Telecommunications Revision

To help you revise, here are the main aspects of the telecommuncations unit. Make sure you look at your revision notes for any of the items in the list you are not sure about. You should also make sure that you have sorted any problems which came up from the homework exercises.

Section 1 - Simple Communication

The speed of sound, distance = speed x time
Communication with and without wires
Audio signals - modulation, carrier waves
Telephones - loudness and pitch

Section 2 - Waves

Transmit signals / carry energy
Frequency, wavelength, speed, energy, amplitude
Distance = speed x time for waves
Wave equation: speed = frequency x wavelength

Section 3 - Radio and Television

Function of aerial, tuner, decoder, amplifier and speaker
Wavebands and their uses (e.g. SW, VHF)
The TV picture tube
Black and white TV
Colour TV - colour mixing

Section 4 - Optical Fibres

What are optical fibres?
Uses of optical fibres - advantages and disadvantages
Laws of reflection, refraction.
Principle of reversibility
Critical angle and total internal reflection
Signal transmission

Section 5 - Satellites

Period of orbit and altitude
Uses of satellites
Geostationary satellites
Dish aerials