Thread: Crystal radio
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Old April 7th 05, 05:53 PM
clvrmnky
 
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On 07/04/2005 8:50 AM, Al wrote:
In article ,
wrote:


We dropped molten solder in a pile of sulpher in a bottle cap.
On 5 Apr 2005 20:45:34 -0500,
wrote:


When I was in high school (many MANY years ago), a classmate of mine
"grew" his own crystal by melting (IIRC) lead and sulfur together.
It was an ugly-looking mess, but it worked.



You were making "galena" which is PbS, Lead Sulfide. I used one for my
first crystal radio in the 50's. Had to find a sensitive spot. You might
be able to find some in a hobby shop (If you can find one.) that deals
with minerals.

You might also try a "blue blade" razor blade. The GIs used them in WWII
for making foxhole radios. The bluing produced a chemical (unknown to
me) that rectified the signal.

For this purpose, almost any anodized metal should suffice. The "Blue
Blades" were, AFAIK, simply anodized and polished high-carbon steel.
The aonodized surface would be covered with fine steel-oxide crystals.
I wonder if anodized aluminium would work? I'm theorizing here that we
want some sort of crystal to interact with a base conductor.

This kind of thing is still done for some special "blue" hack- and
reciprocating saw blades. I think there are even circular saw blades
that are anodized in a similar way. These would be expensive and hard
to come by. I'm sure people will pay to get them rebuilt rather than
toss them out, and I have no idea how an average tinkerer might easily
cut pieces of a think saw blade up!

However, if you can find a hacksaw blade treated in the same manner,
this give supplies for a number of experiments.