Communication: without the internet

Mobile networks usually fail within hours of a large power cut: towers run on batteries for about 1–4 hours, some for a day with a generator. After that you have what you own, what still broadcasts, and people who walk. Write the plan on paper, give every household member a copy, and practise it once.

Radios on standby drain batteries. Agree fixed windows instead: for example every hour on the hour for 5 min in the first days, then 08:00, 12:00, 20:00. If a check-in is missed twice, the plan says what happens (someone walks over, everyone goes to the meeting point).

Keep a paper log: time, who, what was said. After a week nobody remembers who promised what.

A radio that only listens is the most useful and the cheapest. Pick one that runs on AA cells as well as a crank or solar panel, with AM (medium wave), FM and shortwave. Shortwave: listen in the evening on 5.9–6.2 MHz (49 m band) and during the day on 9.4–9.9 MHz (31 m) and 11.6–12.1 MHz (25 m). Write down which stations you hear now, while you can still check who they are.

Licence-free across Europe: 16 channels at 446.0–446.2 MHz, 0.5 W. Buy a set that runs on AA/AAA cells (NiMH rechargeable) rather than a sealed pack, so you can swap in anything. "Privacy codes" (CTCSS/DCS tones) only mute other users; they do not make the call private. For emergency calls keep tones off so everyone on the channel hears you.

Range is mostly about height: stand at an upstairs window or on a hill and 0.5 W reaches surprisingly far.

A car CB with a proper roof or mast antenna outperforms any handheld. A base station on the house with a vertical antenna 8–10 m up can reach the next villages. Channel 9 is the traditional emergency channel, channel 19 the road channel. Radios salvaged from lorries and old cars are common (Salvage).

The licence exam takes a few weekends of study and teaches you antennas, propagation and procedure, which is worth more than the radio. With an HF radio, a wire antenna and a 12 V battery (Electricity) you can talk hundreds of kilometres with no infrastructure at all.

Quarter wave in metres ≈ 71.3 ÷ MHz. Half-wave dipole total ≈ 142.5 ÷ MHz, so each leg is a quarter wave. Cut 3–5 % long, then trim both ends equally until the SWR meter (or the radio's own reading) is lowest.

VHF and UHF (CB partly too) travel roughly in straight lines. The radio horizon in km ≈ 4.1 × (√h₁ + √h₂), heights in metres.

• Two handhelds at 1.5 m: about 10 km in open flat country, 1–3 km among buildings and trees.
• Antenna on a 10 m mast to a handheld: about 18 km.
• Relay on a hill 100 m above the valley: about 45 km. One person with a radio on the highest point links whole villages.

A horizontal dipole only 3–6 m above ground on 3.5–7 MHz throws signals almost straight up; the ionosphere reflects them back down over a circle of 0–400 km with no gaps behind hills. This is how armies talk across a region without repeaters. Works best by day on 7 MHz and at night on 3.5 MHz.

Where am I? Take bearings to two or three landmarks you can identify on the map. Add or subtract 180° (back bearing) and draw lines from each landmark on the map. You are where they cross.

Southern hemisphere: extend the long axis of the Southern Cross about 4.5 times its length; the point below it on the horizon is south. Any star: sight it over two fixed sticks for 15 minutes. Rising means you face east, sinking west, moving right south, moving left north (northern hemisphere).

Stroke a steel needle or razor blade 30–50 times in one direction with a magnet (a speaker magnet, a fridge magnet, a hard-drive magnet). Float it on a leaf or a piece of cork in still water, away from metal. It settles north-south; check which end is north once with the sun, then mark it.

Count every time your left foot lands. Most adults take 60–70 double paces per 100 m on flat ground, more uphill, in mud or in the dark. Measure yours once over a known 100 m and write it on the compass. Tie a knot in a cord, or move a pebble from one pocket to another, every 100 m.

Dead reckoning: known start + bearing + distance = position. Aim deliberately to one side of a target on a road or river ("aiming off") so you know which way to turn when you reach it.