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Crystal radio
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 |
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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? |
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. |
"Tim Wescott" bravely wrote to "All" (05 Apr 05 09:26:07)
--- on the heady topic of " Crystal radio" TW From: Tim Wescott TW Xref: aeinews rec.radio.amateur.homebrew:9149 TW 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. TW A silicon diode will work, it won't be as sensitive but you can get TW one at the local Radio Shack (they carry germanium diodes off and on, TW so they may have some). TW If you're using germanium diodes get some spares -- I've found them TW very susceptible to lightning strikes, at least in the circuit that my TW son and I built. Why bother? Get a solar cell and power a radio with it. There is more than 900watts/metre^2 free energy right outside the window. (mumbling something about "idiots"...) A*s*i*m*o*v .... Hey everbody, I am crushing your head! Crushing it! Crushing it! |
Asimov wrote:
TW If you're using germanium diodes get some spares -- I've found them TW very susceptible to lightning strikes, at least in the circuit that my TW son and I built. Why bother? Get a solar cell and power a radio with it. There is more than 900watts/metre^2 free energy right outside the window. (mumbling something about "idiots"...) A*s*i*m*o*v ... Hey everbody, I am crushing your head! Crushing it! Crushing it! How does using a solar cell prevent a detector diode from getting zapped? 73, An idiot |
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. |
"Asimov" wrote in message
... Why bother? Get a solar cell and power a radio with it. There is more than 900watts/metre^2 free energy right outside the window. (mumbling something about "idiots"...) Yeah, too bad it tends to be go away at night! :-) (And if you were just going to store it anyway, why not start with batteries in the first place?) |
"Bill M" bravely wrote to "All" (07 Apr 05 10:43:57)
--- on the heady topic of " Crystal radio" BM From: Bill M BM Xref: aeinews rec.radio.amateur.homebrew:9179 TW If you're using germanium diodes get some spares -- I've found them TW very susceptible to lightning strikes, at least in the circuit that my TW son and I built. Why bother? Get a solar cell and power a radio with it. There is more than 900watts/metre^2 free energy right outside the window. BM How does using a solar cell prevent a detector diode from getting BM zapped? By mounting the detector diode under the solar cell of course! That wasn't my point however. What I really meant to get at is that high impedance headphones (25K ohms) are hard to find these days as are germanium anything. The better alternative is perhaps the Schottky small signal diodes and a crystal earphone (which are also rare). On the other hand if one powers a small transistor radio from a solar cell charging a battery then it results in something practical. Perhaps it isn't as educational as winding your own coil on a cardboard tube of Quaker Oats and finding a Galena out in the old quarry but there is nothing wrong with not re-inventing the wheel. Do we really need to re-invent it to learn how to be a car mechanic? We would have to be idiots if that was the case. A*s*i*m*o*v .... We're young, rich, and full of sugar, what do we do? |
Asimov wrote:
"Tim Wescott" bravely wrote to "All" (05 Apr 05 09:26:07) --- on the heady topic of " Crystal radio" TW From: Tim Wescott TW Xref: aeinews rec.radio.amateur.homebrew:9149 TW 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. TW A silicon diode will work, it won't be as sensitive but you can get TW one at the local Radio Shack (they carry germanium diodes off and on, TW so they may have some). TW If you're using germanium diodes get some spares -- I've found them TW very susceptible to lightning strikes, at least in the circuit that my TW son and I built. Why bother? Get a solar cell and power a radio with it. There is more than 900watts/metre^2 free energy right outside the window. (mumbling something about "idiots"...) 'cause crystal radios are more fun, and when your 10-year-old puts one together he or she can understand each and every part in it (those charge regulator IC's are kinda hard to grok when you're not firm on how a diode works). -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
Tim Wescott wrote:
charge regulator IC's are kinda hard to grok when you're not firm on how a diode works). Help out an oldster. What the heck does "grok" mean? -Bill |
On Sat, 09 Apr 2005 00:35:11 -0400, Bill M
wrote: Tim Wescott wrote: charge regulator IC's are kinda hard to grok when you're not firm on how a diode works). Help out an oldster. What the heck does "grok" mean? -Bill A word from Robert Heinlein's 1961 novel "Stranger in a Strange Land". Rough meaning is to understand thoroughly and profoundly. "As one character from Heinlein's novel says: 'Grok' means to understand so thoroughly that the observer becomes a part of the observed - to merge, blend, intermarry, lose identity in group experience. It means almost everything that we mean by religion, philosophy, and science - and it means as little to us (because we are from Earth) as color means to a blind man. " From: http://whatis.techtarget.com/definition/0,,sid9_gci212216,00.html Happy trails, Gary (net.yogi.bear) -- At the 51st percentile of ursine intelligence Gary D. Schwartz, Needham, MA, USA Please reply to: garyDOTschwartzATpoboxDOTcom |
Gary S. wrote:
On Sat, 09 Apr 2005 00:35:11 -0400, Bill M wrote: Tim Wescott wrote: charge regulator IC's are kinda hard to grok when you're not firm on how a diode works). Help out an oldster. What the heck does "grok" mean? -Bill A word from Robert Heinlein's 1961 novel "Stranger in a Strange Land". Rough meaning is to understand thoroughly and profoundly. "As one character from Heinlein's novel says: 'Grok' means to understand so thoroughly that the observer becomes a part of the observed - to merge, blend, intermarry, lose identity in group experience. It means almost everything that we mean by religion, philosophy, and science - and it means as little to us (because we are from Earth) as color means to a blind man. " From: http://whatis.techtarget.com/definition/0,,sid9_gci212216,00.html Happy trails, Gary (net.yogi.bear) Well THAT explains it! Thanks, -Bill M |
Bill M wrote:
Gary S. wrote: On Sat, 09 Apr 2005 00:35:11 -0400, Bill M wrote: Tim Wescott wrote: charge regulator IC's are kinda hard to grok when you're not firm on how a diode works). Help out an oldster. What the heck does "grok" mean? -Bill A word from Robert Heinlein's 1961 novel "Stranger in a Strange Land". Rough meaning is to understand thoroughly and profoundly. "As one character from Heinlein's novel says: 'Grok' means to understand so thoroughly that the observer becomes a part of the observed - to merge, blend, intermarry, lose identity in group experience. It means almost everything that we mean by religion, philosophy, and science - and it means as little to us (because we are from Earth) as color means to a blind man. " From: http://whatis.techtarget.com/definition/0,,sid9_gci212216,00.html Happy trails, Gary (net.yogi.bear) Well THAT explains it! And now you grok! - Mike KB3EIA - |
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