The Tesla Spirit Box, also known as the "Spooky Tesla Spirit Radio," is a fascinating device that Nikola Tesla himself found intriguing. It uses a simple crystal radio circuit connected to a computer sound-in jack to generate eerie sounds from various electromagnetic sources. Tesla was reportedly terrified by the mysterious and seemingly supernatural nature of the sounds he observed.
Materials Needed
Here's a list of materials you'll need to build your own Tesla Spirit Box:
- Small Jam Jar (Mason Jar) with a large mouth
- 3 1/4 inch diameter Plexiglas (or polycarbonate) cover lid, 1/8 inch thick
- C1 - 60/141 pf Variable Capacitor (Available at Mike's Electronic Parts # VARCAP141)
- L1 - 680 uh Ferrite Loopstick Antenna (ComtrolAuto #LSA680-1)
- Extension Shaft and Knob for the variable capacitor (ComtrolAuto #ExtKnob-1)
Or you can pick up most of the components in a kit provided by Mike's electronic parts.
Spooky Tesla Spirit Radio Parts Kit
Building the Spirit Box
While detailed instructions for building the radio in 17 steps can be found on Instructables, here's a brief overview of the process:
The Spooky Tesla Spirit Radio is essentially a crystal radio circuit housed in a jam jar. It's designed to plug into a computer and produce sounds by responding to electromagnetic fields or light sources in real time.
The basic L-C (Inductor-Capacitor) circuit used in this radio is similar to the schematic that Tesla experimented with in his early days. The versatile 1N34A crystal germanium diode used here substitutes for the rotating nickel detectors and sensitive relays that Tesla used in the late 1800s.
Once the radio is assembled, you can use a program like Audio Hijack Pro (for Mac) to tweak the radio's output at the computer, creating some great real-time sound effects. You can also record these sounds at the same time.
Applications of the Spirit Box
The Spooky Tesla Spirit Radio can be used to listen to AM broadcasts, but it's primarily designed for fun and experimentation. For example, it can react to lightning, radio frequencies, the light spectrum, the computer screen, RF pulses, electromagnetic fields, and more.
In one demonstration, the Spooky Tesla Spirit Radio was used to give voice to a Mac Hyperspace screensaver. The simple crystal circuit is apparently sensitive to the screen synchronization RF frequencies, providing awesome background sounds.
Conclusion
Building a Tesla Spirit Box is a fun and educational project that allows you to explore the fascinating world of electromagnetic fields and radio frequencies. Whether you're a Tesla enthusiast, a science hobbyist, or just someone looking for a unique DIY project, the Spooky Tesla Spirit Radio offers a unique glimpse into the mysterious and often unseen world of electromagnetic energy.