Galena Crystal Radio Diode Black Vertical Detector Stand With Dome for Sale

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Galena Crystal Radio Diode Black Vertical Detector Stand With Dome For Sale

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Galena Crystal Radio Diode Black Vertical Detector Stand With Dome:
$35.00

ALLORDERS TOTALING $50.00 OR MORE QUALIFY FOR FREE SHIPPING

Crystal Radio Diode Catwhisker Detector StandThis Design uses a Threaded Cast CrystalSame size Crystal as used in some Philmore DetectorsCrystal has 3mm threads and is attached using the screw on base bottomTurn the Knurled Screw on top to Raise or Lower the whisker(Includes a Glass Dome)Crystal Can be easily removed by simply removing the holding screw from the bottom of the baseThe Crystal has a cast insert to prevent thread strippingSee the construction Cross Section Image in the picture Gallery
Crystal Radio Diode Stand 3" Tall and 2.0" Wide at the BaseEasy Screw Terminal Connections to your RadioAnode is marked "A" and Cathode is marked "C" on the PC BoardMuch More stable and easier to adjust than Original Philmore Detector Stand
Heat TreatedPhosphor Bronze Cat Whisker
Includes a Glass Dome
Base is Made of 2 Layers of Solid FiberglassEasily replaceable Whisker and Crystal3 Silicone Rubber feet on base bottom1Crystal Detector ( Actual crystal may vary in shape and size from picture)1 Heat Treated Cats whisker pre-installed in the mountCast CrystalCasting alloy is made from Lead, Tin and Bismuth-Cadmium FreeFully assembled, tested and ready to go.
Working with a Cats Whisker and Crystal can be very tricky and takes a great deal of patience, time, steady hands and acquired skills.The surface of the crystal form a crude and unstable point-contact metal–semiconductor junction that acts like a diode, current can flow from the wire into the crystal but not in the other direction.Operation: To change the contact position, retract the end of the whisker wire at the contact point slightly from the top of the crystal surface and move it to another spot on the crystal Don't slide or drag the whisker while tension is being applied from the whisker wire as this crumbles some crystal surface particles and makes the contact point even more unstable.The most common type was the so-called cat whisker detector, which consisted of a piece of crystalline mineral with a fine wire touching its surface.Replacement Whiskers available.
FACTS ABOUT OLD SCHOOL CRYSTALDIODESMeasuring forward and back resistance ratios of crystal-and-cats-whisker diode. There is a significant differencebetween forward and back resistance readings on an ohmmeter, but the ratio was nowhere close to that of a modern germanium diode,thus limiting the efficiency of the crystal. However, connecting a germanium diode as a bias with the crystal can make a majorimprovements in performance.Not every contact position on the crystal will perform, so fiddling with the ‘cat's whisker’ to find a sweet spot does take patience, a steady hand and some acquired skill.The "cat whisker", a springy piece of thin metal wire, Hardened wire of about 30 gauge iscommonly used.The wire whisker is the anode, and the crystal is the cathode.
Cat Whisker:The "cat whisker", a springy piece of thin metal wire, formed the metal side of the junction. Hardened wire of about 30 gauge was commonly used because it had the right amount of springiness.Crystals that require a light pressure like Galena and Pyrite were used with the wire cat whisker contact; silicon was used with a heavier point contact,while Silicon Caroffere (Carborundum) could tolerate the heaviest pressure.Different crystal minerals require just the right amount of pressure by the wire to work; too much pressure causes the device to conduct in both directions.Cat whisker detector:It consisted of a pea-size piece of crystalline mineral in a metal holder, with its surface touched by a fine metal wire or needle (the "cat whisker"). The contact between the tip of the wire and the surface of the crystal formed a crude unstable point-contact metal–semiconductor junction, forming a diode. The wire whisker is the anode, and the crystal is the cathode; current can flow from the wire into the crystal but not in the other direction.Having a lot of patience and a steady hand are needed when you listen with a piece of the rock. But this can also be very rewarding when you can hear the first station using a cats whisker detector.
Please note : This item not a Crystal Radio, but is installed into a Crystal Radio and used to replace a modern Germanium diode with an older technology developed during the 1920's.