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How exactly this device is detecting all kind of EM waves? There is a cat whisker in it which is nothing but a diode.But how exactly does its resistance change for different EM waves frequencies? Does galena crystal have the property to change resistance for various frequencies?

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It would be helpful to get a reference to the patent you are asking questions about -- also if there is a question about the actual physics of a patent you may consider to ask a scientific question on physics.stackexchange.com –  Soren Jul 8 at 15:27
As a teaser question -- does an invention have to work to be patentable? –  Soren Aug 11 at 14:56

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