Hi I have a friend that son wants to build a crystal radio. I seam to
remember that we grew our own crystal back in the early 60 any help?? Also
where can I find a 1n34 quick have 2 weeks for his science fair.


ka6pnl

Ed
NAS Lemoore

KA6PNL wrote:

Hi I have a friend that son wants to build a crystal radio. I seam to
remember that we grew our own crystal back in the early 60 any help?? Also
where can I find a 1n34 quick have 2 weeks for his science fair.

Hi Ed,
I have an 1N34 (or perhaps it is an 1N60) that I will ship you if you post
me your address. As far as growing one, I don't know about that, but would
like to hear if anyone posts you that info.

72

Bob WB0POQ

On Tue, 05 Apr 2005 02:59:50 GMT, "KA6PNL"
wrote:

Hi I have a friend that son wants to build a crystal radio. I seam to
remember that we grew our own crystal back in the early 60 any help?? Also
where can I find a 1n34 quick have 2 weeks for his science fair.


ka6pnl

Ed
NAS Lemoore

I don't know about growing a crystal, but the most popular choice is
Galena. Iron pyrite and some other minerals also will work. Heck, an
old Gillete "Blue Blade" or other thin double edged blade will work to
some extent, ala the WWI foxhole radios.

One of the nurseries here in Atlanta sells minerals for decorative
purposes. You can order a Galena crystal already mounted, as well.

Acouple of web sites to check out are
The Crystal Set Society http://www.midnightscience.com/

Crystal Radio Resources http://www.thebest.net/wuggy/

Ted KX4OM

Here you can find some nice materials:

http://www.scitoys.com/scitoys/scito...o.html#crystal

cheers

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.
--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

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.

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.

Al

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.

KA6PNL wrote:

Hi I have a friend that son wants to build a crystal radio. I seam to
remember that we grew our own crystal back in the early 60 any help?? Also
where can I find a 1n34 quick have 2 weeks for his science fair.


A silicon diode will work, it won't be as sensitive but you can get one
at the local Radio Shack (they carry germanium diodes off and on, so
they may have some).

If you're using germanium diodes get some spares -- I've found them very
susceptible to lightning strikes, at least in the circuit that my son
and I built.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Speaking of diodes...

Is there any reason you can't use the so-called "zero Vf" microwave Schottky
diodes for a crystal radio for the AM broadcast band? Is it just expense
that keeps people (in a hobbyist capacity) from using them?