Providence Cooperative Survival Communications FAQ Ver 1.12

8/13/2019 Providence Cooperative Survival Communications FAQ Ver 1.12

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This FAQ archived and provided free as a courtesy by

The Providence Cooperative

http://www.providenceco-op.com

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Survival Communications FAQ Version 1.12

DISCLAIMER: The authors and editors of this FAQ panel assume no legalresponsibility for any errors in or misuse of this information, and arenot to be held legally liable or responsible for any death, injury, lossof property, or other negative consequences resulting from use, misuse,or abuse of this information. This document was based upon an earlier FAQ written by another m.slurker, and has received many contributions from m.s members who wishednot to be named here.

Any comments should be sent to me at [email protected], and will be actedon or forwarded to the other authors as appropriate.

This document is being archived at:http://www.grapevine.net/~medintz/surv_faq/comfaq112.txtandhttp://www.providenceco-op.com

Archiving or re-distribution is permitted only according to the terms ofthe document http://www.grapevine.net/~medintz/disclaim.txt. In general,redistribution, use, or storage is approved, but there are certainstipulations and exceptions in that document that must be obeyed.

This document is a work in progress. Suggestions, comments, andrecommendations are always welcomed, and will be acted on or forwarded

as appropriate.

Further information on radio may be gathered from 'The ARRL Handbook'and the 'ARRL Operating Manual', published by the American Radio RelayLeague(http://www.arrl.org)

A topic as broad as communications can never been completely covered,especially in what should be a terse and matter-of-fact FAQ. We'llstart out with the most general description we can provide, and getmore specific deeper in the document.

WHAT IS COMMUNICATION ?

The first step in understanding communications in the context ofsurvival is understanding of the fundamentals of communication itself.Communication is a very complex topic, as difficult to completely defineas truth, beauty, or time; however, in an attempt to cut to the chaseand make our life simple, we'll start with two definitions:

COMMUNICATION is the successful transfer of information from one personto another person or entity.


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COMMUNICATION SYSTEMS are comprised of equipment, methods and techniquesof supporting information transfer, enabling communication to take placebetween two people. (Please note that these definitions are cheap outs,since we haven't defined what we mean by information, but you get it,right? Note that we re also limiting things by requiring at least oneperson in to loop, to reduce the scope of this document.)

What Happens When We Communicate?

In order for any communication to take place, there are three majorrequirements that must satisfied.

REQUIREMENT ONE: There must be a sender and a receiver. For mostsurvival purposes, this means a person trying to send a message and aperson looking for a message sent to them.

REQUIREMENT TWO: The sender and receiver must understand how the messageis to be conveyed, and must understand the message itself. In thesurvival context, this means that both people trying to communicateunderstand how their communication system works (how to operate thecommunications equipment, that one or two lamps have different meanings,how to look up a word in a dictionary) and that they understand themessage (the message in clear and in a common language, that one lampmeans that the British are coming by land and two lamps means by sea.)

REQUIREMENT THREE: the communication system must be capable ofdelivering the message. (There's not so much fog the lamps can't beseen, or that the radios are within range and working properly.

THE ONE RULE OF COMMUNICATIONS: To communicate, the sender creates amessage that both he and the receiver should understand. Then, using acommon system that is capable of delivering the message, the sendertransmits the message to the receiver, who understands the message sent.

SURVIVAL IMPLICATIONS

Failure to communicate is always the result of a failure to meet therequirements. A few specific examples:

The first requirement being that there is someone trying to send amessage and someone expecting to receive it may at first seem obvious,however in practice it is probably the most violated requirement ofcommunications in a survival context, providing the violator with afalse sense of security until they need to communicate. For somereason, somebody buys a CB and thinks they can be in the middle ofnowhere, call for help on channel 9, and Air Rescue magically appears tocome in and save them. Yup, it's a long day in hell when this happens.

It's not just CB owners, either: this requirement gets violated by

amateur radio operators (I'll just call for help on the repeater exceptthey left the directory home and their rig doesn't provide the rightsub-audible tones, or the guy that just answered your CQ or SOS on 40meters thinks you're a crank) and Cell Phone users (whadda ya mean theydon't have service in the middle of a wilderness area or during amassive power outage?).

Nor is this limited to radio: flare guns (It's 2AM, a bear just ate yourcamp partner, and you're fifty miles from civilization in a valley.Shoot a flare off, and you've made your camp brighter for a few seconds


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and pissed off the bear. Feel better?) Air horns (same scenario, maybethe bear leaves if it's loud enough.)

Resolving problems surrounding the first requirement simply means makingsure there is a person listening. Perhaps someone you know, perhapsnot. The 911 system, for example, consists of people continuallymonitoring a phone for incoming messages from senders. World-wide,satellites and many pilots listen to 121.5 Mhz on their radios, lookingfor distress signals. If a CB operator knew someone in the area whoagreed to listen on channel 9 for 15 minutes at 6PM everyday, hischances of being heard then are vastly improved. The ham, who hadpunched in the frequency to his club's repeater, which has along-tone-zero (LTZ) emergency alert system that gets friends from theclub on would be in better shape too; and if the ham's friend waslistening at 6PM everyday on 40 meters, it's doubtful his friend wouldthink he was nuts if he said he needed help urgently. Having a friendlook for a flare on a ridge line a hour before sunrise--and climbing tothe ridge line to fire the flare--would work wonders, too.

Note that in each of these cases, not only was someone listening, butthere was coordination, also, in that the recipient of the messages knewwhen and where to look or listen.

What have we learned?

1) Someone has to Send and someone needs to Listen.

2) Both have to use the same system. Both need to understand themessage.

3) Coordination between the sender and listener vastly increases thelikelihood of successful communications.

A. Types of communications

1. Wired Communications

a)Basic Telephone Service

Current telephone communications, at least in industrialized nations, isthe standard of excellence that most communications systems arecompared. Disparaging comments and annoying customer service issuesaside, standard phone service is nearly universal, approaches 100percent reliability, and offers nearly instant connectivity to virtuallyany person in the industrialized world. Phone service is probably thesingle most utilized form of survival communications, used whenever 911is dialed, or a person phones a friend for help.

While basic phone has never been completely secure, it's become very

apparent that phone services are approaching a nearly total securitycompromise, at least with respect to national agencies. Note that withmodern signaling and billing records systems, every phone call islogged, and the phone number, which is effectively an address to aphysical location for wired phones, is present with each call; this istrue even of pay phones.

The exposure risk associated with basic phone systems is extreme. Anycommunications which is intended to remain private probably shouldn'trely on phones. This is of no bearing for most conventional survival


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scenarios.

Phone service can fail at any time, but due to very good survivalengineering, basic phone service often stays operational days after ACpower fails. Destruction of inside plant (central office switchingequipment, batteries, and power generation) or outside plant (poles,wiring, and transmission equipment) will result in failure of service,of course. Note that in floods, hurricanes, and earthquakes phoneservice often fails in a widespread way, whereas failure in commonstorms and civil disorder is usually localized.

Note that while phone service may continue to be reliable during adisaster, communications may be difficult due to overloading. During thesummer of 1996, a power outage in the Western United States resulted ina flood of calls to 911 systems in several states from people simplyreporting that their power was out; in some areas, 911 failedcompletely, or had hold times in excess of 30 minutes.

a) Private Point-to-Point (Intercoms and Field Phones)

Outside of PBXs located in buildings, private wired communicationsaren't very common. Two notable exceptions are intercom systems thatare used to communicate within a building, and field phones, which areessentially military versions of intercoms. Intercoms are generally

limited in range.So-called wireless intercoms use the AC power line to convey theirsignal, and are generally dependent on AC power themselves. Wiredintercoms usually don t cover more than a few hundred feet in abuilding, due to the wiring difficulties. Such intercoms usually run onbatteries. Field phones are generally used in environments wherecomplete control of the lines of communication exist. The typicalmilitary field phone runs on two D cell batteries, and can operate overup to twenty miles of two-conductor wire.

In general, private wired communications is the most secure, . The wiresthemselves can be followed if not concealed, revealing both points of

communications.1. Radio Signals

There are a huge number of possible options for radio-based survivalcommunications, ranging from getting broadcasts from authorities via a$4 AM radio to portable satellite phones.

a) Broadcast Radio

AM Radio

Let s be blunt. If you can have only one radio, if you have less than

ten bucks to buy equipment, forget CB, Ham, and everything else. Get aportable AM radio. The first radio band for survival, news, andgovernment information is the old AM radio band, from 550 Khz to 1700Khz.

Equipment can be very small, with typical radios 1x3x4 in size, light,low-power (two AA batteries can run a radio for weeks at low volume orwith earphones), cheap (Radio Shack's FlavorRadio is $7), very reliable(single IC), long range (100s of miles for clear-channel radio stationsat night)


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In addition to the radios themselves being reliable, AM broadcast radiostations themselves are also fairly reliable with back-up transmitters,emergency generators, and bomb shelters: a few radio stations in everyarea are part of a extremely reliable network that is a carryover fromthe civil-defense radio network's heydays of the 1950's. The two civildefense frequencies are 640 Khz and 1240 Khz. As a result of the defensenetwork carry-over, and the fact that many AM stations offer talk-radiocall-in formats, AM radio is ideal for getting news and informationduring emergencies, probably more so than any other source.

The military and other government agencies also maintain emergencyportable radio stations for disaster-stuck areas, that are AM stations.Inexpensive AM radios with ferrite bar antennas have a secondarysurvival use as navigation instruments. Such radios have sharp,well-defined nulls where the signal goes dead. If one knows thedirection of the nulls of the radio and the locations of the AM radiostations in the area, it's possible to triangulate your own locationbased on the directions your radio indicates each station is in.Accuracy isn't incredible, but it can generally give a position of +/- 5miles if the radio stations are 50 miles away.

Within the US, there was originally a set of stations set up with whatis known as clear channels that made sure a single, high power station

had no others within hundreds of miles on the same frequency. Currentlythese are known as Class A stations (which run 50,000 watts). Thesestations can be heard for hundreds of miles at night, allowing listenersin disaster-striken ares to hear stations that are in surviving areas.(for example: At night, one can hear WMAQ, Chicago on the eastern edgeof the Colorado Rockies without much difficulty.) Refer to Appendix Afor a list of Class A Clear Channel stations.

a)Two-Way Radio

1)Unlicensed Services

All radio services are regulated in some form, even if it's a law that

states that the service is unregulated. However, there are severallicense-free services in the U.S. Note that other locations aren'tquite as progressive in terms of unregulated services. The U.K., forexample, requires CB radios to be licensed, and doesn't offer a free1750 meter band. YMMV!

CB Radio (AM and SSB)

CB, also known as Citizen's Band (or Children's Band to its detractors)uses an amplitude-modulated signal on forty channels centered around 27Mhz. These radios are limited by FCC regulation to four watts of outputpower going up the antenna. Typically, from a vehicle with an averageantenna on flat terrain this results in a reliable range of ten to

twenty miles.

With a better antenna, considerably longer ranges are possible. However,another FCC regulation requires CB operators to take steps to preventtheir signal from being detectable beyond 150 miles. CB frequencies areplagued with a number of problems, such as overcrowding on certainfrequencies and considerable rudeness.

Typically, Channel eleven is considered a general calling channel, andChannel nineteen is used by truckers. In addition, Channel nine is


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reserved by law for emergency use only.

Refer to Appendix B for a list of Citizens Band Channel Frequencyassignments.

Part 15 Radio Bands

So-called part 15 bands owe their name to the United State's FederalCommunications Commission, which has a set of rules (Part 15) whichallow certain types of unlicensed radio transmitters. There are threemain part 15 bands that are commonly used for two-way voicecommunications (other bands exist under part 15 for a plethora of otherdevices.) The only band that's really significant is the 49 Mhz band;the other two are interesting, but probably impractical.

49 Mhz Radios

The 49 Mhz band is a widely-used consumer radio band, primarily forcordless phones. There are 10 narrow-band FM channels between 49.67 and50.00 Mhz assigned to the band (Refer to Appendix C). The band isrelatively noise-free in non-industrial areas, though the millions ofcordless phones means plenty of interference in highly urban settings.Power output is specified by field strength, 10,000 uVolts/meter at 3meters, and translates to a few milliwatts. The band is most useful for

short-range communications.The receivers of good radios are such that this low power gives a 1/4mile range, though field tests show ranges of 1/8 to 1/2 mile, dependingon terrain. The radios perform amazingly well in difficult, hillyterrain at short range. In very controlled tests using a lab-gradereceiver/antenna, a detection range of three miles was obtained.Equipment is small and light, often only 1x3x7 or smaller; it's offeredby many manufacturers that also make CB radio equipment. Powerrequirements are miniscule, with RX requirements of less then 20milliwatts and TX requirements of 100 milliwatts. (In one test with aradio using three AA lithium batteries, run time in RX mode was twoWEEKS continuous.)

Though very reliable electrically, durability is a concern, as mostequipment is built with light plastic cases and no waterproofing. Costis generally $25-$40 per unit with features of single vs. multiplechannel and voice-operated switching accounting for the cost difference.Note that kiddie walkie-talkies also operate on this band but thereceivers of such radios are worthless.

Due to the proliferation of small, inexpensive 2-way radios for thisband, there is no realistic hope of private communications-indeed, it'sentirely possible that this band will become so crowded as to be uselessin the event of an emergency.

In addition, there are no standard frequency uses or nets on this band.Considering the limited range, the primary use will likely be fortactical communications among a small group, such as coordinating campactivities. One group sends a scout ahead in difficult terrain whilethe rest of the backpacking party waits, with the scout calling back ifthe path taken is viable; this saves hours of useless backtracking.

A secondary use is to place a radio with volume set on maximum on a packthat is cached in a well-camoflauged environment. The squelch keeps theradio quiet, but another radio can transmit sounds allowing the user to


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home-in on the hidden pack.

The 49 Mhz band is smack-dab in the middle of the VHF-low band (30-88Mhz, 25 Khz channel spacing) that the military use world-wide forprimary tactical communications. It should be no surprise then thatthere's quite a variety of ground-based, airborne, and satellite-basedradio equipment dedicated to intercepting, direction-finding, andjamming these frequencies, which include the 49 Mhz band.

Theoretically, consumer 49 Mhz radios and military VHF-low radios shouldinter-operate. However, the reality is that only some military radiosoperate with narrow band FM, and the tuning steps of the radios are 25Khz at best, frequently placing them off-channel. Newer tactical radios,such as the US Army SINCGARS (Single Channel Ground and Airborne RadioSystem, are usually operated in frequency-hopping mode, in which thereis no hope of inter-operability (such radios can however be tuned tosingle channels)

Although highly susceptible to interception and direction-finding, inpractice the range of consumer radios on this band is so limited thatthis highly unlikely to occur unless a party is expressly searching forthe signal in the immediate area; the short range also makes these oneof the few radios immune to satellite-based DF. In urban environmentsthere are literally hundreds of competing signals on the same frequency,

making interception and DF difficult. Note that in scenarios involvingmilitary conflict, operational jammers could make these radios unusableat tens of miles away, and these radios are likely to be unintendedvictims, jammed simply because they're in the middle of a military band,and not due to overt intent.

One group known to us has primary communications based on 49 Mhz radios.The limited range and extremely low power consumption were keys, alongwith the fact that the group stays close together 100% of the time werefactors that lead to the decision.

460 Mhz Family Radio Service (FRS)

The FRS radio service is a recent addition in the US and a goodselection of low cost equipment is available. The radios are relativelylow power 500-600 milliwatts (0.5-0.6 watts), and operate on 14 channelsin the 460 Mhz frequency range using reliable FM modulation. The radioshave a user settable squelch level control to minimize interference. Inaddition, the radios utilize a system known as Continuous Tone CodedSquelch System (CTCSS) which allows an additional degree of interferencecontrol. These radios have a useable range up to 2 miles depending onterrain conditions. Refer to Appendix D for a list of FRS frequenciesand Appendix E for a discussion of CTCSS.

1750 Meter Lowfer Band

In the US, the 1750-meter band allows radios to operate with 1 Watt ofpower into a 50 foot long transmission line/antenna system atfrequencies in the 170 Khz (that s 0.170 Mhz) range with no license.This is a *really* low frequency.

Equipment for 1750 meters is generally as small as one wants to buildit. There are only a few commercially built radios for this band,generally the same size and weight as a larger mobile CB radio. Powerconsumption is quite low, with about 3 watts peak for TX and hundreds ofmilliwatts at most for RX. Cost is generally no more than $200 for a


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top-end commercial built radio.

Antennas are inefficient and large, since the 50 foot limit really needsto be exploited for the radio to work well. Communication is thereforenot very reliable at long ranges; however, at short ranges (a few miles)at night, when the noise level is low, 1750 meters is reliable. Atnight during the winter, it provides the greatest range, with reasonablyreliable contacts at 100's of miles. During the summer this band isplagued with static making it rather unreliable. The 1750 Meter band isa (barely) plausible survival radio band only if it's used for a networkamong users that are located near each other.

There are a few experimenters on this band that perform low-rate datacommunications using exotic modulation methods, but most prefer Morsecode or SSB. There are no regularly monitored channels or survivalnetworks in operation, though some radio enthusiasts in California dohave a regular net.

It is, however, worth noting, that some caving and spelunkingenthusiasts also sometimes use this band, as low frequencies have somelimited ability to penetrate obstacles such as the ground. (The sameprinciple is used by the US Navy, which uses VLF and ELF signals tocontact submarines)

There's one survivalist of note that does use this band: the U.S.Government. A special high-survivability data network known as theground-wave emergency network, or GWEN, can be heard between 150 and 170Khz with a repetitive noise that sounds like a cross between a hiss anda crunching sound. This network is intended to survive a massivenuclear strike and provide low-data-rate post apocalypticcommunications.

Low frequencies are so easy to direction find that they are the basis ofthe first radio-navigation system used for aircraft and ships. Startingat about 200 Khz, there are thousands of low-power non-directionalbeacons (NDBs). Automatic-direction-finding (ADF) radios tuned to an NDBindicate their direction with high accuracy, and many ADF receivers are

capable of tuning the 1750 meter band.On the plus side, although direction-finders work really well here, thelow power and low frequency of the 1750 Meter band make it effective forcovert communications; few receivers tune this low, and even fewerpeople even bother to listen. Due to the inefficiencies of the antennasystem jamming is difficult, and there is no known deployed jammingequipment capable of disrupting this band. Micro-power AM and FM

Also permitted under part 15 is low-power (100 milliwatts) AMtransmitters with a 10 foot antenna restriction on the same band as

broadcast AM radio.

The AM band shares many characteristics and difficulties of the1750-meter band. Equipment is generally always hand-made, usually fromAM broadcast kits. Receivers can be cheap AM receivers, but a viablecommunication system will likely use a sensitive medium wave or shortwave radio receiver. Cost of the transmitter can be as low as $20, thereceiver $5 to $5000.

Transmitter size is generally the size of a small mobile CB, about


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2x6x6. Power consumption is minimal, under 1/2 watt. Reliablereception ranges of a 1/4 mile or so are common, though with goodreceivers and quiet band conditions (at night, during the winter time)on an unoccupied AM channel (rare in its own right) ranges of 100's ofmiles have been obtained.

Signals are easy to direction find (indeed, many aircraft ADF systemsalso tune the AM radio band) and it s trivial to jam weak-signalreception in the AM band when Mother Nature isn't doing it herself withthunderstorms. No nets are known to use micro-power AM, though some pirate-radiobroadcasts violate the FCC's power specification and some of thesetransmit vaguely survival-related gloom-and-doom conspiracy radioprogramming. This (with legal power, and probably better, community-related programming, of course) is probably the only viable use for thisband in a survival context (weak as though that may be.) Micro-power FM stations are also permitted, but the large bandwidth andlow power allowed makes micropower FM even more useless than AM.

(1) Licensed/Regulated Services

(a) Amateur ( Ham ) Radio

The bands listed below all require a license for use in the UnitedStates and most other countries with one important exception: Under USlaw (Part 97 of the FCC regulations), a station may lawfully use any andall means at its disposal to locate help in the case of a legitimateemergency.

6-Meter Band

The six-meter band (50-54 Mhz ham band) is considered sort of a"schizophrenic" band, that can't make up its mind whether to be aworldwide/distant contact band or a local VHF band. It generally hasbeen known to be used as both of these. The use of this band is

primarily a local phenomenon-extremely popular in some areas andcompletely silent in others.

2-Meter Band

2 Meters (144-148 Mhz.) is one of the most commonly used bands in theUnited States. Frequently these days, when a ham buys his first radio,it's a mobile or handheld 2-meter FM transceiver. SSB and CW arerarely, but occasionally used on this band. However, 2M is a favoritefor amateur radio satellite and amateur Earth-Moon-Earth communications,and for technical reasons these methods require the use of SSB or CWrather than FM. This band, along with the 70-centimeter (432-450 Mhz)band, are among the most popular bands for local packet (data) radio

communications, and are also hands-down favorites for Radio AmateurCivil Emergency Service (RACES) and Amateur Radio Emergency Service(ARES) communications. Licensure for the use of the above three bandsin the United States is granted on the basis of two multiple-choicewritten examinations covering radio theory, amateur practice, and FCCregulations. The ARRL (website address above) maintains a list ofexamination sessions, and study guides for these exams are on the shelfin most libraries and bookstores.

MF/HF Bam Bands:


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In the United States, ham radio bands exist at 1.8 Mhz, 3.5 Mhz, 7 Mhz,10.1 Mhz, 14 Mhz, 21 Mhz, 24 Mhz, and 28 Mhz. These bands are allcapable of long-distance communications, depending on atmospheric andsunspot conditions, and have all been used for worldwide communication.The most common emissions modes are CW (Morse Code) and Single Sideband,but certain data communications are also used. Equipment for thesebands is all over the range in terms of price and complexity-low-powerCW-only single frequency transmitters can be built for $20, and high endall-band all-mode transceivers can be bought for several thousanddollars. Literature on use of these bands is common, with "Low-ProfileAmateur Radio" by Jim Kearman being an excellent (if basic) primer forpeople who want an introduction into low-power HF operation without muchin the way of an antenna. A license from Federal CommunicationsCommission is required to transmit on these bands (with limitedexceptions explained above), and the license is based upon examinationof the licensee's understanding of radio theory and law, and ability toreceive and understand signals in the Morse code.

(1)Commercial Carrier and Emergency Services

Cellular Phones

A Cellular phone is essentially a low-power UHF transceiver. When a

call is made, the phone signals a fixed station called a 'cell.' Thecell transfers the signals between the radio waves and the phoneexchange. (A gross oversimplification, but detail is not required here).Cell phone conversations are not private, any more than any other radioconversation. Technically, the law says that they may not be monitored,but this law is unbelievably easy to violate. Scanners able to pick upcell frequencies are not sold to civilians any more, but they can bebuilt.

Cell phones also depend upon a working cell. A power outage for anextended period could result in shutdown. Also, cells can be overloaded.In the event of a disaster, a cell can handle a given number of calls.Calls that exceed the cell capacity will be rejected, rendering

communications ineffective.Paging

Paging is essentially a method of one-way radio communication. Anindividual makes a telephone call to a given phone number, and isprompted to enter a message. This message is then sent out over VHF orUHF radio to a specific pager. Some paging service allows the displayof phone numbers.

Others actually permit one to email a message to a pager. This servicehas an advantage, in that it can discreetly summon one to check in or gosomewhere as needed, but is dependent upon a network of transmitter

towers and phone lines, and therefore might not be fully functional in adisaster. In June of 1998 the complete failure of the Galaxy IVsatellite caused a shutdown of 90% of the pagers in the continental US.This single point failure shows the fallacy of relying on a single commssystem.

a)Radio Operation and Procedures

A radio-based communication system depend on two main elements to work:operational radio hardware, and procedures that allow the sender and


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receiver to communicate.

1)Radio Equipment, Antennas, and Propagation

The dB or decibel (1/100th of a Bel) is a comparative measurement basedon a log scale. That is, there's something measured against areference. The decibel allows a very wide range of signal power to berepresented with small, manageable numbers:

Power Change Decibels 2X 3 dB 100X 20 dB 1,000,000X 60 dB 0.5 X -3 dB 0.000001X -60 dB

Things that increase a signal are usually called gains and things thatdecrease a signal s strength are called losses, and both are usuallymeasured in dB, with gains being positive and losses negative. Notethat if we compare power to a fixed reference, such as a 1 Watt or onemilliwatt, the dB can also be a measurement of actual power; atransmitter with a 20 dBW output, for example, has 100 Watts of power.

There two major factors that determine total radio performance, known as

station gain (what the equipment does) and path loss (what theenvironment does to the signal between the stations.)

It may seem confusing, but it's as simple as this: If station gain isgreater than path loss, you can communicate, otherwise, you can't. Ifyou can't communicate, you need to fix one or more parts of the radiosystem until you have enough station gain. Use more power, a moresensitive/selective receiver, better or higher antennas. Typicalstation characteristics follow:

Station Gain Factors Good Base SSB CBTransmit power +10 dBW (12 Watts)Transmitting antenna height gain +3 dB

Transmitting antenna gain 0 dBReceiving antenna height gain +3 dBReceiving antenna gain 0 dBReceiver sensitivity +149 dB (-149 dBW)Total Station gain 165 dB

The ultimate goal of the radio system is to get a signal to the receiverthat's stronger than the background noise, so the signal can be heard.This is known as signal-to-noise ratio, and receiver sensitivity isusually stated as the lowest power level that will result in a givensignal-to-noise ratio, typically 10 dB. Note that the receiversensitivity is actually how much a signal can be reduced before it can tbe heard (-149 dB) but it counts as a positive, as we have 149 dB in our

station gain account that we can lose before we can't hear a signalanymore.

The path loss is how of the signal is reduced by the environment.Distance, air, mountains, water vapor are some of these factors.Distance alone reduces the signal at a rate of the square of thedistance, e.g., a signal two miles away is one-quarter the strength of asignal one mile away, just because of the distance. Path loss varies(just a little bit) with the frequency used until one gets tomicrowaves, where path loss jumps significantly.


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Under ordinary conditions between two stations on average terrain, pathloss goes this way:

Frequency 10 Miles 25 Miles 50 Miles27 Mhz (CB) -135 dB -152 dB -174 dB144 Mhz (2M ) -134 dB -157 dB -175 dB

For a good SSB CB radio, we have 165 dB of station gain, and we cancommunicate as long as path losses are less than this; on averageterrain, this is somewhere between 25 and 50 miles. Note that if theantennas used are poor and low to the ground, this will change thingsconsiderably, as we'll see in a few paragraphs.

In situations where the signal is bouncing around, such as short waveradio signals, loss includes both distance and the efficiency that thesignal is reflected; when conditions are good, this reflectionefficiency can be 100%, and only the distance matters. Likewise, if asatellite is used, the path loss is pretty much a result of just thedistances between the ground stations and the satellite involved.Distance-only path losses run about -110 dB for 100 miles, or a typicallow-earth orbit, and -151 dB for 22,500 miles, or geo-syncronous orbits.No place on earth is more than 12,500 from any other location, so thepath loss for a perfectly reflected short wave signal is somewhere

in-between.Not that it's done, but our 165 dB of station gain is quite a bit morethan the 151 dB path loss of a geo-synchronous satellite, so it'strivial for the satellite to hear a SSB CB or a 2-Meter Amateur radio.Indeed, several emergency systems depend on this: simple 1/2 wattemergency-radio beacons are detected with low-earth orbit satellites,and the newer 5-watt beacons are detected by geosyncronous weathersatellites.

In the late 1980's and early 1990's the space shuttle carried the SAREX(Satellite Amateur Radio Experiment) program. Astronaut hams utilizingthe 2 meter (144-148 Mhz) band communicated to thousands of earth bound

hams, many utilizing only low power (0.5-5 watt) hand held radios.(1)Basic Radio Antennas

Antenna Effectiveness

Antennas can be measured by listening to a standard transmitter on thefrequency of interest, and changing the antenna and noting the changesin the signal. Higher-end radios have meters that show relative signalstrength, using numbers of 1 to 9 (S1...S5...S9) and then dB over S9;each S-unit is typically 6 dB. Using a calibrated receiver, we didmeasurements of a local weather station (near the amateur 2-meter band)to illustrate several antennas. We used the best antenna (which isn't

very good at all, actually) as a reference, and then compared severalportable antennas:

Antenna Sig. Strength dB % SignalDiscone at 20 feet S9 0 dB 100%1/2 Wave Rod 6 S5 -24 dB 40%Rubber duck, 6 S3 -36 dB 2.5%

Doing the same thing at CB frequencies:Antenna Sig. Strength dB % Signal


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Dipole at 20 feet S9 0 dB 100%Rubber duck, 6 S0 -54 dB .0004%

Poor antennas will reduce station gain; indeed is we use the SSB CBexample where we had 165 dB of station gain, and change the antennasused to rubber duck antennas, the station gain plunges to just 51 dB,not even enough to cover five miles! What these measurements show isthat antennas can compromise perfectly good equipment, and that it takesa good antenna for a radio to work well.

There are several types of antennas that are easily built with wire orstiff metal rods that are suitable for survival use and are also goodantennas. As a general rule, if you want maximum range and stationgain, use a good antenna and place it as high as possible, includingclimbing up mountains or hills.

(a) 1/4 WaveLength Vertical

This is perhaps the simplest antenna. Basically, it's a vertical rod orstiff wire fed by a feed line at the bottom and cut to about one quarterof the desired wavelength. It radiates uniformly in all directions, andis the most common type for handheld and vehicle-mounted radios.

(b)Dipole

Another simple antenna. Basically, it consists of two wire "legs" of1/4 wavelength each pointed in opposite directions, and eitherhorizontal or sloped. This antenna is most commonly used for Medium andHigh-Frequency ham radio and short wave listening (1.8-30 Mhz). Itradiates most strongly in a direction perpendicular to the long axis ofthe wires. The overall length in feet is calculated by the simpleequation: 468/Freq (in Mhz). For example a dipole cut to operate on3950 Khz (3.95 Mhz) would be 468/3.95 or 118.5 feet total length of59.25 (60 feet) on each leg. This length if generally only critical fortransmitting.

Quads and Yagis

Quads and Yagis are two types of directional antennas. A Yagi has acenter element, called a driven element, which is connected to the feedline from the transmitter. This element is cut to roughly one- quarterof the desired wavelength, and mounted on a horizontal boom. Then,slightly shorter elements, called "director elements" are cut andmounted on the boom on one side of the driven element. Slightly longerelements, called "reflector elements" are cut and mounted on the otherside, and the whole antenna is generally mounted on a rotatable mount.The director and reflector elements are typically each 5% shorter oflonger than the previous one of the same type. These types of antennaetend to be highly directional, favoring the direction towards thedirector elements, and are frequently used for HF, VHF, and UHF ham

radio stations.

(1)Signal Operating Instructions and Radio Nets

Signal Operating Instructions (SOI) is the military name given to awhole host of methods and procedures to communicate; essentially, SOI isa protocol of behavior for people and equipment to communicatesuccessfully.

The single most important thing to remember is that that it takes


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someone listening for communications to work, and the best radios in theworld are useless if no one hears you call for help. Establishing orconnecting to a radio net of listeners, making sure that someone is outthere listening for you, is the single most important step to take inradio communications. Period.

Schedules

It's impractical for most people to listen to radios continuously, sohaving a schedule for stations on your net to listen makes radiocommunication practical. Either use a published schedule, or a regularinterval (every day at 7pm, for example) for the net to come on-line.

Guard Channels

All radio users need to be on the same frequency to communicate. Aspecial listening frequency makes monitoring easy; for example, on CBradios, channel 9 is used only for emergency traffic, so you can listento this channel and know if you hear something, it is (at least intheory) important. In many areas, there are amateur radio repeaterswith a feature known as LTZ (Long-tone-zero) which is used to turn onreceivers of regular listeners, for when help is needed. Your radio netshould have a guard channel to listen to when the net isn't active, anda one or more net channels for when it is. (Depending on other factors,

these channels may be changed regularly or not.)Codes

In general, the use of codes, ciphers, and other encryption on mostradios is illegal in the United States if the intent of the code is toobscure the meaning of a message. There are legal uses for codes in CBand ham radios-see below under "Brevity and Message Coding"

Authentication

Authentication is the art of verifying that all people in a given netare people who have legitimate access, for example through the use of

unannounced questions. For example, during World War Two, it was apopular perception that no German soldier would know anything aboutbaseball. As a result, American GI's would frequently quiz each otherabout baseball trivia to be sure that everyone present was in fact anAmerican. (There have been horror stories about American generals whoknew nothing about Shoeless Joe Jackson and spent more time under guardthan they would have liked, which goes to prove that an authenticationsystem should not be so haphazardly managed on a large scale)

Brevity and Message Coding

Radio communication takes time and bandwidth. Certain codes have becomeagreed-upon conventions to compress a relatively large amount of

information into a relatively small amount of space. For example,almost everyone who listens to a CB or to police radio has heard the"Ten codes" in which a sender may say "Ten-four" and be understood byeveryone listening as having said "Your message is acknowledged" Referto Appendix H: Amateur Radio Q-Signals for an additional standard listof specialized abbreviations.

SOI Spares

Having extra copies of your Signal Operating Instructions can be a


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double-edged sword. On one hand, if your SOI is at all complex orelaborate, losing your only copy could be crippling. However, if yournet's integrity depends upon not having your procedures widely known, anextra SOI is a copy of the SOI waiting to fall into the wrong hands.Alternately, multiple copies of SOI's with attached authentication codesmay also be utilized.

1. Visual Signals

Morse code by light

Ships carry a set of blinker lights for communication by morse code.These lights are essentially searchlights fitted with shrouds orshutters that can be quickly opened or closed.

Semaphore

In the days before wired telegraphy, a code was used to send messagesover long distances called semaphore. Basically, the sender stood atopa hill holding a brightly colored flag in each hand. He would face thereceiving station and raise his arms up out to his sides, and the angleat which he held his arms would signify a given numeral or letter.

Three-in-a-row rule (whistles, gunshots...)

In general, three of any signal repeated at a regular interval signifiesdistress. For example, a hunter who is lost can fire three shots in theair a few seconds apart. Theoretically, anybody in the vicinity willhear the three shots and realize that the hunter is in some sort ofdistress, and will be able to figure out the direction to search fromthe sound of the shots. As a practical matter, it's unlikely that such asignal will be taken seriously unless the sender waits until after dark.After dark during hunting season at least the local game officer will behunting you.

American sign language

Sign language consists of an alphabet and a set of symbols eachrepresented by a set of hand signals. This information is quiet,covert, and generally unknown within the non-hearing impaired community.Like Morse and Semaphore is could provide a clandestine and usefulcommunications alternative with practice.

GLOSSARY

AM: Amplitude ModulationCTCSS Continuous Tone Coded Squelch System (CTCSS) Refer to Appendix E

CW: Continuous Wave

DTMF: Dual Tone Multi-Frequency Refer to Appendix GFM: Frequency ModulationLTZ: Long Tone Zero - Transmission of a DTMF '0' for a long relative time (usually > 2-3 seconds) used for specific control of repeaters and related equipment.

LSB: Lower Side BandModulation: The mechanism for impressing information (voice or data)


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onto a carrier frequency.NET: Network

SSB: Single Side BandUSB: Upper Side BandSub-Audible: Refer to CTCSS

Appendix A: AM Class A Clear Channel Stations

FREQ CALL CITY STATE640 KYUK BETHEL AK650 KYAK ANCHORAGE AK660 KFAR FAIRBANKS AK670 KDLG DILLINGHAM AK680 KBRW BARROW AK700 KBYR ANCHORAGE AK720 KOTZ KOTZEBUE AK750 KFQD ANCHORAGE AK770 KCHU VALDEZ AK780 KNOM NOME AK820 KCBF FAIRBANKS AK840 KABN LONG ISLAND AK850 KICY NOME AK

890 KBBI HOMER AK1020 KFFR EAGLE RIVER AK1080 KASH ANCHORAGE AK1170 KJNP NORTH POLE AK1090 KAAY LITTLE ROCK AR580 CMJP CIEGO DE AVILA, CAM. CA640 KFI LOS ANGELES CA680 KNBR SAN FRANCISCO CA810 KGO SAN FRANCISCO CA900 CMJV CIEGO DE AVILA CA1070 KNX LOS ANGELES CA850 KOA DENVER CO1080 WTIC HARTFORD CT

750 WSB ATLANTA GA1040 WHO DES MOINES IA670 WMAQ CHICAGO IL720 WGN CHICAGO IL780 WBBM CHICAGO IL890 WLS CHICAGO IL1000 WMVP CHICAGO IL1190 WOWO FORT WAYNE IN840 WHAS LOUISVILLE KY870 WWL NEW ORLEANS LA1130 KWKH SHREVEPORT LA1030 WBZ BOSTON MA1090 WBAL BALTIMORE MD

760 WJR DETROIT MI830 WCCO MINNEAPOLIS MN1120 KMOX ST. LOUIS MO1110 WBT CHARLOTTE NC1110 KFAB OMAHA NE660 WFAN NEW YORK NY710 WOR NEW YORK NY770 WABC NEW YORK NY810 WGY SCHENECTADY NY880 WCBS NEW YORK NY


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1130 WBBR NEW YORK NY1180 WHAM ROCHESTER NY700 WLW CINCINNATI OH1100 WTAM CLEVELAND OH1170 KVOO TULSA OK1190 KEX PORTLAND OR1020 KDKA PITTSBURGH PA1060 KYW PHILADELPHIA PA1210 WPHT PHILADELPHIA PA550 CMAA PINAR DEL RIO PR740 CMAC PINAR DEL RIO PR740 CMAB PINAR DEL RIO PR650 WSM NASHVILLE TN820 WBAP FORT WORTH TX1080 KRLD DALLAS TX1200 WOAI SAN ANTONIO TX1160 KSL SALT LAKE CITY UT1140 WRVA RICHMOND VA710 KIRO SEATTLE WA1000 KOMO SEATTLE WA1170 WWVA WHEELING WV

(As a personal note from the editor, WBBM-780 Chicago deserves specialcredit for being a solid general news outlet in normal times)

Appendix B: Citizens Band Channel Frequencies

Channel Freq Channel Freq Channel Freq Channel FreqNumber Mhz Number Mhz Number Mhz Number Mhz

1 26.965 11 27.000 21 27.215 31 27.315 2 26.975 12 27.105 22 27.225 32 27.325 3 26.985 13 27.115 23 27.255 33 27.335 4 27.005 14 27.125 24 27.235 34 27.345 5 27.015 15 27.135 25 27.245 35 27.355 6 27.025 16 27.155 26 27.265 36 27.365 7 27.035 17 27.165 27 27.275 37 27.375

8 27.055 18 27.175 28 27.285 38 27.385 9 27.065 19 27.185 29 27.295 39 27.395 10 27.075 20 27.205 30 27.215 40 27.405

Appendix C: 49 Mhz Channel Frequencies

Base Handset 46.61 49.67 Cordless phone Ch 1 46.63 49.845 Cordless phone Ch 2 46.67 49.86 Cordless phone Ch 3 46.71 49.77 Cordless phone Ch 4 46.73 49.875 Cordless phone Ch 5 46.77 49.83 Cordless phone Ch 6

46.83 49.89 Cordless phone Ch 7 46.87 49.93 Cordless phone Ch 8 46.93 49.99 Cordless phone Ch 9 46.97 49.97 Cordless phone Ch 10

Appendix D: 460 Mhz Family Radio Service (FRS) Channel Frequencies

01: 462.5625 08: 467.5625 Modulation is FM02: 462.5875 09: 467.587503: 462.6125 10: 467.6125


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04: 462.6375 11: 467.637505: 462.6625 12: 467.662506: 462.6875 13: 467.687507: 462.7125 14: 467.7125

CTCSS (Coded Tone Carrier Squelch System)

The CTCSS System prevents unwanted noise and/or conversation from beingheard through your FRS radio's speaker. Only signals with the correctcode will be heard. To use the system each radio must:

A) be on the same channel B) have the same CTCSS Code selected.

When enabled, the Privacy Code is transmitted with each voice message.All receivers programmed with the same code will open their speakercircuits and the message will be heard.

It is VERY important to note that conversations on your FRS radio areNOT private. Any other FRS radio or scanner can eaves drop on yourconversation. Also, it is always best to monitor, with the monitorbutton, prior to transmitting to prevent disrupting any nearbyconversations that you may not hear on the channel.

Appendix E: Continuous Tone Coded Squelch System (CTCSS) Sub-audble audio frequencies in Hertz

01: 67.0 09: 91.5 17: 118.8 25: 156.7 33: 210.702: 71.9 10: 94.8 18: 123.0 26: 162.2 34: 218.103: 74.4 11: 97.4 19: 127.3 27: 167.9 35: 225.704: 77.0 12: 100.0 20: 131.8 28: 173.8 36: 233.605: 79.7 13: 103.5 21: 136.5 29: 179.9 37: 241.806: 82.5 14: 107.2 22: 141.3 30: 186.2 38: 250.307: 85.4 15: 110.9 23: 146.2 31: 192.808: 88.5 16: 114.8 24: 151.4 32: 203.5

Appendix F: Emergency Frequencies HF Marine emergency frequencys. 2182, 4125, 6215, 8291, 12290, 16420 voice communications (SSB)

Aviation 121.5 Mhz Voice or beacon Military 223.0 Mhz Voice or beacon EPIRB 121.5, 223.0, 406mhz 406 beacon is digital only with beacon on 121.5 and 223.0

CB channel 9, 27.065 VHF marine freq Channel 16, 156.800mhz GMRS 462.675 unoffical emergency/traffic/travel aid request freq. FCC

estimates that %30 of the US is monitored by an official group REACT on this freq.

Non-emergency but usefull frequencies:

NOAA weather 162.40, 162.475, 162.55, 162.525, 162.5

Ham calling freq 6 meters 52.525


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2 meters 146.52 1 3/4 meter 223.5 70cm 446.0 1296 1294.5

Appendix G: Dual Tone Multi-Frequency (DTMF) Audio Frequencies

These are the tones transmitted when you press a key on your telephone touch pad. The tone of the button is the sum of the column and row tones. The ABCD keys do not exist on standard telephones.

1209 1336 1477 1633

697 1 2 3 A

770 4 5 6 B

852 7 8 9 C

941 * 0 # D

Appendix H: IARU Phonetic Alphabet

In a noisy environment, phonetic spelling of certain words made be

required for understanding. This is the standard phonetic alphabet utilized by military and aviation as specified by the International Administrative Radio Union, which is a international governing body on communications standards.

Example: IARU - Say: "IARU I Spell, India, Alpha, Romeo, Uniform"

A: Alpha N: November B: Bravo O: Oscar C: Charlie P: Papa D: Delta Q: Quebec E: Echo R: Romeo

F: Foxtrot S: Sierra G: Golf T: Tango H: Hotel U: Uniform I: India V: Victor J: Juliet W: Wiskey K: Kilo X: X-Ray L: Lima Y: Yankee M: Mike Z: Zulu

Appendix I: Amateur Radio Q-Signals

These signals are a form of legal code, used to shorten Morse Codemessages by compressing a complete idea into three letters. Following

the Q signal with an question mark makes it interrogative

QRG: Will you tell me my exact frequency?/Your exact frequency is _____ QRL: Are you busy?/I am busy. Please do not interfere.QRM: Is my transmission being interfered with?/Your transmission is being interfered with ___ (1= nil; 2=slighly; 3= moderately; 4= severely; 5= extremely)

QRN: Are you troubled by static?/I am troubled by static ___(1-5 as under QRM)


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QRO: Shall I increase power?Please increase power.QRP: Shall I decrease power?/Please decrease power.

QRQ: Shall I send faster?/Please send faster.QRS: Shall I send slower?/Please send slower.QRT: Shall I stop sending?/Please stop sending.

QRU: Have you anything for me?/I have nothing for you.QRV: Are you ready?/I am ready.QRX: When will you call me again?/I will call you again at ____ hours.

QRZ: Who is calling me?/You are being called by ____ QSB: Are my signals fading?/Your signals are fading.QSK: Can you hear me betwen your signals and if so can I break in on your transmission?/I can hear you between my signals; break in on my transmission.

QSL: Can you acknowledge receipt of a signal?/ I acknowledge receipt.QSN: Did you hear me on (____) kHz?/I heard you on (____) kHz.QSO: Can you communicate with ____directly or through relay?/I can commicate with ____directly or through relay.

QSP: WIll you relay to ____?/I will relay to ____.QST: General call preceding a message to all stations.

QSX: Will you listen to ____ on ____ kHz?/I will listen to ____ on ____ kHz.

QSY: Shall I change to transmission on another frequency?/Change to transmission on ____ kHz.QTB: Do you agree with my counting of words?/I do not agree with your counting of words. I will repeat the first letter of each word or group.QTC: How many messages have you to send?/I have ____ messages for you.

QTH: What is your location?/My location is____ QTR: What is the correct time?/The correct time is ____ (Timezone stamp)

Documents

Providence Cooperative Survival Communications FAQ Ver 1.12