For those who have been in a cage and have no idea what Citizens Band Radio is, it is a group of 40 frequencies between 26.965 MHz and 27.405 MHz in the 11-meter radio band for use by citizens without the need for a license to operate. This isn't a radio for broadcasting as you would hear on your AM/FM/Satellite radio. This is for 2-way communications. CB Radio runs on an amplitude modulation (AM) carrier or Upper/Lower Single Side Band (SSB) waves. There are many different types of CB radios, including hand-held walkie-talkies with a built-in antenna, mobile units for vehicles or motorcycles with roof/trunk/bumper mountable antennas, and home base stations with roof antennas.
How far can you talk on the CB radio? It all depends on several circumstances, which are power output strength, height/style of antenna, and your geological location, local terrain, and atmospheric conditions. On walkie-talkies, you can expect up to 1-2 miles at best at street level. On a mobile unit, 2-5 miles. On a base unit. 5-30 miles or more depending on the above-stated circumstances. Locally, I have reached as far as 70 miles on my base at home and 187 miles on my mobile (from atop Mt. Washington at a 6,288-foot elevation in New Hampshire, speaking to someone in Hartford, Connecticut) The farthest I have reached locally on a walkie talkie is 25 miles from atop Mt. Wachusett (about 2000 feet elevation) in Princeton, Massachusetts to Waltham, Massachusetts which is near Boston. Please remember, however, that I have top-of-the-line antennas; therefore, I get out much further than your typical Radio Shack style setups, as I often seek higher elevation. Anyway, local conversations are what is called line-of-sight transmission.
- Simple Explanation -
There is a phenomenon that allows long-distance communications that is called Ionospheric Radio Wave Propagation, aka “skip” or “DX”. It is when solar magnetic radiation emanating from sunspots (magnetic storms on the sun) charges the Earth’s ionosphere which is over over 30-250 miles high up in the sky causing it to act like a mirror for radio signals below 30mhz so it is possible for the signals to bounce off the charged ionosphere and end up 100 miles away, or up to 10,000+ miles away on the other side of the world. Signals also bounce off of terrain and water to allow for multiple skips. Sunspots, which cause skips, are on an 11-year cycle; therefore, skip conditions go on an 11-year cycle (intensity-wise), and in 2006 we were at the lowest activity part of the cycle. The cycle will peak again in 2037/2038. “Skip” isn’t always happening. Some days it is very strong, and you can talk all over the world. Other days there is no skip, and you can only talk line of sight. It completely depends on sunspot intensity on the surface of the sun. There is no solid way to predict when skip conditions will be present. The only real thing you can do is turn on your radio and see the current conditions for yourself.
- Detailed Explanation -
(Courtesy of the National Oceanic & Atmospheric Administration - Space Environment Laboratory)
- Ionospheric Radio Wave Propagation -
The Sun’s electromagnetic radiation is a continuum that spans radio wavelengths through the infrared, visible, ultraviolet, x-ray, and beyond. Ultraviolet radiation, through a process termed photoionization, interacts with upper atmospheric constituents to form an ionized layer called the ionosphere.
The ionosphere affects radio signals in different ways depending on their frequencies (see Figure 1), which range from extremely low (ELF) to extremely high (EHF). On frequencies below about 30 MHz, the ionosphere may act as an efficient reflector, allowing radio communication to distances of many thousands of kilometers. Radio signals on frequencies above 30 MHz usually penetrate the ionosphere and, therefore, are useful for ground-to-space communications.
The ionosphere occasionally becomes disturbed as it reacts to certain types of solar activity. Solar flares are an example; these disturbances can affect radio communication in all latitudes. Frequencies between 2 MHz and 30 MHz are adversely affected by increased absorption, whereas on higher frequencies (e.g., 30–100 MHz) unexpected radio reflections can result in radio interference.
Scattering of radio power by ionospheric irregularities produces fluctuating signals (scintillation), and propagation may take unexpected paths. TV and FM (on VHF) radio stations are affected little by solar activity, whereas HF ground-to-air, ship-to-shore, Voice of America, Radio Free Europe, and amateur radio are affected frequently. Figure 2 illustrates various ionospheric radio wave propagation effects. Some satellite systems, which employ linear polarization on frequencies up to 1 GHz, are affected by Faraday rotation of the plane of polarization.
- Solar Flare Effects -
A solar flare is a sudden energy release in the solar atmosphere from which electromagnetic radiation and, sometimes, energetic particles and bulk plasma are emitted (Figure 3). A sudden increase of x-ray emissions resulting from a flare causes a large increase in ionization in the lower regions of the ionosphere on the sunlit side of Earth. A sudden ionospheric disturbance (SID) of radio signals can ensue. An SID can affect very low frequencies (e.g., OMEGA) as a sudden phase anomaly (SPA) or a sudden enhancement of signal (SES). At HF, and sometimes at VHF, an SID may appear as a shortwave fade (SWF). This disturbance may last from minutes to hours, depending upon the magnitude and duration of the flare.
Solar flares also create a wide spectrum of radio noise; at VHF (and under unusual conditions at HF) this noise may interfere directly with a wanted signal. The frequency with which a radio operator experiences solar flare effects will vary with the approximately 11year sunspot cycle; more effects occur during solar maximum (when flare occurrence is high) than during solar minimum (when flare occurrence is very low). A radio operator can experience great difficulty in transmitting or receiving signals during solar flares.
- Energetic Particle Effects -
On rare occasions, a solar flare will be accompanied by a stream of energetic particles (mostly protons and electrons). The more energetic protons, traveling at speeds approaching that of light, can reach Earth in as little as 30 minutes. These protons reach the upper atmosphere near the magnetic poles. The lower regions of the polar ionosphere then become heavily ionized, and severe HF and VHF signal absorption may occur. This is called a polar cap absorption (PCA) event. PCA events may last from days to weeks, depending upon the size of the flare and how well the flare site is magnetically connected to Earth. Polar HF radio propagation often becomes impossible during these events.
- Geomagnetic Storm Effects -
Sufficiently large or long-lived solar flares and disappearing filaments (DSF) are sometimes accompanied by the ejection of large clouds of plasma (ionized gases) into interplanetary space. These plasma clouds are called coronal mass ejections (CME). A CME travels through the solar wind in interplanetary space and sometimes reaches Earth (Figure 5). This results in a worldwide disturbance of Earth’s magnetic field, called a geomagnetic storm. Another type of solar activity, known as a coronal hole (CH), produces high-speed solar wind streams that buffet Earth’s magnetic field; geomagnetic storms that may be accompanied by ionospheric disturbances can result.
These ionospheric disturbances can have adverse effects on radio signals over the entire frequency spectrum, especially in auroral latitudes. In particular, HF radio operators attempting to communicate through the auroral zones (the regions of visible aurora, or “Northern Lights”) during storms can experience rapid and deep signal fading due to the ionospheric irregularities that scatter the radio signal. Auroral absorption, multipathing, and nongreatcircle propagation effects combine to disrupt radio communication during ionospheric storm conditions. During large storms, the auroral irregularity zone moves equatorward. These irregularities can produce scintillations that adversely impact phase-sensitive systems on frequencies above 1 GHz (e.g., the Global Positioning System). Geomagnetic storms may last several days, and ionospheric effects may last a day or two longer.
- AM vs Single Side Band (SSB) -
Here is a little technical explanation of the difference between AM and single sideband (SSB). I will try to keep it simple. You see, AM radio waves are a combination of a carrier wave and two single sideband waves. Picture the carrier wave as a bus, and the single sideband waves are signs on each side of the bus. Each sign carries half of the total message. CB radios that are equipped for SSB may transmit on either AM or one of the single sidebands of each frequency. So, say you are able to remove the bus and one sign from the picture, and the entire message is put on one sign by itself. That is what single sideband is. It focuses all of your power and message onto one single sideband wave instead of a carrier and 2 single sideband waves as it does on the AM band. So, in fact, a 40 Channel CB radio technically has 120 operation modes (40 AM, 40 Upper Sideband, and 40 Lower Sideband). Each of the 40 channels includes the AM, upper single sideband, and lower single sideband waves. Now, when transmitting on AM, your output power is split between AM, upper single sideband, and lower single sideband.
Maximum legal power output is 4 watts on AM. The actual output power is 12 watts but is split between the AM carrier, upper single sideband, and lower single sideband. But when you transmit solely on one of the single-sideband waves, your entire output power is focused on that particular sideband wave. Therefore, you get a total output of 12 watts on the single sideband wave, which significantly increases your output range.
Anywho, truckers and locals usually hang out on the AM band to chit chat. There is a group of hobbyists that love to use the AM band for long-distance communications. They also use a lot of CB radio jargon that would sound like a foreign language to people who don't know the lingo. I personally prefer to hang out on the Upper/Lower SSB, which is mostly hobbyists. We use ham radio "Q codes," which are similar to the "10-4" type of codes most people have heard of. The Q codes are 3 letters each. So the stereotypical idea that only truckers use CB radios is false. But because of that stereotype, many people who do use CB radios won't admit it for fear of being made fun of for it.
CB radio peaked in the 70’s. At first, you needed a license, and the FCC watched over the band like a hawk. However, you no longer need a license, and the FCC doesn’t pay too much attention to the band and will leave you alone as long as you are not causing interference with anything important. The hobby peaked again in the early to late 1990s; however, since then the hobby has greatly waned.
People ask me how partaking in this hobby is fun. Honestly, I can't explain it. Maybe the idea is that you are communicating with someone without the aid of wires, cell phone towers, or the internet. Just radio waves from your house, car, handheld, etc. It's an old technology and not new and state of the art. But it is very entertaining if you like that sort of thing. There is a challenge to making communications long distance using the Earth's ionosphere as a mirror, whereas when you use cell phones, there is virtually no challenge, short of some areas where cell phone service is minimal.
Regarding people who use the AM band... For some people, it is for safety while on the road. Many truck drivers have CB radios in their trucks, as well as people who travel often by car. They use it for an emergency, for directions, and local information on where the best restaurant is or where they can get a good deal on gas. They also just use it to talk to people on a long drive. On a long drive, talking to someone can help the drivers feel that they are not alone and/or keep them entertained. Also, the police love it because it helps keep long-distance or even short-distance drivers awake.
As for the SSB... For some, it's an attempt to see how far away they can contact someone on the radio or to have a civilized conversation away from the AM band riffraff. Sure, sideband has its own riffraff, but it isn’t close to as bad as it can be on the AM band. For some, they just enjoy talking to people that they don’t really know, but great friendships can and do happen on the CB radio. Why do I do it? My #1 reason is for ionospheric radio wave propagation, aka DXing (long-distance communications) aka “shooting skip”. Secondary reason would be the fascination with talking over radio waves without the help of modern communications technology. You can easily go in a chat room or message board on the internet to meet people you don’t know, but doing so over radio waves makes it a bit more challenging and is a more involved experience, in contrast to a passive hobby that takes little effort on the person's part. I find that the CB radio hobby takes a little more effort and yields, in my opinion, greater satisfaction.
My handle (CB radio name) is “Extreme”. I use that when talking locally on the AM band, which I rarely do. For DXing (long distance) on the SSB bands, I use a call sign from an international CB Radio SSB group called American Eagle SSB CBers Club. It is a group of about 1450+ people living worldwide who share a common interest, communicating on a CB radio on the SSB modulation waves. In that group, I am known as “2 American Eagle 813” or simply “2AE813”. In 2006, I took over as Director of Operations of the group. I am in another club called Sierra Fox DX Group, and in that group I am known as 2SF1701. That group has around 500 people in it. I am also in a DXing group with over 300 members, started on the CB Radio Forum, and my call sign is RF717. I am also a member of approximately another half dozen CB radio DXing groups.
On Sideband, when talking DX, people can send each other what is known as “QSL” cards. QSL means received transmission. It is from a group of “Q Codes” that people use on SSB instead of the usual 10 Codes that are used on AM, such as 10-4, which means "received," or any trucker jargon that they use. It's more like a heavily watered-down version of amateur radio (ham radio) than anything. Many ham radio operators will disagree, but the root basis is somewhat similar. QSL cards are like a certificate, business card, or however you want to look at it. Basically, it is proof on paper that you did make contact with someone far away. The paper will include call signs, date, time, frequency, and locations. Due to higher postal/printing costs as time goes on, many choose to do an e-mail QSL card instead of a hard copy.
Well, that is CB radio in a nutshell. If you have any questions pertaining to the hobby, please feel free to contact me. I will do my best to answer your question for you, and if I am unable to answer your question for you, I will gladly point you in the direction where you should be able to get an answer for your question, as I know where to find the experts in the field.
73 (best wishes, which you will often hear misstated as 73’s, which translates to best wisheses, as 73 is already plural in meaning.) I hope to hear you out on the airwaves! If atmospheric conditions are just right, you may very well hear me on your radio. American Eagle 813, in the clouds on the summit of Mount Washington in the White Mountains of New Hampshire, is QRX (standing by).
