communication Flashcards
What is AM?
Broadcasts a signal at a constant frequency, but will add a carrier wave. Amplitude Modulation. More interference. Greater distances and obstacles.
reacts with the ionsphere
What is FM
Frequency is changed. Changes in frequency are detected. Clearer and higher quality signal. Less interference. Less distance, and can’t move around objects.
Advantages of AM
Cheaper, greater distances, simple
Advantages of FM
Better sound quality, less interference, less radiated power
What is sound?
a mechanical wave that progress through a medium.
How do speakers work?
motor and cone
higher volume higher amplitude. higher pitch higher frequency.
How do microphones work?
the pressure of the sound waves on the diaphragm move the coil - generates current - vibration of sound - proudce currents - convert into sound
Radio waves
electromagnetic waves to sound a radio consists of a circuit to transform power from a battery to radio frequency.
Passing analog to digital
through the binary system and boolean logical. analogue wave into a digital number.
What are Optical fibers
transmissions of data using light: reflection inside the glass.
Advantages of Optical fibers
noise resistance, less signal attenuation, higher bandwidth (larger amount of information + faster), lighter
Copper Cables
cheaper, stronger
Satellites
Help meteorologists predict weather and track hurricanes. - Are used mainly for communication: beaming TV signals and phone calls around the world
- A group of more than 20 satellites make up the Global Positioning System, or GPS.
larger areas, higher resolution, faster, easier, cheaper
Geo satellites
STATIONARY, the signal is clear and no need for adjustments
The signal may delay because of the distance
poor signal around the poles
TV, weather, GPS
what is the motor in the speaker
drives the speaker back and forth - voice cole (copper wire and former, electricity moves through the wire generating a magnetic field, it can be made stronger, weaker, or turned off) ) + magnet (focuses the magnetic field, electric signal moves)
what is the cone in the speaker
translates movement into pressure waves that travel through air. Voice coil movement into air, suspension system, dust cap, tinsel leads that can deform easily.
disadvantages of AM
affected by storms, noise due to carrier wave
disadvantages of FM
short distance, complex receiver and transmitter, expensive
boolean logic
a mathematical approach to reasoning, and or if, takes on binary variables true 1 false 0
analogue advantages
easier to process, best suited for audio and video, higher density = refined information
digital advantages
less noise, lower cost, more secure, easy to store, longer distances, higher rate of transmission and data
disadvantages of optical fibers
cost, installation, fragility
polar satellites
resolution is higher
provide global coverage
not continuous viewing
Large scale mapping, military and global weather.
