In the words of the fictional character Jeff Trasel from the novel "Patriots:
A Novel of Survival in the Coming Collapse"
: “If you don’t have Com, you don’t have jaaack“. The subject of radio communications as it relates to Prepping is an often misunderstood topic. Understanding radio communications issues can also be confusing, complicated, and daunting for the newcomer. There is a lot to know about the subject, and speaking as one that has spent a good part of his life experimenting with radio communications, it seems that the more I learn about radio communications, the more I learn how much I have to learn! In this article I would like to share much of the information that I have gleaned about radio communications technology and it’s applications. I will attempt to present this article in a way that the reader can glean real world applications, and in a way that it is easy to understand for the novice.
Before delving into any technical issues about radio, one must establish what it is that one wants and needs their communications systems to accomplish. Communications is yet another area where rule 6-P applies; that is, “Proper Prior Planning Prevents Poor Performance“. Proper planning is absolutely crucial to accomplishing your communications related goals. Communications equipment can be somewhat costly, depending on what it is designed to do. The main question one must ask when planning a crisis communications system is, “What is it exactly that I want my crisis communications system to accomplish?” Crisis communications planning must be approached from a system wide mindset and not a compartmentalized mindset. This means you have think of the big picture and you must be cognizant of how all the pieces of your communications plan fit together before you start buying equipment This will allow you to better utilize your limited resources as it relates to what equipment you will buy and how you will use it. It will also prevent significant headaches later on.
Although there are plenty of arguments pro and con in the “preparedness” world about this, I would advise anyone that is serious about establishing a crisis communications system to consider becoming a licensed Amateur Radio operator. Communications equipment is like any other preparedness related equipment. If it is purchased and then left in a box until needed, it will not work as intended at the moment of truth. Becoming a skillful radio technician and communicator is an on-going process. This is true whether you go down the Amateur Radio road or not. You must know the strengths, weaknesses, and limitations of your equipment. If you don’t, then you can’t reasonably expect to know how to use the equipment under less than ideal circumstances. I use the following illustration to make the point. In our county, the local health department recently had several of it’s employees take a “Ham Cram” class and they received a Technician Class Amateur Radio license. The health center also received Amateur Radio equipment through federal and state grant funding. The reality is, even though several of the employees are licensed Amateurs, the equipment does not get utilized because none of the employees have truly applied themselves to learning the “hands on” and “how to” of Amateur Radio. This shows that just because one has a license to do something, it doesn’t necessarily follow that one is proficient at the task which one is licensed for. Once you decide what it is you want to accomplish, then it’s time to consider your options. The first options I will discuss are those which are available to be purchased and used by anyone and that does not require a license to operate. Then I will delve into what Amateur Radio can do for your crisis communications plan.
The first option I will discuss is a system know as the Family Radio Service (FRS) . It consists of fourteen Ultra High Frequency (UHF) frequencies. FRS radios are limited to an output power of 0.5 watt, and can be purchased at a low price from many retailers. The low power output means that the range of these radios are limited. One advantage is that FRS radios use FM modulation as opposed to AM. This means that FRS frequencies are not as susceptible to noise or interference from power lines, as can be seen with handheld Citizens Band (CB) radio which will be discussed later. Another possible advantage to FRS radios and UHF signals in general is that they often perform better in urban environments. This is because signals in the UHF frequency range penetrate buildings better than signals in other frequency bands. FRS channels 1 through 7 are shared with the General Mobile Radio Service (GMRS), channels 8 through 14 are for FRS use only, and channels 15 to 22 are for GMRS use only. This is why most FRS radios are pre-programmed with 22 channels. The GMRS only channels should not be used unless you possess a GMRS license. GMRS will be discussed later.
There are many practical uses for FRS, and it can be used in situations where one needs non-secure voice communications over an area of five miles or less. You should only expect FRS to work reliably for approximately 1 to 2 miles. The range will depend greatly upon the surrounding terrain, because propagation of radio waves in the UHF frequency range is limited to line of sight. This means that the radio wave will only travel as far as the horizon. I will also discuss line of sight in depth later in this article. One drawback to FRS is that is a very popular system, and there will be many other people sharing a very limited pool of frequencies. Many manufactures of FRS radios will tout “privacy” features on their radios. Do no misunderstand what they are talking about here. The “privacy” features do not encrypt or make your communications secure in any way. These features utilize a combination of Digital Coded Squelch (DCS) and Continuous Tone Coded Squelch System (CTCSS) techniques. I know that sounds very technical, but think of it in this way. If you activate DCS or CTCSS, then the only time the squelch of your radio will open (this means you will hear audio coming from the speaker) , is when the radio transmitting the signal is transmitting the same code that you have programmed your radio to receive. Because of this, there may be someone else operating on your frequency, but if they do not have the proper transmit tone programmed, then you will not hear them. DCS or CTCSS do not change the fact that FM receivers by their design will always “capture” the strongest signal. This is known as the “capture effect”. This means that the strongest of any two or more signals will override weaker signals in the receiver. DCS or CTCSS allows you to reduce the amount of frivolous traffic that you will hear on the radio, but it in no way makes your communications secure or private. Anyone with a programmable scanner receiver or an FRS radio will be able to eaves drop on your communications.
Also, remember that is always possible that organized adversaries may utilize FRS radio equipment to coordinate their attacks, assaults, and other activities. In the event of a crisis, it would be of great value to have the ability to constantly monitor the FRS channels for this type of activity. Obtaining this communications intelligence (COMINT) could keep you and your family safe and could give you the early warning you need to prepare for an imminent an assault. For reference the FRS frequency table is as follows, expressed in MegaHertz (MHz):
CH 1 462.5625 (Shared with GMRS)
CH 2 462.5875 (Shared with GMRS)
CH 3 462.6125 (Shared with GMRS)
CH 4 462.6375 (Shared with GMRS)
CH 5 462.6625 (Shared with GMRS)
CH 6 462.6875 (Shared with GMRS)
CH 7 462.7125 (Shared with GMRS)
CH 8 467.5625 (FRS only)
CH 9 467.5875 (FRS only)
CH10 467.6125 (FRS only)
CH11 467.6375 (FRS only)
CH 12 467.6625 (FRS only)
CH 13 467.6875 (FRS only)
CH 14 467.7125 (FRS only)
CH 15 462.550 (GMRS only)
CH 16 462.575 (GMRS only)
CH 17 462.600 (GMRS only)
CH 18 462.625 (GMRS only)
CH 19 462.650 (GMRS only)
CH 20 462.675 (GMRS only)
CH 21 462.700 (GMRS only)
CH 22 462.725 (GMRS only)
The Multiple Use Radio Service (MURS) is another communications system that can be used by individuals and which requires no license to operate. MURS is similar to FRS in operation but MURS frequencies are in the Very High Frequency (VHF) band. MURS radios operate at a maximum output power of 2 watts. This is slightly higher than FRS radios which are limited to 0.5 watts. MURS radios can be purchased through many different on line retailers and communication equipment suppliers. The effective range of MURS radios is similar to FRS radios and depending upon terrain, will typically range from 1 to 5 miles for hand held units. In urban areas this may be decreased due to the types and number of structures in the area. This is because VHF signals don’t penetrate buildings and structures as well as UHF signals. MURS range may be increased in some rural areas because signals in the VHF frequency range tend to propagate better over open, flat terrain. It should be noted that VHF signals from MURS radios are subject to the same limitation as UHF signals from FRS and GMRS, in that they are line of sight, and the signals will only travel as far as the antenna can “see”. One advantage to MURS is that you are allowed to use external gain antennas with MURS frequencies. An externally mounted, elevated antenna will improve the performance and range of most any radio because of the “line of sight” principle. Logic dictates that the higher the antenna is, the further it can “see”. The legal antenna height for MURS is limited to no more than 60 feet above ground, or no more than 20 feet above the structure that it is mounted on. An external gain antenna is of great benefit to the performance of most types of transmitters and receivers, not just MURS radios. (A transmitter is any radio that sends out or “transmits” a signal and a receiver is any radio that “receives” or picks up a signal.) Also, “antenna gain” is a term that describes how well an antenna performs. The higher the gain, the better the performance.
It should also be noted that some driveway monitors, including those made by “Dakota Alert” use MURS frequencies. The advantage to this arrangement is that you can carry a MURS portable radio on your person while you are out working around your retreat, and you can receive alerts from the driveway alarm. Some of these MURS based driveway alarms include a push to talk (PTT) base station for your home, which means that not only can the indoor base receive the driveway alerts, but a person inside the house can transmit from the base station and have communications with another person carrying a MURS portable radio. As with FRS, possible adversaries may use MURS equipment to coordinate their activities, so it is worthwhile to monitor these frequencies for COMINT. The MURS frequency table is as follows, expressed in MegaHertz (MHz):
151.820 (FM narrow mode)
151.880 (FM narrow mode)
151.940 (FM narrow mode)
154.570 (FM wide mode, shared with business band)
154.600 (FM wide mode, shared with business band)
The next communications system I will discuss is the Citizen’s Band (CB) radio. CB radio has been in existence since the late 1950s, and now consists of 40 pre-programmed channels in the 27 MHz band. CB radio has some limitations that, in the opinion of the author, make it a poor choice as a survival related communications tool. CB radio has many things that work against it. CB is limited to 4 watts of output power. CBs also operate in the Amplitude Modulation (AM) mode. AM modulation, in conjunction with CB’s place at the top end of the High Frequency (HF) radio spectrum, makes it very susceptible to interference from power lines and other sources. Try a real world test to prove this point. The next time you are driving underneath high voltage power lines, tune the AM radio in your car to an unoccupied frequency. You will hear a great deal of noise that comes over the speakers of your car radio. Now tune it over to a vacant FM frequency. You will not hear the line noise. This same phenomenon affects CB radio and greatly limits it’s utility, especially in cities, towns, and urban areas where high voltage lines are present. The low transmit output power also severely limit’s the distance that a CB signal will travel. Some CB radios utilize “side-band” technology. This means that the radio takes a standard AM signal and divides it into two halves, upper and lower sideband. This allows slightly more power to be used to create the voice signal. This single sideband (SSB) mode can be selected by a knob on properly equipped CBs, tuning to either Upper Side band (USB) or Lower Side band (LSB). Sideband technology does increase the output power of a CB, but only to about 12 watts PEP (peak envelope power).
A decent antenna will improve CB performance whether it is installed in a vehicle as a mobile installation or as a base station inside a structure with which you can utilize external gain antennas. CB can work well in point to point simplex applications (such as one retreat communicating with another on a direct frequency), but there are better solutions for base to base communications to be found in the realm of Amateur Radio. One advantage to CB is that he radios typically operate of 12 volts DC, which makes it more practical to provide back up power. A deep cycle battery or other 12 volt DC system can provide this power. Amateur radio gear that will be discussed later also runs on 12 volts DC. You can easily install a CB base station at your retreat by connecting a mobile CB radio to a 12 volt DC power supply. The key to effective CB base station installation is to get the antenna up in the air as high as possible. Most of the time, radio waves in the 27 MHz propagate effectively as ground waves. This means that once again, the waves travel “line of sight”. However, at some points in the 11 year solar cycle, the Maximum Usable Frequency of the Ionosphere (more on that later in the Amateur Radio section) will increase to the point where to 27 MHz signals can propagate across the country and even across the world while using very low power levels. This can be fun to “shoot skip” as the CB’ers say but in reality 27 MHz skywave is not very reliable, so 27 MHz signals can only be depended on to function “line of sight” with regular reliability.
Another advantage to CB use is that is very widespread and having CB radio capability promotes interoperability with others. This could be very useful during a bug out when traveling on roadways and you are in need of information. As most red-blooded American’s know, CB is widely used in the trucking industry and those trucks can be treasure trove of useful information. For that reason, even though I don’t rely solely upon CB for my crisis communications plan, I do always have CB equipment available for use if needed. As with the other equipment mentioned earlier, CB is easily monitored and intercepted. This means your communications are not secure and an adversary using CB radio could use it against your retreat. Also note that there are several CB channels available for “remote control” purposes. These are intended to be used for RC aircraft, cars, etc. Under normal circumstances, I would certainly obey these restrictions but if needed, and if the user had the proper equipment, these channels could provide the user with less congested frequencies to conduct voice communications. CB frequencies can also be monitored by some programmable scanner receivers. The CB frequency table is included below for your reference, expressed in MHz:
CH 1 26.965
CH 2 26.975
CH 3 26.985
CH 4 27.005
CH 5 27.015
CH 6 27.025
CH 7 27.035
CH 8 27.055
CH 9 27.065
CH 10 27.075
CH 11 27.085
CH 12 27.105
CH 13 27.115
CH 14 27.125
CH 15 27.135
CH 16 27.155
CH 17 27.165
CH 18 27.175
CH 19 27.185
CH 20 27.205
CH 21 27.215
CH 22 27.225
CH 23 27.255
CH 24 27.235
CH 25 27.245
CH 26 27.265
CH 27 27.275
CH 28 27.285
CH 29 27.295
CH 30 27.305
CH 31 27.315
CH 32 27.325
CH 33 27.335
CH 34 27.345
CH 35 27.355
CH 36 27.365
CH 37 27.375
CH 38 27.385
CH 39 27.395
CH 40 27.405
CB Remote Control Channels
26.995
27.045
27.095
27.145
27.195
Amateur Radio
The next section we will discuss is Amateur Radio. Amateur Radio is, in the opinion of the author, the most viable form of communications for a crisis. I say this because all of the communications systems discussed up to this point are fixed in nature and are not designed to be flexible. These radios use only pre-programmed, non-tunable channels. They are designed to be used by untrained, unlicensed individuals and they are designed in a way that will limit there effective range so as to prevent harmful interference to other untrained, unlicensed users. Amateur radio on the other hand is just the opposite. It is flexible by nature, and for many reasons.
Amateur Radio (otherwise known as Ham Radio) has been around for almost 100 years and consists of many different frequency bands ranging from 1.8 MHz to 1240 MHz. Amateur Radio operators are licensed in the United States by the Federal Communications Commission (FCC). To be an Amateur Radio operator, one must pass a written multiple choice test which consists of different elements such as operating rules, electronic theory, radio frequency energy (RF) safety, antenna theory, and others. There are three levels of Amateur Radio license in the U.S. and they are Technician Class the entry level license), General Class ( an intermediate license) and Extra Class (the highest level of license). Many folks I have spoken with over the years have told me that they didn’t want to get involved with Amateur Radio because they didn’t want to learn Morse Code. The reality is that Morse code proficiency is no longer required to obtain an Amateur Radio license and hasn’t been for several years.
Obtaining an Amateur Radio license has never been easier. License exams are administered by volunteers with an FCC approved Volunteer Examiner Coordinator (VEC). Most communities are within an easy car trip of a testing location. The cost is very low and once you obtain the license, you renew it every 10 years at no cost. You can find a testing site near you by going to this web page. The American Radio Relay League (ARRL) is the America’s national association for Amateur Radio and you can explore their informational web site at ARRL.org . The questions and answers to the tests are published in pools that are updated every three years. As such it is very easy to study for these tests because you already have access to all of the possible questions and answers before the test. The VEC’s must select questions only from this pool so, it’s not a subjective test. There is ample study material available at w5yi.org and other internet sources. This includes study manuals and study software. I’m not giving anybody a plug here but I can tell you that the Gordon West study manuals that are available at w5yi.org are great material to use, and they helped me pass all of my exams easily. Amateur Radio equipment can be found at reasonable prices on the Internet (such as eBay), from other Amateurs, or at local “Hamfests”, which are swap meet for Amateur Radio gear. Find a local Amateur to help you out. We are a helpful bunch and will bend over backwards to get someone into the hobby and look forward to "Elmering" (mentoring) someone.
To get started in Amateur Radio, the first test you need to take is the Technician Class test. This test consists of a 35 question multiple choice test. After passing this test, and after you receive your first callsign from the FCC, you will have operating privileges on all Amateur Radio bands from 6 Meters (50 MHz) and up. This will provide you with access to the entire VHF and UHF amateur frequency bands. The propagation characteristics (meaning how radio waves travel) of these frequency bands can allow you to communicate both locally and regionally (out to about 50 miles, depending on system configuration). Frequency bands differ from “channels” in that “channels” (as applied to FRS, GMRS, MURS, CB) are pre-set and synthesized meaning that you can’t change the frequency. This means that you will have a lot of stations competing for a very limited amount of radio spectrum. With Amateur Radio however, the user selects the operating frequency and there is much more spectrum space available to carry out interference free communications. The two most commonly used bands available to Technician Class licensees are the 2 Meter band (144 to 148 MHz) and the 70 cm band (420-450 MHz). The Technician Class will also give you limited voice operating privileges on the 10 Meter HF band from 28.300 to 28.500 MHz. The 10 Meter band is at the highest portion of the High Frequency (HF) amateur bands. This means you will give you a taste of what HF radio is all about. 10 Meters propagates very similar to CB radio so you will only be able to communicate over long distances beyond line of sight when propagation conditions are favorable.
The second license available is the General Class license. This test consists of 35 multiple choice questions. There are many advantages to pursuing the General class upgrade after you pass the Technician test. Amateur Radio licenses build on one another, so when you upgrade to the next license class, you retain all of the privileges that you have previously earned and then receive more. The biggest advantage to the General class license is that it gives you much broader access to the High Frequency (HF) bands. The General class license will give you operating privileges on every Amateur band, whereas the Technician license limits your activities as an incentive for you to upgrade your license. The HF bands allow you to communicate locally, regionally, nationally, and even worldwide when the geomagnetic ionospheric conditions are favorable. More on those conditions later.
The third and final class of Amateur Radio license is the Extra Class license. This test consists of 50 multiple choice questions. The Extra Class is highest level of Amateur Radio license issued buy the FCC. The only advantage to earning the Extra Class license is that it gives one additional slivers of access to some of the HF bands. Your level of interest in furthering your expertise and study is what will motivate you to seek the Extra Class license or not. I know many amateurs who have been a General for many years and they have seen no need to upgrade. I have met others who challenged and took all three license exams and passed on the same day! [JWR Adds: And when you pay the day's test fee ( $15) that covers all of the tests that you take on that day.] So it really depends on one’s personal motivations as to whether one pursues this goal.
Band Allocation
I will now provide a description of each of the most commonly utilized Amateur Radio bands and equipment and how they can be utilized in communications planning. Before talking about the bands, one must have a grasp of a few basic concepts and terms. First, the designation “meter” as it applies to the description of radio bands is the measurement in meters between the peaks of the radio waves at a given frequency. Think of it this way. Radio waves, if they could be seen with the naked eye, would appear much as waves in the ocean do. They have peaks and lulls at timed intervals. The “meter band” measurement is the measurement between the middle of the peak of one wave and the middle of the peak of the following or preceding wave in meters (or centimeters in some cases) at a given frequency.
The second concept one must understand is antenna resonance. When an antenna is resonant, that means that the antenna absorbs and thereby radiates most all of the Radio frequency (RF) energy that is applied to it. If the antenna is not resonant, it will reflect a given portion of the power applied to it back to the transmitter. The amount of reflected power will be proportional to just how far out of resonance the antenna is. The amount of power reflected back as compared to the amount of forward power applied is known as the Standing Wave Ratio (SWR). Typically, an SWR of greater than 2:1 indicates antenna inefficiency and may the reflected power may damage your transmitter. An antenna analyzer is very helpful in attaining antenna resonance but is a very costly piece of equipment and is out of the price range of most Amateurs, and the theories of inductance and capacitance as they effect antenna tuning are way beyond the scope of a small article. A good rule of thumb to remember is that the lower one goes in operating frequency, the larger the antennas become due to the unchangeable laws of physics. But fear not, there are many things you can do to get a good signal on the air, which will also be discussed.
The third concept one must understand is the concept of radio wave propagation. Propagation is simply the method by which a radio wave travels from point A to Point B. There are two major ways that radio waves propagate. The first is by “line of sight” as discussed earlier. Line of sight means that the radio wave will only travel as far as the antenna can electrically “see:” This is typically the distance to the visual horizon plus about 15%. There are two very simple formulas for calculating line of sight which I have found to be very useful in determining how far a radio signal will travel. They are:
Radio Line of Sight:
D=v(2Hr)+v(2Ht)
Where:
D= approximate distance to radio horizon in miles
Hr= height of receive antenna in feet
Ht= height of transmit antenna in feet
Visual Line of sight:
Approximate distance in miles= 1.33 X v (height in feet)
Another quick reference table regarding radio line of sight that may be useful:
Where:
Range=approximate radio range in miles
TX Ant. Height= height of transmitting antenna in feet
RX Ant. Height= height of receiving antenna in feet
Range TX Ant. Height RX Ant. Height TX Ant. Height Range
8 10 5.5 150 21
10 20 5.5 200 23
11 30 5.5 300 28
12 40 5.5 400 32
13 50 5.5 500 35
16 75 5.5 750 42
17 100 5.5 1000 48
The second mode of propagation is by “Skywave”. This concept is a bit more complex but with time and experience, one can get a pretty good grasp as to how skywave will behave on certain bands, at certain times of the year, and at certain times in the sunspot cycle. Skywave involves HF radio waves (which are frequencies of 3 to30 MHz) being sent up and then reflected back to the Earth’s surface by the Ionosphere at distances of hundreds or thousands of miles away. Skywave propagation is made possible thanks to the Ionosphere. The Ionosphere several layers of electrically charged particles that range from about 30 to 600 miles above the earth’s surface. It is comprised of several layers including D, E, F, F1 and F2. The D layer ranges from about 35 to 55 miles above the surface. The D layer is an enemy to skywave propagation but fortunately it is only in existence during the day and it vanishes at night. The D layer does nothing to reflect signals, but it will absorb and attenuate daytime signals, especially in the 160, 80, 75, 60, and 40 Meter Amateur bands. It is often known to Amateurs as “That Dang D”. The E layer ranges from 55 to 75 miles above the surface. The E layer is an occasional player in skywave propagation and can reflect signals back to Earth at distances of several thousand miles under proper conditions. E layer skywave propagation is often sporadic in nature, and can effect frequencies that are well above the HF part of the spectrum. The F1 and F2 layers exist only in the daytime (like the D layer). At night, the F1 and F2 layer combine to form the F layer. The F layer in it’s various forms ranges from 125 to 300 miles above the surface. The F layer is responsible for most reliable skywave communications.
The Ionosphere is “ionized” by Ultraviolet (UV) rays and X-Ray radiation from the sun. The sun goes through stages of activity and inactivity that waxes and wanes over an 11 year period. This means that the amount of radiation from the sun goes up and down, and that in turn effects the Ionosphere. The rule of thumb is that as more sunspots, (which are dark and comparatively cool areas) develop on the visible surface of the sun, the more ionizing radiation the sun emits. This means that sky wave propagation is usually enhanced due to increased ionization in the Ionosphere. Increased solar activity is a double edged sword however, and during solar flares, which are sudden, large emissions of solar radiation, HF communications can be adversely affected to the point where HF radio is blacked out and unusable. This occurs because of disruptions in the Ionosphere as well as in the earths magnetic field, which also plays a role in skywave propagation. As most Preppers know, severe solar flares can induce huge currents in the power grid which could cause severe damage and in turn lead to power outages that could last for years in the worst case scenario, such as the Carrington Event of 1859.
A good understanding of Ionospheric and Geomagnetic activity is a must for any serious user of HF radio. The term Geomagnetic refers to the relationship between the Earth and it’s magnetic field, which is mostly concentrated at the poles. There is ample information available to HF radio users that can allow one to reasonably predict what sky wave propagation will be doing at a given frequency at a given time. There are four measurements that can be used to make this estimation. These measurements are the A index, the K index, the Solar Flux Index (SFI) and the Sunspot number. The A index is a general measurement of activity in the Earth’s magnetic field over the past 24 hours and indicates an average trend of geomagnetic activity. The K index indicates the nearly real time level of disturbance in the earth’s magnetic field, as observed at observatories around the globe and then averaged. The K index is generally updated at three hour increments. The rule of thumb is that the higher the A and K indices are, the more disturbed the magnetic field is. This means that HF communications may be degraded, especially at higher latitudes and over the poles. The Solar Flux Index is a measurement of radio energy that is being emitted from the sun at 2800 MHz (10.7 cm wavelength). The higher the solar flux, the higher the level of ionizing radiation being emitted from the sun. This usually means that HF communications will be enhanced, because the Ionosphere is receiving more ionizing radiation. The last measurement is the Sunspot number. This is a simple method which indicates the number of dark spots that are visible on the sun’s surface. The more sunspots that are visible, the more ionizing radiation that the sun emits. What does it all mean? It means that you want to see a low A index, a low K index, a high Solar Flux Index and a high sunspot number for good HF propagation. If the A and K index are high, HF communications may be disrupted. If the SFI and sunspot numbers are low, it means that most of the higher HF frequencies will not be usable for sky wave. These current indices can be found at www.solarham.com .
This all brings me to the next concept that one must understand about HF radio and radio waves in general. It is the concept of Maximum Usable Frequency (MUF). MUF is the maximum frequency at which, at any given time, the Ionosphere will refract a radio wave back to the earth’s surface. The MUF will change with the seasons, the time of day, and the point of the sunspot cycle. The east majority of the time, the MUF is 30 MHz or below. This is why VHF and UHF radio waves are line of sight. Any VHF or UHF waves that get transmitted up into the Ionosphere are not reflected back to Earth and pass into space. This is why if you want to have access to transmit on frequencies that will reliably propagate over long distances (greater than about 50 miles most cases), you will need to have an HF radio station. There are exceptions to this but it usually involves Sporadic E layer propagation as mentioned above, which is an unstable and fleeting form of propagation. It can be fun to work this type of propagation during normal times but don’t count on it to work as a part of your crisis communications plan. There also other Amateur Radio systems other than HF that you can use to communicate over long distances (such as EchoLink), but these typically rely on the Internet infrastructure which most Preppers are at pains not to do.
The first individual band to be discussed is the 160 Meter band or commonly known as “Top Band“ to Amateurs. This band ranges from 1.8 to 2.0 MHz and is the lowest amateur band and is in the MF (Medium Frequency) part of the electromagnetic spectrum. The typical operating mode for 160 Meters is Lower Side Band (LSB). The propagation characteristics of the 160 Meter band are usually similar to what you would expect from a broadcast AM radio station. Note that the 160 Meter Amateur band is located just above the AM broadcast band which runs from about 510 KHz to 1.710 MHz. The 160 Meter band is not utilized by most Amateurs because the antennas for 160 Meters are typically very large for the reasons of antenna resonance described above. Like most Amateur bands, 160 Meters has quirky propagation characteristics at times, and it changes with the seasons and sunspot cycle. 160 Meters is greatly affected by D layer absorption and is nearly unusable during the daytime hours during the summer, but can propagate great distances at night during the winter. 160 meters also suffers from a high atmospheric noise level at times. Another great rule of thumb to remember is that the lower one goes in operating frequency, the higher the atmospheric noise levels become. Atmospheric noise is also generated by lightning and thunderstorms to the point where MF and HF can be become unusable due to static crashes.
The next band is the 80 and 75 meter bands. Those two terms are sometimes used interchangeably. The 75/80 Meter band ranges from 3.5 to 4.0 MHz and the default voice communications mode is Lower Side Band. This band will be of potentially great use to the Prepper. 75/80 Meters has the ability to communicate regionally, beyond the range of typical VHF and UHF systems which will be discussed later. 75/80 fills a unique gap in HF coverage, and can provide statewide communications. This is where most statewide emergency communications “nets” take place. Groups such as the Amateur Radio Emergency Service (ARES) and state Emergency Operations Centers (EOCs) conduct most statewide HF operations in this band. It has been said that most disasters are local and regional in nature. This makes 75/80 very useful because of it’s propagation characteristics.
The best propagation mode for the Prepper on this band is to use Near Vertical Incidence Skywave (NVIS). This involves the counter intuitive placement of an antenna that is very close the ground, within about 8 feet or so. It needs to be just high enough that people or animals cannot touch it. This proximity to the ground causes the radiated energy to ascend towards the Ionosphere at a very steep angle. This means that when the waves are reflected back to earth, they are also returned at a very steep angle. This makes the coverage pattern of an NVIS antenna to be much closer to the transmitting station, typically within a range of 25 to 300 miles. This makes it the perfect choice for a Prepper that wants regional communications. There is information later in the article about how to build an easy and inexpensive dipole antenna for 75/80 that can be configured for NVIS. 75/80 typically covers out to about 200 miles during the day, but can extend out several thousand miles at night when the D layer and its associated absorption disappears. 75/80 is very susceptible to D layer absorption during local daylight hours. 75/80 also suffers from higher noise levels during the day, especially during the summer months.
The next band is 60 Meters. This band is unique in that it is the only Amateur band that is channelized. The center frequencies for 60 Meters are 5332, 5348, 5368, 5358.5, 5373, and 5405 kHz. These are center frequencies and not the dial frequency that will be displayed on the display of an HF radio. The corresponding dial frequencies are 5330.5, 5346.5,5357.0,5371.5, and 5403.5 kHz. The channel width is limited to 2.8 kHz in the Upper Side Band mode. This band is allocated to the Amateur Radio service on a Secondary basis only, and the Primary users are typically federal government users. Secondary users must always yield to Primary users. Power on this band is currently limited to 100 watts Peak Envelope Power (PEP) into a half wave dipole antenna (whose construction is described later in this article). Most amateur radios do not have the ability to transmit in this band without modifications. 60 Meters is useful in that it fills a propagation gap between the 75/80 Meter and the 40 Meter bands. 60 Meters does not suffer from as much atmospheric noise as 75/80 Meters but 60 Meters is still susceptible to D layer absorption. NVIS antennas may also be used effectively on 60 Meters, and it useful for communications within the same state and with surrounding states. The main problem is that not very many Amateurs are on the air on 60 Meters.
The next band is the 40 Meter band, which covers 7.0 to 7.3 MHz. The default voice operating mode is Lower Side Band. 40 meters is typically the highest frequency amateur band that can be used for effectively for regional communications. 40 Meters differs from 75/80 Meters and 60 Meters in that it’s regional range usually extends from about 200 to 500 miles during the day and extends to several thousand miles at night. 40 Meters is typically better than 75/80 Meters for communications with states in the same general region of the country. This makes 40 Meters a good regional band but not necessarily a good band for statewide communications. A disadvantage to 40 Meters is that it is still shared with international broadcast stations in some parts of the world, especially above 7.2 MHz. The international stations don’t usually cause a problem during the day due to the D layer but they are the bane of 40 Meter operations at night.
The next band is the 30 Meter band., which ranges from 10.1 to 10.15 MHz. 30 Meters is different from the previously mentioned bands in that it is limited to the use of digital communications modes only. PEP is limited to 200 watts. Voice communications are not allowed on this band. Digital communications can be as simple as the old stand by Morse Code and as advanced as modern software suites which allow users to interconnect radios with computers and then send and receive data packets over the air. There are many digital modes that can be used on Amateur Radio bands. The advantages to digital modes is that you can send and receive large amounts of data faster than it can be relayed by voice. Digital modes are also very useful in situations where signals are very weak and voice communications cannot be established. There are many inexpensive digital interfaces available to connect radios to computers, and most of the software is freeware or available at a very reasonable cost. Digital modes are not restricted to just 30 meters and they can be used on the other amateur bands as well. Another advantage to digital modes is that while they are not considered encryption (because of open, public source protocols), they can defeat the very casual listener that doesn’t have the proper receive equipment. 30 Meters can propagate regionally, nationally and world wide depending upon the propagation conditions.
The next band is the 20 meter band which ranges from 14.0 to 14.35 MHz. The default voice operating mode is Upper Side Band. 20 Meters is what some Amateurs refer to as the “work horse band” because of it‘s useful propagation qualities. There are many types of operations that take place on this band, including a great deal of “nets”. Nets are formal on the air gatherings of Amateurs for different purposes. 20 Meters is generally open year round and typically only closes down at night as the MUF due to de-ionization of the Ionosphere. 20 Meter propagation is generally nation wide in nature, but it will occasionally propagate regionally on shorter skywave hops. Depending on how far away the station is that you need to establish communications, 20 Meters may be a good bet. I know Amateurs that maintain 20 meter contact schedules with other stations that are located on opposite ends of the country. 20 Meters does not suffer from D layer absorption as the lower bands do, and atmospheric noise levels on 20 are typically low except during thunderstorms. This makes 20 Meters an all around good band for talking with friends across the country.
The other HF bands I will group together. They are:
17 Meters from 18.068 to 18.168 MHz
15 Meters from 21.0 to 21.450 MHz
12 Meters from 24.890 to 24.990 MHz
10 Meters from 28.0 to 29.7 MHz
These bands are useful for nation wide and world wide propagation depending upon the solar and geomagnetic conditions. The default voice operating mode for these bands is Upper Side Band. I would point out that 10 Meters is a very large band and it is the only HF amateur band that allows Frequency Modulation (FM) operations. This is allowed from 29.6 to 29.7 MHz. This is because FM transmissions are wider than Single Side Band (SSB) signals so they require more space (bandwidth). 10 Meters is a big enough band to allow for the increased bandwidths. FM is an advantage over AM and even SSB in that it is not as susceptible to line noise interference from power lines. 10 Meter FM would be a decent choice for point to point simplex communications between retreats. 10 Meter ground wave propagation behaves very similar to Citizens Band propagation because the frequencies in which they operate are very close together. This also an advantage because some CB antennas can be re-tuned for use on the 10 Meter band. Digital modes are also allowed on these bands.
Here’s great HF radio hands on skill. You can build a simple HF wire dipole antenna at very low cost and with just a few parts. You will need some copper antenna wire (preferably with a steel core for strength), and three insulators (which can be made from ceramic, plastic, glass or even wood) . The insulators need to be at least 3 inches in length. You will also need a length of 50 Ohm coaxial cable (such as RG8) with the appropriate connector for your radio. This is typically a type PL-259 in most Amateur Radio applications. You will also need some rope to support the antenna, as well as a soldering iron and electronics solder to make all of the connections permanent.
Just follow the following steps, using the formula:
I=468/f
Where:
I=dipole antenna length in feet
f= the intended operating frequency in MHz.
This gives you the overall length that your wire antenna needs to be. Then, divide this number by 2 and cut two pieces of wire to this length. Place an insulator between the two pieces of wire. This will be the center insulator. It is usually best to drill a hole in each end of the insulator, and then wrap the antenna wire through the hole, wrap the free end around the antenna a few times within an inch or two of the center insulator, and solder the connections. Do this on each side of the insulator, so that you have one end of each of the two equal length wires attached to the center insulator. Then place an insulator on each end of the two wires using the same procedure. Then go back to the center insulator and strip the outer jacket off of your 50 ohm cable to a length of a few inches (dependent on the length of your insulator). Then separate the outer shield from the center conductor, making certain that the two do not contact one another. Then solder the center conductor (stripped of insulation) to one leg of the dipole at the center insulator and solder the shield to the other side of the dipole, also at the center insulator. Then you will want to attach the coax to the center insulator using a heavy wire tie or other strong attachment to reduce stress on the insulator connections to keep them from breaking in the elements. Then you can tie of the ends and center insulator of the dipole to trees or other similar elevated structures. Route the cable and connector to your radio and test with an SWR bridge. An SWR of 2:1 or less should be adequate for most radios. Many modern HF radios already have a SWR bride built in. You may need to slightly lengthen or shorten the antenna to get it to resonance. This is a very inexpensive and easy way to build an HF dipole antenna. I have made several of these, one for each amateur band from 80 to 10 meters, and I keep them in my crisis communications kit for immediate set up and use. You can read a great article about this project at http://www.ehow.com/how_6002278_build-dipole-antenna-hf.html .
Then next band is the 6 Meter band, from 50 to 54 MHz. as a Technician Class licensee, a new ham would have full access to this band and all others above it. 6 Meters propagates mostly ground wave and there are many FM repeaters in this band. More on repeater operations in the 2 meter and 70 cm band descriptions. SSB is widely used on 6 Meters, and it occasionally will propagate via sky wave via the E layer of the ionosphere. Skywave on 6 Meters is not reliable but is an interesting mode to work distant or “DX” stations on. 6 Meters is in the VHF low part of the spectrum, and signals in this frequency range tend to propagate further via ground wave than other frequencies that are above or below it. It is no coincidence that many state police agencies have used VHF Low for the last 60 years. It is because of VHF Low signals propagate better over large, rural areas than VHF High or UHF frequencies do. If you wanted to communicate via simplex ground wave with another retreat, this would be the most ideal band.
The next band is the 2 Meter band from 144 to 148 MHz. 2 Meters is quite possibly the most popular and widely used band, and FM is the most common mode. There are many repeaters in the 2 Meter band. A repeater is a station is installed at an elevated point, typically on a large communications tower or on top of a building or mountain. A repeater uses two frequencies simultaneously. The repeater receives on an input frequency, amplifies the signal to higher power, and retransmits it from the elevated antenna on an output frequency. This allows two stations that would otherwise be unable to communicate due to Line of Sight problems to establish communications. Other communications options on 2 Meters are the use of “simplex” frequencies. This just means transmitting directly from one station to another on the same frequency without use of repeaters. It’s the same principle as voice operations on the of the bands that don’t allow use of repeaters. There are also SSB operations on 2 meters, and digital operations are allowed at higher throughput rates. This means you can send more data, faster. This is because the band is larger and there is more spectrum available. There are thousands of 2 Meter repeaters in operation across the country. Some of them have back up power sources, some do not. It is the recommendation of the author that you not rely on repeaters in your crisis communications plan. This is because the repeaters may become congested with radio traffic or there power may fail in a crisis situation. Always have plan to establish simplex communications with your family, friends, and your retreat, without relying on a repeater if at all possible.
The next band is the 70 cm band from 420 to 450 MHz. The most common operating mode is FM, but there extensive digital and Amateur Television (ATV) operations in this band. Yes, you can actually transmit “Ham TV”! There are many repeaters on the air in this band, especially in urban areas. 70 cm performs well in urban areas because UHF radio waves tend to penetrate buildings and structures better that frequencies in other ranges. Simplex operations are also common on 70 cm. 70cm is widely used as a “backbone” band for linked repeaters. Some repeater operators have linked their systems together so that in some cases, one can communicate statewide on a VHF or UHF repeater. 70 cm is often used to relay this link data. Both 2 Meters an 70 cm are often used in Amateur satellite operations. There are several satellites in earth orbit that have amateur radio repeaters on board. While this is fun to play with and is a tool for your communications tool belt, satellites have limited utility for consistent, reliable communications with other specific stations. This is because most of the satellites are in a Low Earth Orbit and the orbit is circular in nature. This means that the satellite circles the earth about once every ninety minutes. When combined with the rotation of the earth, this means that passes over a given location are limited in occurrence and short in scope. Satellites are also heavily used and it can be difficult to establish contact on them. For this reason they should not be relied upon to provide time sensitive communications for the Prepper.
The other two commonly used bands I will lump together. They are the 33 cm band from 902 to 928 MHz and the 23 cm band from 1240 to 1300 MHz. These bands are great for the digital or ATV operator. They provide ample bandwidth for data throughput an the antennas for these bands are very small. Voice and repeaters are also used on these bands. There is not a lot of activity on these bands in the rural areas of the country, but they are more active in the urban areas. They are also outside the range of most cheap scanners, which provides some protection from the casual listener. Again, encryption is no allowed on any of the amateur bands but the squeaks and squawks of digital are meaningless to the untrained and unequipped listener.
The next area that must be addressed for a reliable crisis communications system is back up power. This can be accomplished in many ways. The good news is that most Amateur Radio systems and other related communications equipment operate from 12 Volts DC negative ground. This means you can connect this equipment to a car battery or preferably (if using a battery), to a marine deep cycle battery. Maintenance free lead acid batteries make good back up power sources for radio. Of course, you need to have a back up plan to recharge the batteries without the grid. This can be done using a variety of systems including solar panels, wind generators, or hydro generators connected to a battery charging conditioner to prevent damage to the battery pr to the charging system. One can also use a standard gasoline, diesel, or natural gas powered generator to power a 120 Volts Alternating Current (VAC) to a 12 VDC power supply for the radios. These 120 VAC to 12 VDC power supplies are commonly used to power Amateur Radio equipment from the grid under normal conditions. Do not rely on grid power to at any point in your crisis communications plan.
In my situation, I utilize HF radio on 80 through 10 Meters for back up long haul communications , as well as 2 Meter and 70 cm simplex for local use. I use the repeaters regularly, but I don’t rely on it. Our local 2 Meter repeater also has a limited back up power source. I work about 10 miles form my home and I have 2 Meter radios installed in all of our vehicles, including my work vehicle. I have a very understanding employer. I have 2 Meters and 70 cm installed at my home and I can communicate with my family regardless of grid condition. I have utilized this before when a disaster struck our town and cellular phone communications were out for hours. The only communications I had with home were by Amateur Radio. The cell network was overloaded and damaged, and it was good to know that even when bad things happened, I could inform my family of my status. It was a huge relief to my wife because she had been very concerned about my well being, and all of her phone calls to me got the familiar “We‘re sorry, all circuits are busy now. Please try your call again later” or something to that effect. She knew what to do in order to contact me due to rule 6-P.
Another area of great interest to the Prepper is utility monitoring. This a complex subject, but it boils down to listening to all different types of frequencies and modes to figure out what’s happening in the world. Engage in and learn about this activity and you would be surprised at what you will hear. I advise you not to do anything that is illegal. In some states, it is unlawful to possess a police scanner in a vehicle, so make sure that you know your local laws. Consider installing a wideband scanner receiver, and a high gain external base antenna at your retreat. The author recommends the Uniden Bearcat BC9000XLT or equivalent and the Antenna craft ST-2 antenna. They make a great pair. You can monitor local public safety entities as well as other government entities. Many of these entities encrypt their radio traffic so you cannot listen to them. It is unlawful to decipher these communications. Most of theme use a very secure protocol and most attempts at decryption would be moot for most people anyway. It is also unlawful to intercept cellular telephone or other encrypted communications, so don’t do it. Also, some entities utilize a P25 digital modulation protocol, and if that’s the case where you live, then you will need to acquire a P-25 digital trunking scanner to receive them.
Shortwave broadcast, while somewhat on the decline from some parts of the world, is still alive and well. You will interesting news and content that the regular lap dog media will not report. This includes a great deal of alternative and Christian media that would be snubbed, defamed and marginalized by the politically correct main stream media. The author’s favorite shortwave broadcast station is WWCR out of Nashville, Tennessee. They operate on the frequencies of 3.215, 4.840, 5.935, 7.465, 7.490, 9.350, 9.985, 15.825,12.160, and 13.845 kHz AM. There are also many broadcasters from around the world still on shortwave. This could prove to be a vital news source in the vent of an information blackout here in the U.S. Most amateur HF radios have wide band receivers so an HF station doubles as a shortwave receiver. There is also a great deal of military and government traffic on the HF bands. Military monitoring is also a popular pastime that could have utility in a crisis. It is still considered lawful in the U.S. (Yet, anyway. Many countries have outlawed it). A decent scanner receiver (like the BC 9000XLT) will cover the 225 to 406 MHz range where most UHF military operations take place. With an outdoor antenna, you can hear military aircraft operating hundreds of miles away in the AM, non-encrypted mode. Most scanners will also allow you to monitor amateur frequencies, weather broadcast stations (which are a great source for civil emergency alerts), civilian aircraft, taxi cabs, busses, railroads, transportation departments, and utility companies. A great source for local radio frequency information for your area is the database here. There are also many other web sources for the frequencies for your area. Engaging in utility monitoring will remind you of how important it is to utilize Communications Security (COMSEC). It will remind you to mindful of what information you transmit in the open. Also remember that in a collapse scenario, do not transmit from your retreat unless absolutely necessary. If it is necessary, keep your transmissions very brief, and consider using a modular addition encryption protocol. Line of sight transmissions can be DF’d. That means an adversary can use Direction Finding techniques to locate your retreat. Skywaves are much more difficult to DF but it can be done, so keep your HF transmissions short as well. Spend most of your time listening and use COMINT to your advantage.
Another thing to remember is to not completely discount grid based communications systems as a part of your plan. I’m not saying that you should rely on these systems. You absolutely should not. But many of these systems, if they are operating in some capacity may have utility to you even if they are compromised and not reliable. Landline phone companies for example are required to maintain battery and generator back up power for their network switches. Remember that the landline network providers still provide the Plain Old Telephone System (POTS) backbone that interconnects telephone voice circuits to cellular sites. Also consider installing a landline phone in your home for this reason, if it fits into your budget. It does in my home because it is a part of my DSL internet package. Landline phones, as long as they are not the cordless type, will typically continue to work during a short-term power outage because the phone is powered by telephone company equipment and not by the power to your home. Cordless phones require AC power to your home or back up power supply to operate. You can purchase battery back up units for cordless phones that provide several hours of talk time during a power outage. I picked one of these units up at a Hamfest for $5. Also consider installing Skype on your computer which provides free IP-based video chat capability if you have a web cam, microphone, speakers, and a broadband Internet connection for your computer. Also remember to use e-mail and text message capability if you have it. Text messages or e-mails can sometimes get through to members of your family and friends who do not have a crisis communications system even if the voice circuits are overloaded and unavailable. You may need these methods to communicate with folks that didn’t prepare ahead of time.
A lot of folks also don’t know that most cell phone carriers have e-mail gateways into their text messaging system. This means you can send an e-mail and it will be delivered to the recipients cell phone as a text message. Text message charges apply.
Check out the table below to look for you carrier:
Alltel number@alltelmessage.com or number@message.alltel.com
AT&T number@mobile.att.net
Bell Canada
number@txt.bellmobility.ca
Centennial Wireless
number@cwemail.com
Cellular South
number@csouth1.com
Cincinnati Bell
number@gocbw.com
Metro PCS
number@mymetropcs.com or number@metropcs.sms.us
Nextel
number@messaging.nextel.com
Omnipoint
number@omnipointpcs.com
Qwest
number@qwestmp.com
Sprint
number@messaging.sprintpcs.com
Suncom
number@tms.suncom.com
T-Mobile
number@tmomail.net
TracFone
number@mmst5.tracfone.com
Telus
number@msg.telus.com
U.S. Cellular
number@email.uscc.net
Verizon
number@vtext.com
Virgin Mobile
number@messaging.sprintpcs.com
Alaska
Alaska Communications Systems number@msg.acsalaska.com
General Communications Inc.
number@mobile.gci.net
Puerto Rico
Centennial Wireless
number@cwemail.com
Claro
number@vtexto.com
Trachoma
number@number@mmst5.tracfone.com
U.S Virgin Islands
Centennial Wireless
number@cwemail.com
Trachoma
number@mmst5.tracfone.com
For more carriers, see:
http://en.wikipedia.org/wiki/list_of_SMS_gateways.
I hope this information is useful to you in your preparation efforts. May God bless you and your families as we endure these turbulent times in our world. don’t forget to make preparations in other necessary areas as well. Beans, bullets, and band aids should be squared away before you invest in communications. And most importantly, remember to walk daily with the Jesus Christ. He is the way, the truth, and the life, and no one will come to the father but through Him.
