crystal radio

This will pick up signals from many hundreds of miles away. An american POW in Viet Nam once made one just from a bit of wire, he didn't even have a magnet for an earphone.

It's worth making coil winders, lots of them going at once tends to be very noisy

rusty nail joule thief
electricity from radio waves
more electricity from radio waves
transmitting a signal using light
making a crystal radio on youtube
elegant experiment showing polarisation of radio waves
hertz's demonstration of radio waves
interesting explanation of coherer-activated toy robot (at bottom of page)
detailed info about making diodes & capacitors out of houshold materials; also using an LED as the diode, just in case you don't have an RF diode handy
recycled speaker intercom
breaking a wineglass by singing
stephen gray
semaphore telegraph
my email is
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