9.0 MESSAGE HANDLING

Messages may be handled verbally. Where phonetics may clarify the words of a message, the following I.T.U Phonetic Alphabet is recommended.

Phonetic Alphabet

A - Alpha

B - Bravo

C - Charlie

D - Delta

E - Echo

F - Fox-trot

G - Golf

H - Hotel

I - India

J - Juliet

K - Kilo

L - Lima

M - Mike

N - November

O - Oscar

P - Papa

Q - Quebec

R - Romeo

S - Sierra

T - Tango

U - Uniform

V - Victor

W - Whiskey

X - X-ray

Y - Yankee

Z - Zulu

Phonetic Numbers

0 - ZERO

1 - WUN

2 - TOO

3 - THUH REE

4 - FOR WER

5 - FIFE

6 - SIX

7 - SEVEN

8 - ATE

9 - NINER

10 - WUN ZERO

Distress Calling

One who finds himself in a situation where immediate emergency assistance is required (at sea, in a remote location, etc.), would call "MAYDAY" on whatever frequency seems to offer the best chance of getting a useful answer. "MAYDAY" is from the French m'aidez (help me). The Operator involved should be prepared to supply the following information to the stations who respond to his "MAYDAY".

The location of the emergency, with enough detail to permit rescuers to locate it without difficulty.

The nature of the distress.

The type of assistance required (medical aid, evacuation, food, clothing, etc.)

Any other information that might be helpful in locating the emergency area or in sending assistance.

Note: Messages out of distress state should have priority over incoming messages.

Written Messages

When the messages are official and formally received in writing, the following message format must be used:

A message contains four (4) parts:-

I Preamble which gives:

(a) Number of message;
(b) Precedence;
(c) Handling instructions
(d) Station of origin;
(e) Check (number of the words in the text);
(f) Place of origin;
(g) Time filed;
(h) Date

II Address

To be as complete as possible, telephone numbers, if possible.

III Text

IV Signature:

Who has originated the message.

The use of message forms improves the speed of dispatch and also makes for easy filing. (Form Attached).

The preamble is transmitted in the order given above as set out on the message form attached.

The number of the message beginning with the 001 at the beginning of each year.

a. The precedence may be 'EMERGENCY' by which is meant any message having life and death urgency to any person or group of persons. This includes official messages authorized by the NDC during emergencies requesting supplies, materials, or instructions vital to relief of stricken populace in emergency areas. In normal times, this category is very rare. EMERGENCY MUST NEVER BE ABBREVIATED.

b. The precedence may be `Priority' -
TRAFFIC ABBREVIATED `P' and includes important messages having a specific time limit. It can be allocated to official messages not covered in the Emergency category; press dispatches and other emergency related traffic not of the utmost urgency; notification of death in a disaster area; personal or official.

c. The precedence may be `Welfare' -
Abbreviated `W'. It includes inquiries as to health and welfare of an individual in the disaster area; and advisory messages from the disaster area indicating that all is well.

d. The precedence may be `Routine' -
Abbreviated `R' and refers to most normal traffic.

e. The precedence may be `SIMULATION' in which case it is written out `SIMULATION EXERCISE'.

HANDLING INSTRUCTIONS

This is optional, normally follows an `HX prosign' followed by A through G with or without numbers, indicating how the message should be disposed of.

HF PROSIGN

HXA (Followed by a number) Collect telephone call authorized by addressee within ...... miles. If no number, collect authorization is unlimited.

HXB (Followed by a number) If message is not delivered within ...... hours of the filing time, notify originating station.

HXC Report to the originating station, the date and time of delivery (TOD).

HXD Report, to originating station, date, time and method of delivery of message.

HXE Delivery station to get reply from addressee and to originate message back.

HXF (Followed by a date) Hold delivery until ....... (date).

NOTE

If more than on HX Prosign is used, they can be combined if no numbers are to be inserted: otherwise, the HX should be repeated.

The other items in the preamble are self-explanatory.

10.0 MESSAGE HANDLING TECHNIQUE

The objective is to handle all messages received accurately and with dispatch.

Rules for Net Discipline

A good net is a disciplined net, and discipline must be enforced or the efficiency of the net suffers.

1. Priority must be given to messages out of the stricken area over messages to the area.

2. The net must start on time on the assigned frequency.

3. Ensure that your station is on the net controller's frequency.

4. Be ready to report present when called. Avoid being late.

5. List your traffic; but if you have none, say so when you check in. The proper designation is given first, followed by the number of your message. Be familiar with the check-in procedure of the net.

6. Transmit only when called upon to do so except when you have an emergency. If you are re-checking into the net, announce "recheck" and keep your transmission brief as possible.

7. Address all transmissions to the net controller unless he instructs you otherwise.

8. Answer promptly when called. Stay alert.

9. Do not leave the net until you are excused either singly or by a general securing of the net. If you must leave the net temporarily, be sure to get the net controller's permission, then report back as soon as you return by saying "recheck".

10. Answer the net controller's questions briefly and to the point.

11. Know your procedure. The more thoroughly familiar you are with the procedure, the more valuable you are as a net station.

11.0 RECORDS AND FILING

Station Log

Many administrations require that a station keep a log of the contacts made giving the frequency, mode, power, time and date of each contact. The attached form includes a remarks column in which notes pertaining to future schedules, malfunctioning of the equipment, propagation conditions may be entered. Official messages should be entered on the separate form provided. It is preferable though not mandatory that the log should be in a bound volume and the pages numbered.

Inventory

An inventory of all equipment at the station must be kept in a hard cover book. The inventory should show the date that the equipment was acquired and installed and should be kept up-to-date as additional equipment is acquired or as consumable (batteries, etc.) are consumables.

Message File

All messages received and sent from the station should be numbered consecutively and placed on file; incoming messages should be separate from outgoing. Such records should include date and time received and dispatched and if known, what action was taken.

Maintenance Records

A record should be kept of the routine maintenance and repairs to all substantial equipment at the station, including the consumables on standby generating plant.

Routing of Messages

All communications must be sent in accordance with the accepted practice of the EOC Office and filing procedures.

12.0 STATION LOG

DATE CHANNEL OR FREQUENCY SIDE BAND POWER STATION WORKED REPORT TIME REMARKS
RECEIVED SENT IN OUT

13.0 SAFETY PROCEDURES

Safety is of paramount importance. Every precaution should be taken to ensure that the equipment is perfectly safe, not only for the Operator himself but also for other personnel working in or visiting the station. Double Pole switches should be used for all mains circuits and interconnecting switches should be fitted so that individual items may be isolated. The whole station should be controlled by one master switch located in a prominent position so that, if anything goes wrong, the whole system can be switched off before anything is touched.

All antennas should be safeguarded against lightning either manually by switching to a good earth when the station is not in use or by the use of the lightning arrestors. Great care should be exercised before touching feeders if these have been disconnected during a thunder storm.

Most shocks sustained from electronic equipment are derived from the 120/240 mains line lead. Also, be sure the electric circuit feeding the station is of adequate capacity and that the fuses/circuit breakers do not exceed the recommended rating.

Emergency antennas and inverted V antennas are often near ground level. These portions of the antenna should be protected, and no one should be allowed within 3 feet of these antennas while the station is transmitting. This is a safeguard against radiation burns.

Stations are advised to insure against risk of damage to the equipment by whatever cause, and against liability to damages against persons who may be injured as a result of component failure or other accident in the station.

Smoking in an enclosed area where batteries are on charge is a hazard.

Coffee and soft drinks must not be placed on equipment or where they may accidentally be spilled on the equipment.

14.0 RADIO FUNDAMENTALS

15.0 RADIO STATIONS

There are three main types of Radio Stations.

1. Mobile Radio - for use and installation in motor vehicles.

2. Base Radio - for use as fixed station e.g. in an office.

3. Portable Radio - For personal use, easy to carry in one's hand.

Yet another type is the man pack Portable Radio which is a mobile radio equipped with a battery pack.

Main Frequency Bands

HF (High Frequency) - 3 - 30 MHz
VHF (Very High Frequency) - 30 - 300 MHz
UHF (Upper High Frequency - 300 - 3000 MHz

Main Radio Components

i. Transceiver - Combination of Receiver and Transmitter

ii. Power Supply - Used to provide energy for transceiver.

iii. Microphone - Device to change voice vibrations into electrical impulses.

iv. Speaker - Device to change electrical impulses in to audible sound.

v. Antenna - Device used to pick up or radiate RF energy.

Except for portable radios all components can be separate entities. In portable radios, all four components are included in a single unit.

16.0 RADIO OPERATIONS AND PROCEDURES

All operators are to know power equipment and location of fuses of all equipment.

Control & Equipment

1. ON - OFF Power Switch - Turns Radio On or Off.

2. Volume Control - Control audio output level of speaker.

3. Mute/Squelch Control - Eliminates background noise and affects receiver sensitivity.

4. Channel Control - Allows selection of channel on multi-channel radios.

5. Frequency Tuning Control - Allows selection of frequency.

6. Indicator Lights - Used to indicate power on, signal receive, transmitter on or channel number etc.

7. Microphone - Two main functions

(i) Push to talk switch (PTT) - used to change radio from receive to transmit.

(ii) A microphone to convert speech to electrical signals.

Network Modes

These are: (i) Simplex
(ii) Repeater
(iii) Dispatch

(i) Simplex - Applicable to both HF and VHF Bands. This mode is characterized by direct radio to radio communication using a single frequency. HF communication is almost always in this mode. VHF also use this mode but range is much more restricted than HF.

(ii) Repeater - Applicable to VHF and higher bands. This mode used two frequencies, one for transmit and the other for receive. An intermediate "amplifier" receive the weak signal from the radio, amplifies it and retransmits it on another frequency. The Repeater does this automatically.

This extends the range significantly depending on the size of the amplifier.

However, if the Repeater fails, communication is impossible (even if both radios are adjacent) in the mode.

(iii) Dispatch - Applicable to VHF and higher bands. This is similar to the Repeater mode but without automatic operation. An Operator is required to retransmit the received message on the second frequency. Radio users will only be able to hear the Operator but not the other radio users.

Application - Emergency use of Radio as
(iv) Repeater - Discourage direct conversation e.g. taxis

Operating HF Radios

The operation of the HF radio is complex and a number of available factors can assist or restrict communication. Considerable training and experience is necessary for effective use of HF radio. While VHF and UHF systems are usually employed in line of sight communications, HF if is effective over, short, medium and long distances. Distances in excess of 3000 km are within the capabilities of HF radios.

HF Propagation

HF propagation has two distinct features GROUND WAVE and SKY WAVE. Some of the energy radiated from the Transmitter follows the ground contours and is termed GROUND WAVE. GROUND WAVE Transmissions are usually short range because a significant amount of the energy is absorbed by the terrain during the transmission. Pure Ground Wave transmission are not subject to fading. However, topography and terrain can block signals over relatively short distances depending on the location of any two stations at a given time or place.

The situation with SKY WAVE transmission is totally different. Energy from the Transmitter is radiated into the ionosphere. The ionosphere is formed by layers of gas surrounding the Earth. Gases within these layers are ionized - electrically charged - by radiation from the sun and become conductive. The layers retract or bend radio signals back towards the Earth. This allows transmission over considerable distances. This situation is complicated by the fact that the ionosphere varies in height and density with the time of day, season and solar activity. Solar storms can completely disrupt HF transmission. The ionosphere layers also bend signals at varying degrees depending on the frequency in use. This means that operating frequencies must be carefully chosen according to the time of day and the distance of the communication path required. Generally lower frequencies are more suitable for night time use while higher frequencies are chosen for daytime use. Due to alteration in height and composition of the ionosphere, fading occurs on HF transmission.

There may be a gap in the coverage of the transmission between the ground wave and sky wave. This is termed the Skip Zone or distance. The signal in this zone is too weak for any useful purpose. The problem associated with the Skip Zone may be overcome by relay techniques via a third station that has sky wave communication with both ends of the link. Additional procedures that may assist include changing frequency or changing the type of antenna in use, always remembering to return to the original contact frequency if no contact is made on alternate frequency.

HF Base Stations

Fixed HF radio base stations may be controlled locally or remotely. Locally controlled bases have their transmitters and receiver combined (transceiver) and connected to an external antenna. The transceiver is usually a mobile radio connected to a mains operated 12V power supply, with a battery back-up.

Remote Control

Due to local electrical noise problems or difficulty in finding sufficient space for antennas, HF transceivers may be remotely located but controlled from a central point by telephone landlines or radio link.

To achieve optimum performance HF base stations should be sited so that they are:

(i) located away from electrical noise sources such as power lines, industry, computers, portable generators etc.

(ii) allow sufficient space to erect antennas with appropriate orientation.

(iii) are installed in areas with good conductivity (moist ground)

Mobile Communications

HF Mobile transceivers are used to provide communication from vehicles operating in the field. Several interference problems may be encountered as a result of the following:

1. Vehicle components such as spark plugs, alternators, oil and fuses sensors, wind screen wipers, motor and engine management computers.

2. Proximity to other vehicles.

3. Proximity to industrial areas and machinery.

4. Atmospheric conditions such as thunderstorms and high humidity.

5. Topography/high mountains can block signals thus causing fade-out between other station or repeater.

Antennas

The antenna is a critical part of HF Communication, both transmission an reception. There are two main types in common use.

(1) Auto Tune Antenna - these antennas are automatically tuned according to the frequency selected.

(2) Tapped Wired Antenna - This type of antenna has various taps along its length marked with frequencies corresponding to channels of the transceiver. These tap-lengths have been previously calculated for optimum antenna gain.

(3) Random length wire antennas which must be used with an automatic tuning unit (ATU).

All Correspondence concerning the National Emergency Management Organisation [NEMO] should be addressed to:-

The National Emergency Management Organisation, P. O. Box 1517, CASTRIES

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