View single post by ArizonaEvp
 Posted: Sep 1st, 2012 06:34 AM
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Joined: Jun 26th, 2009
Location: Heart Of Arizona Indian Country, Arizona USA
Posts: 662
Slider2732 wrote: Thanks Joe..kinda spendy at $6.84, but at least they do have them :)

I'm growing piezo crystals at the moment, in the hopes of making an earphone in the future (Baking Soda/Cream of Tartar method). But, more realistically, am looking at piezo flat buzzers from greetings cards etc. Will build an enclosure and see how it goes.
Just tried out a crystal radio build and the original telephone handset speaker works fine, so am going to use that for the meantime.

Does anyone know what the original core for the coils was made of ?
I'm going to be using ferrite, larger than the original coils above for more turns...but just wondered if it was indeed ferrite on the original.

Hi Slider,

The earpiece from an old telephone will work just fine. can use meteorite for a detector.  Pyrite is metallic and so is galena.  Remember those "foxhole" crystal sets.  They used a razor blade and pencil lead for their cat whisker.

I looked around the net and didn't find any info on they made their coils.  I suppose one could always contact them through their website.