way radios, these frequencies are also used for television, cell phones and the internet.

If you are thinking about buying two-way radios, for personal or commercial use, it is good to know the differences between these two sets of radio frequency bands. Knowing what your radio is capable of, what type of environment you will be using your radio in, and what frequencies are designated to what use in your country are all important when deciding on what type of radio you will buy. Here are some differences between UHF and VHF, and how it affects how you use your radios.

VHF

The ITU (International Telecommunication Union) has designated VHF (very high frequency) radio waves at 30 to 300 MHz. These waves are longer than UHF waves (typically one to ten meters) and are most often used for long distance communication.

The key to transmitting radio waves a long distance along VHF waves is to keep both the transmitting radio and receiver above all possible interfering objects. VHF frequencies, due to the length of their wave, are unable to transmit through many objects like walls, hills and dense forests. Typically, transmissions sent along these waves are sent and received high above the earth. Air traffic control uses 118-137MHz for all communication, and air navigation beacons use 108-118 MHz. In addition, FM radio and television also use VHF frequencies, where most of their signals are sent and received high atop towers spaced all over cities and counties.

In each country, VHF and UHF frequencies are assigned to certain designations. Here are just a few:

  • 7-1001 MHz – Cable TV
  • 30-46 MHz – Licensed two-way land mobile communication
  • 43-50 MHz – Cordless telephones
  • 87.5-108 MHz – FM radio broadcasting (You’ll recognize these numbers as they pop up the same on your car radio)
  • 156-158 MHz – Marine Radio (maritime emergency and contact frequency)
  • 162.40-162.55 MHz – NOAA Weather Stations

On two-way radios, antennas can be used to increase the distance that signals are transmitted. Below 30 MHz, wavelengths are too long to do this. If using your radio on VHF or UHF, an antenna right on your radio can help with communication over longer distances.

UHF

UHF (ultra-high frequency) radio waves are shorter waves designated from 300 MHz to 3,000 MHz. They are 1 decimeter to 1 meter in length, and are also affected by mountains, hills, buildings and walls, more so than VHF frequencies. One advantage to UHF over VHF is that antenna can be much smaller when used on higher frequencies. At times, a base antenna is needed for a radio using VHF, whereas a small antenna on the radio can be used for UHF. In addition, there are many more frequencies available using UHF, which can be extremely useful in areas with a higher population density. In contrast, the shorter wavelength of the UHF decreases the distance at which signals can be transmitted. The line-of-sight between sender and receiver is much shorter with UHF waves. With both VHF and UHF radio signals can be intensified and sent over longer distances using both antenna and repeaters.

There are many things that affect the signal strength of radio waves. Physical obstructions, solar wind, moisture and the time of day all degrade the strength of radio waves. The higher the frequency, and shorter the wave, the more these easily degraded the waves are. So VHF waves degrade less and can be sent over much longer distances versus UHF waves. In order to increase these distances, we can use repeater signals that receive messages from various radios, and use larger antenna to then send the signals back out.

In addition to repeaters, all over the world are large towers and masts that receive and send radio signals constantly. Because these towers reach high above most buildings and are often set in open fields, they are able to send and receive transmissions from much greater distances. When used with the many frequencies available on UHF, a massive amount of data is sent through each tower every day.

For personal use, a simple analog radio set to VHF is more than capable of sending and receiving messages for great distances (as long as physical obstructions are not weakening the signal). For commercial use, radios using UHF waves give large populations access to many more channels than VHF. Add to that repeaters high atop towers, and distances can be increased to hundreds of miles.

 

 

Analog vs Digital Radios

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Analog vs Digital Radios

Analog vs Digital RadiosIn the two-way radio world, there are two types of radios you can buy: analog and digital. Even though most would think that like cell phones, digital is the way to go, both have their pros and cons. What to buy depends on a number of different factors. Before you can decide which radio fits into your lifestyle or work place, let’s see what makes them different.

Analog radios use FM (frequency modulation) waves. These waves produce clear voice transmissions, but cannot filter out other noise around the sender. They are also not able to transmit signals past a few miles.

Analog radios are relatively inexpensive when compared to digital radios. They are far less complex and easy to use.

Analog radios have been in existence since the early 1900s and have therefore exhausted their advancement abilities.

There is no privacy on an analog radio as there is on a digital radio. A conversation can be heard by anyone else tuned into that station.

Digital radios are a bit more expensive than analog, but have far more capabilities, such as:

  • Voice filtering
  • Direct and group calling
  • Text messaging
  • Farther signal transmissions
  • Call privacy
  • TDMA protocol increases band usage, reliability and battery life

There are two kinds of digital radios, TDMA (Time Division Multiple Access) and FDMA (frequency-division multiple access). A TDMA radio uses the full 12.5 kHz channel and splits it into two time slots, using 6.25 kHz each. By splitting the band, more users can transmit on one channel, sending and receiving messages in succession based on time. TDMA radios have a higher battery life than FDMA, have reduced interference and many more voice and data channel options than FDMA radios.

FDMA radios, which are fewer in number than TDMA, use the frequency band by splitting it into narrow sub channels. It does not use the full 12.5 kHz that TDMA does. Fewer frequencies are available for use on an FDMA radio, and often upgrading is needed as more users are added. In contrast to the TDMA radios, FDMA radios are not vulnerable to timing issues. They can also be used with other digital and analog radios.

In many situations, analog radios are capable of performing the functions that many people require. They are relatively inexpensive and easy to find. Most also do not require a license, as we mentioned in our previous blog. They are also far less complex than digital radios and can typically be picked up and used by anyone with no learning curve. In addition, for emergency personell, analog radios can actually work better than digital radios. When a sender is speaking on a radio, noise behind them can be filtered out by a digital radio. But in some instances, especially when the background noise is particularly loud, a digital radio can actually error and confuse the two sounds, therefore creating confusion for the receiver.

In contrast, digital radios are, like cell phones, becoming the replacement for analog radios. They have many of the same capabilities as cell phones such as text messaging, group calling, privacy during calls and increased reliability. They have far more available frequencies to use, and can be conversational in fashion (the sender and receiver can speak at the same time). With the use of repeaters, their range can extend for hundreds of miles, and even without they are far superior in range to analog radios. Unlike analog, digital transmissions can be in any form such as voice or data.

Analog radios have reached the peak of their advancement. They are simple to use and are often all that is needed on a personal level. When an individual or company needs a more advanced radio that is capable of messaging, location services and more, they look to digital radios. As they become more and more popular, their price goes down. Their uses, like cell phones, will keep multiplying as technology progresses. They can be used on the TDMA protocol which has solved the problem of too many users on the same channels, and tend to be more reliable than most other radios, especially when used at great distances. If you’re a hunting guide or hiker, an analog radio might be all you need. But when your company is looking for advanced radios that can do it all, look to the world of digital radios.

 

FRS and GMRS Radios – What a Consumer Should Know

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There are two main types of handheld radios in the united states, FRS or Family Radio Service, and GMRS or General Mobile Radio Service. The two types differ in a number of ways, but what many don’t know is that a license is needed for one, and not the other.

 

FRS

The Family Radio Service was created in 1996 for use by individuals in close range. The FRS system uses frequency modulation (FM) rather than amplitude modulation (AM) which increases its predictability, as opposed to the CB band. Most FRS systems are found at local sports and hunting stores, and used between family members and friends. They are relatively inexpensive, can be used by anyone and are easy to find.

Unlike their more powerful big brother, GMRS, the FRS system is only allowed 500 milliwatts (half a watt) of power according to the FCC. Because of this, their range is very limited. Most FRS radios will work up to about 1 mile apart. Large trees, buildings or hills will interfere with and reduce the range of communication.

Each different radio service operates on specific channels. FRS radios are allowed on channels 1-14. Specific to FRS are channels 8-14, but channels 1-7 are shared with GMRS radios. FRS radios also use codes on each of these channels to filter out unwanted noise from other FRS users. Although this can increase privacy between talkers, it does not guarantee that others cannot hear what is being said. (Learn More about FRS Radios)

 
FRS and GMRS

GMRS

The GMRS system, as mentioned previously, is like the big brother to the FRS. Like the FRS, GMRS uses FM rather than AM waves to send signals, but unlike the FRS, GMRS can use up to 50 watts of power. Typically though, most GMRS radios use between 1 and 5 watts of power. Their range is a bit better than FRS radios, with typical hand-held devices being somewhere in the 1-2 mile window. Some mobile units with higher antennas can have a range up to 5 miles.

Today GMRS radio’s range is expanding exponentially, due to what is known as Wide Area Service. Similar to cell phone towers that are placed all around the country, wide area service providers are placing radio repeaters high atop buildings and other tall structures. Instead of a signal going directly from one radio to another, the signal is sent to the repeater, and then to the intended radio recipient. This repeater service increases the range dramatically, with each individual repeater being able to send out signal up to a 20 mile diameter around it. The range for GMRS radios using repeaters can be up to hundreds of miles.

GMRS radios share channels 1-7 with the FRS, but have their own specific channels of 15-22. On channels 15-22, GMRS radios are able to be used in duplex mode (where signals can be sent and received at the same time – explained in our previous blog on two-way radios vs. cell phones) whereas on channels 1-7 all radios can only be used on simplex mode.
In general, GMRS radios are higher powered, have an increased range, and are typically are bit more expensive (but also higher quality) than the FRS radios. The main, but often unknown, difference between the two is that in the United States, GMRS radios can only be used by licensed operators. (Learn More About GMRS Radios)

 

Licensing for FRS and GMRS Radios

Before 1987, the FCC required that businesses using GMRS radios be licensed. In 1987, this law switched to individual users. Today, anyone above the age of 18 can apply for a GMRS license (no test required). The fee is $85 and the license is good for 5 years, where at which time it can be renewed. Businesses with licenses that were obtained prior to 1987 can still renew for a fee, but new businesses cannot apply as such. Only individuals can get new licenses, and the licenses of businesses that were grandfathered in cannot be changed drastically.

In addition to the licensee, their immediate family can also use the GMRS radio under their license. GMRS licensees can communicate with FRS users under the FCC law, along with other GMRS licensee holders.

 

FRS and GMRS Radios, Which One Should I Use?

Are you a business with many employees, or a hunter who will only use a radio once a week? Do you travel long distances away from the people you need to communicate with, or are they merely a few hundred yards away? Cost is also a factor to consider, the cost of the radios themselves, and also the fee to get licensed. If you are a large company with employees, the licensing fee can be costly, but also well worth it. As a recreational user, an FSR radio is likely a better option for you. (Get More Tips On Choosing Your Radio

emergency situations

Emergency Situations – What Are Your Options?

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Classifying emergency situations is subjective. Depending on each person’s view, emergency situations could be as small as the toaster smoking. Fortunately most of us consider emergency situations to be at least somewhat life threatening. During such emergency situations, it is imperative that people are able to communicate. Not just emergency personnel, but everyday citizens need to talk to their family and contact others for help. As we have seen with situations like the brown out, 9-11 and hurricane Katrina, there are different modes of communication that are better than others in catastrophic situations.

 
emergency situations

Landline Phones In Emergency Situations

Although landline phones do not count on cell towers or satellites to operate, they do often need a modem nowadays. If your phone is serviced through a company like Verizon, make sure to ask if your landline will operate without power. Many won’t. If yours does, also keep in mind that landlines, unlike cell phones, are not required to be hooked up to a local 911 center. If your power is out, a landline phone might be your best option short term.

 

Internet – Email In Emergency Situations

If you have power, or a cell phone, your internet and/or email might be a good way to contact family members who are far away. Also, you can access local websites to see what is going on, where power is out, and if there are any instructions for people at that time. Utilize Facebook, see what people around you are doing, and keep in contact with others. But, if you don’t have power or cell phone access, none of these are options.

 

Cell Phone In Emergency Situations

For most every day emergencies, cell phones are the best option available. To call a tow truck, to let your wife know you broke your wrist playing softball, or when you just need some Chinese food. But what about during a hurricane or a blizzard? Most of the time cell phones work well even in these situations, until everyone tries to use their phones at the same time. Cell towers get overloaded, and quickly no one is able to get a call out.
When there are more disastrous events, such as hurricane Katrina, cell towers actually lose power. If they are knocked down by wind or water, they will no longer transmit a signal. If they lose access to the A/C power needed to run them, they also will not transmit signal. In addition to towers losing power, if power is out among your neighborhood or city, you will also have a difficult time charging your phone. During a long term outages, a car is an option, but keep in mind that fuel might be hard to get, and the battery in your car is charged by your car running. Some cars do not even charge a cell phone unless the motor is on, so use gas sparingly.

 

FRS Radio In Emergency Situations

FRS radios are a good option during an emergency; they are just typically unable to reach others at long distances. The emergency channel used for FRS and GMRS is the same, so likely if you are tuned into that channel, you can reach emergency personnel within a few miles distance. If you live in a remote area though, your best bet is a GMRS or Ham radio.

 

GMRS Radio In Emergency Situations

GMRS radios require you to obtain a license, but are able to send and receive signals from other radios from many miles away. GMRS radios use repeaters on tall buildings and towers to send and receive signals out over very far distances. As long as the repeaters are intact, the radios will work, and you can contact a larger number of people than FRS radio can.

 

Ham Radio In Emergency Situations

Using a ham radio, people have reported being able to chat with others across the world, using repeaters of course. A license is required, but well worth it. And with some practice, in an emergency situation ham radios can be invaluable. You can get them as stationary or portable devices, and with some tinkering, and additional antennas, you can reach out to most anyone. The test to get licensed is not particularly hard, and knowing Morse code is no longer needed, but it does take some studying. Overall according to preppers and the like, the Ham radio is your safest bet in an emergency.
Remember that in an emergency, communication is important, but so is being prepared. In addition to whatever form of communication you choose, make sure you have batteries, water, some source of heat and extra food. A generator is always a plus, just remember to keep extra fuel at home (stored appropriately) for it. Keep your phone or radio charged, and don’t panic. Clear headed, calm individuals are always beneficial in an emergency and can be of great help to emergency workers and their very own fellow citizens.