Something in Crystal

I fancy something a little more lighthearted having depressed myself with the numbers game of dying in the UK this winter (Winter Deaths) so here’s how to make a simple.


A battery free radio useful for listening to AM broadcast radio stations in your local area.

Why this?
Sometimes the fiendishly complicated modern radio gear fails.
Add a EMP pulse and no matter how much the “experts” bleat about they’ll put their radios in steel boxes, etc, a lot of us “normal” people won’t. Once a radio is fried, that’s generally it with modern electronics.

In a time where you can’t just send it a way or wave a credit card round, you’ll be left with two choices. Fix it (often WAY BEYOND the skill set of the average person) or replace it with all the logistical let alone financial problems that will introduce.

So, it’s useful to know how our “ancestors” played with radio WAY WAY back in days where life was lived at a gentler pace.

So, here is how to make a schoolboys crystal radio aka foxhole radio.
Funny thing about this one compared to all the sophisticated digital high-tech stuff out there? No batteries, and it’s EMP proof.

Questions & Answers 

  • No you can’t talk to people with it.
    You can only hear AM broadcast radio.
  • No you don’t need to license it
  • No you don’t need a degree or college diploma to make it.
    I made my first one aged 8.
  • What about the components? Look round the house and garage.
  • No you don’t need soldering irons.
    On mine? I just twisted the wires round each other and held the joints using thumb tacks into a little piece of board.
  • No in-depth instructions to follow apart from the picture.
    Most moms will manage this very well as they often make the best “junkyard engineers” well-practiced fixing and making things for the kids.
  • As people seem to love lists:
    Wire, enameled or “varnished” about 40 feet is best
    Toilet roll paper center *ideal size, found world-wide
    Razor blade *doesn’t have to be hard backed
    Cigarette lighter to heat the blade to a “blue color”.
    Ordinary graphite Pencil tip * BIC / Biro pens won’t work
    Safety pin round 1″ to 1 1/2″ in length
    Tacks – A bit of board
    Crystal Ear-piece


Click to enlarge

Easy to construct, it can be a little FIDDLY to get it going and will usually only pick up the closest AM radio station. At night, it may pick up more than you’ll be able to make out clearly!

The piezo sounder came from an old home telephone BUT you can find these things in all manner of beeping, trilling, ringing, alarm type thingies. The only complicated bit when using a reclaimed sounder is the resistor. Look for the color banding. It should read (working from one end ) BROWN, BLACK, YELLOW. You MAY get away with a lesser size of resistor which is identified as BROWN, BLACK, ORANGE (10 K ohms)
If making the “speaker” is too complicated, too fiddly for you to make I completely understand. I included it because you never know if you’ll need to know how to make one. So instead of that, use a simple crystal ear phone.

To buy a Crystal Ear phone is only a few $’s from Radio Shack (Tandy) or Ebay,
The advantage of having a crystal ear piece in your survival kit is it works with a lot of different radios AND doesn’t use a lot of power. (Caution. when plugging in to a conventional radio, TURN THE VOLUME TO NIL AND SLOWLY INCREASE IT!)

That’s good OPSEC to use an earpiece. After all why broadcast your location?

Why is that important?
I was wandering through the woods one night trapping rabbit and luckily the game keeper had his “walkie-talkie” clipped to his belt to communicate with his “mate”. It crackled and spoke to him. I heard it, he cursed, I got away!

Don’t forget to heat the razor until it “blues”, or, if it is NON stainless steel, rusty seems to work too!

Use only light pressure of the graphite pencil stub is needed. It will be very quiet using a salvaged telephone sounder. Better to use a crystal ear piece.

The wire you’ll find in all sorts of things.
From door buzzers to electric motors. Look for the “varnished” type wire. It should be slightly less thickness than the safety-pin you’ll be using. Only scrap the varnish off the ends you twist together.
As for holding the “coil” on? Duct tape!

Long aerials work a treat, the longer the better.
An aerial is just a long bit of wire NOT TOUCHING or connected to the ground.

Don’t use it in a lightning storm, you could get fried by a lightning strike.

Yes it is VERY quiet and PROBABLY poor sound quality with a DIY earphone.
There again with the junk coming out of radios nowadays, that could be to your advantage.

I mentioned above that you can buy kits.
They are available mainly from the Internet BUT that wasn’t the idea of this article. This is a REALLY basic thing to make from what is scrap material.

So that’s it.
A bit of fun for the technically interested.
For me it led into getting interested in all sorts of radio bits and pieces.
I stopped short of becoming a radio ham though, too many ‘stuck up’ idiots.

To REALLY upset the radio hams, find me on 27.555 MHz USB.
C/S 26FB962, Yes, I’m one of those radio bandits!


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