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Emergency Radio Communications Guide

Ham (Amateur), CB, Shortwave, GMRS/FRS & MURS — how they work and how to use them

This guide explains, in plain language, how to communicate by radio when the internet and phones are down. It covers what each type of radio is, what it can do, which frequencies/channels matter in an emergency, and the basic procedures for calling for help.

Legal note (normal times): Transmitting on ham (amateur) frequencies requires a license (easy to get — see below). GMRS requires a cheap license (no test). CB, FRS, MURS need no license. Shortwave listening needs no license (you're only receiving). In a genuine life-or-death emergency, calling for help on whatever radio you have is generally accepted (the ham rules, 47 CFR §97.405, say nothing in them stops a station in distress from using any means it has). Listening is always legal. Learn and practice before you need it.

1. The quick version — what to grab and what to know

Need Best tool License Range (typical)
Talk to family nearby (same property / neighborhood) FRS / GMRS walkie-talkie (FRS) FRS none; GMRS cheap 0.5–2 mi (up to 5+ with GMRS + height)
Talk across town / coordinate a group GMRS (with repeater) or Ham VHF/UHF (GMRS) GMRS cheap; Ham test 5–50 mi via repeater
Talk regionally / long distance / into other states Ham HF (Amateur radio) Ham (General class) 100s–1000s mi
Hear news & official broadcasts from anywhere Shortwave receiver (Shortwave radio) none (listening) Worldwide
Road / vehicle convoy, truckers CB (Citizens band radio) none 1–15 mi
Text messages and positions between family and neighbors, passed radio to radio Mesh radio (Mesh radio guide) none ¼–5 mi per hop, further with relays

Three things everyone should know:

  1. Monitor, don't just transmit. A cheap receiver tells you what's happening.
  2. Higher antenna = more range. Antenna height matters more than watts (why: line-of-sight drawing).
  3. Have a plan: agree on a channel/frequency and check-in times with your group in advance (write them down — see the card at the end).

📚 Go deeper: ARRL ARES Field Resources Manual, p. 6 — what to do first, checklists, message forms; NOAA Weather Radio brochure — how alerts work.

2. In the Illinois Valley 🏔️

The valley is ringed by mountains (Klamath Mountains): VHF/UHF needs a repeater on a peak (why: radio waves travel in straight lines), and NOAA warns that mountain valleys may get little or no weather radio even inside the usual 40-mile range (NOAA brochure, p. 3).

Side-view diagram: a mountain between two valleys blocks the direct path between two handheld radios, but both have a clear straight line up to a repeater on the peak Valley to valley, VHF/UHF gets through by way of a repeater on a peak that both radios can see (a diagram drawn for this guide).

(Club websites, Nov 2026 — verify. Full lists: Illinois Valley guide.)

📚 Go deeper: FM 24-18, p. 144 — radio in mountains; FM 24-18, p. 102 — picking a radio site; NOAA Weather Radio brochure, p. 3 — reception in valleys.

3. How radio actually works (the 60-second version)

📚 Go deeper: NEETS Module 10, p. 100 — the ionosphere by day and night; NEETS Module 12 — AM, FM and SSB.

4. CB Radio (Citizens Band) — no license, simple, vehicle-friendly

📚 Go deeper: FM 24-18, p. 55 — repairing a broken whip antenna (repair drawing); Citizens band radio — channels, history and photos.

5. FRS / GMRS / MURS — the walkie-talkie families

These are the little handheld radios ("walkie-talkies"). Great for family/group.

FRS (Family Radio Service) — no license

GMRS (General Mobile Radio Service) — cheap license, no test

MURS (Multi-Use Radio Service) — no license

In hill country: use high ground, get clear of buildings and leafy trees (they soak up more signal than evergreens), and keep away from power lines (good radio sites; poor radio sites).

📚 Go deeper: FM 24-18, p. 102 — choosing a good radio spot; Walkie-talkie — photos of handheld radios.

6. Ham (Amateur) Radio — the serious emergency option

Ham radio is the backbone of emergency communications. When everything else fails, hams relay health-and-welfare traffic, weather, and coordination across towns, states, and continents (Amateur radio; Amateur radio emergency communications).

Licensing (USA) — easier than you think

Three license levels, each a multiple-choice test (questions are public — you can study the exact pool):

  1. Technician — entry level. Grants VHF/UHF (local, repeaters) plus some HF. Enough for local/regional emergency comms. ~1 evening of study.
  2. General — adds most HF privileges → long-distance / cross-country.
  3. Amateur Extra — full privileges.

Get at least a Technician license now while it's easy, and ideally General so you can use HF for long distance. In a true life-or-death emergency, calling for help without a license is generally accepted (see 47 CFR §97.405) — but you'll be far more effective if you've practiced.

The main ham bands and what they do

Repeaters — how hams get range from a handheld

A repeater is a radio on a tower/hilltop that receives your weak signal and re-transmits it with a big antenna and power, massively extending range. To use one you set your radio to the repeater's output frequency, an offset (so it transmits on the input), and sometimes a CTCSS "tone." Local repeater lists (and emergency nets) are worth printing out for your area (Repeater).

Simplex (radio-to-radio, no repeater)

If repeaters are down, you talk simplex — directly, radio to radio, line of sight. The national 2m simplex calling frequency is 146.520 MHz.

Wilderness protocol: back-country hams listen and call on 146.52 for 5 minutes at the top of the hour, every 3 hours from 7 AM to 7 PM, so someone beyond a repeater can be relayed (ARRL manual, p. 84).

HF from a valley: "NVIS"

A wire dipole hung low — 1/10 to 1/4 of a wavelength up (roughly 25–60 ft on 80m, worked from the formula in section 8) sends its signal almost straight up; it comes back down like a fountain over a few hundred miles with no skip zone, and the hills matter much less (FM 24-18, p. 279; the "fountain" drawing; Army NVIS antennas; Near vertical incidence skywave).

Diagram of radio signals from a low antenna going almost straight up 300 km to the ionosphere layers and coming back down over mountains 10, 25 and 50 km away NVIS: a low antenna sends HF almost straight up, and it falls back like a fountain on the stations around you, hills and all (FM 24-18, p. 283).

Nets

A net is a scheduled on-air meeting. In a directed net a net control station says who talks next. Listen first, check in when invited, keep a log, and tell net control if you leave (ARRL manual, p. 7, 18).

Ham digital & data (advanced, FYI)

Hams can also send text/email/images with no internet via Winlink (email over radio), FT8 (weak-signal), and APRS (position/text). Useful but needs more gear and practice (Winlink, FT8, APRS).

📚 Go deeper: ARRL manual, p. 14 — ARES, traffic nets and RACES; FM 24-18, p. 278 — NVIS in full.

7. Shortwave (SWL) — hearing the outside world

📚 Go deeper: NBS Circular 120 — build a crystal set step by step; NBS Circular 121 — a sharper version.

8. Antennas, power & range (the practical stuff)

Build a wire antenna (half-wave dipole)

Total length in feet = 468 ÷ MHz (3–50 MHz; FM 24-18, p. 47), cut in two equal halves with the coax at the center. 3.980 MHz (Oregon Emergency Net): 117.6 ft · 7.2 MHz: 65 ft · 14.3 MHz: 32.7 ft. Look first: center-fed wire antenna between two supports, improvised half-wave doublet, how a dipole radiates.

  1. Any wire works in an emergency; copper or aluminum is best.
  2. Insulators at the ends and center — plastic or glass (plastic spoons, bottle necks) beat wood or rope. The wire must touch nothing else (FM 24-18, p. 55; improvised insulators; Insulator).
  3. Tie one end through a spring or strip of inner tube so swaying trees don't snap it.
  4. Adjust length and height for the strongest signal from a distant station. ⚠️ Transmitter off before touching the antenna — it can cause serious injury (p. 56).

Diagram of a wire dipole antenna hung between two trees: two equal halves of wire with insulators at the ends and center, coax from the center down to the radio, total length 468 divided by the frequency in MHz A half-wave dipole: total length in feet = 468 ÷ MHz, two equal halves, coax at the center (a diagram drawn for this guide).

Drawings of antenna wire tied through improvised insulators: plastic spoon, button, bottle neck, rubber or cloth strip, dry wood, nylon rope loop and plastic bag; best plastic and glass, good wood, fair cloth and rope Insulators from scraps: plastic and glass are best, dry wood good, cloth and rope only fair (FM 24-18, p. 87).

For 2m/70cm, a J-pole from TV twin-lead is cheap (ARRL manual, p. 12; what twin-lead looks like; Twin-lead). Rocky mountain ground is a poor ground, so use a dipole, or a vertical with a counterpoise — wires spread just above the ground (FM 24-18, p. 144; wire counterpoise; ground-plane antenna). Set up high on a slope, not in a ravine, and away from your own generator and battery charger — they add noise (p. 102–103).

Batteries: a car battery survives only about 20 deep discharges; deep-cycle batteries take 1,000 or more, and shallow use lasts far longer (about 800 cycles at 80% discharge vs 6,000 at 20%). Recharge stored sealed batteries about every 3 months. Charging batteries give off hydrogen — no sparks or flames (Practical Action, p. 5–6).

Lightning: a lightning switch grounds the antenna whenever you're not using it — No. 14 or heavier copper wire to a water pipe or ground rod, never a gas pipe (NBS Circular 120, p. 8; Lightning arrester).

📚 Go deeper: FM 24-18, p. 55 — field repair and expedient antennas; NEETS Module 10 — how antennas work.

9. How to call for help (procedure)

  1. Listen first. Make sure you're not interrupting other emergency traffic.
  2. Use the emergency call:
    • Voice distress: say "MAYDAY, MAYDAY, MAYDAY" (life-threatening) or "PAN-PAN" (urgent but not immediately life-threatening), then your info (Mayday, Pan-pan).
    • On CB, call on Channel 9. On ham, break into the local emergency net or call on a repeater / 146.520 simplex.
  3. Give the essentials — slowly, clearly, repeat:
    • Who you are (name / call sign).
    • Where you are (address, cross-streets, GPS coords, landmarks).
    • What the emergency is (injury, fire, trapped, etc.).
    • What you need (medical, rescue, relay a message).
  4. Spell hard words with the phonetic alphabet (below).
  5. Stay on, don't wander off frequency. Keep the radio on so responders can call back. Repeat your message at intervals if no answer.

NATO phonetic alphabet

Alpha Bravo Charlie Delta Echo Foxtrot Golf Hotel India Juliet Kilo Lima Mike November Oscar Papa Quebec Romeo Sierra Tango Uniform Victor Whiskey X-ray Yankee Zulu. Numbers: say digits individually ("one-two-zero"). (NATO phonetic alphabet)

Common "pro-words"

📚 Go deeper: ARRL manual, p. 58 — procedure words, phonetic alphabet, signal reports; Pub 102, pp. 148–149 — the international voice distress procedure, with worked Mayday examples.

10. Passing messages for others

Much of radio's work after a disaster is carrying short messages for people with no radio. Send in this order (ARRL manual, p. 36): EMERGENCY (life and death — when in doubt, don't) → PRIORITY (important, time-limited) → WELFARE ("Is my family OK?" / "All well here") → ROUTINE (last).

📚 Go deeper: ARRL manual, p. 33–34 — welfare form, standard texts, how to write a radiogram; ICS 213 General Message form — the standard paper form emergency offices use.

11. When the radio can't reach: signals without one

📚 Go deeper: FM 3-05.70, p. 318 — signaling devices and how to use them; Signals and Morse guide — mirrors, ground symbols, Morse by light and sound; AFH 10-644, p. 509 — the Air Force signaling chapter, with pictures.

12. If this goes wrong

Problem Try this
Nobody answers Get higher and clear of buildings and leafy trees; hold the radio upright; try a repeater
Repeater ignores you Check the offset and tone
Two radios won't talk Same channel and same mode? Same privacy code on FRS?
HF is dead Lower band at night, higher in daytime (rule of thumb)
Buzz or hum Move away from power lines, generators, chargers (FM 24-18, p. 103)
Broken antenna Splice it, or replace with wire of the same length (whip repair drawing)
Battery dies fast Lower power, transmit less, listen at set times

📚 Go deeper: FM 24-18, p. 106 — sources of interference; FM 24-18, p. 55 — field repair of antennas, guys and masts.

13. A sensible emergency radio kit (shopping / checklist)

📚 Go deeper: ARRL manual, p. 10–12 — basic and 72-hour go-kit checklists; Amateur Radio Emergency Service — how volunteer emergency hams are organized.

14. Print-and-keep frequency card

Fill in your group's agreed channels and local repeaters, then print this page.

=====================  EMERGENCY RADIO CARD  =====================
 Our group PRIMARY channel : _______________   Mode: _______
 Our group BACKUP channel  : _______________   Mode: _______
 Check-in times (daily)    : _______  _______  _______

 CB emergency / help ....... Channel 9
 CB highway / travel ....... Channel 19
 Ham 2m simplex calling .... 146.520 MHz  (FM)
 Wilderness protocol ....... 146.520 - 5 min at top of hour,
                             every 3 hrs, 7 AM to 7 PM
 NOAA Weather Radio ........ 162.400 / 162.425 / 162.450 /
                             162.475 / 162.500 / 162.525 / 162.550 MHz
 FRS/GMRS family channel ... _______   (GMRS license #: __________)

 Local repeaters (output / offset / tone):
   1) ________ MHz  /  ____  /  tone ______  (____________)
   2) ________ MHz  /  ____  /  tone ______  (____________)
   3) ________ MHz  /  ____  /  tone ______  (____________)

 Distress voice: "MAYDAY x3" (life threat) or "PAN-PAN x3" (urgent)
 Say: WHO you are - WHERE you are - WHAT's wrong - WHAT you need
 No radio? Three fires / three shots / ground symbols V and X
==================================================================

📚 Go deeper: ARRL manual, p. 59 — a phonetic alphabet to print alongside; NOAA Weather Radio brochure, p. 2 — how the broadcasts and SAME county codes work, with station frequencies.

15. Where to learn more offline (already in this kit)

Practice now: tune around, learn your radios' menus, program the channels above, and do a test check-in with your group. Skills and muscle memory matter more than gear.

📚 Go deeper: NEETS Module 17 — how radio systems work; NASA hand soldering workbook — repairing radios and cables.

Pictures & diagrams

Look before you try it. 🖼️ = drawings in the books on this drive; 📷 = photos in the offline Wikipedia.

How radio travels

The radios

Antennas you can build

Siting and repair

Calling for help and passing messages

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