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πŸ“‘ Signals, Morse Code & Messages

How to get a message across with no phones and no working radio: learning Morse by ear, sending it by lamp, whistle, flag or smoke, calling for help from the ground to an aircraft, mirrors and signal fires (and their danger in fire season), semaphore, alarm codes, runners, message forms, a neighborhood OK/HELP card plan, and what to listen to. The books are in Comms-Signals\Morse-Code, Comms-Signals\Visual-Sound-Signals and Comms-Signals\Messaging-Plans. Radios: the Radio guide and the Radio-Weather folder.

⚠️ Rules that prevent the worst outcomes


πŸ‘‚ Learning Morse by ear

Morse is sounds, not dots on paper. Think of each letter as a sound ("di-dah" is A), never count dots and dashes, and practice by whistling or saying the sounds aloud (TM 11-459, pp. 3–5).

Two proven methods (Pierpont, pp. 159–161; pp. 171–172):

A 30-day plan (rule of thumb, built on Koch's rules). A partner sends from the table below by whistle or flashlight while you write what you hear. If you fall behind, stretch the plan β€” accuracy matters more than the calendar.

Days What to do (two half-hour sessions a day)
1–2 Two letters that sound very different, such as K and M, in random mixes, until you get 9 in 10.
3–20 Add one letter each time you reach 90% on a 5-minute mix. A common Koch order: K M R S U A P T L O W I N J E F Y V G Q Z H B C D X (general practice).
21–25 Numbers, then period, comma, question mark and slash. Keep mixing in all the letters.
26–28 Procedure signals (AR, K, SK, BT, AS) and the calling routine below. Short real messages.
29–30 Whole messages with your partner, by lamp and by whistle, across a field.

If you also learn to send on a hand key: the key and how to hold it; Telegraph key.

πŸ“š Go deeper: Pierpont β€” the whole learning method; TM 11-459 β€” the Army's sound-method lessons.

πŸ”€ Morse quick reference (print this)

International Morse, from Pub 102, p. 21 and ITU-R M.1677-1, pp. 4–5. Read . as "di" (short) and - as "dah" (long). Pictures and sound files: Morse code. To translate, hear it played, flash it as a signal lamp or practise sending it: the πŸ“‘ Morse code tool. Printed charts: Pub 102 Morse chart, Navy NEETS chart.

Letter Code Letter Code Letter Code Letter Code
A .- H .... O --- V ...-
B -... I .. P .--. W .--
C -.-. J .--- Q --.- X -..-
D -.. K -.- R .-. Y -.--
E . L .-.. S ... Z --..
F ..-. M -- T -
G --. N -. U ..-
Number Code Number Code Mark Code
1 .---- 6 -.... Period .-.-.-
2 ..--- 7 --... Comma --..--
3 ...-- 8 ---.. Question ..--..
4 ....- 9 ----. Slash -..-.
5 ..... 0 -----

Procedure signals β€” each is sent as one run-together sound with no gap (ITU, p. 5; Pub 102, pp. 24–25, 140; Prosigns for Morse code):

Signal Code Means
SOS (SOS) ...---... Distress
AR .-.-. End of message
K -.- Over β€” your turn to send
BT -...- Break between message parts
SK ...-.- End of contact
AS .-... Wait
8 dots ........ Error, I'll resend
R / DE / CQ Received / "this is" / calling all stations

Timing is everything (ITU, p. 5; Pub 102, p. 9): a dash is 3 dots long; the gap inside a letter is 1 dot, between letters 3 dots, between words 7 dots. With a lamp or horn, make dots a little shorter so they can't be mistaken for dashes. The standard lamp speed is about 40 letters a minute.

Timing diagram of the words AT ME in Morse as black bars on a ruler of dot lengths: dots 1 long, dashes 3, gaps of 1 inside a letter, 3 between letters and 7 between words AT ME as on-and-off time: a dash is 3 dots; the gaps are 1, 3 and 7 dots long (a diagram drawn for this guide).

How to call (ITU, p. 7): their call sign (no more than twice), DE, your call sign, K. They answer the same way. End each message with AR; whoever sent the last message ends the contact with SK. Without radio licenses, give each household a short call sign β€” two letters is enough (rule of thumb).

πŸ“š Go deeper: ITU-R M.1677-1 β€” the official standard; Pub 102 β€” tables and procedure; NEETS 12, p. 48 β€” another Morse chart.

πŸ”¦ Morse without a radio: light, sound, flags and smoke

If this goes wrong Try this (rule of thumb)
Dots and dashes blur together Very short dots, long dashes, clear gaps
They keep missing words Lengthen the gaps, not the letters; send each word twice
Lamp can't be seen by day Use a mirror or a flag

πŸ“š Go deeper: Pub 102, pp. 17–20 β€” sound, flag and arm signaling; Signal Book 1916, p. 34 β€” whistle and drum codes.

πŸ†˜ Distress signals and talking to aircraft

Body signals to aircraft β€” stand in the open, move slowly and repeat until understood (FM 21-60, p. 59; the signals drawn):

Signal Means
Both arms straight up "Pick us up"
One arm up "All OK, do not wait" β€” easy to confuse with the one above, so be deliberate
Lying on your back, arms stretched overhead "Need medical assistance"
Arms waving, crossed overhead "Do not land here"
Cloth waved up and down / side to side Yes / No
Arms out to the sides, slowly raised and lowered again and again Official distress signal (Pub 102, p. 140)

Eleven small drawings of a person signaling to an aircraft with arms and body, each labeled with its meaning, such as Pick us up, All OK do not wait, and Need medical assistance urgently Body signals to a pilot, each with its meaning; face the aircraft in the open and move slowly (FM 3-05.70, p. 330).

How a plane says "understood" (Pub 102, p. 144; AFH 10-644, p. 518): it rocks its wings by day, or flashes its landing or navigation lights twice at night (or flashes Morse T or R). Not understood: it flies straight and level without rocking, or flashes RPT (aircraft replies drawn; Search and rescue).

πŸ“š Go deeper: FM 21-60, p. 59 β€” body signals drawn; Pub 102, p. 140 β€” official distress signals; Distress signal.

βœ–οΈ Ground-to-air symbols (print this)

The code in use worldwide today has five symbols (ICAO) (Pub 102, p. 144; AFH 10-644, p. 516; FM 3-05.70, p. 329). See them laid out: FM 3-05.70 drawing, Pub 102 chart:

Symbol Means
V Require assistance
X Require medical assistance
N No
Y Yes
↑ (arrow) Proceeding in this direction

Making them seen (AFH 10-644, pp. 514–517):

  1. Big: lines at least 3 ft wide and 18 ft long, bigger if you can, about a 2:3 shape (size drawing). The Army manuals disagree (4 m Γ— 6 m in FM 3-05.70, p. 329; 1 m Γ— 6 m in FM 21-76, p. 243) β€” bigger is always better.
  2. Straight lines and square corners β€” nature has none.
  3. Contrast: outline it with green boughs, rocks or brush so it casts shadows. Orange cloth vanishes against green or brown (contrast example).
  4. One path in and out, so you don't scuff it.
  5. High, open ground seen from every side β€” a field, a river gravel bar, a logged ridge (local examples: rule of thumb).
  6. A cloth banner on a pole catches the eye and shows a pilot the wind (pennants and banners).

Diagram of an L-shaped ground symbol with sizes: each line 3 ft wide and 18 ft long, the symbol 27 ft tall, ratio 1 to 6 Sizes for a ground symbol: each line 3 ft wide and 18 ft long (1 to 6), the whole symbol about 18 by 27 ft (AFH 10-644, p. 515).

⚠️ Don't mix codes. The older 18-symbol Army code (FM 21-60, p. 60) gives X a different meaning. Teach only the five above.

πŸ“š Go deeper: AFH 10-644, ch. 21 β€” size, contrast and placement with photos; FM 3-05.70, p. 329 β€” the five symbols drawn.

πŸͺž Signal mirrors

The best daytime signal. A mirror flash has been seen up to 100 miles away and it works even on hazy or overcast days (AFH 10-644, p. 509). See Signal mirror.

Aiming without a sighting hole (AFH 10-644, pp. 510–511):

  1. Hold one arm out and make a V with two fingers, with the plane or distant hill in the V (drawing; FM 3-05.70 drawing).
  2. Tilt the mirror so the bright spot of light lands on your fingers, then work it through the V onto the target.
  3. Or line the target up with the top of a 4–5 ft stake, and sight along the mirror's top edge onto the stake top (drawing).
  4. Keep sweeping the horizon even when nothing is in sight β€” a pilot may see you first.

Drawing of a person flashing a mirror at a helicopter, sighting over the top of a stake that lines up with the aircraft Aiming with a stake (step 3): line the stake top up with the aircraft, then tilt the mirror until the flash lands on the stake top (AFH 10-644, p. 511).

πŸ“š Go deeper: AFH 10-644, pp. 509–511 β€” mirror aiming with pictures; Signal Book 1916 β€” the heliograph and lantern.

πŸ”₯ Signal fires and smoke β€” and the wildfire danger

What the manuals teach (AFH 10-644, pp. 511–512):

⚠️ Illinois Valley: June to October, do NOT build signal fires.

πŸ“š Go deeper: AFH 10-644, pp. 511–514 β€” fire and smoke signals; Firewood guide β€” ashes and fire-season burning rules.

🚩 Flags, semaphore and signal stations

Simple flag colors (FM 21-60, p. 37; Army flag signals drawn): red = danger; green = all clear / understood; yellow = disregard. At night use colored flashlights. Good for a gate or a lookout.

Semaphore spells words with two flags (or bare arms) held at clock positions β€” by day and in sight only. Pictures: Bluejackets Manual, pp. 444–447 and Flag semaphore; full charts: Bluejackets alphabet, Signal Book 1916 hand-flag chart, FM 24-5 semaphore code.

Siting a flag or lamp station (Signal Book 1916, pp. 43–44):

πŸ“š Go deeper: Bluejackets, p. 444 β€” semaphore drawn; Signal Book 1916 β€” semaphore and station siting; FM 21-60 β€” arm-and-hand signals.

πŸ“£ Whistles, bells and alarm codes

Make a household/neighborhood signal card (rule of thumb β€” fill in your own and post it):

Signal Means Answer
3 blasts, repeated I need help β€” come to me 2 short blasts: "heard you, coming"
String of short, sharp blasts / rapid bell General alarm (fire, intruders) β€” act on the plan None needed
Red cloth on the gate Danger, don't come in
Green cloth on the gate All clear

πŸ“š Go deeper: Signal Book 1916, pp. 38–41 β€” alarm and distress signals; FM 24-5, p. 129 β€” alarm devices.

πŸƒ Runners, relays and written messages

Briefing a runner (FM 24-5 (1939), pp. 68, 70) β€” tell them:

Spoken messages must be short. The runner repeats it back to you and memorizes it (p. 70). Write it down whenever you can.

Speeds and relays (FM 24-5, pp. 69, 71–72): a runner covers about 3 mph routine and 5 mph priority (urgent: as fast as they can and still arrive); a rider 6 and 8 mph. On dangerous routes send two runners in sight of each other, each with a copy, or use two routes. Mark routes with arrows at forks. For long, frequent runs, set up relay posts β€” say, a house halfway to O'Brien (rule of thumb).

Use a standard form. The ICS 213 has To, From, Subject, Date, Time (24-hour clock), Message, Approved by, Reply and Replied by. The sender keeps a copy; the reply comes back on the bottom (ICS Forms Booklet, pp. 65–66; the blank form; Incident Command System). Log every message and event with date and time on an ICS 214 activity log (p. 68).

The ham "radiogram" works on paper too (ARRL manual, p. 34): number and precedence, address, text of 25 words or fewer (X for a period), and signature. The "check" is the word count, so the receiver knows nothing was lost (a filled-in example, part by part).

Precedence (ARRL, p. 36): EMERGENCY (life or death β€” when in doubt, don't) β†’ PRIORITY β†’ WELFARE β†’ ROUTINE.

Short codes save time:

πŸ“š Go deeper: FM 24-5 (1939) β€” messengers, relay posts and a message center; ICS Forms Booklet β€” print blank 213 and 214 forms now; ARRL manual, pp. 33–39 β€” radiogram form and numbered texts.

🏘️ The neighborhood OK/HELP plan

From the rural edition of Map Your Neighborhood (MYN Rural, pp. 1–2):

  1. Pick a Neighborhood Communication Site everyone knows: a mailbox cluster, a crossroads, or a central home or barn.
  2. After a disaster, each household takes its OK/HELP card there with name, date and time, plus the kind of help needed, and tapes it up.
  3. Anyone who can help writes on the card what they'll do and when, then reports back.
  4. Someone checks every home.

Who to check first (MYN Discussion Guide, p. 8): HELP homes, then homes with no card β€” people there may be hurt. Then recheck the OK homes. Print the HELP/OK window card now (what it looks like).

Your household plan: a meeting place, a way to find each other if separated, and an out-of-area contact, posted at home (Oregon 2 Weeks Ready, p. 6; FEMA, p. 18). Add the neighborhood site, your signal card and a check-in time (rule of thumb).

Locally: the county plan counts on door-to-door notice, broadcast stations and amateur radio, and the RVCOG Disaster Registry lists residents needing special help (County EOP, p. 71). Know who they are on your road.

πŸ“š Go deeper: MYN Discussion Guide β€” the first meeting, 9 steps after a disaster, neighbor map; MYN Rural β€” rural sites, wells and propane.

πŸ“» Listening when you can't transmit

πŸ“š Go deeper: NOAA Weather Radio brochure β€” how SAME alerts work; Radio guide β€” shortwave, crystal sets and local frequencies.

⚠️ Old advice in the library to ignore

Book and page What it says Do this instead
Scout Handbook 1911, p. 230 Morse chart It is American (railroad) Morse, different for many letters. Use the International table above.
Scout Handbook 1911, p. 232; Seton, p. 132 Myer "wigwag" flag code Obsolete. Use Morse by flag (left = dash, right = dot) or semaphore.
Signal Book 1916, p. 37 Phonetic alphabet "Able, Boy…" Use the NATO alphabet (Alpha, Bravo…) in the Radio guide.
Seton, p. 271 Two smokes = "I am lost"; three smokes = "good news"; a two-shot/one-shot hunters' code Today three of anything = distress.
FM 21-60, p. 60 18-symbol ground code; X = "unable to proceed" Use the 5-symbol code: X = need medical help.
FM 3-05.70, p. 328 Whistle heard "1.6 km (3/4 mile)" 1.6 km is 1 mile, not 3/4. Plan on 200 yards.
AFH 10-644, pp. 513–514; FM 3-05.70, pp. 319, 321 Tree torches, gasoline smoke pots, pen flares, tracer rounds Fire and explosion hazards. Never in fire season.

πŸ“š Go deeper: Pub 102 β€” today's international distress signals; AFH 10-644 β€” the modern survival-signaling chapter.


πŸ–ΌοΈ Pictures & diagrams

Look before you try it. πŸ–ΌοΈ = drawings in the books on this drive; πŸ“· = photos in the offline Wikipedia.

Morse code

Light, sound and smoke

Talking to aircraft

Signal mirrors

Flags and semaphore

Messages and neighbors

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