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Set 5

This is paraphrased from the article "How to Build a 'Foxhole Radio' ", from All About Radio and Television by Jack Gould, Random House, 1958. The book is long since out of print, and too dated for most libraries to hold a copy. It is a simple set, but curiously it does not include a slider for the coil, even late in the article after the razor blade is dropped for a crystal and a condenser is added.

Tools required are:

A hammer
A pair of pliers
A pocket knife


Board, at least 8 inches by 6 inches (200 by 150 mm)
Cardboard tube, 2 inches in diameter by 6 inches long (50 mm by 150 mm)
Insulated (enameled) copper wire, 28 gauge
Pair of crystal earphones (which in 1959 cost 2-3 dollars U.S.)
3 new nails
4 metal thumbtacks (not plastic push pins)
A used blade that fits a safety razor. A plain white looking blade often works better than "blue" blades (direct quote)
Big safety pin
Pencil with a fat lead

Make 4 little holes in the cardboard, 2 at each end, with one of the nails. Push about 6 inches (150 mm) through hole 2, and then pull the wire up through hole 1. Wind the wire around the tube, making sure the turns lie side by side and not on top of one another. Wind for a total of 120 turns. Afterwards measure off 6 more inches of wire at the end and cut. Push the end of the wire down through hole 3 and up through hole 4. Lay the coil on its side at the back of the board. Fasten it to the board with 2 thumbtacks, making sure the thumbtacks do not touch any of the wire.

The razor blade is placed in front of the coil. Lay it on the board, and gently fix it in place with two metal thumbtacks. Do not push the thumbtacks all the way in.

Sharpen the pencil so there is a long piece of lead showing. Break off the lead, and wire it to the tip of the safety pin. Bend the head of the pin back so that it will lie flat on the board. Place the pin to the right of the razor blade. Hammer a nail through the head of the pin until it almost touches the pin.

Remove the insulation from the ends of the wires coming from the coil, as well as from the ends of all wires used to make connections. Hammer a nail just to the left of the coil. Leave it sticking up just a bit. Wrap the bare wire from the end of the coil around this nail. Take another wire and wrap a bare end around the thumbtack holding the left side of the razor. Push the tack all the way down to make contact. Take the other bare end of the same wire and wrap it around the nail.

Hammer a nail to the right of the coil and attach the coil wire as above. Use another wire to connect from this nail to one of the terminals of the earphones. Take another wire and wrap the bare end around the nail holding the safety pin. Hammer this nail in to hold the wire in place, but not so tightly that the pin cannot move a little. The other end of this wire attaches to the other free end of the headphones.

The antenna attaches to the nail that connects with the coil and razor blade (A). The ground wire attaches to the other nail, where the coil connects with the earphones (B). Hook up the headphones, and gently move the pin and pencil lead across the razor blade until you hear a broadcast. Once you hear it, don't move the pin, because you are more than likely going to lose it if you do. If there are more than one stations nearby broadcasting near the same frequency, you are likely to hear overlap. To solve this, you can add a condenser. A variable type can be used, as in the illustration. It is recommended that it have 17, 19, or preferably 21 plates. Or you can use a fixed capacitor of around .002mF, or you can build your own (see the condenser article on the Crystal page). If a variable condenser is used, the post attached to the fixed plates should be connected to the nail that connects the coil to the blade (A). The condenser's other post is attached to the other nail (B). Once a station is found using the pin and blade. The condenser is turned until the signal becomes clearest. Also note that in the illustration a crystal and detector have been substituted for the razorblade. The wire that was attached to the blade is attached to the crystal's post, and the wire that was attached to the pin is attached to the detector's post. A safety pin can still be used instead of the cat whisker (see the introduction of the Crystal page).

2 posted on 11/05/2004 10:51:32 PM PST by snippy_about_it (Fall in --> The FReeper Foxhole. America's History. America's Soul.)
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To: shield; A Jovial Cad; Diva Betsy Ross; Americanwolf; CarolinaScout; Tax-chick; Don W; Poundstone; ..

"FALL IN" to the FReeper Foxhole!

Good Saturday Morning Everyone.

If you want to be added to our ping list, let us know.

If you'd like to drop us a note you can write to:

The Foxhole
19093 S. Beavercreek Rd. #188
Oregon City, OR 97045

3 posted on 11/05/2004 10:52:35 PM PST by snippy_about_it (Fall in --> The FReeper Foxhole. America's History. America's Soul.)
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To: snippy_about_it; Denver Ditdat
Great thread today Snippy. This is a crystal radio Spiderboy and I built last winter.

The chasis with circuit schematic carefully applied.

Winding the coil

Coil taps for limited tuning.

The complete radio. The the candy striped wire running to the left is going to a cold water pipe. The antenna was snaked out behind.

Have I ever mentioned the Telegraph ssytem we have in the house?

71 posted on 11/06/2004 1:36:54 PM PST by Professional Engineer (Those who can, do. Those who can't, vote democrat.)
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To: snippy_about_it; SAMWolf; Neil E. Wright; Iris7; Aeronaut; E.G.C.; alfa6; Samwise; aomagrat; ...

Borden Radio Company

Several people wrote in to QST magazine about foxhole radios during World War II. Among those was young Lieutenant Paul M. Cornell, W8EFW, who wrote of a design he used in the Pacific in 1945. It was one of the first such articles that mentioned using a pencil lead for a contact. This Borden Radio Company kit is named after him in appreciation for his article in the September, 1945 issue of QST Magazine.


Also, build McGuyver's transpacific fiber optic decrypto tap and satellite uplink using one (1) each Paper Clip, tomato soup can (it's the acid), a Dixie Chicks cassette pulled out and wrapped tightly around John Edward's neck brace (John Edwards not included).


This afternoon Innovations (sponsored by Siemens) covered the development of the fiber optic cable, noting that more capacity exists than is being utilized, encouraging all patriots to blog more, post more graphics, use five servings of Blackberries a day.

PSAs being produced using celebrities, e.g., Jonnny Five, Data, holograms of Isaac Asimov.


What Ronald Reagan was to the Cold War, so will George W. Bush be to the War on Terror. Now this:

82 posted on 11/06/2004 6:38:51 PM PST by PhilDragoo (Hitlery: das Butch von Buchenvald)
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