Build Your Own Crystal Radio Kit

Science Buddies staff scientists worked long and hard and with selectivity to develop a crystal radio kit that will:

1. make your radio project successful, and
2. avoid the many problems of the amateur radios at toy stores that are called "crystal radios"

With this Crystal Radio Kit, you will become a radio experimenter as you learn the basic radio circuit elements required for receiving radio signals. Plus, you'll be able to listen to AM radio broadcasts with something you made yourself!

What is a crystal radio?

From the Science Buddies Website: 

A crystal radio is a very simple radio that was popular in the early history of radios. It is an electrical circuit that can pick up and play sound from AM radio stations. Rather than rely on outside electrical sources, like batteries or plugs, crystal radios get their power directly from the radio waves. The parts of a crystal radio include an antenna, a tuning coil, a diode detector/crystal detector (labeled as "detector"), earphones/earpiece, and a connection to an electrical "ground."

What makes this crystal radio set different from all of the others out there?

• Easy-to-understand online instructions with lots of pictures, making this an excellent and simple crystal radio for beginners.
• A pre-assembled amplifier/speaker unit and connecting cable, which enables you to hear stations much more easily than with the traditional ceramic earbud used in most crystal radio kits. We tried many options and found the speaker allowed for easier set up of the antenna and testing of the radio.
• Predrilled holes for easy assembly of clips to the wooden base.
• A heavy-duty coil form that will stand up to practically anything imaginable, so you can continue using your homemade crystal radio long after your project is completed.
• Pre-punched holes in the coil form make it extremely easy to wind the wire.
• Professional-quality, nickel-plated brass clips for all connections, making them secure without the need for soldering.
• Wire for the outdoor antenna, which many others charge extra for.

This crystal radio kit provides the perfect set up for an engaging science fair project! Discover how to build a crystal radio receiver with Science Buddies' detailed online instructions: Build a Crystal Radio. Next, experiment to see how many AM stations you can receive, how far they are from your location, and the radio frequency they are broadcasting on. Learn by building a high-quality, durable crystal tube radio that you can actually use for years to come!

Instructions for this kit are available online. See below for links to the instructions and more.

You will also need from home: 

• Philips head screwdriver
• Metal grounding rod; this can be an exposed metal water pipe, metal fence, or a 3 foot length of copper pipe from the hardware store
• Plastic zip ties
• Wire cutters or a strong pair of scissors
• Double sided tape
• 9V battery 
• Masking tape
• Permanent marker
• Access to a yard, park, or other open space

Instructions are NOT included with the kit, but are available online from Science Buddies.

If you have questions about your kit, please see the following FAQ article from Science Buddies:

• Build Your Own Crystal Radio FAQ

• 1 1N34A germanium diode
• 1 120 picofarad ceramic disc tuning capacitor
• 1 82kΩ, 5% ¼-watt carbon resistor
• 1 105 feet 22 AWG enamel-coated magnet wire
• 1 Cardboard tube, 2 ⅛ inches diameter, 4 inches long
• 4 #6 nickel-plated Fahnestock clips
• 7 #6 x ½ inch screws
• 1 #6 washer
• 1 #8 x ¾ inch screw
• 2 #8 washers
• 1  ⅛ inch inner diameter black plastic knob
• 1 Brass rod, ⅛ inch diameter, 7 inch long
• 1 Mono audio cable
• 1 Mini audio amplifier
• 1 Wooden mounting board
• 1 2" square sandpaper, fine grit