The John Adams Crystal Radio Kit is an educational kit first manufactured by the John Adams Trading Company in 2004 in China. The kit contains a complete set of parts to build a working crystal radio. It comes with a crystal earpiece, variable tuning capacitor, ferrite rod, ferrite coil, springs, germanium diode, and wires. The antenna coil has two taps marked long and short to cover different bands. The kit comes with a comprehensive 6-page booklet showing how to assemble the radio, circuit diagram, and tips on how to improve the reception.
Crystal Radio Kit Review
This is a nice little crystal radio kit in a similar style to those early Tandy and Radio Shack ones that I remember from my youth. The fabrication of the springs and base panel is to a good standard. The crystal earpiece is loud and clear, and overall the radio performs well after a little modification.
With the correct diode, I was able to receive some nice strong stations. The ferrite coil and tuning capacitor are of good specification providing reasonable selectivity.
Building the Kit
This was a well thought out and designed radio, and the building instructions were clear to understand. The circular part is made of thick card with punched holes. All you have to do is to install the springs, wires, and components. The interconnecting wires usually connect from the underside to keep the front uncluttered and clean.
You will need to pay special attention to the antenna coil and installation of the ferrite rod. The photograph on the box is not correct; however, the manual shows the correct way to install it. The following pages in this multi-page article might help in the build so you can have a working radio to enjoy.
Cost / eBay
I bought this on eBay for around five pounds and thought it was good value. Buying the components such as the crystal earpiece, tuning capacitor, and ferrite rod individually would have cost far more, hence I thought it was a good deal.
I came across some minor issues such as the diode not being germanium; however, this article will help iron out these issues so that you can have a working radio. If you bought one of these and it never worked for you then this article might help.
The crystal earpiece is a very good design and is very loud. The ferrite coil and tuning capacitor are also very good specification and I was able to receive four stations that were clear and strong.
This Article Continues...Crystal Radio Kit John Adams
John Adams Crystal Radio Kit Diode
John Adams Crystal Radio Kit Crystal Earpiece
John Adams Crystal Radio Kit Variable Capacitor
John Adams Crystal Radio Kit Ferrite Coil Wiring
John Adams Crystal Radio Kit Manual
John Adams Crystal Radio Kit Parts
John Adams Crystal Radio Kit Box