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The awesome Craig Smith is at it again. He continues to explore the venerable crystal radio, now focusing on miniaturization. And that, of course, means on thing: Mint Tin Crystal Set! Craig writes…

I’ve made a half dozen battery-free crystal radios in about eight weeks. But I always wanted to try to stuff one inside of an Altoid tin for on-the-go. The short ground wire and long antenna wire that connect via an RCA plug, store neatly inside the tin. The 2000 ohm crystal earphone would fit in the tin if the long tube was chopped off. 200 turns of a 27 gauge wire on a 5/8” cylinder gets me tuning in the upper AM band. Perhaps I need to include a 3” copper ground spike to get a good ground in the field. Or would clipping onto a damp root be a better ground? Input?

Input?

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Gareth Branwyn

Gareth Branwyn is a freelancer writer and the former Editorial Director of Maker Media. He is the author or editor of a dozen books on technology, DIY, and geek culture, including the first book about the web (Mosaic Quick Tour) and the Absolute Beginner’s Guide to Building Robots. He is currently working on a best-of collection of his writing, called Borg Like Me.


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Comments

  1. I’m hoping the next version includes HD radio.

  2. Very cool. Crystal sets are a lot of fun. I wonder if you could have a fixed coil, use a trim capacitor mounted through the tin and replace the cat’s whisker with a diode? I may try that myself. I have played with various antenna, ground scenarios. You could use a cold water pipe, assuming its metal. However, an 8′ ground rod is typically recommended. A lot will depend upon the soil conditions in your area. I don’t think you will have much luck with a 3″ spike, but I would try it anyway. Get your antenna up as high as possible.

  3. Lance Drew says:

    Nice one! truly a great innovation. I wonder will the next issue be internet compatible so that I could connect to online radio so that it can cover hundreds of station. =)

  4. Dave Brunker says:

    Shinyyyyy… @_@ I’d love to build one.

    What I used for grounding was a ground clamp on the cold water faucet in the kitchen. Wife is mildly irritated by it but as long as I keep the wire running behind the faucet and around the baseboard she tolerates it. Here’s one example from a hardware store. http://www.homedepot.com/h_d1/N-5yc1v/R-100154668/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

  5. HC Smith says:

    Are there plans for this available online? I am a beginner and would love to recreate this. Thanks!

    1. Craig says:

      For a beginner start with a bigger set. There is a yahoogroup for crystal radio building. Also a website called STAY TUNED has dozens of plans, several for the beginner. Nothing like pulling in a station on a first build with no batteries and a piece of fools gold (pyrite) for a crystal. As the hobby continues, Galena crystals, Germanium diodes, dual coils, …