Sage-Tips

Why audio signals Cannot be transmitted directly into space?

Audio signals cannot be transmitted as such because the length of transmitting antenna required would be too large and impracticable.

What are the two types of audio signals?

Microphone Level This is because of the nature of how microphones work; while there is some variation, in general they produce a very low voltage and always require a pre-amplifier to boost up the level before it is usable for recording or public address.

Where is noise most likely to affect the signal?

– Noise is an unwanted as well as a disturbing signal which interferes with the main signal and corrupts the parameters of the signal. It is most likely to be entered at the channel and therefore affects the signal in the transmission line.

What is the minimum length of antenna?

In a line of sight radio communication, a distance of about 50 km is kept between the transmitting and receiving antennas. If the height of the receiving antenna is 70m, then the minimum height of the transmitting antenna should be : (Radius of the Earth = 6. 4×106m)

Are sound signals current or voltage?

Audio signals are representations of sound as electrical alternating currents between 20 Hz – 20,000 Hz (range of human hearing). Microphone audio signals are signals produced by microphone transducers. Electrically, they are measured in millivolts (mV) or decibels relative to voltage (dBV or dBu).

Why is noise unwanted?

Noise is unwanted sound. Sound is produced by vibrating objects and reaches the listener’s ears as waves in the air or other media. When an object vibrates, it causes slight changes in air pressure. These air pressure changes travel as waves through the air and produce sound.

What is the height of transmitting antenna for audio frequency?

For proper transfer of signal (modulation) the height of the antenna should be comparable to the wavelength of the signal which is to be transferred (at least one-fourth in length).

What size antenna is comparable?

size of antenna should be comparable to the wavelength of the signal.

Are audio signals AC or DC?

Audio signals are AC (alternating current) electrical signals. They are typically measured as AC voltages or as decibels relative to voltage (dBu or dBV). It’s important to note these values are rms (root mean square) rather than peak values.

Why don’t we transmit the digital signal directly?

And there are many reasons why we don’t transmit the digital signal directly: Complex modulation schemes allow us to pack more bits in each symbol hence achieving higher data transfer speeds. The frequency of the carrier signal affects where in the frequency spectrum the transmitted signal lives.

Can a signal be transmitted without information?

When we say transmitted signal, we do assume the signal carries information, but fundamentally, we can transmit a signal without information. After all, the electricity coming into our homes is a signal! We mostly use electromagnetic waves to send signals.

Why can’t we use a channel with infinite bandwidth for transmission?

To transmit such a signal, you would need a channel with infinite bandwidth, which doesn’t exist. Not to mention the interference effects such a system would cause. 2)Unless your transmitted signal is of a few Gigahertz, the antenna size of your application would be really large.

Why is it difficult to recover lost information from an electromagnetic signal?

Because there are many electromagnetic signals present in the atmosphere and the information signals we transmit are weak and easily susceptible to noises present so the quality degrades and the receiver will not able to regenerate the exact information from the received signal which was transmitted