An EMP or a severe solar event is a low-probability, high-consequence risk, and a Faraday cage for at least one backup radio is a cheap enough hedge that it is worth doing even if you think the odds are small.
What a Faraday Cage Actually Protects Against
A properly built enclosure blocks the electromagnetic pulse that can damage or destroy unshielded electronics, whether from a nuclear detonation at altitude or a severe geomagnetic storm. It does nothing for a radio you are actively using outside the cage at the time, which is exactly why this is about a backup, not your daily-carry gear.
You Don’t Need to Buy Anything Special
A metal ammo can with a tight-sealing rubber gasket makes a genuinely effective, cheap Faraday cage, as does a metal trash can with a well-fitted lid. The key requirement is a continuous conductive metal shell with no significant gaps, not a specific expensive product marketed for this purpose.
What Actually Belongs Inside
Wrap each item individually in something non-conductive, like a cardboard box or cloth bag, before placing it in the metal container, since direct contact with the metal shell can defeat the shielding. A spare handheld radio, spare batteries, and a basic solar charger are the highest value items to protect this way.
What a Faraday Cage Won’t Fix
It protects the gear inside it from this one specific threat and nothing else. Your daily radios, the ones actually in use during any normal event, get no benefit from a cage sitting in a closet, which is why this is a supplement to your redundancy plan, not a replacement for having a working radio you actually use and practice with regularly.
Pair this with storing and rotating batteries for a backup radio that’s actually ready to go when you need it.
For the fuller picture on building real emergency communications capability, see my Emergency Communications and Preparedness pillar page.