How to Build a "Foxhole Radio"
from the book All About Radio and Television
by Jack Gould
Illustrations by Bette J. Davis
Random House, 1958
One of the things that makes television and radio interesting is that you can use right away the information you have learned.
We are going to build a radio that is different from any you have seen. In the radio will be these things:
Radios of this kind were actually used during World
War II. American G.I.'s in Italy put several of them
together. At night when they sat near the front lines,
they listened to phonograph records played on a radio station in Rome. That is why the set you are going to make is called "The Foxhole Radio." If you live within twenty-five or thirty miles of a station, you can hear a program on your foxhole radio, too.
- An old safety razor blade
- A safety pin
- A broken point from a lead pencil
These are the only tools you need to build the foxhole radio:
These are the parts that you will need:
- A hammer
- A pair of pliers
- A pocket knife
A board. Any piece of wood will do. Just make sure it is at least eight inches long and six inches wide. It can be bigger if you like.
A piece of cardboard tubing. This should be two inches in diameter, like the tubes on which ribbon is wrapped in five-and-ten-cent stores. The tube should be six inches long.
A spool of insulated copper wire. You may have to buy this at a radio store. Ask for No. 28 gauge; this is just the right size. The wire will cost about 75 cents.
A pair of earphones which you can put over your head like the pilot of a jet airplane. The phones can be bought at a radio store for two or three dollars.
Three new nails. The nails can be either an inch or two inches long. Anything you have will do.
Four metal thumbtacks, not plastic tacks
A used blade that fits a safety razor. A plain white-looking blade often works better than "blue" blades.
A big safety pin
A pencil with a fat lead
Let's put all the tools and parts on a table like this and see if we have everything before we begin:
You will need to know how the parts are used and what you must do to make the foxhole radio. This is the way the set looks when it is all finished.
First, we start with the coil.
Unwind a long piece of wire from the spool and stretch it out straight across the floor.
Pick up the piece of cardboard tubing, and with one of the nails make two little holes at one end of the tube and two little holes at the other end. We'll number the holes 1, 2, 3 and 4. Now the tubing looks like this:
Push about six inches of the wire through Hole No. 2. Now pull the wire up through Hole No. 1. You can see that the two holes give us a way to hold the wire in place at one end of the tubing.
Hold the tubing in your left hand. With your right pick up the wire and carefully wind it around and around the tube. Do this until you have a total of 120 turns of wire around the tubing. Make sure the turns lie side by side on the tubing, not one on top of the other.
After you have put 120 turns of wire around the tubing, measure off six inches of wire. Then cut the wire with your pliers. Push the end of the wire down through Hole No. 3 and then pull it up through Hole No. 4. Now you have made a nice sturdy coil that will stay in place.
Put the board in front of you on a table, and lay the coil on its side on the back of the board. Take two of the thumbtacks, and fasten the coil to the board. Make sure the thumbtacks do not touch any part of the wire.