The Radio of Last Resort

Should power in your area go down out in times of crisis, this radio of last resort (the most elementary emergency radio possible) could be a life saver for you. Depending on your age, you might have heard of a crystal radio kit. This may have been used by your great grandparents or possibly mentioned in a high school science class.  

Intro to AM Radio Technology

This vintage and mostly unchanged technology allows you to receive AM (Amplitude Modulation) radio stations without using any electricity or batteries.  You would be able to obtain weather information. You can also receive other emergency messages broadcast from any operational AM radio station up to about 100 miles away.  Today we are almost fully reliant on the internet as a basis for our communications. This also requires keeping our power grids across the country up and running.  What would happen to things if our internet and cell towers go down due to cyber-attacks or even worse? 

Where to Buy a Crystal Radio

Brand new crystal emergency radio kits are available on eBay and are relatively inexpensive (about $30). You need a long antenna wire and also a shorter earth ground wire.  A spool of wire (aka magnet wire) costs about 5 dollars, also available on eBay and will cover both.  A very long antenna wire is required to capture the weak radio wave energy.  One spool of very thin copper wire (50 feet) is cut into two lengths. One end is for the antenna (30-40 feet), and one for the earth ground wire (10 feet or so) .  Also, make sure your radio kit also includes an earpiece. A special earpiece operates on the very low power signal so you will not be able to use a wired traditional headphone set you might already have.      

In case you were wondering, why have a last resort radio if power grids are down and a major crisis is on hand? Well, there is a good likelihood that some radio station many miles away will still be broadcasting to provide important information.  In the US, the Emergency Alert System (EAS) is a national public warning system. This requires radio and TV broadcasters (including cable and satellite operators) to provide the US President with capability to address the American people within 10 minutes during a national emergency.  This system allows the civilian population can be alerted to natural disasters. It can also alert you for acts of terrorism and other man-made disasters or threats to public safety.

How does a Crystal Radio work?

So how does this radio work? Radio waves transmitted through the air from the broadcast station contain energy. This radio (using an extra-long wire antenna) captures the tiny amount of energy in the radio wave, tunes it to a specific frequency (radio station), and then converts it to sound. The radio includes a mechanical tuner (aka a dial) to select the station you want and listen with an earpiece.  

The radio consists of a small board with electronic parts soldered to it, screw type posts to connect the antenna and ground wires, and a jack to plug-in an earpiece. Set-up is straightforward.  A short wire (cut a length from the wire spool) will connect to earth ground by attaching it to a metal stake driven into the ground. You can also alternatively connect it to your house copper water line. This is typically near where it enters your house (usually in the basement). The other end attaches to the ground post on the crystal radio.  The antenna wire connects to the other post. It extends out to its fullest length (a great place is in your attic). 

Conclusion

To set your expectations, this technology is ancient in comparison to today’s modern technology (iPhones, internet, satellite) but it absolutely does work.  A crystal radio is a novelty item and very few people know about it. But you do know about it, and hopefully understand why you should obtain one because it’s truly a radio of last resort. An emergency radio should be part of your emergency plan.

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