How do radio communications work?

Answer 1

Radio waves are a form of electromagnetic radiation, created whenever a charged object (in normal radio transmission, an electron) accelerates with a frequency that lies in the radio frequency (RF) portion of the electromagnetic spectrum. In radio, this acceleration is caused by an alternating current in an antenna. Radio frequencies occupy the range from a few tens of hertz to a few hundred gigahertz.

Electromagnetic radiation travels (propagates) by means of oscillating electromagnetic fields that pass through the air and the vacuum of space equally well, and does not require a medium of transport (such as the aether). When radio waves pass an electrical conductor, the oscillating electric or magnetic field (depending on the shape of the conductor) induces an alternating current and voltage in the conductor. This can be transformed into audio or other signals that carry information. The word 'radio' is used to describe this phenomenon, and television, radio, radar, and cell phone transmissions are all classed as radio frequency emissions.

AM broadcast radio sends music and voice in the Medium Frequency (MF—0.300 MHz to 3 MHz) radio spectrum. AM radio uses amplitude modulation, in which louder sounds at the microphone causes wider fluctuations in the transmitter power while the transmitter frequency remains unchanged. Transmissions are affected by static because lightning and other sources of radio add their radio waves to the ones from the transmitter.

FM broadcast radio sends music and voice, with higher fidelity than AM radio. In frequency modulation, louder sounds at the microphone cause the transmitter frequency to fluctuate farther, the transmitter power stays constant. FM is transmitted in the Very High Frequency (VHF—30 MHz to 300 MHz) radio spectrum

Answer 2

If something charged is accelerated then everything else charged is subject to a force from the something. The force drops off with distance as an inverse square law. (The particles which carry this force are called photons).

So the radio transmitter violently accelerates electrons in the mast and the electrons in the antena of the domestic radio feel a force and move. This is a small electic current which is amplified to drive the loudspeaker.

Answer 3

AM or FM, radios are the most common wireless communications device on the face of the planet. In fact, way back in its early history, the term for radio was "wireless," which now denotes an entire industry! We take them for granted, these little radios, finding them playing in cars, homes and offices, tagging along with joggers, tradesmen and teenagers after school.

In fact, the lowly radio we see so much of today is the heart of virtually every "wireless" device we see for sale today. Cellular phones, pagers, televisions (yes, televisions) wireless LANs, most everything "wireless" (with the exception of infrared devices) uses radio to get from here to there. The funny thing is: most every kind of radio transmitting device uses some form or variation of either AM or FM to do its job.

Answer 4

Sound waves don't travel very far so we need a radio to carry them over long distances. We convert sound into an audio frequency electrical signal. This is then mixed with higher frequency electrical oscillations to get to the RF 'carrier' frequency which is transmitted over the required distance. At the other end, the process is reversed and audio is recovered, amplified and output through the loudspeaker.
The principles are simple. The devil is in the detail.

Answer 5

Marconi is often known because the inventor of the radio in 1895 _______ The Roots of Radio in the course of the 1860s, Scottish physicist, James Clerk Maxwell anticipated the life of radio waves; and in 1886, German physicist, Heinrich Rudolph Hertz established that quick ameliorations of electric powered modern ought to correctly be projected into area contained in the range of radio waves reminiscent of those of light and warm temperature. In 1866, Mahlon Loomis, an American dentist, effectively established "prompt telegraphy." Loomis replaced into able to make a meter linked to at least one kite reason yet another one to flow, marking the first generic party of prompt aerial verbal replace. Guglielmo Marconi Guglielmo Marconi, an Italian inventor, proved the feasibility of radio verbal replace. He despatched and received his first radio signal in Italy in 1895. by 1899 he flashed the first prompt signal in the course of the English Channel and a couple of years later received the letter "S", telegraphed from England to Newfoundland. This replaced into the first useful transatlantic radiotelegraph message in 1902.

Answer 6

sound waves are converted into electrical impulses by a microphone. Electrical impulses are converted into radio wave low frequency electromagnetic radiation by a transmitter. EM radiation is converted to electrical impulses by a reciever. Electrical impulses are converted to sound waves by a speaker.

Answer 7

higher the frequency of sound longer the distance it reached.
sound with lower frequency we can listen but it never reached for long distance............

in radio communication device convert our voice to higher specific frequency to reach upto receptor.......... then receptors device decodes that sound with specific frequency it by converting it into lower frequency to which we can hear that voice............

Answer 8

radio waves are like light but with longer wavelengths hence they are invisible

Answer 9

ok..
1st...Either put batteries in
2nd...Plug it into the mains
3rd...Tune in unless you have DAB..
4th...listen to Ken Bruce.. he is really funny.
5th... hahahaha..

Answer 10

Very well on the whole!