Emergency Communications Primer
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On various emergency preparedness forums, it's not uncommon for someone to ask about what piece of equipment they should have for "communications".  That question is really impossible to answer in the abstract, because it depends on exactly whom one wants to communicate with.  So before purchasing any equipment, one should give that matter some very serious thought.  The finest communications equipment is really of very little use if you have nobody with whom to communicate.  And when you give thought to this, it's quite possible that very modest equipment, given some thought, will prove very useful.

 The purpose of this page is to give some ideas as to what is possible with regard to communications.  Again, no one solution is perfect for every person or every situation.  So I will not answer the question of what kind of "comms" you should have.  Instead, I hope to give some ideas as to what kind of communications is possible, so that when you identify your needs, you will have some idea as to how you can meet those needs.

I.  Receiving information.

I've been a ham radio operator for over thirty years.  But if I had to chose the single most important piece of communications equipment for almost any conceiveable disaster, I'd probably chose an AM radio.  As my sole piece of communications gear, this would certainly have its limitations.  But in almost any conceiveable situation, I can be reasonably assured that I would be able to learn something useful with this one radio.  Since most people already own a radio, this is probably a good starting point for thinking about your other communications needs.  A radio receiver will not allow you to have two-way communications with anyone.  But it will allow you to receive information, which will allow you to assess that information.  The information you receive on a broadcast radio is not, of course, going to be completely reliable in any circumstances.  And in some circumstances, it may be very unreliable.  But in some cases, even the fact that the unreliable information is being disseminated to the public might be an important piece of information to know.  

A.  AM Radio

While it has been overtaken in popularity by FM over the past couple of decades, standard AM broadcasting has been in existence for over 80 years.  There are AM stations, many of which are very powerful, in every state of the Union, and in virtually every country of the world.  In most areas, there is at least one radio station with at least some committment to public service, and in many cases, that station is an AM station.

AM radio has an important advantage over FM and TV that the signals are generally propagated over much greater distances.  This effect is much more pronounced at night, but it is also true to a lesser extent during the daylight hours.  Because of this effect, AM radio could be an important resource during a regional or even national disaster, in which other regions are less affected.  In such a situation, even if all local radio stations were off the air, it is extremely likely that one would be able to hear stations in less affected areas.

The quality of AM radios on the market vary considerably.  This is not universally true, but I have noticed that most portable radios, even of rather dubious overall quality, generally have fairly good AM receivers.  On the other hand, many aftermarket car stereos, even very expensive ones, sometimes have very poor AM receivers.  So it is a good idea to check out the radios you own, and determine which ones work better than others.  Take the time to tune up and down the dial, both during the day and at night, to see which stations you can hear on which radios.

 As a general rule, original equipment radios in most automobiles (but not more expensive aftermarket stereos) generally have excellent AM reception.  There are undoubtedly exceptions, but I have found that most automotive manufacturers include very high quality AM radios.  So for most people, the car radio is probably the best available AM receiver.  (When the engine is turned on, radio noise from the engine sometimes obliterates the reception, and in those cases, the reception would be the best with the engine turned off.)

As you carefully tune up and down the AM dial, from 530 to 1700 kHz, you might be surprised at how many stations you can hear, even during the daytime.  For example, in Minneapolis, MN, I'm routinely able to hear stations in Duluth, MN, and Yankton, SD, during the day. 

During the nighttime hours, I can't hear those same stations, partly because they are covered up by other stations from further away.  But at night, it's possible to hear a different station at almost every point on the dial.  Also in Minnesota, almost every night, I'm able to clearly hear a station in Spanish on 530 kHz.  This station is located in the Turks & Caocos Islands.  Since there are no U.S. stations on this frequency, this distant station comes through quite clearly almost every night.  On 800 kHz, I can simultaneously hear several stations.  Each of these would be very clear if they were the only station on the frequency.  They are difficult to hear only because they are all interfering with each other.  One of those stations is in Bonaire, Netherlands Antilles, which is very close to the coast of South America.  This example makes clear that if, in the event of some wide-scale disaster in North America, if all or most North American radio stations were off the air, then reception of South American stations would not be difficult.  They're already there with strong signals.  The only reason they can't be heard now is because other closer stations are interfering with them.  If, indeed, some disaster knocked every North American station off the air, then the South American stations would be quite easy to receive, even with a typical car radio.  And if the entire Western Hemisphere went silent, I am quite confident that there would be some stations from Europe or Asia that could be heard, at least occasionally, in North America with similar equipment.  This is why I believe that, given almost every imagineable disaster scenario, there would be something to listen to on the AM dial.

Most disasters, of course, are not going to so extreme as to knock every radio station on the continent off the air.  In a regional disaster affecting only one part of the country, most stations in other regions will continue broadcasting as usual.  Therefore, AM radio could be an important source of information during regional disasters.

(Note:  In the Western Hemisphere, almost all AM radio stations are 10 kHz apart.  In other words, they occupy a spot on the dial ending in a zero, such as 540, 550, 560, etc.  In the rest of the world, most stations are 9 kHz apart, and occupy the frequencies 531, 540, 549, 558, etc.  There are a few frequencies, (540, 630, etc.) that are common to the entire world.  But most European and Asian stations cannot be tuned in accurately on a North American digital radio, because such radios only tune the frequencies ending in zero.  This is of little practical consequence in most cases, but to have much chance of hearing Asian or European stations, one would need either a radio with an analog tuner, or a digital tuner that is not restricted to the channels ending in zero.)

It's a good idea to become familiar with which stations you can hear in your area during normal times, both during the day and at night.  As noted above, in Minneapolis, I am able to routinely listen to Duluth, MN, and Yankton, SD.  At the very least, by tuning the AM dial, I would be able to learn how widespread any regional disaster was, simply by knowing which stations were still on the air at their normal power levels. 

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Also, during a local disaster, it might be advisable to learn what information is being broadcast in other areas.  For example, if all local stations are off the air, or only broadcasting "official" information, it would be good to know how other regions of the country are reacting.

I noticed during Hurricane Katrina that WWL, the radio station in New Orleans, was not broadcasting network newscasts.  Apparently, they were also simulcasting on all or most of the other surviving local radio stations.  So a local listener, with only this source of information, would have little knowledge of how the disaster was being reported in other areas.  But many out-of-state radio stations could have been heard.

In some disasters, this information might be vital.  If the local media in my area, Minnesota, are only giving official information, or if they are off the air entirely, there might be a debate raging as to how the rest of the nation should solve the "Minnesota problem".  As one of the people affected by that debate, I would want to know how it was progressing.  And hearing a network newscast on an out-of-town station might provide that information.

At night, the possibilities for AM listening are much greater.  On almost any given evening, I am able to hear many stations very reliably.  Among other places, these stations are located in Chicago, Detroit, Nashville, Denver, Salt Lake City, and Toronto.  Even during a widespread disaster, some of these stations will probably be in unaffected areas, and will be talking not to me, but about me.  Knowing what they are saying about me could be vital.

Also, the mere existence or non-existence of these stations after a disaster could provide vital information.  I have a general idea of which stations I ought to be able to hear.  By looking for those stations, I can determine whether they are off the air entirely, whether they are broadcasting emergency information to local residents, or whether they are broadcasting normal programming.  This information alone would give some indication as to the scope of the disaster.  And as noted above, in an extreme disaster devastating all of North America, the AM radio would give some indication as to conditions in Europe or Asia.

In most cases, no additional antenna is required.  However, adding an external antenna will often improve reception.  There are active antennas that one can purchase, and they do improve reception.  However, any piece of wire, will generally make a good antenna.  The longer this wire, the better.  But once you reach about fifty feet or so, you start reaching the point of diminishing returns.  The exact configuration of the antenna is not as important as you might think.  Just spreading out a piece of wire and dangling it from a convenient tree will often make a big difference.

 Some AM radios do have a terminal to connect an antenna, but most do not.  Adding an external antenna to a car radio is very simple--you can just attach the wire to the car's antenna.  For a portable radio without an antenna jack, you can simply wrap the wire around the radio several times, without making a direct electrical connection.  In fact, you can sometimes improve reception simply by placing the AM radio near a telephone that's plugged in, or wrapping the telephone cord around the radio several times.  The telephone wires serve as an antenna, and the signal is coupled to the radio by the wires wrapped around the radio.

Most AM radios have fairly good built-in antennas.  You should be aware that these antennas are very directional--they cannot receive signals well off the ends of the radio.  Therefore, for best reception, you might need to rotate the radio.

Virtually any small AM radio will be better than nothing in an emergency, and most people already own one.  If you need a good one that's inexpensive, then I would recommend this one from Sony:

Sony AM-FM Radio  

B.  FM Radio

FM radio does not have as great a range as AM radio.  Also, it's a gross over-generalization, but fewer FM stations seem to have much capablity to disseminate news and information.  Of course, this is also true of most AM stations.  But the FM dial could be a source of information during a disaster.

Generally, most FM stations have an effective range of about 50 miles.  This will vary considerably, of course.  But other than during relatively rare conditions, very few FM stations can be heard over distances of much more than a hundred miles.  It is possible, however, to increase your listening range somewhat.  Your location, in particular your antenna's location, is the most important factor.  In general, from a high location, you will be able to hear more stations than from a lower location.  An good FM or TV antenna, at a high location, pointed in the direction of the station you want to hear, can often provide reception of stations a hundred or so miles away.  Most stereo receivers, both automotive and home stereos, as a general rule, generally provide good FM reception.

Again, it's a good idea to become familiar with what stations can normally be heard in your area.  The best way to accomplish this is to tune up and down the dial and see what's there.  During a disaster, you can repeat this process, and thus gain some knowledge as to the geographic scope of the disaster.

One particularly useful aspect of FM radio is that there are very inexpensive radios available that are extremely small.  Often, these radios can be found at the dollar store.  Some of them use small headphones, and some rest over your ear.  They are often found at dollar stores.  In fact, my son received one such radio as the prize in his Burger King kid's meal.  (He also once received a very adequate compass, which leads me to believe that such meals could probably provide a wide variety of survival gear.)

These inexpensive radios work surprisingly well, and in most areas will receive several stations.  They are so inexpensive as to be disposable, and also very light weight.  As such, it's very easy to keep one in your purse or briefcase so that in any situation, you have access to at least some outside information.

C.  Satellite Radio

The two providers of satellite radio service are Sirius and XM radio.  While they are popular, I am personally loathe to pay a monthly fee to listen to the radio.  However, having an XM radio receiver available for emergencies might be a prudent precaution, even without paying for the service.   XM radio includes channel 247, which is intended for providing emergency information in the event of a disaster.  It's probably not possible to predict the quality of this information, but my philosophy is that any information is useful, as long as it is critically analized.  Channel 247 can be heard on any XM receiver, regardless of whether the owner has paid the monthly subscription fee.  Therefore, the only cost is the cost of the receiver.

Receivers, such as this one, are available for about $50:

XM Radio

"Boom box" receivers for XM have been available, but generally at a higher price.  The one linked above is intended for use in a car, and plays through the car stereo.  It is hooked to the stereo either with a cable to plug into the stereo "auxiliary in" jack, or with an adapter that goes in where a cassette would go (not included).  However, this unit will also generate an FM signal, so it can be picked up on a normal FM radio.  Therefore, it could be used with any FM radio, as long as you have a source of 12 volts to plug in to.

I've also considered the possibility of subscribing to the service if any kind of disaster appeared imminent.  Of course, many disasters are not predictable, and after the disaster has hit, subscribing might be impossible.  So this option has very limited utility.

I've also considered that after purchasing the receiver, I could give the instructions for activating it to a friend or relative in another state.  They would have instructions that if there were a disaster in my area, and they were not able to contact me, to subscribe to the service for me.  Again, there might be some utility in having access to the regular XM news channels during an emergency, and this would allow that possibility at minimal cost.

Sirius does not appear to currently have any provisions for broadcasting to non-subscribers, with a system similar to XM's channel 247.  Therefore, XM would appear to be the logical choice for contingent satellite radio.

Of course, during a disaster involving destruction of most of the nation's infrastructure, I have doubts that XM radio would be one of the first services to be restored.  Possibly I'm wrong, in which case it would be nice to have the receiver.  But for many regional disasters, XM might be a good source of information.

D.  Television 

Until Hurricane Katrina, I discounted the value of television during an emergency.  Most people own a battery powered radio and/or a car radio.   Most people do not own a battery powered television.  Therefore, if emergency officials were acting entirely rationally, they would use radio as the primary means of reaching the public, because more people would be able to hear whatever they had to say.  Unfortunately, emergency officials apparently do not operate entirely rationally.  During the aftermath of Hurricane Katrina, I listed quite a bit to WWL radio, and this same information was being simulcast on most or all of the other surviving radio stations in New Orleans.  It was evident that the radio station staff in many cases were using heroic efforts to stay on the air, and they served their community well.  However, I was shocked to learn that, in many cases, much more information was available on the national cable television networks.  Local officials were invariably drawn to TV cameras, even though most of the population was unable to watch televsion, much less cable television.

Therefore, I conclude that being able to watch televsion (or at least listen to it) during an emergency might be critical, and I do have a battery operated television available.  Such televsions are very inexpensive, so purchasing one is probably advisable.  Unfortunately, the batteries might cost more than the television itself.  Most operate on 8 D-cell batteries, so be sure to stock batteries.   And unfortunately, a television will run down your batteries much faster than a radio would, so having extra batteries is probably a good idea.

One unforeseen consequence of the switch in 2009 to digital television in the United States was the relative unavailability of battery-powered methods to watch or listen to television.  Prior to the switchover, there were a wide variety of very inexpensive battery powered (or 12 volt) televisions available, sometimes for less than $20.  In addition, there was a wide selection of radios that received TV sound (at least channels 2 through 13).  Unfortunately, probably because few people give thought to the problem, these inexpensive battery-powered televisions seem to be a thing of the past.  In addition, because TV sound cannot be received without some computing power built into the radio, it is unlikely that we will see radios that receive TV sound.

There are a couple of solutions to the problem, so that you will have a television available in an emergency if the power goes out.  The first, of course, is to break down and buy a battery operated (or 12 volt) television, even though they are now more expensive than the used to be.  The least expensive one I've been able to find is this one, for $69.95, which includes the important DC adapter, so that you can run it from your car or an external 12 volt battery, which will ensure much longer life than with the internal batteries:

7 Inch Digital TV

For a complete buyer's guide for battery-operated TV's and 12-volt TV's, please visit my battery operated RV page.

Most of the TV's shown below are still available, and would serve well as emergency televisions. But since writing this page, many other 12 volt televisions have come on the market. However, they are not marketed as 12 volt televisions. But since they use a 12-volt "wall wart" AC adapter power supply which can be unplugged, it is a simple matter to run them using a car battery or automotive "jump start" battery with a cigarette lighter socket.

One of these is the Craig CLC501, which is a very lightweight 15 inch high definition TV. I purchased one on sale for about $100, and they are also available on Amazon:

You will also need a 12 volt cord, which is available from Radio Shack. When purchasing this cord, take the TV AC adapter with you to the store to make sure that you're getting a cord with the same polarity. If you wish to purchase online, this cord is readily available:

And in an emergency, you can of course simply cut the plug off the existing AC adapter and wire it directly to a 12 volt battery.

Undoubtedly, many other inexpensive TV's will work just fine on 12 volts. However, the voltage typically is not advertised. So when you're at the store, you need to look at the AC adpater for the TV. If it says that it provides 12 volts (or perhaps 13.7 volts), and you can unplug it from the TV, then the TV will work fine on 12 volts with a suitable cord.

Another option is to use one of the older battery-operated analog TV's and use it with a digital TV converter box.  In 2009, the Government, in its infinite wisdom, was distributing coupons for TV viewers to purchase a converter, generally at no additional cost beyond the coupon.  A few of these converters operated off 12 volts, and it is quite simple to operate them from battery power.  Full instructions can be found here:  __________.  Even though those converters are no longer available at no cost, they can still be purchased.  One model that will operate from 12 volts can be found here:  _________.

Another method is to use a laptop computer with a TV tuner card.  (It should be noted that laptop computers can be notorious battery hogs, but if you have a reliable method of recharging your laptop without commercial power, this might be a good solution.)  For example, one TV tuner that can plug in to your computer's USB port can be found here:

USB TV Tuner

Finally, while not ideal, in some cases, it might be easiest to simply run your existing TV from an inverter, which will change 12 volts DC to 120 volts AC.  Inverters, and other power options, are discussed in more detail below.  It should be noted that for maximum battery life, it is generally best to use the smallest possible inverter that is large enough to run the device in question.  In other words, don't use a 300 watt inverter to run a 100 watt TV, since this
will run your battery down faster.

This inverter would be about the right size for most small TV's.  It is large enough to operate the TV, but small enough so that it does not drain your battery more than necessary:

Black & Decker 100 Watt Inverter

Cable televsion

Cable television comes into your house, obviously, through a cable.  If the cable gets physically broken, then you won't have any signal.  And if the power goes out at one of many critical locations, then you won't have any signal.  Therefore, if you currently have cable television, you should have some awareness of how to connect an external antenna.  In most urban areas, a simple set of rabbit ears, or even a short piece of wire plugged into the antenna jack, will perform adequately.  In rural areas, you might need an outdoor antenna.  But in general, it would be very unwise to depend on cable television as your sole source of information.  

Satellite television

In general, the satellite television signal is dependent upon national infrastructure, and not local infrastructure.  Therefore, if you have a regional power outage, your satellite televsion should continue to function.  In a national disaster (or if the satellite were destroyed), then this signal would probably disappear.

An important point to keep in mind, however, is that your reception of satellite televsion, even if the signal is there, probably depends on your having electrical power.  In some cases it might be appropriate, but in many cases, it strikes me as unwise and wasteful to run a generator simply to watch televsion.  Therefore, if you have satellite television, it would be wise to have some awareness as to what stations you can receive with normal rabbit ears, and have a battery operated television available.

E.  Shortwave receivers 

Shortwave radio relies on the fact that radio signals in the shortwave bands are reflected off the earth's ionosphere, very high elevation levels of the ionosphere.  The reason why standard AM radio signals can be heard at long distances during the nighttime is that signals of this frequency are generally reflected by the ionosphere at night, but not during the daytime.  Different frequencies are generally reflected different distances, depending upon (among other factors) the time of day or night.  The standard AM band is near the low end of the frequencies that are reflected by the ionosphere.  In general, these low frequencies (540-1700 kHz, or 0.54-1.7 MHz) are reflected only at night.

In general, as the frequency increases, the signal is reflected better during the day, and not as well at night.  At a frequency of about 30 MHz, the signals stop being reflected, either day or night.  This means, that any given time of day, there is some range of frequencies that can be propagated large distances.  Shortwave radio takes advantage of this phenomenon.  At most times of day, there are some shortwave frequencies that can be propagated worldwide.  

There are two general categories of signals that can be heard with a shortwave radio.  The first general category is broadcasting--in other words, radio stations that are broadcasting to the general public, either in their own country, or to people in another country.  The second general category is communications between two stations.  These signals are not intended for the general public, although in most cases, anyone with an appropriate receiver can hear them.

There are a surprisingly large number of stations in the first category--that is, broadcast stations broadcasting to the general public.  It is becoming somewhat less common, but many of these stations are operated by governments, with the intention of broadcasting to people in other countries.  The best known example is probably the Voice of America, which transmits programs in many languages to people in other countries.  Another very large such station is Radio Netherlands, which transmits programs in many languages, including English.  In England, the BBC World Service broadcasts considerable programming worldwide in English and other languages.  In recent years, the BBC has stopped transmitting programs specifically directed at North America, the assumption being that most persons in North America have internet access, and can listen via the internet.  But even though the BBC does not transmit specifically to North America, it is still possible to hear some of their English programming.  There are also a large number of religious and political broadcasters, many of which are located in the United States.   

At almost any given time of day, even with the least expensive receiver, it is generally possible to hear multiple shortwave broadcast stations.  In general, the evening hours provide the most variety.  And at least some of these broadcasts will be in English.

Many government broadcasters, such as the BBC, are cutting back on shortwave broadcasting.  But still, there are stations that can be heard from thousands of miles away.  And during an extremely widespread emergency affecting one continent, it wouldn't be unreasonable to think that some of these broadcasters might increase their programming to that continent for the duration of the emergency.  (For example, following the earthquake in Haiti, the BBC increased the amount of programming that it was beaming to the Carribean.)

To receive shortwave broadcasts, even the most inexpensive receiver will generally provide something to listen to.  For example, Walgreens sells one "world band" receiver for about $20, and it's often on sale for even less.  While this small receiver looks very unimposing, it would provide access to at least some information during a national emergency.  Of course,  a more expensive receiver would probably provide better results.

While not a stellar performer, this radio will receive some strong shortwave stations, and also provide fairly good AM and FM reception, for less than $12:

Coby CXCB91

For a few dollars more, this radio will provide somewhat better reception, if what you're interested in hearing is major shortwave broadcast stations:

Grundig GM400

For updated information on inexpensive shortwave receivers, please visit my shortwave receiver page.  In particular, the Tecsun PL-600 shown at the bottom of the page is an excellent all-around receiver.  It is currently the least expensive receiver available which can be used to tune SSB, CW, and digital signals, and currently sells for about $67.  It also contains a good quality AM, FM, and longwave receiver.

Most international shortwave broadcasts are located in specific frequency bands on the shortwave dial, and the most productive frequency to listen to will vary from night to day.  In general, during the nighttime hours, you will hear many broadcast stations just above and below 6 MHz, and between 9.5 MHz and 10 MHz on the shortwave dial.  During the daytime hours, you will probably hear more stations just above 15 MHz.  And during both the night and the day, you will frequently hear stations between 11.5 MHz and 12 MHz.

The other category of signals on the shortwave dial are communications between two stations, not necessarily intended for the general public.  One example would be communications between aircraft, and communications by ships.  The other large category is amateur radio operators, who do not broadcast to the public, but communicate between themselves.

Some of this communications is carried on by digital means.  Much of it can be deciphered by hooking the radio to a computer.  However, much of the communications takes place either with "single sideband" (SSB) voice, or Morse code (often referred to as "CW".)  To be able to listen to either of these types of communications, you do need a radio that is capable of "single sideband".  On some older radios, the radio will be said to have a "BFO".  Most inexpensive portable shortwave radios (such as the ones linked above) are not capable of receiving single sideband or CW.  However, fairly good receivers that can receive SSB and CW are available.  And as a general rule, these receivers are usually better at picking up broadcast stations than the less expensive portable radios.  One excellent choice is this Grundig receiver.  While it's a very small portable, it's performance begins to approach that of more expensive communications receivers:

Grundig G6

During an emergency, the most common long-distance signals on the air will probably be amateur radio operators (or "hams" as they are known).  Most of these hams will be using SSB, and can be heard quite easily with rather inexpensive radios.  They are not generally broadcasting to the general public.  But during a widespread emergency, listening to their conversations might give insights into local conditions in different areas.  Most amateurs are capable of operating their stations using battery power, so even during times of widespread infrastructure failure, it wouldn't be unreasonable to expect that a large number would be on the air.

The most common frequencies to find amateurs are:  3.5 - 4 MHz, 7-7.3 MHz, 14-14.35 MHz, 21-21.450 MHz, and 28-29.7 MHz.  In general, the higher frequencies will be better during the day, and the lower frequencies will be better at night.

 Most of the inexpensive portable shortwave radios have a built-in telescoping antenna.  For many purposes, this built-in antenna actually works quite well.  However, adding a longer antenna usually results in better reception.  An antenna for receiving can be extremely simple.  Simply stretching out a piece of wire often results in a quite good receiving antenna.  It is best if the wire is as long as possible, that it be outside, and that it not touch other objects.  But even if you simply spread a piece of wire along the floor, it can make a world of difference.  In general, the longer the antenna, the better.  But after you reach feet feet or so, you reach the point of diminishing returns.  Five hundred feet would probably be better, but adding another ten feet probably won't do much good.  Some shortwave receivers have a connection for plugging in an external antenna, and you may wish to purchase a plug of the right size to connect your antenna.  But if that is not avaiable, you can simply clip it directly to the telescoping antenna.  

If you have a television antenna, you can also attach it to the radio's antenna.  The television antenna itself generally will not receive many shortwave signals.  However, the wire leading to the TV antenna simply acts as a wire antenna.

In a pinch (literally), you can even become an antenna.  If you simply touch the telescoping antenna, you might find that you have improved reception.

And even if the power is out, if the radio has a power cord, it may improve reception to plug it in to the wall socket.  This is because the house wiring serves as an antenna.

It is reasonable to wonder whether nuclear weapons would affect radio propagation.  It is likely that there would be some effect on the ionosphere.  In some cases, propagation might even be enhanced, although it's probably likely that some propagation would be degraded.  However, it's very likely that these effects would be very short-lived.  The ionosphere undergoes changes on a daily basis due to the sun's energy output, and this energy output makes the effect of nuclear weapons pale in comparison.  So it's reasonable to assume that any of these effects would vanish within hours or days.  However, in the immediate aftermath of a nuclear attack, it would not be unreasonable to assume that some shortwave propagation might become difficult or impossible.  (Note:  the effect being discussed here is the effect upon earth's ionosphere.  A nuclear attack may have distinct effects upon equipment, which is discussed in more detail below.)

F.  "Scanners"

Scanning receivers, or "scanners" generally receive VHF and UHF signals.  These receivers can receive many or most police department, fire department, and emergency services radios, along with various business radios.  Generally, any business that uses portable radios or radios in its vehicles would be something that one could receive.  "Scanning" is a relatively popular hobby, and there are generally sources available on the internet listing particular frequencies in use in a given area.  If you do wish to be able to listen to such communications in an emergency, it is very important to learn these frequencies beforehand, and program them into the radio.  Such a radio can be set to monitor many channels by scanning between them, and stop when it hears a transmission, hence the name.

Some areas, notably larger metropolitan police departments, have switched their radios to "trunking" systems, in which the signals can change frequencies.  For best reception of these signals, a scanner specially designed for "trunking" systems really needs to be used.  However, many departments still use the older equipment (which, in my opinion, is more reliable in a disaster), so there are still many signals available even with one of the less expensive scanner.

Like FM radio, these signals can travel only within the "line of sight" between the two antennas.  In an oversimplified nutshell, the signals can only be received if the receiving antenna can "see" the transmitting antenna.  Generally, you will have very good reception of departments and businesses in your own jurisdiction, even with little thought given to the antenna.  If you plan to listen to signals in outlying areas, some thought should be given to the antenna.  But for the most part, the signals of interest will be the local signals, so an external antenna is rarely necessary.

These receivers will also be able to monitor local ham radio operators, many of whom will be using portable or mobile equipment, often through repeaters (see below for for information on repeaters).  The most common frequency where you would be able to hear hams would be 144-148 MHz.  Most scanners are also capable of receiving FRS, GMRS, and MURS radios, which are discussed in more detail below.

Recently, a number of manufacturers have made portable receivers that cover both the HF (shortwave) spectrum, as well as VHF and UHF, often at very reasonable prices.  These generally also receive standard AM, FM, and sometimes TV broadcasts.  Such a unit would provide a very versatile piece of equipment for receiving information, since it essentially combines a shortwave radio with a scanner (and AM-FM radio).

II.  Two-way communication

A.  Telephones

1.  Landline telephones

The normal telephone system is surprisingly robust, and fails very rarely.  It is dependent upon commercial power, although it has traditionally maintained some backup capability.  Therefore, it's conceivable that in some even rather severe disasters, it might remain functional.  Therefore, for example, it probably wouldn't hurt to include a telephone jack (and a standard electrical outlet) in the fallout shelter.  True, it probably won't work at such time as you need to occupy the fallout shelter.  Still, though, wouldn't you feel silly if you were sitting in the dark in your shelter and you heard the phone ring in the house, or you heard the television come back on?  It goes without saying that you should own at least one telephone that plugs into the phone jack, but does not plug into an electrical outlet.  The telephone network is generally more reliable than your electrical power, but if all of your telephones require power, you would be without communications even though the phone system was functioning flawlessly.

One preparedness item that is often overlooked is a prepaid telephone card.  Obviously, in a "SHTF" situation, it will be of no use.  But for personal emergencies, or even a regional disaster, it could be quite useful for making either local or long-distance calls.  There could be many situations where you need to use a pay phone (even though they are becoming uncommon) and don't have any change, or need to make a long-distance call from someone else's phone.  The prepaid card allows you to dial a toll-free number, enter the prepaid card number, and then dial any local or long-distance number.

These cards are very inexpensive, and are available at most supermarkets, drug stores, or convenience stores.  Buying one before an emergency and keeping it in your wallet is a prudent thing to do.  In fact, there's no reason why you can't copy down the access codes, and share them with family members.  Even if you deplete the card, it is generally possible to recharge it by using a credit card, and the cost for calls is considerably less than just using a credit card to make the call.  (If you do need to use a Visa, MasterCard, or other major credit card to make a call, you can do so by dialing the access number for a long distance carrier, such as 1-800-CALL-ATT; however, the cost for these calls can be very expensive.)

Prepaid phone cards can also be easily ordered online.  (You don't receive a physical card, but you receive the access codes, which you can print.)  The following site has a good search engine for locating inexpensive cards:

ComFi phone cards

2.  Cellular telephones

Some people conceptually realize that their telephone is hooked to a wire, and that if something cuts the wire, the phone will stop working.  But they view their cellular phone differently, since they don't see the wire.  They often assume that the cellular phone will keep working, no matter what.  This is not a good assumption.

 The cellular telephone is really just a radio transmitter and receiver, and it needs to communicate with another radio transmitter and receiver at the nearest cellular tower.  If enough of those towers are destroyed or lose power for a long enough period of time (generally, not more than hours), then the cellular network will stop functioning.

Whether or not the cellular network ceases functioning, and whether or not your landline telephone ceases functioning, are dependent upon many of the same variables.  But to some extent, they are independent of each other.  So it's quite possible that one will cease functioning before the other does.  So if you have a cellular phone and a landline phone, one of them might be working after the other one stops working.  Predicting which will go first is somewhat difficult.  It's somewhat counterintuitive, but the landline phone might actually be somewhat more reliable, although they both probably have approximately the same level of reliability.

But since they are somewhat independent, having both will increase the overall reliability somewhat. 

Even if the cellular infrastructure is undamaged, there are limits as to the call handling capability of those networks.  And during emergencies, the volume of calls is often very high.  Therefore, a cellular telephone is not a particularly reliable method of communications during an emergency.  If it does work (which it very well may), that is certainly a good thing.  But you can't really count on it working during any kind of widespread emergency.

It should be noted that in a situation where the network is overloaded, the text messaging or e-mail available on many cellular phones might prove more reliable than the telephone itself.

Despite their limitations, cel phones are very useful during many personal emergencies, and many people have one for that reason.  Some of these people pay $30 a month to be prepared for these "emergencies".  If you truly need a cellular phone only for emergencies, there are much more economical alternatives.

If you are already paying for cel phone service, you might try doing what I did.  One day, I called my cellular provider and asked them whether they had any less expensive plans, since I didn't use the thing very much.  They were quite adamant that $30 was their least expensive plan.  I thanked them for the information and told them I would think about it.  After thinking about it, I called them up again and told them to cancel my service.  A very nice operator asked me if, before cancelling, I would like to speak to the "customer retention" department.  A very nice gentleman in the "retention" department told me how sad they were to be losing me, and asked me whether I would be interested in their $10 per month plan.  For this price, I get 30 minutes per month, which is about 29 minutes more than I normally use in a given month.  I told him that I was interested, and I remain a satisfied customer of their $10 plan.

If you don't currently have a cel phone, the cheapest phone available seems to be about $6.67 per month from Virgin Mobile, and probably about the same price from other "prepaid" providers.  For these services, you buy a phone for about $20 at a retailer, and then pay in advance for airtime.  The Virgin Mobile plan (and probably other plans) requires that you purchase $20 of airtime every three months, whether you use it or not.  So it works out to $6.67 per month if you only occasionally use the phone.

An even cheaper alternative, if you intend the phone only for true emergencies, is to purchase any used cellular handset at a garage sale, on e-Bay, or wherever you can find it.  Even though this phone is not activated, it can be used to make calls to 911, anywhere in the country where it is receiving a signal.  You just push 9 1 1 SEND, and you should be connected to the local 911 dispatcher.

I have more information regarding cheap phones for emergency use (either with prepaid service or for 911 use only), on my Emergency Cell Phone Page. Such phones are available new starting for about $5. Because most buyers purchase relatively expensive minutes, the sellers make their money by selling airtime. Therefore, they give the phones away practically for free. When you buy one of these phones, you are under no obligation to purchase airtime. Therefore, they are a very economical way of ensuring that you have a phone available for emergency use.

In some areas, you can also make collect or credit card calls from such a phone, although these calls are outrageously expensive (about $2 per minute).  But if it's a true emergency, this might be a viable option.  And if such calls are rare, it can be a much cheaper option than paying a monthly fee.  In my market, to place such a call, you dial any 10 digit number (the number you are calling, although it can be any number you make up), and then push the SEND button.  You will be routed to a system that gives you instructions on how to place the call.  This option is not available everywhere, and it seems to be disappearing.

To test a phone like this, you could call 911.  However, that is not advised, since that number is reserved for emergencies.  A better option is to try calling 611 SEND or *611 SEND.  You will either get an operator for a local cellular provider, or you will get a recording stating that your phone is not recognized.  Either way, you will be fairly certain that the phone works.

Especially with an old phone that you bought at a garage sale, it's quite possible that the batteries are in poor shape.  If you obtain such a phone to keep in your car, it would be very advisable to also obtain an adapter that you can plug into your car's cigarette lighter.

3.  Satellite Telephones

There are telephones available that do not depend on the local cellular network, but instead depend on satellites orbiting overhead.  During a regional emergency, these would be expected to keep working even if all local communications were not.  They are generally very expensive, both for the purchase of the telephone, and for the airtime.  So they are probably not viable options for most people.  But for those travelling in extremely remote areas, they might be worth considering.  Such phones are available for rent, so a person planning on being in a remote area for a relatively short period of time may consider renting such a phone.

4.  Private telephone systems

It is quite simple to connect two telephones together and be able to talk, independent of the phone company.  This requires two or more telephones, wire running between them, and a source of power (such as a battery).  Connecting the phones in this manner is almost trivially simple, and even if the wire connecting them is a few miles long, the phones would work quite well.  Essentially, the phones would need to be wired in parallel, with a battery also in parallel.  In most areas, a single wire can be run between the two stations.  For the second wire, each station could be connected to a good ground rod.

The more difficult proposition would be making the phones ring.  This is possible, but requires more expertise.  For most people, it would probably be simpler to run a separate circuit with a doorbell or buzzer to alert the person on the other end to pick up the phone.

 The situations where such a system would be useful are probably quite rare.  But for situations such as providing communications between neighboring buildings, building such a phone system might be a viable option.

B.  Two-way radio


 Millions of Americans own "FRS" (Family Radio Service) radios.  These are small, inexpensive, two-way radios.  They are relatively low power, and FCC regulations require that these radios have built-in antennas, with no provision for an external antenna.  These radios operate on UHF frequencies.  The possible range of these radios depends considerably on the environment in which they are used.  This is because UHF radio signals can generally only be transmitted within the radio's "line of sight".  In other words, these radio waves have only a limited ability to penetrate obstacles.  Therefore, the range of the radios usually depends very little on the actual distance between the two radios.  Instead, it is much more dependent on the obstacles between the two radios.  If two persons were attempting to use one of these radios on the tops of two mountains, they would generally be able to communicate, as long as the two mountains were within sight of each other, even if they were many miles apart.  On the other hand, if the two radios were located on opposite sides of a large building, they might be unable to communicate, even though they were only a few hundred feet apart.

Obstacles between the two radios which might limit their range could include buildings, hills, and the curvature of the earth.  Obstacles such as vegetation and wooden structures would pose less of a hindrance to communications.

Many of these small radios are sold in packages that claim ranges of a certain number of miles.  These claims are virtually meaningless.  A "ten mile" set of these radios is not necessarily any better than a "two mile" set.  The mileage claims reflect little more than the hyperbole of the manufacturer.

FRS radios generally have fourteen channels, although a few older models might have fewer channels.  Generally, all such radios are of fairly good quality, so even the most inexpensive set might actually perform quite well.  Many of these radios have a feature that allows the user to select a "privacy code".  The term "privacy" implies that using this feature assures the user of some security of communication.  Many users believe that other radios cannot hear them if they select the "privacy code".  This is not true.  The "privacy code" merely prevents the user from being able to hear persons he doesn't want to hear.  If someone else wishes to listen, the fact that another person is using a privacy code will not provide any privacy.

As noted above, the effective range of FRS radios depends mostly upon whether or not there is a clear path between the radios.  In general, a radio which is higher above the terrain will be able to "see" further, and will have a greater range.    In typical use, it's probably reasonable to expect a range of a half mile or a mile.  Remember, the radio will have much greater range at a higher location.  Also, such a radio used in a vehicle will not have as good a range, because of the obstacle imposed by the vehicle.  Sometimes, merely holding the radio above your head, or moving toward a window in the direction you want to communicate, can make a profound difference.

A close relative of the FRS radio is the GMRS radio.  Most of these radios sold today are 22 channel models.  The channel numbers are not necessarily standard, but in most cases, channels 1 through 7 correspond with FRS channels 1 through 7, although the GMRS radio is allowed to use more power.  Therefore, a GMRS radio and an FRS radio are able to communicate with each other on those channels.  Because of the greater power, it will have a somewhat better ability to penetrate obstacles, and will have a somewhat better range.  However, it is still affected by those obstacles.

Channels 15 through 22 are channels that are used on only GMRS radios, and these channels cannot be used to communicate with FRS radios.  These channels also use the higher power levels.

GMRS radios have the potential to have one important advantage over FRS radios.  Unlike FRS radios, it is legal to attach an external antenna to a GMRS radio.  Since the height of the antenna is the most important factor in the radio's range, a GMRS radio could have a very good range if it were connected to an antenna at a high location.  Unfortunately, the people who market these radios made an unfortunate marketing decision which has made most of them considerably less useful.

If a GMRS radio had only channels 1 through 7 and 15 through 22, then it would only have fifteen channels, but it would be legal to have a jack to connect an external antenna.  But the manufacturers decided that these radios would sell better if they were "22 channel" radio instead of "15 channel" radios.  So they decided to add FRS channels 8 through 14.  When a GMRS radio is tuned to channels 8 through 14, it is no longer a GMRS radio.  When it is on those channels, it becomes an FRS radio.  On those channels, FCC regulations require the radio to use less power.  The power level is a relatively minor problem, although it should be kept in mind that these radios will probably have somewhat less range on channels 8 through 14.

 But the major problem is that if these radios contain channels 8 through 14, then they are not allowed to have an antenna jack.  Therefore, even if the user intends to use them on channels 1 through 7 and 15 through 22, it is not possible to connect an antenna, even though an external antenna would greatly extend the radio's range.

 It is possible to purchase 15 channel GMRS radios, although they are more expensive (but generally of very high quality) than the 22 channel models.  It is also possible to purchase an older 15-channel model, which was produced before the marketing people decided that "22 channel" models will be more attractive.  Generally, on these 15-channel models, it is possible to use an external antenna.

With an antenna at a high location (such as on top of a house), a GMRS radio can have surprisingly good range.  Since so many people own FRS radios, having a GMRS radio with an outside antenna would allow communication with neighbors over a quite large area.  And two GMRS radios, each with an external antenna, could communicate over a very large distance.  Again, the actual range depends on the terrain and obstacles between the two radios.  But communications over ten or more miles would not be difficult in many cases.

GMRS radios do require a license in the United States, which costs $80.  However, millions of people own the cheap "22 channel" models and have ignored the license requirement.  If you use channels 8 through 14 of a "22 channel" model, then you are actually using an FRS radio, and do not require a license.  If you do purchase a 15 channel model and connect an external antenna, then you should obtain a license and use your callsign, since you will be able to be heard over a very large area.

Without an external antenna, it is extremely unlikely that one would get caught transmitting without a license.  Still, it is required.  But since a license is not required for channels 8 through 14, the easiest way to avoid breaking the law is simply to use those channels.  Some GMRS radios might have higher power on the other channels (although I suspect many do not), but the power is not the critical factor.  Since it's just as easy to use them legally on channels 8 through 14, you may as well do so.

Both FRS and the 22-channel GMRS radios are very cheap, and it's not uncommon to find them for only a few dollars.   Here, for example, you can get two Motorola radios for under $20:

Motorola FRS-GMRS Radios

 A close relative of GMRS radio is MURS (multiple user radio service).  These radios are somewhat more expensive, and they do not require a license.  Typically, these radios will allow the use of an external antenna, and will have a greater range for that reason.  These radios will function about as well as a GMRS radio.  It is not possible for a MURS radio to communicate with an FRS or GMRS radio; they can only communicate with other MURS radios.

2.  CB Radio

Citizens Band (CB) radio has been around since the 1950's.  It achieved great popularity during the CB craze of the 1970's, when millions of people owned these radios.  Many of these people remember those times, and one main memory is the fact that there were so many users that the radios became virtually unusable because of interference.  However, the CB craze died many years ago, and there are relatively few users on many channels.  Today, a CB radio could actually be a viable means of communications over a few miles.  CB radios have the great advantage of low cost, and can be put to good use in many applications, particularly in vehicles.

For example, the following CB radio, which is more or less about as good as any other CB radio (other than SSB units, as explained below) costs only about $30:

Midland CB Radio

For about the same price, there are also a number of handheld CB radios available, such as this one:

Hanheld CB Radio

For some applications, the convenience of a compact unit such as this might be useful.  The radio itself will perform about the same as a larger unit.  And having an antenna mounted directly on the unit is useful in situations where you don't want to install an external antenna.  However, the antenna that is mounted on the unit, because of its small size, will be extremely inefficient.  This might be fine if you only need to talk a mile or less.  However, any CB will perform much better with an external antenna.  It is possible to use an external antenna with this radio, and with most other handheld CB's.

For communications between two fixed locations, a CB radio could actually be a solution over distances of ten or twenty miles, if some care is given to the installation.  The most important factor, once again, is the height of the antenna.  It is also possible to use directional ("beam") antennas which will increase the range in one direction.  If two locations need to be linked, installing "beam" antennas at each end, pointing toward one another, it might be possible to ensure reliable communications over fairly long distances.  Single sideband (SSB) CB radios are more expensive, but they do allow communications over somewhat longer distances.  It should be noted that for the advantage, both radios need to be SSB radios.  However, the SSB radios can all be switched to function as normal AM CB radios.

CB radios that can be used for SSB (and also AM, for communication with normal CB radios) generally start at about $150:

SSB CB Radio

One trick that might be useful in some applications is to use a horizontal antenna to reduce interference.  Most CB radios use vertical antennas, and vertical antennas are generally much easier to install on a vehicle.  In general, the range between two CB radios will be much greater if both antennas are vertical, or if both antennas are horizontal.  Since most CB radios use vertical antennas, there will be less interference if you are using a horizontal antenna.  Therefore, if you intend to communicate between two fixed locations, and with nobody else, using horizontal antennas on both ends will reduce interference and allow for more reliable communications.

More discussion regarding CB antennas can be found on my CB Antenna Basics page.

Most CB radios operate on 12 volts DC, for ease of use in a vehicle.  To use one in a building with commercial power, it is necessary to purchase a power supply.  But if the intention is to use the radio during emergencies, a better solution might be to use a 12 volt battery.  More discussion of power supplies is included below.

3.  Amateur (Ham) Radio

There are several hundred thousand amateur radio operators, or "hams" in the United States.  Amateur radio requires a license from the FCC, which requires passing a written test.  Until recently, most licenses also required passing a Morse code test, but this requirement has recently been deleted.  Morse code ("CW", short for "continuous wave", the technical term) can be a very effective means of communication, especially in an emergency, and it is still allowed on the air and quite popular.  But a Morse code test is no longer required to obtain a license.

The written tests are relatively simple to pass, and almost any intelligent person would be able to pass them with a few nights of "cramming".  However, it is probably worthwhile to take a little bit longer time to learn about the hobby, as studying for the test will give you a greater understanding of the capabilities of amateur radio, and will allow you to "hit the ground running" after you receive your license.

I have published a study guide to help you pass the test for the entry-level (technician) license.  Information on that book, which is available in paperback or as an eBook is available at this link.

One important restriction of amateur radio is that, with very rare exceptions, it cannot be used for business communications of any kind.

Many study materials are available in books and online, and many local radio clubs offer classes and encouragement to beginners.

 a.  VHF and UHF

Many beginning amateurs start on VHF and UHF, using radios which are very similar in intrinsic capability to GMRS radios.  Amateur radio operators, however, frequently use "repeaters" on VHF and UHF.  A repeater is simply a transmitter and receiver that someone (frequently a local radio club) has installed on top of a tall building or other high location.  By using a repeater, it is possible to communicate over a very large area with just a portable handheld radio, or a mobile radio mounted in a vehicle.  Many of these repeaters are open to any ham who wants to use them, although if one is a frequent user, being involved in the club and helping with the financial support of the repeater is encouraged.

VHF and UHF radios which can be used through repeaters are quite inexpensive.  Very good radios can be purchased for under $150.

Many, but not all, of these repeaters have emergency backup power sources.  Therefore, some of them might be on the air during a disaster.  However, many repeaters do not have backup power, and some of them are intended for specific uses during emergencies.  Therefore, it is not wise to depend on repeaters for routine personal use during a disaster situation.  Also, on very wide range repeaters, it is quite possible that hundreds of other people will be listening at any given time.  This is especially true during a disaster, when many hams instinctively tune their radio to the local repeater for information. 

"Simplex" communication on VHF and UHF can provide good results, especially if some thought has been given to the type and location of antennas.  Generally, the possible ranges will be similar to those possible with GMRS radios.  But because most amateur radio equipment can use somewhat higher power levels than GMRS radios, and since hams generally give a bit more thought to their antenna systems, somewhat larger ranges can be expected.  Once again, the range of such a radio depends largely upon the number of obstacles between the two stations, so it is dangerous to generalize as to how many miles can be covered.  But distances of 10 to 30 miles are not unreasonable in most cases, if some thought is given to the antenna.

b.  HF

Even though many hams begin on VHF and UHF, the High Frequency ("HF") frequencies provide many more interesting possibilities, and provide the means for worldwide communications.  "HF" is simply another term for "shortwave", which we've already discussed.  HF or shortwave signals are reflected by the earth's ionosphere, which is located many miles above the earth's surface.  Since the ionosphere is high above the earth, there are few obstacles between it and a station on the ground.  Since there are few obstacles, even low power levels can be used to communicate over extremely long distances.  It does require more skill to use the HF frequencies, but that skill is learned relatively easily with practice. 

Radios which are capable of transmitting and receiving on the HF frequencies are generally available for about $600.  Generally, these radios have a power output of about 100 watts, and many of them are also capable of transmitting and receiving on VHF and UHF.

A large expensive antenna is often helpful for use on HF, but it is generally not necessary.  Most hams rely on homemade wire antennas which are tied to trees or buildings.  With a bit of skill, such an antenna can be made for less than twenty dollars.  Some hams are not allowed to have outdoor antennas, and many have made very well functioning "invisible" antennas to use in such areas.  A large antenna or an expensive antenna, while certainly nice, is rarely necessary.

For a beginner on HF, I would recommend a 100 watt radio, and there are several inexpensive ones on the market.  In many cases, it is advisable to use less power.  For example, using the radio at 5 watts will only use 1/20th the battery power of using it at 100 watts.  Even though it's often not necessary, it is nice to have the capability of using greater power on occasion.

There are a few similar radios, but only 5 watts.  The most popular such radio is the Yaesu FT-817.  It is extremely small and only weighs a few pounds.  I own one, and it is the radio I use over 90% of the time.  I have communicated all over the world with it.  However, on some occasions, the additional power might mean the difference between being able to communicate, and not being able to.  And espeically for a beginner, the additional power can make life much easier.  So unless the small physical size of the radio is important, I would recommend a 100 watt radio for the beginner.

Most amateur HF communication is with single sideband (SSB) voice.  However, Morse code (CW) is still very popular.  And if radio conditions are poor, it is often possible to reliably communicate using CW, when a voice SSB contact would be impossible.  So for reliability of communications, I would encourage beginners to give CW a try.  For many emergency communications needs, it would work extremely well.

I frequently use my 5-watt FT-817 while camping.  I typically take about five minutes to set up a wire antenna in some trees, plug the radio into a battery, and I can communicate worldwide.  Morse code (CW) is the mode I usually use.  Especially with a possibly marginal antenna, the CW signal often gets through where voice would not.  Most of my camping involves being in close proximity of a vehicle, and carrying a radio that weighs a couple of pounds, along with a battery that weighs several pounds, is not much of an issue.  However, there are a large number of hams who enjoy operating during backpacking trips, when every ounce must be carefully accounted.  Many of these hams use extremely small radios, often mounted in an Altoid's tin, which weigh only a few ounces, and power them with very small batteries, such as several AA cells.

Most of these radios are homemade, and virtually all of them are CW only.  They are extremely minimal, but they can provide communications over hundreds or thousands of miles quite reliably.  Frequently, when these hams are in a remote wilderness area, they use their radios to send messages home.  A ham on the other end is frequently willing to make a phone call or send an e-mail for them.

In an emergency situation, I plan to use my radio equipment in a similar fashion to send messages to friends and relatives in other states.  In many emergencies, the local or regional infrastructure could be destroyed, but would be functioning in other nearby areas.  I have written down the times and frequencies of "nets" or networks in other nearby states.  At these times and frequencies, there are other hams who are willing and able to relay messages.  And even if their local infrastructure is not functioning, they have the capability to relay the message to other nets.  So in all but the most extreme of disasters, I know that I can send messages to friends and relatives in other states either advising them that I am OK, or advising them of any needs.  A return message from them might be more problematic, but by checking into the same net the next day, I would be able to receive any return message relayed through the same ham who made contact with them initially.

4.  Approximate range of various radios

The range of various radios will vary considerably, depending on many factors.  Therefore, it is extremely difficult to say that a certain type of radio has a range of a certain number of miles.  However, people frequently want to know how many miles a certain radio will communicate.  Therefore, I have put together the following table.  But please take this table with a huge grain of salt.  If I have stated that a certain radio can communicate 5 miles, please do not depend on this being absolutely true in all cases.  It is an extremely rough estimate, which will vary considerably given your own conditions.  In some cases, it might be considerably more.  In some cases, it might be considerably less.  Murphy's law being what it is, assume that it will be considerably less, until you have done some testing and concluded that, indeed, in your situation, it will communicate this number of miles.

But the following table might be helpful for planning.  If you know you need to communicate five miles, then this table might give you some suggestions of what might work in your situation.  If you need to communicate six miles, the "five mile" solution might be workable.  But in another situation, the "five mile" solution won't even cover one mile.  But the following numbers are probably true about half the time--in a given situation, if you need to communicate a certain distance, then the solution shown below will work about half the time, and won't work about half the time.

Since this is addressing two-way communications, you need to consider the type of radio on each end.  Locate one radio on the top row, and the other radio on the side column.  Where the row and column intersect, this is a rough approximation of how many miles the two radios can communicate.

The table can be found at this link






III.  Power Supplies

There seem to be a lot of people who own rather large electrical generators.  In fact, I am one of those persons.  When I ask some of these people why they own these generators, I'm often surprised to learn that their primary purpose is to make coffee or make toast.  They don't seem to realize that toast and coffee were actually invented prior to electricity.  There are many suitable ways to make coffee and toast that do not involve electricity.  One can make better coffee and toast without electricity than you can with electricity.  And if you need to generate the electricity yourself, it's not a particularly efficient way to make coffee and toast.  So coffee and toast, in my opinion, are not particularly good reasons to own a generator.

But for any kind of electronic communications, you will need a certain amount of electricity.  And if you want to be able to communicate electronically without commercial power, you'll need to figure out how to generate it yourself.  Fortunately, for all but the rarest of communication needs, large amounts of electricity generally are not necessary.  So owning a large generator is not a prerequisite to communicating.  Certainly, if you're going to run a generator to make coffee or toast, then you may as well use that same electricity for your communications needs.  But it is not necessary to do so.

This is because most effective communications can be done with relatively small amounts of power.  Virtually all electronic equipment can be operated quite well from 12 volts DC.  Since most people own an automobile, they already own a very good battery and recharging system, which is sitting in their driveway.

Running an automobile simply to charge a battery is quite possible, although it is somewhat wasteful of fuel.  But for occasional use, it will serve the needs of many.

For longer term use, some kind of solar system is probably ideal, since it has few moving parts, requires no external fuel, and will work more or less indefinitely.  A large system is not required.  Some people may prefer a somewhat larger system, but for most of my needs, a single solar panel of approximately 5 watts generally meets my needs.  I purchased this panel on eBay, and it cost about $20 with shipping.  If you search eBay for "VW SOLAR" or "VOLKSWAGEN SOLAR", you will find several for sale at any given time.  While very minimal, this one is adequate for most of my needs.

A similar solar panel is also available from Coleman:

Coleman Solar Panel

Solar panels of this type are very small, and they only provide a small amount of current.  But they do provide enough current to run a small radio or television, or to charge a battery.  While these give you only a very modest solar system, they do provide enough electricity to operate small electronic devices more or less indefinitely, and for the money, are a very prudent investment.

The sun doesn't necessarily shine when you want to use the electricity.  And with a solar panel of this type, it would be dangerous to connect it directly to 12 volt electronics, since during bright sunlight, it may be putting out much more than 12 volts.  Therefore, some method of storing the electricity is required.

As noted above, most people own a very suitable item for storing this electricity, namely, their car battery.  But since car batteries are not particularly portable, and they are often messy, a somewhat more convenient alternative might be called for.  In my case, I purchased an automotive jump-start battery on sale.  This battery is rated at about 10 amp hours (that is, it can presumably provide one amp for ten hours, or ten amps for one hour), and it comes in a convenient sealed package.  It is quite small, but it is adequate for my communication needs.

The original model I purchased was this one:

Jump Start Battery

This is a very basic unit with a relatively small battery.  In fact, it's probably not much good for its intended purpose of starting a car with a dead battery.  But it was excellent for powering electronic devices of all types.  After several years of abuse, it still holds a partial charge.  I finally purchased a new one so that I would have reliable power, but the old one can still be used to run a radio for a few hours.

Some of the more expensive units of this type include a built-in inverter to provide 120 volts AC.  I used this one with a small inverter that plugged into one of the 12 volt sockets with good results.

I also own one of these small solar battery chargers, which will recharge AA, C, or D rechargeable batteries. 

Solar Charger

It can basically recharge two batteries during one sunny day.  This doesn't sound like a lot, but it would be plenty to listen to a small transistor radio for a few hours per day, more or less indefinitely.  (Note, this charger can only be used with rechargeable NiCd and NiMH batteries.)

For more information on power inverters for emergency use, please visit my inverter page.

There are a number of small radios available that do not require batteries, because they operate with a hand crank. Some of thes are available for less than $20. While radios such as this do have their place, there are a number of inherent shortcomings. First of all, on most of them, the crank itself is made out of plastic. While some of them are fairly durable, it does seem like the kind of thing that will eventually break. I suspect that for most people, having a few spare sets of alkaline batteries will probably outlast the crank.

Also, in most of these radios, the hand crank actually recharges a battery. It's typically best not to leave rechargable batteries run down, so the internal battery in these radios will eventually wear out. In most cases, you could probably still listen to the radio, as long as you keep cranking continually, but this would not be very convenient.

If you are interested in buying one of these radios, I would recommend the following one, as being the best trade-off between price and quality:

 American Red Cross FR250 Emergency Radio    

The identical radio is offered under a number of brand names, including Grundig and Eton. This model includes shortwave, and also NOAA weather broadcasts. I own one of these, and it provides good reception. Its best to keep a spare set of batteries, but it's nice to know that the radio will keep working even if the batteries go dead. This radio also has a built-in light and the ability to charge your cel phone, which could be very useful in some emergencies.

IV.  Electromagnetic Pulse (EMP)

One often-discussed effect of nuclear weapons is the electromagnetic pulse (EMP) generated by such weapons.  During a nuclear explosion, huge amounts of electromagnetic energy (in other words, radio waves) are given off.  This, first of all, can cause local effects.  However, in general, if one is close enough to a nuclear blast to experience these local EMP effects, then EMP is probably the least of his worries.

But during a high-altitude nuclear blast on the edge of outer space, these EMP effects can interact with the earth's magnetic field, and cause the EMP effects to be felt over thousands of miles. 

In an oversimplified nutshell, and EMP is an extremely strong radio wave, on many frequencies at the same time, but for an exceedingly short time.  If this radio wave is received by a piece of electronic equipment, and it is sufficiently strong when it is received, then it can damage the electronic equipment.  It would be akin to taking a piece of electronics and connecting it directly to a strong radio transmitter.  As one might expect, the electronics could easily be destroyed.

The EMP wave is so strong that, if it is picked up by a sufficiently large antenna, it would be as strong (for a tiny fraction of a second) as the signal coming directly out of a transmitter.  However, the EMP signal needs an antenna in order to be received.  If a piece of electronic equipment doesn't have an antenna, then it won't pick up the EMP wave.

Obviously, very few experiments have been conducted to determine the effects of a high-altitude nuclear explosion over a populated area.  But the general consensus seems to be that the "antenna" needs to be at least a few feet long.  If a piece of electronics is not connected to an "antenna", then it will probably not be damaged by an EMP wave.  But if it is connected to an "antenna", then there's probably a fairly good chance that it will be damaged.

The good news is that any electronic device you own, if it is not connected to an "antenna" at the time of the EMP event, will probably suffer no damage.  The bad news is that many devices are routinely connected to "antennas".  As far as the EMP event is concerned, any sufficiently long piece of wire or metal will serve as an antenna.  And these wires certainly include power wires, telephone wires, and even metal water pipes.  Devices "plugged in" to one of these "antennas" at the moment of the EMP event could be damaged or destroyed. 

So if you have a radio that is plugged into a wall outlet, it is quite possible that it will be destroyed by EMP.  If you have a radio with a power cord that is stretched out, it might be damaged by EMP.  If you have a computer that is plugged into a power outlet or a phone outlet, it might be damaged by EMP.  In fact, if you are touching a metallic fence at that fateful moment, you might be damaged by EMP.  Perhaps some items that are plugged in will not be damaged, but it's probably safer to assume that they will be damaged.  Therefore, if one is prudent, it would be wise to store at least some of your vital electronic equipment so that it is not connected to any external wires, such as power cords, headphones, etc.

Frequently, the subject of "Faraday cages" arises.  A "Faraday cage" is simply a metallic container that is completely sealed on all sides.  One example would be a metal trash can whose lid is firmly attached to the can. (Grounding is not necessary, and might even be counter-productive.)  In theory, a Farady cage will completely shield its contents from EMP.  So a piece of electronic equipment, with no external wires, stored in a metal garbage can, it seems to me, would be more or less bullet-proof from the effects of the EMP.  Personally, I believe that storing it with no external wires attached would be sufficient in the vast majority of cases.  But the Faraday cage would provide an additional level of protection.

It is also frequently surmised that an EMP attack would destroy all automobile electronic ignitions.  Again, experiments have not been conducted where a nuclear device has been detonated at high altitude over a modern automobile.  So the truth is that we don't know the exact effects.  In my personal opinion, I have little doubt that some automotive electronics would be destroyed.  Automobiles do contain some "antennas", such as spark-plug wires, and other automotive wiring.  But most of this wiring is shielded by the automobile itself, which forms an imperfect Faraday cage.  So I believe that some, and probably most, automobiles will be functional after an EMP event.  Of course, I have no way of knowing for sure.

It does seem likely, though, that an EMP event would render most electrical power systems and telephone systems inoperable.  The electrical and telephone wires form an excellent very long antenna to receive the EMP wave.  Even if only a small fraction of the devices connected to the power lines and phone lines were destroyed, it is likely that the whole system would fail.

Also, it seems to me very unlikely that an enemy with a single nuclear device, or just a few nuclear devices, would use that device for a high-altitude EMP attack.  The effect seems to be well established, but it's never really been tested, and never will be tested other than as an act of war.  Given the uncertainty, it seems to me unlikely that an enemy would use a precious nuclear device in such a manner, when the effects on a city are much better understood.  Also, delivering the weapon to a high altitude would pose logistical problems, and delivering the bomb by land or at a lower altitude using an airplane are probably much simpler.

It also seems to me that any enemy launching an EMP attack could expect immediate retaliation.  After all, it is a nuclear attack on the United States.  The enemy would be aware that it had only a short window of opportunity to launch any further attacks.  Therefore, it seems to me most likely that an EMP attack would only take place as part of a general nuclear attack, quite possibly as the first shot.  The EMP attack, and the widespread failure of the electrical and telephone networks, might thus serve as the only warning of the beginning of a nuclear war.

Of course, power outages, even widespread power outages, are often caused by things other than nuclear wars.  So a mere power outage would not signal the beginning of a nuclear war.  But the radio could serve to confirm whether or not there had been an EMP attack.  If the power suddenly fails, a battery radio (one that had been stored with no external wires) could immediately confirm whether local radio stations were still on the air.  If they were, this means that their power is still functioning, and that a nuclear war has probably not started.  If all local stations are off the air, this would mean a regional power outage, but this could still be explained by other causes.  This is why it is important to have some familiarity with which radio stations can be received in your area during the day, and at night.  If every single radio station, even in relatively distant areas, is off the air, this would be a strong indication that there has been an EMP attack, which is likely the one of the first shots of a general nuclear war.  The silent radio dial would be a strong indication that you might need to make final preparations for this catastrophic event.


The foregoing has been a very basic discussion of many communications concepts, and is all extremely general.  I have made little effort to provide specific details.  It is my hope, though, that I have given the reader some understanding of the general capabilities of various means of communications, and provided some ideas as to what might be possible.

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