Where can I find coke (coal)?

I am building a crystal radio but I need to find a piece of coke...  Can I make it somehow?

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lemonie7 years ago
Coke isn't what you need I think, but if it is- bake coal in a sealed container (keep air out) to red-hot, then let it cool without exposing to air.

L
jtobako lemonie7 years ago
You don't need the sealed container-that's for charcoal, not coke (and not nessisary there, either, unless you need a high yield or are doing something like vine charcoal).  For coke, you burn the volatiles out of coal in an open fire-when the coal bubbles and goes to glowing red, that's coke.  BTW, a coal fire is not self-supporting, it will go out if there isn't a forced air supply or draft keeping it going, so you might have to keep track of your coal in a wood fire : )

It's not easy to find coal or coke, best bet is a power plant that runs on coal (like the University of Minnesota steam-heating plant) or a blacksmith that still uses coal rather than gas. 
lemonie jtobako7 years ago
I've made coke, it's like making charcoal. If you quench a red-hot coal fire with water you don't get the same thing. Blacksmiths use coke, and they might be a practical source.

L
jtobako lemonie7 years ago
I am a blacksmith-I have used charcoal and coal (and propane).  You start with coal and burn it into coke, basically like burning wood to get the good charcoal for cooking.
lemonie jtobako7 years ago
Charcoal-burning is something of an art, I'd like to do it big-scale...
Getting coal to very hot is not the same as coking-it. Coke and coal-cinders are not the same thing. Although I'm talking about coke as a material rather than a hot-carbon-fire.

L
jtobako lemonie7 years ago
Sorry, I think we are using the same words to mean different things.  As I learned the terms, coke is to coal as charcoal is to wood. 
Erm... not a totally sealed container, right?  Specifically what I'm worried about is pressure building up from whatever gasses come off the coal, and then the container exploding because it cannot contain this pressure.

I'm guessing that what you have in mind is a homemade retort,sort of like these for making charcoal:
https://www.instructables.com/id/Drawing-Charcoal/
https://www.instructables.com/id/mini-charcoal-maker/
https://www.instructables.com/id/Make_your_own_BioChar_and_Terra_Preta/
https://www.instructables.com/id/How-to-Make-some-Charcoal/

At the same time it is desired that the poor seal is not so leaky that the gasses surrounding the coal are of oxidizing character, like pure fresh air would be.

Let me know if I've got it wrong, and that's not what you're talking about at all.
mirzah17 years ago

There is no coal or coke in a Crystal Set, Probably what you want is the crystal made of Galena which does look like coal-- may be hard to get now, but you can use a high frequency Diode instead as the Detector.

jtobako mirzah17 years ago
There are several ways to get the detector-galena is one, but so is the rust on a razor blade or a chunk of coke. 
Jaycub7 years ago
If you need a piece of carbon you could probably get away with using some charcoal.
mirzah17 years ago
P.S. Try thttp://oldheadphones.com/crystal/index.html for info