how does a radio pick up signals?

Answer 1

From the antenna.

Answer 2

The radio receiver picks up all radio signals in you part of the country via its antenna. The clever bit is the 'selectivity' i.e. being able to select one station from another using precise frequency adjustment aka the 'tuner'. This is what happens when you turn your dial - you can hear all the various stations. Try tuning your analague set to SW and scan through the channels, there are loads and loads of signals all superimposed on top of each other and very difficult to distinguish one from another - this is usually because your set does not have expensive circuitry to allow precise selection. stations broadcasting on MW are spread fairly far enough apart to allow clarity without crosstalk. Modern car radios auto track radio stations as you drive between different transmitters, but a few years ago you had to re-tune manually to the next frequency of the nearest transmitter.

A bit of a ramble - hope it helps.

Answer 3

Radio signals are produced from a transmitter and on a particular frequency. When a receiver aerial picks up that signal, on the same frequency, the receiver translates it into a sound by means of a circuit capable of so doing.
Radio Ham.

Answer 4

The simplest radio is a crystal set which consists of a tuned circuit to which the antenna/aerial is attached at one end and an earth connected at the other. The tuned circuit is a resistor/capactor combination which determines the frequency of the transmitter to be received. The signal is then de-modulated with a diode or "cat's whisker" and rendered as audio in a set of headphones.

Answer 5

from radio waves

Answer 6

Check out how stuff works for detailed info: