Elliptic Curve Crypto - Recent changes [en]

Elliptic Curve Crypto - Recent changes [en] https://www.ellipticcurve.info/Special:RecentChanges Track the most recent changes to the wiki in this feed. en MediaWiki 1.42.3 Tue, 16 Jun 2026 12:36:12 GMT Crystal radio https://www.ellipticcurve.info/index.php?title=Crystal_radio&diff=573&oldid=572 https://www.ellipticcurve.info/index.php?title=Crystal_radio&diff=573&oldid=572 <p><span dir="auto"><span class="autocomment">Notes: </span> tuning cap</span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 04:22, 18 May 2026</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l22">Line 22:</td> <td colspan="2" class="diff-lineno">Line 22:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Crystal diodes have been made out of razor blades, pencil leads, safety pins, etc. The original "crystal" was a galena (lead or silver sulfide) crystal with the anode soldered in place with an alloy of bismuth, lead, tin and cadmium called "Wood’s Metal." A normal tin-lead solder alloy or even leaded or lead-free silver-bearing solder is probably adequate, since cadmium is even more toxic than lead.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Crystal diodes have been made out of razor blades, pencil leads, safety pins, etc. The original "crystal" was a galena (lead or silver sulfide) crystal with the anode soldered in place with an alloy of bismuth, lead, tin and cadmium called "Wood’s Metal." A normal tin-lead solder alloy or even leaded or lead-free silver-bearing solder is probably adequate, since cadmium is even more toxic than lead.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>There is an expression in Spanish, “‘la ley’ o ‘el sistema’ de plata o plomo” that describes the theory of operation of these crystal diodes, although, nowadays, crystal diodes are mostly forgotten <ref>Heart of Stone. https://www.sparkmuseum.org/heart-of-stone/</ref> and that expression is more used as a metaphor to describe the ''modus operandi'' of organized crime cartels. The use of radio equipment to communicate of course implies some organization of activities of some sort, but not necessarily criminal. “Un sistema de plata o plomo” would be a catchphrase for an early type of crystal radio set, probably powered and capable of transmitting as well as receiving, the perceived criminality of it relating to the spread of gossip at lightning speed. Early radio communications technology may have in use in rural Mexico and the Wild West of the U.S. long before it was acknowledged to have been invented. Banditos, by communicating over long distances, knew instantly when strangers rode into town and when and where to organize their attacks and robberies. And remember, in the language of the banditos, silver is always something given, while lead is something received, so, in that language, a system of silver or lead is capable of transmitting or receiving, but probably not both at the same time. And the systems that were powered were probably powered by silver oxide or lead acid batteries. One may assume those men were skilled at silversmithing, early photography and electroplating, etc.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>There is an expression in Spanish, “‘la ley’ o ‘el sistema’ de plata o plomo” that describes the theory of operation of these crystal diodes, although, nowadays, crystal diodes are mostly forgotten <ref>Heart of Stone. https://www.sparkmuseum.org/heart-of-stone/</ref> and that expression is more used as a metaphor to describe the ''modus operandi'' of organized crime cartels. The use of radio equipment to communicate of course implies some organization of activities of some sort, but not necessarily criminal. “Un sistema de plata o plomo” would be a catchphrase for an early type of crystal radio set, probably powered and capable of transmitting as well as receiving, the perceived criminality of it relating to the spread of gossip at lightning speed. Early radio communications technology may have in use in rural Mexico and the Wild West of the U.S. long before it was acknowledged to have been invented. Banditos, by communicating over long distances, knew instantly when strangers rode into town and when and where to organize their attacks and robberies. And remember, in the language of the banditos, silver is always something given, while lead is something received, so, in that language, a system of silver or lead is capable of transmitting or receiving, but probably not both at the same time. And the systems that were powered were probably powered by silver oxide or lead acid batteries. One may assume <ins style="font-weight: bold; text-decoration: none;">that </ins>those men were skilled at silversmithing, early photography and electroplating, etc.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== The cat’s whisker ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== The cat’s whisker ===</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l28">Line 28:</td> <td colspan="2" class="diff-lineno">Line 28:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A very fine sharp wire called a “cat’s whisker” is allowed to touch the surface of the galena crystal where it will allow electrons to pass into the crystal but it will not be able to pick up any electrons from the crystal. (The solder alloy bonded to the other side of the crystal will pick up and conduct electrons freely.) Commercially available “cat’s whisker” diodes are typically encased in clear glass and sold as “fast recovery” diodes.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A very fine sharp wire called a “cat’s whisker” is allowed to touch the surface of the galena crystal where it will allow electrons to pass into the crystal but it will not be able to pick up any electrons from the crystal. (The solder alloy bonded to the other side of the crystal will pick up and conduct electrons freely.) Commercially available “cat’s whisker” diodes are typically encased in clear glass and sold as “fast recovery” diodes.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>There are many interesting ways to make inductors and variable or fixed capacitors.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>There are many interesting ways to make inductors and variable or fixed capacitors. <ins style="font-weight: bold; text-decoration: none;">The 36.5–365pF denomination of capacitor in the circuit appears to be available as a high power commercial radio station transmitter tuning capacitor, but quite expensive and somewhat difficult to explain or justify for an unpowered receive-only crystal radio set …</ins></div></td></tr> </table> Mon, 18 May 2026 04:22:29 GMT Rational Point https://www.ellipticcurve.info/Talk:Crystal_radio