EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: dusan on August 20, 2022, 09:36:04 am
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Can somebody explain this double speak to me?
Datasheet: https://www.nikom.biz/pdf/1N60_DEC.pdf (https://www.nikom.biz/pdf/1N60_DEC.pdf)
Do they just call it "germanium diode" but it is shottky silicon diode?
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Its a point contact diode. www.rfwireless-world.com/Terminology/Point-Contact-Diode-Vs-Hot-Carrier-Diode.html (http://www.rfwireless-world.com/Terminology/Point-Contact-Diode-Vs-Hot-Carrier-Diode.html) Old School but very handy in RF detectors. Theres a clue to its age in the part number.
Note the very, very low junction capacitance and tiny Vf at low currents.
Its the crystal in a crystal set. https://en.wikipedia.org/wiki/Crystal_radio (https://en.wikipedia.org/wiki/Crystal_radio)
Also very popular in distortion pedals back in the day.
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I don't think it's point contact, I don't see a wire thare. Point contact are usually in DO-7 package, this one is DO-35.
Here on the left is DO-35 planar diode and on the right is DO-7 point contact diode:
https://www.nasobchodik.sk/images_101197-2/1n34a-1n270-do-35-do-7-moc-germ%C3%A1nium-usmer%C5%88ova%C4%8D_thumbs.jpeg (https://www.nasobchodik.sk/images_101197-2/1n34a-1n270-do-35-do-7-moc-germ%C3%A1nium-usmer%C5%88ova%C4%8D_thumbs.jpeg)
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A 1N60 is a Germanium diode. It is used a a detector/RF rectifier in radios.
Measure the voltage drop with a multimeter. A Germanium diode will have about a .3 V drop. Silicone have about .6 volt drop.
Shottky diodes have less drop. .2 V or so.
These are the point contact or hot carrier diodes.
More modern replacements for Germanium diodes.
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Germanium part number reused for silicon Schottky diode.
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Correct it’s a silicon Schottky diode. They are actually slightly inferior to Ge diodes at very low forward bias.
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I'm sure I have some fossil ones. Or do I .....
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Beware, some "germanium" diodes are fake:
https://youtu.be/Lyos1D7_2OI