I made a copper coil around a tube and had a copper arm that moved along the copper winding. I could change stations. I thought the germanium diode was the power source. But i really never understood it. My dad helped me build it in the 50's...I would check it now and then to see if it still worked... It always did. Lost track of it in the 80's.
Sometimes the answer is not to cross an old bridge, nor to burn it, but to build a better bridge.
The diode only serves to rectify or "detect" the signal. The Power source is the radio waves them selves which is why the sound will not be too loud unless you add an amplifier stage. BUT...then you gotta have batteries, it never ends, lol.
rockguy wrote: The diode only serves to rectify or "detect" the signal. The Power source is the radio waves them selves which is why the sound will not be too loud unless you add an amplifier stage. BUT...then you gotta have batteries, it never ends, lol.
Hear, hear. The power source is the transmitter station; sometimes, they'll mention how much energy they use to generate the radio signal, sometimes up to 50,000 watts.
Another way of thinking about the diode is that it accumulates the signal. The radio waves draw electric charge back and forth through all the wires in your radio hundreds of thousands of times per second. The diode skims some energy out of each cycle, so that enough builds up to push on the speaker membrane. But the amplitude of the radio signal changes all the time, pushing the speaker membrane more, and then less.
"the qualities of these bacteria, like the heat of the sun, electricity, or the qualities of metals, are part of the storehouse of knowledge of all men. They are manifestations of the laws of nature, free to all men and reserved exclusively to none." SCOTUS, Funk Bros. Seed Co. v. Kale Inoculant Co.
What does a metric clock look like? I bet it is nothing like this tiny ad: