How can I build a radio from almost nothing?

Answer 1

It depends on what you mean by "almost nothing." The most basic type of receiving circuit is what is called a "tank" circuit, which is a resistor/capacitor network placed between an antenna and a ground connection.

You have to have a diode to create the voltage drop to power an earphone. You can make a lot of the parts if you have some cardboard, metal foil, and enamelled copper wire. You can make the capacitor by urinating on a 4 inch square of corrugated cardboard and sandwiching it between a piece of lead foil and a piece of copper foil.

You can make the tuning coil out of a 6 inch length of cardboard tube and some enameled copper wire, with a wiper made from a strip of springy steel.

You can make the diode out of a piece of metallic germanium with a "cat's whisker" made of very fine hard drawn iron wire.

You might even make your own ear piece if you had the right piece of springy metal to make a diaphragm and some 30 gauge enameled wire to make the coil and a piece of soft iron the right size and shape to make the core of the coil.

So this is what it takes. It's hard to explain without pictures, but you can find them on the internet, if you do a search on "crystal radio." It will not be very loud, and it can only pick up strong local AM stations. But it works.

The classic crystal set and how to make it was described in the Boy Scout Handbook in the 1940s and 1950s. They used pickle juice instead of urine, but we swore it got better reception with a wee-wee capacitor. You might find the old handbook at a yard sale, flea market, or used and rare book store.

By the way, "HAM" is short for "amateur," and refers to Amateur Radio. Radio amateurs build sophisticated equipment using much more than "almost nothing," but if you want to understand these things, the hobby of Amateur Radio is a good starting place.

You can do an internet search on "amateur radio," or go to the American Radio Relay League's web site.

Answer 2

The professor from Giligans Island used a coconut shell, palm tree leaves, and a transistor from broken parts from the ship.

I've seen books at Amazon.com on how to build a HAM radio. Not sure what HAM stands for.

Answer 3

parts speakers plug ins