How do i make a radio without the crystals?

Some people have told  me about using a penny to make a radio. The objective though is to make a radio without the crystals

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-max-7 years ago
i figured out u can use an amp instead of a earpiece.
orksecurity7 years ago
AM or FM?

For AM, all you need is a tuned resonator, a diode, and an earpiece; see A solid state diode -- or the cat's whisker Andy mentioned, which is a primitive diode -- is indeed a crystal, but not a resonant crystal (which is what's usually meant when the word "crystal" is used in electronics).

jeff-o7 years ago
A crystal is just one way (and the easiest way) of obtaining a stable frequency for tuning the radio.  There are plenty of other oscillator types that would work, too.
Re-design7 years ago
Try some of these designs.  Most don't use any 'crystal' but do have some sort of detector.  You can't build a radio without some sort of detector.
lemonie7 years ago
The objective? Is this some kind of assignment for a radio-receiver?
Using thermionic valves would get you around "crystals"

AndyGadget7 years ago
If you're talking about the simplest of radio circuits, early ones used a piece of galena crystal (a lead ore) in a  cat's whisker detector in the set.  People have also used a piece of coal as the crystal, which performs the same function - you have to probe the whisker around on the coal until you find a spot which works. 
OK, it's still a crystal, but not an encapsulated crystal diode.
If you're talking about a more advanced design than this, then you have no chance.  Transistors and diodes ARE crystals.
Sandisk1duo7 years ago