VHF Procedures

VHF Procedures - General

Microphone Techniques.

The efficient use of VHF radio depends to a large extent on the operator's method of speaking. As the distinctive sounds of consonants are apt to become blurred in the transmission of speech, words of similar length containing the same vowel sounds may sound alike. Special care is necessary in their pronunciation.

Special care is also required in handling the microphone. Do not hold the microphone too close to your mouth because it may cause distortion or slurring of words and you may have to repeat your message to be understood. Speak all words plainly and end each word clearly in order to prevent the running together of consecutive words. Avoid any tendency to shout, to accent syllables artificially or to speak too rapidly. The following points should be kept in mind when using a radiotelephone.

Speed

Keep the rate of speech constant, neither too fast nor too slow. Remember that the operator receiving your message may have to write it down.

Rhythm

Preserve the rhythm of ordinary conversation. Avoid the introduction of unnecessary sounds such as “er” and “um” between words.

If the communication link is unreliable, or the wording of the text complex or confusing, use the command WORDS TWICE or, upon request, repeat the message using the phonetic alphabet. This should ensure that the information within the text of the message is received correctly.

Procedural Words and Phrases

While it is impractical to set down precise phraseology for all VHF procedures, the following words and phrases should be used where applicable. Words and phrases such as OK, REPEAT, TEN-FOUR, OVER AND OUT, BREAKER BREAKER, COME IN PLEASE, or slang expressions should not be used.

Table 1

Word or Phrase Meaning for VHF Radio Procedures

ACKNOWLEDGE Let me know that you have received and understood this message.

AFFIRMATIVE Yes, or permission granted.

BREAK To indicate the separation between portions of the message. (To be used where there is no clear distinction between the text and other portions of the message.)

CHANNEL Change to channel .......... before proceeding.

CONFIRM My version is _____. Is that correct?

CORRECTION An error has been made in this transmission (message indicated).  The correct version is _____.

GO AHEAD Proceed with your message.

HOW DO YOU READ? How well do you receive me?

I SAY AGAIN Self-explanatory (use instead of “I repeat”).

NEGATIVE No, or that is not correct, or I do not agree.

OVER My transmission is ended and I expect a response from you.

OUT Conversation is ended and no response is expected.

READBACK Repeat all of this message back to me exactly as received after I have given OVER. (Do not use the word “repeat”.)

ROGER I have received all of your last transmission.

STANDBY I must pause for a few seconds or minutes, please wait.

SAY AGAIN Self-explanatory. (Do not use the word “repeat”.)

THAT IS CORRECT Self-explanatory.

Phonetic Alphabet for VHF radio

The words of the International Telecommunication Union (ITU) phonetic alphabet should be learned thoroughly. Whenever isolated letters or groups of letters are pronounced separately, or when communication is difficult, the alphabet can be easily used.  When it is necessary to spell out words, the following table should be used. The syllables to be emphasized are shown in bold type.

Table 2

Letter Word     Pronounced as

A         Alfa         AL FAH

B         Bravo     BRAH VOH

C         Charlie   CHAR LEE or SHAR LEE

D         Delta      DELL TAH

E         Echo       ECK OH

F         Foxtrot     FOKS TROT

G         Golf         GOLF

H         Hotel       HOH TELL

I I         India      IN DEE AH

J         Juliett      JEW LEE ETT

K         Kilo         KEY LOH

L         Lima        LEE MAH

M         Mike       MIKE

N         November NO VEM BER

O         Oscar     OSS CAH

P         Papa        PAH PAH

Q         Quebec    KEH BECK

R         Romeo     ROW ME OH

S         Sierra       SEE AIR RAH

T         Tango      TANG GO

U         Uniform    YOU NEE FORM or OO NEE FORM

V         Victor        VIK TAH

W        Whiskey   WISS KEY

X         X-ray        ECKS RAY

Y         Yankee    YANG KEY

Z         Zulu          ZOO LOO

Example: To report a missing child with the surname Schmidt: SIERRA, CHARLIE, HOTEL, MIKE, INDIA, DELTA, TANGO

Numbers

Table 3

Numbers Expressed in Words

0 - ZERO             6 - SIX

1 - ONE              7 - SEVEN

2 - TWO             8 - EIGHT

3 - THREE           9 - NINE

4 - FOUR             . - DECIMAL

5 - FIVE             ?,000 - THOUSAND

All numbers except whole thousands should be transmitted by pronouncing each digit separately. Whole thousands should be transmitted by pronouncing each digit in the number of thousands followed by the word THOUSAND.

10 becomes ONE ZERO

75 becomes SEVEN FIVE

100 becomes ONE ZERO ZERO

5,800 becomes FIVE EIGHT ZERO ZERO

11,000 becomes ONE ONE THOUSAND

68,009 becomes SIX EIGHT ZERO ZERO NINE

Time

The twenty-four hour clock system should be used in expressing time in the Maritime Mobile Service. It should be expressed and transmitted by means of four figures, the first two denoting the hour past midnight and the last two the minutes past the hour.

Some examples of time using the twenty-four hour clock system are shown in Table 4.

Table 4

Some Times as Expressed by VHF Procedures

Time                    Expressed as

12:45 a.m.           0045 ZERO ZERO FOUR FIVE

12:00 noon          1200 ONE TWO ZERO ZERO

12:45 p.m.           1245 ONE TWO FOUR FIVE

12:00 midnight     0000 ZERO ZERO ZERO ZERO

1:30 a.m.              0130 ZERO ONE THREE ZERO

1:45 p.m.              1345 ONE THREE FOUR FIVE

8:30 p.m.              2030 TWO ZERO THREE ZERO

The calling examples used are sample call signs only.

Calling

Before transmitting, listen for a period long enough to ensure that harmful interference to transmissions already in progress is not likely to occur. If such interference seems likely, wait until the transmissions in progress are completed before making your call.

A station having a distress, urgency or safety message to transmit is entitled to interrupt a transmission of lower priority.

Single Station Call

When establishing communications with a specific station, transmit the call sign of the station being called, followed by the call sign of the station making the call, as shown in the following example.

Example

Sea Wolf (said once or if communication conditions are difficult not more than 3 times)

THIS IS

Riding Hood

OVER

Reverse Calling example - This is Riding Hood calling Sea Wolf

Avoid REVERSE calling as this is incorrect procedure.

Remember that the identifier of the station being called is always spoken first, followed by THIS IS and your own station's identifier.

Replying

When you hear a call directed to your station, reply as soon as possible. Advise the calling station to proceed with the message by means of the words GO AHEAD, or, if you are occupied, by saying STAND BY followed by the estimated number of minutes until your reply. Do not ignore the call. This may result in unnecessary calling, which uses up valuable air time in a crowded environment.

Example

Riding Hood

THIS IS

Sea Wolf

GO AHEAD

OVER

Replying to Calls when Information Is Missing

When you hear a call, but are uncertain the call is intended for your station, do not reply until the call is repeated and understood.

When your station is called but the identity of the calling station is uncertain, you should reply immediately, using the words:

STATION CALLING (your station's identification)

SAY AGAIN

OVER

Termination of Communications

To terminate communications, simply conclude your transmission with the command OUT (which means  “conversation is ended and no response is expected”).

Example

Sea Wolf

THIS IS

Riding Hood

RECEIVED MESSAGE REGARDING DINNER

Riding Hood

OUT

Corrections and Repetitions

Corrections and Repetitions during Transmission

When an error has been made in transmission, the word CORRECTION should be spoken, the last correct word or phrase repeated and the correct version transmitted.

Examples

AT DOCK ALPHA ONE

CORRECTION DOCK ALPHA TWO

Repetitions after Completion

If the receiving operator desires a repetition of a message, the words SAY AGAIN should be transmitted. If repetition of only a portion of a message is required, the receiving operator should use the following appropriate phraseology:

SAY AGAIN ALL BEFORE ... (first word satisfactorily received).

SAY AGAIN ALL BETWEEN ... (last word correctly received prior to the missing segment) and ... (first word

correctly received after the missing segment).

SAY AGAIN ALL AFTER ... (last word satisfactorily received).

Examples

Riding Hood

THIS IS

Sea Wolf

SAY AGAIN ALL BEFORE “DOCK”

OVER

Riding Hood

THIS IS

Sea Wolf

SAY AGAIN ALL BETWEEN “PROCEED” AND “TIME”

OVER

Sea Wolf

THIS IS

Riding Hood

SAY AGAIN ALL AFTER “LOCATION”

OVER

Request for repetition of specific items of a message should be made by speaking the words SAY AGAIN followed by the identification of the message desired.

Examples

SAY AGAIN LOCATION

SAY AGAIN TIME

Unsuccessful Call

When a station called does not reply to a call sent three times at intervals of two minutes, the calling station shall cease and not renew the call until after an interval of three minutes. Before renewing the call, the calling station shall attempt to ascertain that the station being called is not in communication with another station.

Signal Checks

It is sometimes necessary to verify that your transmitter and receiver are operational. This can be done by:

1. establishing contact on the working channel and conducting your tests (the actual wording of the test is given in the example below),

2. not exceeding ten seconds for signal checks,

3. using the readability scale listed below when giving the report, remembering that a readability of 3 to 5  indicates to the receiving station that it is being copied 100 percent.

Readability Scale

1 = Bad (unreadable)

2 = Poor (readable now and then)

3 = Fair (readable with great difficulty)

4 = Good (readable with minor difficulty)

5 = Excellent (perfectly readable)