These home made transistors sacrifice a point contact diode to get the small chip of germanium, and form the other two electrodes with metal foil glued to paper. Given that germanium point contact ...

Instead of bothering with tiny wires, Brattain attached a single strip of gold foil over the point of a plastic triangle ... current came out the other contact. Here's why it worked: Germanium ...

With nothing more complex than a germanium point-contact diode and an oscilloscope, you can quickly, easily, and cheaply resolve microwave signals, as we are shown with a 2.4GHz wireless mouse.