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Communications (not so) Basics Bill Finkelstein SV Raptor Dance WB6JAO
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Simplex VHF Channels Channel Number Frequency Channel Number Frequency MHz 01A156.05063A156.175 05A156.25065A156.275 6156.30066A156.325 07A156.35067156.375 8156.40068156.425 9156.45069156.475 10156.50071156.575 11156.55072156.625 12156.60073156.675 13156.65074156.725 14156.70077156.875 16156.80078A156.925 17156.85079A156.975 18A156.90080A157.025 19A156.95081A157.075 20A157.00082A157.125 21A157.05083A157.175 22A157.10087A157.375 23A157.15088A157.425
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LINE OF SIGHT, GROUND WAVE, SKY WAVE
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IONOSPHERE REGIONS The ionosphere is the uppermost part of the atmosphere, it is ionized by solar radiation. Ionization is converting an atom or molecule into an ion by light (heating up or charging) from the sun on the upper atmosphere. Creates an horizontally stratified medium where each layer has a peak density and a definable width, or profile. Thus, it influences radio propagation
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IONOSPHERE REGIONS
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PROPAGATION, HOPS SKIPS ZONES
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MF, HF CRITICAL FREQUENCIES Maximum Useful Frequency (MUF) Frequency of optimum transmission (FOT) /Optimal Working Frequency (OWF) Lower Absorption Frequency (ALF) / The lowest Usable frequency (LUF): Above Critical Frequency
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UHF, VHF, SPORADIC E, AURORAS, DUCTING Temperature Inversion / Troposphere Ducting: Certain weather conditions produce a layer of air in the Troposphere that will be at a higher temperature than the layers of air above and below it. Such a layer will provide a "duct" creating a path through the warmer layer of air which has less signal loss than cooler layers above and below. These ducts occur over relatively long distances and at varying heights from almost ground level to several hundred meters above the earth's surface. This propagation takes place when hot days are followed by rapid cooling at night and affects propagation in the 50 MHz - 450 MHz range (6 meter, 2 meter, 1 1/4 meter and 70 centimeter bands). Signals can propagate hundreds of kilometers up to about 2,000 kilometers (1,300 mi).
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9 Emergency Communications Basics Communication Skills Listening Listening is at least 90% of communication. Listening also means avoiding unnecessary transmissions. Do NOT transmit if you are panicked, take a deep breath before talking. Microphone Techniques For optimum performance, hold the microphone close to your cheek, and just off to the side of your mouth. “If you can’t lick it, your microphone is too far away!” Speak a little slower and pause longer between transmissions.
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10 Emergency Communications Basics Communication Skills Brevity & Clarity Each communication should consist of only the information necessary to get the message across clearly and accurately. Plain Language All messages and communications during an emergency should be in plain language. Big words may not be understood. Avoid words or phrases that carry strong emotions. Do not use slang or jargon (technical slang)
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USE official terminology (Pro-Words): Clear - end of contact Over - used to let a specific station know when to respond Go ahead - Used to indicate that a station(s) may respond Out - Leaving the air, will not be listening Stand by - A temporary interruption of the contact Roger - Indicated the transmission has been received correctly and in full Wilco – Will Comply (do not use with “Roger” it’s implied) Avoid improper usage/non-standard words: “come back”, “over and out” (please respond, but I’m not listening!), etc. 11 Emergency Communications Basics
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12 Emergency Communications Basics Spoken Emergency Signals: “MAYDAY MAYDAY MAYDAY” – The highest priority urgency call. The vessel calling is threatened by grave or immediate danger and requires immediate assistance. “PAN PAN PAN” – (pronounced “Pawn Pawn Pawn”) Known as an “urgency” call – the vessel calling has an urgent message concerning the safety of a vessel or person. “SECURITE” – The safety signal – used for official messages about the safety of navigation or important weather warnings. “SILENCE” – (pronounced “SEE Lonce”) The Net Control may declare silence on a specific channel. Only those units actively involved in the incident may transmit on that frequency. “Seelonce feenee” – Net Control has ended the Silence period.
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13 Emergency Communications Basics May Day - Distress Information MIPDANIO: Mayday, Identify, Position, Distress, Assistance, Number of crew, Information, Over. The Call: – “Mayday, Mayday, Mayday”, – This is (vessel name repeated three times, followed by call sign if available) The Message – Mayday (vessel name) – My position is (position as a LAT-LONG position or bearing and distance from a fixed point) – I am (type of distress, e.g. on fire and sinking) – I require immediate assistance – I have (number of people on board and their condition) – Any other information e.g. "I am abandoning to life rafts" – “Over”
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14 Emergency Communications Basics “Breaking” In (the applies to general conversations too, not just nets!): If a net is in progress, wait for a pause between communications and simply say “Break, (Your boat name).” Net Control will say “Go Ahead (Your boat name).” Unless higher priority emergency traffic is under way. Double Break “Break Break” is equivalent to an Emergency call “Pan Pan Pan”. Triple Break “Break Break Break” is equivalent to a “Mayday Mayday Mayday”.
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15 Emergency Communications Basics Communication Skills Phonetics Certain words in a message may not be immediately understood. The best way to be sure it is correctly understood is to spell it. Numbers are always pronounced individually. The number “sixty” is pronounced as “six zero.” Nine is pronounced “NINE er” Four is pronounced “FOW er” Three is pronounced “Tree” Single syllable words are hard to understand, Yes is “Affirmative”, No is “Negative” Standard practice for unusual words is to first say the word, then say “I spell,” then spell the word phonetically. Use the ITU phonetic (see next slide)
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Emergency Communications Basics ITU Phonetic Alphabet Letter Code word Pronunciation AA Alpha AL FAH BB Bravo BRAH VOH CC Charlie CHAR LEE DD Delta DEL TAH EE Echo ECK OH FF Foxtrot FOKS TROT GG Golf GOLF HH Hotel HOH TELL IIIndia IN DEE AH JJ Juliette JEW LEE ETT KK Kilo KEY LOH LL Lima LEE MAH MM Mike MIKE Letter Code word Pronunciation NN NovemberNO VEM BER OO Oscar OSS CAH PP Papa PAH PAH QQ Quebec KEH BECK RR Romeo ROW ME OH SS Sierra SEE AIR RAH TT Tango TANG GO UU Uniform YOU NEE FORM VV Victor VIK TAH WW Whiskey WISS KEY XX X-rayECKS RAY YY Yankee YANG KEY ZZ Zulu ZOO LOO 16
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17 Emergency Communications Basics Emergency Nets What is an Emergency Net? An “Emergency Net” is a group of stations who provide communication in an emergency. Net Formats Directed (formal) Nets: A Net Control Station (NCS) organizes and controls all activity. To call another station you must get permission from the NCS.
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Emergency Nets You need to “check in” to a net: When you first join the net When you have messages, questions or information to send To become part of a directed net wait for (Net Control Station) NCS to ask for “check-ins” and listen to any specific instructions such a “check- ins with emergency traffic only” At the appropriate time (or when directed) check in with: Your call sign only Your call sign followed by “with traffic” Your call sign followed by “with Priority Traffic” Your call sign followed by “with Emergency Traffic” Then wait for NCS to respond before offering more information 18 Emergency Communications Basics
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