Radio is the communication layer that survives when the internet and the mobile network do not, and it is almost entirely one-directional for a household: you can listen to a great deal, legally and for nothing, and you can transmit very little without a licence.
That asymmetry shapes the whole page. Listening is where the value is.
Receiving is free, transmitting mostly is not
Listening to any broadcast in the UK needs no licence at all. A television licence covers television and BBC iPlayer; it has nothing to do with radio. Scanning, shortwave listening and receiving anything you can pick up is unrestricted.
Transmitting is regulated, and the rules are worth knowing rather than guessing:
Transmitting without the required licence is an offence, and more practically it can interfere with services that matter. Listen freely; transmit only on what you are entitled to.
Which band gets you what
- FM, roughly 88 to 108 MHz. National and local stations, good quality, line-of-sight-ish range of tens of miles. BBC local radio is the designated emergency broadcaster in the UK, and in a regional emergency it is where instructions go out.
- Medium wave, also called AM, roughly 530 to 1600 kHz. Poorer quality, much longer range, and dramatically better at night. Cheap sets receive it.
- Long wave, around 150 to 280 kHz. Very long range. Historically the national fallback, but the UK long wave service has been progressively wound down and should not be relied on as a permanent option.
- Shortwave, roughly 3 to 30 MHz. International broadcasting, and genuinely global at night. The way to hear what is being said outside your own country when domestic sources are unavailable or untrustworthy.
- DAB, digital. Good quality, more stations, and the least robust of the lot.
For resilience, FM and medium wave are the two that matter, with shortwave as the bonus.
Why DAB is the wrong resilient choice
This is the part most people have backwards, because DAB is the newer technology.
DAB fails abruptly. Digital reception works until the signal drops below a threshold, and then it stops completely, or bubbles and cuts out. There is no degraded-but-usable state.
FM degrades gracefully. As the signal weakens it gets noisier, and a hissy FM signal is still perfectly intelligible speech. In an emergency, intelligible speech is the entire requirement.
DAB also uses more power, which matters when you are running a set off batteries or a wind-up handle for weeks.
And it needs the transmitter network to be running. So does FM, but the older analogue infrastructure is simpler and there is more of it.
Own a set that does FM and MW. If it also does DAB, fine. If it only does DAB, it is the wrong set for this purpose.
Night changes everything on medium wave
Worth understanding because it turns a local receiver into a national one for free.
By day, medium wave travels along the ground and gets perhaps a few tens of miles.
After dark, the ionosphere changes and signals bounce off it and return to earth hundreds of miles away. The same cheap radio that gets three local stations in the afternoon will pick up stations from across the country and from the continent at night.
Shortwave does the same, more so. Shortwave at night reaches across the world, which is why it was the medium of international broadcasting for a century.
The practical use: if you need news from outside your immediate area and local transmitters are off, wait until dark and tune slowly across medium wave and shortwave. It costs nothing and it works.
The set to actually own
Buy it before you need it and test it. A radio still in its box in a cupboard is an assumption, not a plan. Wind it up, tune it, find your BBC local radio frequency and write that frequency on the case in marker, because scanning for it in the dark while worried is exactly when you will not find it.
Keep spare batteries in the same place, and check them annually.
Note the frequencies of BBC local radio for your area, Radio 4, and one or two shortwave international broadcasters, on a card kept with the set.
Two way radio you may legally use
PMR446 handhelds are the household option: licence free, cheap, and they work.
- Realistic range is a few hundred metres in a built-up area and a few kilometres in the open with line of sight. The packaging claiming eight or ten kilometres is measuring hilltop to hilltop with nothing in between.
- They are genuinely useful for: keeping a household in contact around a property and neighbourhood, coordinating a group on foot, and staying in touch with somebody who has gone to fetch water or check on a neighbour.
- Everybody can hear you. There is no privacy on PMR446, and the sub-channel codes do not provide any: they only stop your set announcing traffic you are not interested in.
- Agree a channel and a check-in time in advance and write them down. See meeting points and a household plan.
CB radio is licence free in the UK and gets further than PMR446, particularly with a decent aerial, and it has an established road and rural user base.
Amateur radio
The only route to genuinely long-distance two-way communication that a household can legally have.
It requires an Ofcom licence obtained by examination. The entry level Foundation licence is deliberately accessible: the syllabus is short, the exam can be taken online, and the cost is modest.
It is worth considering seriously if this subject interests you, because a licensed amateur with a modest set and a wire aerial can communicate across the country and beyond without any infrastructure whatsoever. Amateur operators have a long history of carrying emergency traffic when other systems fail.
It is not something to acquire during an emergency. The licence takes study, and the skill takes practice. Either do it now or accept that receiving is your capability.
In a genuine emergency, the rules permit transmission to save life on any frequency by any means. That is a real provision and it is not a licence to practise beforehand.
Getting a better signal
Costs nothing and often makes the difference.
- Height and a window. Radio waves do not like walls, and moving to an upstairs window frequently transforms reception.
- Extend and orient the aerial. For FM, the telescopic aerial is directional: rotate it. For MW, the aerial is a ferrite rod inside the case, so rotate the whole radio instead, which is why turning a radio changes AM reception.
- A long wire helps enormously on shortwave and MW. Several metres of ordinary wire clipped to the aerial or draped out of a window will pick up stations an internal aerial cannot.
- Get away from electrical noise. LED lights, chargers, switch-mode power supplies, dimmers and solar inverters all generate broadband interference. Turning things off in the house can raise a station out of the noise.
- Listen at night for anything distant.
- Use headphones, which extends battery life considerably and helps you hear a weak signal.