In the 1921 world of sports, California beat Ohio State in a 6-0 thriller at the Rose Bowl, and in a bizarre preview of World War II, the U.S. tennis team retained the Davis Cup, smashing the Japanese 5-0. But what was really interesting that year was the New York Giants beating the New York Yankees in the World Series. The most unique historical fact of the series was not that George Steinbrenner couldn't be blamed for the defeat, but that it was broadcast for the first time on radio. The station was WJZ in New York.

One of the most popular radios in that day was a crystal set made in Pittsburgh by Westinghouse called the Aeriola. In an early example of "horizontal integration," Westinghouse also owned radio station KDKA which that year was enjoying its status as #1 in drive time with all of the best demographics. Of course, it was also the *only* station in town.

It was a time of great blessings in the fledgling radio industry: there was no Larry King, no Don Imus and no Howard Stern. And while radios were considered expensive (US$25 for the Aeriola), they were easily built at home with readily available parts. Tens of thousands of radio fans did just that, using diagrams and articles found in newly launched wireless magazines, and joining dozens of radio clubs whose rosters swelled by the month.

Now if this scenario sounds the least bit familiar, it ought to: this was the *first* electronics revolution, the first paved lane of the information superhighway. Millionaires were made overnight, fronting start-up companies who plunged into the uncharted waters of electronic delivery of media. There were hucksters, preachers, politicians, celebrities, and everywhere you tuned, there were ads. The curious thing is that, seventy-seven years down the road, the nature of AM radio remains virtually unchanged. And even though FM radio was supposed to bury AM, these ethereal properties have retained their premium price tags.

So little have things changed that it's actually possible to build a near duplicate of the old home-made crystal sets and tune to today's AM signals. What's more, with a few minor changes, you can also tune in world wide radio on the short wave bands. In fact, when I built my first set, I wired it up incorrectly and ended up not on the AM band but on short wave. The first station I heard was an English transmission of Radio Japan!

Click on the image above to view a diagram of the radio.

You can buy complete crystal set kits from a number of venders, but I say, "Don't do it!" Not only is building your own crystal set fun for the whole family, but it's easy to do and can be done for $30-40 (or less depending on what you can find in your junk box). Why, you can have your set up and running in less time than it takes to program your VCR!

Here's what you need:

1) An oatmeal box (ah...minus the oatmeal). Quaker Oats gets the best reception :-) (And the Quaker Oats box is almost identical to the ones they made in 1921.)

2) 40-50 feet of 22 gauge enameled magnet wire (Radio Shack #278-1345 $4).

3) A 1N34 crystal diode (RS #276-1123 10 for $1).

4) 6 Fahnestock clips (Antique Electronic Supply #SH-11-4034 $1).

5) A 365 pf variable capacitor (AES #CV-235 $11).

6) A 5" x 7" piece of pine board.

7) A couple of feet of 18 gauge insulated hook-up wire (RS #278-1220 $4).

8) A set of 2,000 Ohm earphones (from AES or Xtal Set Society for about $15) or a high impedance crystal earphone which is less sensitive but $10 cheaper (from AES).

For a really cool "authentic" look, route the edges of the pine board, stain and varnish it before you start the project. Stick rubber feet on the bottom (RS #64-2346). Antique radio trivia: In the old days, folks swiped Mom's breadboard from the kitchen to build their electronic gizmos, hence the term "breadboard," still used today to indicate a surface on which electronic parts are mounted.

If you've got kids around the house in the 6-12 year old category, consider doing this with them. You'll all be amazed at the magic of building your own radio. Using the diagram shown, screw the Fahnstock clips in place. Wind ten turns of the magnet wire around the outside of the oatmeal box (top coil). Punch two small holes in the box at the top and bottom of the winding through which you can slip the bared ends of the wire. This will allow a little tension on the wire as you wind. Now wind thirty turns of magnet wire an inch below the top coil. Again punch two small holes in the box at the top and bottom of this bottom coil. Winding is the hardest part of the whole project and you may have to do it several times before you get it right. Try not to overlap the winds.

Next, attach the tuning capacitor and the box to the breadboard. Cut all the hook-up wire you'll need to size and bare both ends of all the wires. The reason for using the Fahnstock clips is that you won't need to solder and you can take the whole thing apart and experiment later. Slip the diode into its clips and the two headphone clips into their clips. For best results, you should solder the connections on the tuning capacitor but alligator clips will suffice. You're done!

If you've been paying attention, you may be wondering, "Hey, what about the battery?" Well, that's what makes the crystal set so unique. It uses the power--minuscule though it might be--from the transmitting station to run the set. Think of the antenna as a net strung out to catch the electromagnetic waves emanating from the station. The wave is made up of two parts, the "carrier" and the audio which "rides" the carrier. When the wave hits your antenna, a voltage is induced. This voltage pulsates with the audio being sent on the carrier. The crystal set is simply a tuned circuit designed to resonate at the frequencies of the AM band. By adjusting the variable capacitor you may single out individual stations transmitting near the resonant frequency of the set.

Of course, for the set to work, you have to have it hooked up to an antenna and a ground. If you live in a city, you won't need much of an antenna as there will be plenty of powerful signals ripping through your house. In the country, away from broadcasters, the signals will be weaker and you'll need more of an antenna to pick up enough signal to power your set.

The antenna needs to be as long as you can make it and not connected to anything electrical. The ground can be attached to the ground rod of your home's electrical or telephone service using insulated wire, bared at the ends where it's connected to the rod and the set. Even without a ground, just using an antenna, you should be able to hear some signals.

Unless you're in a city, the best time for listening is after sundown. AM wave propagation gets better as the night wears on. Turn off any lights with dimmer switches, as the noise they put out will wipe out any signal you may receive. Computers may generate a fair amount of noise too. Turn the tuning capacitor slowly when looking for stations. Listen carefully. It helps to be in a quiet room.

The best thing about crystal sets is that there's almost no way to hurt this radio. You can have it wired completely backwards, and since there's no power supply, you can't destroy any of the components. The fun thing about crystal sets is that there's no end to the experimenting. Hundreds of designs and construction ideas have been knocking around for decades. This is only one. By reworking the coil, you can tune other broadcast bands. As long as the transmissions are AM modulated you have a chance of picking them up.

From my location in central Virginia, the night I finished my set, I picked up three New York City stations, two from Cincinnati and stations from Detroit, Lexington (KY), Cleveland and Chicago. The nearest station was Charlotte (NC), the farthest was Chicago.

The best source for further information on the subject of crystal radios is The Xtal Set Society. They publish "The Xtal Set Newsletter," many books on the subject and even sell kits and parts. An excellent source for crystal set parts is Antique Electronic Supply. They sell complete kits, parts and books. They also go a step further and have thousands of hard-to-find tubes and parts for all manner of early radios and equipment.

- Ken Reitz [8/26/98]