GENERAL. The Commandos use both technical and non-technical methods of
7-1. TECHNICAL COMMUNICATION.
a. AN/PRC 77. The AN/PRC-77 set covers the 30
to 75.95 MHZ band in 5 KHZ increments. It is a
medium weight radio that is best utilized for squad
or platoon operations. The following chapter
outlines assembly, operation, and trouble-shooting
for both radios.
1. Radio assembly
(a) Check and install the battery
(b) Inspect the battery box for dirt
(c) Check battery condition
(d) Place battery in box
(e) Close battery cover and secure
(a) Inspect antenna for damage
(b) Screw antenna into radio (screw
into base first if using the whip antenna)
(a) Inspect the handset for damage
(b) Push handset onto audio connector
and twist to lock into place
4. Operation and frequency setting
(a) Set frequency.
(b) Push handset button. Allow approx
1 second for battery to come to full power.
PROBLEM CORRECTIVE ACTION
1. No power 1.a. Check battery
2. High pitch in handset 2.a. Clean handset and audio connector with eraser
3. Continuous keying 3.a. Press push to talk button on handset
4. Will not key 4.a. Press push to talk button on radio
4.b. Change handset
5. Will not transmit 5.a. Check frequency
5.b. Check antenna
5.c. Check handset
6. Will not receive 5.a. Check frequency
5.b. Check antenna
5.c. Check handset
b. MOTOROLA TALK-ABOUT. The Motorola Talk-About radio is the primary tactical
radio for the Command Squadron. Primary and alternate channels without codes will be
randomly selected for each Commando operation. Brevity codes will be used to
transmit channel changes during the operation.
c. Radio Procedures
(1) Prowords. Procedure words or prowords are words used to expedite message
handling on circuits where radiotelephone procedure is employed. They are used in
standard phrases between radio operators to shorten and minimize transmissions.
(a) "THIS IS" - This transmission is from the station whose designator
(b) "OVER" - This is the end of my transmission to you
and a response is necessary. Go ahead, transmit.
(c) "OUT" - This is the end of my transmission to you and no answer is
required or expected.
(d) "ROGER" - I have received your last transmission satisfactorily.
(e) "SAY AGAIN" - Repeat all of your last transmission. Followed by
identification data means "Repeat ________________ portion indicated".
(f) "WAIT" - I must pause for a few seconds.
(g) "WAIT-OUT" - I must pause longer than a few seconds.
(h) "I SPELL" - I will spell this word phonetically.
(j) "CORRECT" - You are correct, or what you have transmitted is
(k) "CORRECTION" - An error has been made in this transmission.
Transmission will continue with the last word correctly transmitted.
(l) "DISREGARD THIS TRANSMISSION" - This transmission is in error.
Disregard it. Used to cancel transmission while in progress and never used to cancel
a transmission after a receipt has been received.
(m) "SAY AGAIN" - Repeat all of your last transmission. Followed by
identification data, means "Repeat ______________ (portion indicated).
(n) "ALL AFTER" - The portion of the message to which I have referenced
is all that which follows _________________.
(o) "ALL BEFORE" - The portion of the message to which I have reference
is all that which precedes ___________________.
(p) "WORD AFTER" - The word of the message to which I have reference is
that which follows____________.
(q) "WORD BEFORE" - The word of the message to which I have reference is
that which precedes___________.
(r) "I SAY AGAIN" - I am repeating transmission or portion indicated.
(s) "AUTHENTICATE" - The station called is to reply to the challenge
(t) "I AUTHENTICATE" - The group that follows is the reply to your
challenge to authenticate.
(u) "AUTHENTICATION IS WRONG" - Check your authentication system.
(2) Call Signs. Calls signs are used to identify callers on a radio net.
Units are NEVER identified in the clear.
7-2. NON-TECHNICAL COMMUNICATION.
a. HAND AND ARM SIGNALS. Commando’s must be proficient in communicating via hand
and arm signals. Under many circumstances, use of verbal or technical means of
communication may not be possible due to the situation and enemy proximity.
1. Bounding Overwatch: Places the 2. Call Leaders Forward: Signals element
Squadron into a bounding overwatch and/or section CDRs forward to the SQDRN
movement. Usually followed with CDR.
signals to sections for overwatch
3. Move Out: Initiates movement 4. Increase Speed: Usually
or alerts unit to begin movement. means to double time or initiate assault.
5. Danger Area: A slashing motion across 6. Map Check: A signal to inform
the throat. Usually followed by “Scroll the unit of the reason for a stop
to the road” or security to indicate the
method of crossing.
7. Pace Count: A signal asking for 8. Head Count: Signal is relayed to the
the current pace count (meters). back and the count is sent forward when in
9. RTO: Signal for the RTO to come 10. Rally: Used to direct the unit
forward. to indicate arrival at the ORP. If
followed by a pointing motion, it
designates enroute rally points.
11. DISPERSE. Used to direct the unit 12. Halt: Stop forward movement
to increase separation and seek
maximum cover and/or concealment such
as with the approach of enemy forces.
13. Freeze: Freeze in place and make 14. ENEMY IN SITE: Alternate
no movement (usually indicates enemy signals include weapon upside down
presence). or a “pistol” made with the hand
pointed at the enemy upside down
15. ACTION (Right, Left, etc): Indicates 16. COLUMN: Column or file. (FM 21-60
the direction of attack. uses this signal for Travelling
17. ON LINE: On line formation 18. WEDGE: Wedge formation.
19. OUT OF ACTION: For a crew served 20. DECREASE SPEED: Slow movement down.
weapon that is out of ammo or
21. COMMENCE FIRING: Start firing or 22. CEASE FIRING: Stop Shooting
23. SECURITY: Two fingers pointed towards 24. TRAVELLING OVERWATCH. Signals
the eyes means move security team forward. squadron to open up and move in a
traveling overwatch formation
b. OTHER SIGNALS. Other types of communication may be effected by other means.
a. Authentication. There are two methods of authentication, challenge and reply
and transmission authentication. The operational distinction between the two is that
challenge and reply requires two-way communications, whereas transmission
authentication does not. Each SOI will include an authenticator chart randomly
created. A set letter combination is sent. The authentication letter is read
directly below the second set letter. If the letter is at the bottom of the pad, the
first letter in the top of the column is the authenticator. For example: Set letters
DK would have an authenticator of J.
(1) When challenged for authentication, you select two letters at random
(Except Z) to use for challenge.
(CALL SIGN) THIS IS (CALL SIGN) AUTHENTICATE KILO VICTOR OVER.
(2) To find the reply, go to the authentication tables KTC 1400( ). Use
table "SET 01, PERIOD 01".
(3) Locate the first letter (K) in the LINE INDICATOR COLUMN at the left side
of the table, follow the (K) row to the right until you find the next letter (V).
(4) The letter directly below (V) is the reply (S).
(CALL SIGN) I AUTHENTICATE SIERRA OVER.
(1) Trigraph Method.
(a) A trigraph can be easily constructed for low level encryption. The
base/key letter is determined by the SOI.
(b) To use the trigraph to encrypt:
1. Located the unencrypted letter along the top row.
2. Follow the column down to the set letter. (For example:
Unencrypted letter J, SET Letter F, Encrypted letter is P).
(c) To decrypt, find the SET letter in the first column. Find the
encrypted letter in the key letter’s row. Read the unencrypted letter from the top
Tri-graph Chart (Key Letter B)
b. Tap Code. The tap code was developed for SERE situations to effect
communications while in captivity. A series of taps is used to identify the letters
of words to be spelled out. That tap code chart here is used only as a reference and
should never be used except during training. Each letter is identified by a sequence
of two sets of taps. The first sequence follows the first column “A F L Q V.” The
second series identifies the letter in that row (i.e. two taps followed by three taps
is the letter H). Entire conversations were conducted in the prison camps of Vietnam
using this system. It is NOT a secure means of communication.
A B C D E
F G H I J
L M N O P
Q R S T U
V W X Y Z
Tap Code Chart
c. Pro-Word Numeric Encryption. A pro-word (one or two words) is designated to
conduct an expedient encryption of numbers during an operation used primarily to
report grid coordinates and frequencies. Each letter of the pro-word is assigned a
number in sequence beginning from the number 1. For example, pro-word “SHARK LINED”
would be used to send the the grid coordinate 482933 (RNHEAA). The transmission may
include set letters for the pro-word and would sound like this: “F24 this is F25, I
set Sierra Lima, I send Romeo November Hotel Echo Alpha Alpha Over.”
7-4. REPORT FORMATS. Transmissions are sent with only the line and number followed by
the pertinent information (i.e. “ALPHA FOUR FOUR, THIS IS DELTA SEVEN SIX, LINE ONE
HALTS PAPA UNIFORM SIX THREE THREE SEVEN EIGHT ZERO”)
a. MEDEVAC Request. PROWORD MEDAC
(1) LZ Codename and location (6-digit UTM coordinates).
(2) Radio frequency and call sign (secure/nonsecure).
(3) Number of patients by precedence (URGENT, PRIORITY or ROUTINE).
(4) Special equipment required; e.g. hoist, penetrator, whole blood, etc.
(5) Number of patients by type (litter or ambulatory)
(6) Number and type of wound, injury, illness, etc.
(7) Method of marking pickup site (PZ)
(8) Patient nationality and status
(9) Terrain description (obstacles, slope, etc.).
b. Cache Report. PROWORD UNDER
(1) Purpose of cache (who intended for/functional purpose).
(2) Method of caching (concealment/burial/submersion).
(3) Contents (itemized list and how packaged). Use MARGE Bundle codes.
(4) Description of containers (number, size, weight).
(5) General area (country, province, town, village).
(6) Immediate area (initial reference point (IRP) and instructions (azimuth)
to final reference point (FRP).
(7) Cache location (FRP and exact measurements (feet or meters)).
(8) Emplacement details (depth, type soil, physical covering, etc.).
(9) Operational data (equipment needed, routes to and from site, security
(10) Date of emplacement/duration (how long contents will remain usable).
(11) Sketches/diagrams (aerial sketch with route from IRP to FRP).
c. Initial Entry Report. PROWORD ANGUS
(1) Mission Designator and SFODA codename.
(2) Location (6-digit UTM coordinates).
(3) Casualties. - Code name of personnel who are unable to continue the
mission using code words listed below.
UNCLE - Killed in Action.
FROST - Wounded in Action (explain).
SPARK - Captured or Missing in Action.
(4) DTG contact/linkup made with friendly elements.
(5) Strength of FID/guerrilla force.
(6) Location of MSS/patrol base (6-digit UTM coordinates). If different from
(7) DTG surveillance established on target/area.
(8) Additional information.
d. Situation Report. PROWORD CYRIL
(1) Location of outstation(s) (6-digit UTM coordinates).
(2) Guerrilla/FID strength.
(3) Condition of detachment (excellent, good fair, poor).
(4) Enemy contact information (DTG, causality/status).
(5) Major activities since last report (what, where and when). Include post
PSYOPS and TACAIR, etc. results in this paragraph. Also include non-nuclear
destruction of targets.
(6) Projected major activities (what, where and when).
(7) Additional information.
e. Intelligence SPOT Report. PROWORD BORIS
(1) Size/type of unit (how many).
(2) Activity (what are they doing).
(3) Location (where are they).
(4) Uniform (who are they by unit identification, if unknown
(5) Time, DTG (if observed over a period of time state start and stop time).
(7) Personalities (VIP's who can be identified).
(8) Source (if source is member of your unit - omit. If source
is by other means, i.e. indigenous personnel, so state. Follow-up with VALUE report).
(9) Evaluation (Enemy intent).
(10) Additional information.
f. Helicopter Landing Zone Survey Report. PROWORD HELIX
(1) Codename (operational element selects codename).
(2) Location (6-digit UTM coordinates).
(3) LZ size (in meters).
(4) DTG (time aircraft is required on station).
(5) Wind direction (cardinal direction wind is blowing from) and
velocity in knots.
(6) Recommended approach heading (magnetic).
(7) Open quadrant(s) (measure open quadrant from center of HLZ and report as
a series of azimuths in magnetic degrees. The open quadrant indicates acceptable
(8) Soil composition.
(9) Obstacles (type, height in feet, azimuth and distance from center of
(10) Authentication used by LZ security element (smoke, strobe, panel).