PAPER III Category R : COMMUNICATION SYSTEMS - RADIO BASICS (Maintenance) ___________________________________________________________ General knowledge of the application and identification of electrical cables used in Aircraft radio installation, crimping and soldering techniques, bonding continuity and insulation tests. Detailed knowledge of the Alternating Current and calcula- tion of Instantaneous value, RMS value, frequency and ampli- tude from the given data; star and delta connections and calculation of power in three phase system. Detailed knowledge of series and parallel resonance of AC circuits and their use; calculation of resonant frequency of a circuit from a given information; effect of change in the frequency on the impedance, current and phase angle. Detailed knowledge of the composition, performance (stabili- ty and tolerance) and limitations of the fixed resistors (carbon composition, carbon film, wire wound and metallic film) and description of various types of variable resistors (wire wound, carbon film, thermistors and voltage dependent resistors and varistors). Construction and functioning of small AC and DC motors and generators. Knowledge of series and parallel circuits, filters, imped- ance matching circuits, resonance, series and parallel resonant circuits, Q factor, Bandwidth. Detailed knowledge of AC and DC measuring instruments. Detailed knowledge of thermionics emission; constructional features, application, limitations and functioning of thermionic valves. Detailed knowledge of materials, application and properties of semi-conductors. Knowledge of construction, symbols, doping process, opera- tion, application and characteristics of PNP and NPN tran- sistors; comparison with vacuum tubes. Knowledge of construction, symbols, operation and anode characteristics of vacuum and gas-filled tubes; knowledge of their construction and application. Knowledge of construction and principles of autotransform- ers, single and three phase transformers Knowledge of construction and principles of operation of saturable reactors and magnetic amplifiers; bias; phase sensitive half wave and inputs and outputs, polarity sensi- tive inputs and outputs, pushpull outputs and effects of stage gains and cascading on time response. Knowledge of use and theory of oscillators and multivibra- tors. Knowledge of symbols, truth tables and equivalent circuits for logic gates. Knowledge of the terms, operation and application of Flip Flop logic. Knowledge of the terms used, basic operation, interfacing of the major components of a Computer. Knowledge of operation, use and types of Medium Scale Inte- gration (MSI) Devices. Knowledge of the types and operation of displays (LED, Liquid crystal etc.). Knowledge of CRTs and its application in aviation. Knowledge of functions performed and overall operation of a microprocessor. Knowledge of handling of microelectronic circuit devices (Electrostatic Sensitive Devices (ESD)). Knowledge of electrical power distribution systems, the operation and construction of static inverters, rotary inverters and transformer rectifier units. Knowledge of modulation and demodulation, amplitude, fre- quency and phase modulation, AM and FM receivers, transmit- ter, superhatrodyne principle; balanced modulator. Detailed knowledge of radio frequency transmission lines, coaxial cables, current and voltage distribution, impedance of lines, standing waves, standing wave ratio, matching, tuning stubs, waveguides, attenuation in waveguides, reso- nant cavities. Knowledge of interference caused by electrical and ignition system to radio apparatus, methods of minimizing or suppressing such interference, bonding and screening. Knowledge of identification, use, propagation characteris- tics and identification of the band spectrum. Knowledge of terms connected with, construction and identi- fication for various types of antennas; the voltage and current distribution along antenna of various length; char- acteristics of ground planes. Knowledge of very high frequency (VHF) and high frequency (HF) airborne communications; frequency bands allocation; the methods of propagation and the ranges expected, both day and night; calculation of approximate ranges of communica- tion (line of sight) with given data. Knowledge of the performance levels expected and specifica- tions of typical airborne HF and VHF communication systems; the principle of operation, installation practices and procedures, functioning of the operating controls and indi- cations and maintenance of typical HF and VHF communication transceivers. Knowledge of the theory of operation, performance level and specifications of an Audio Integration System. Knowledge of working principles and testing of Lead Acid and Nickel Cadmium batteries. Knowledge of method, purpose, chemical combination, flux used, tinning for Soldering. Knowledge of Bonding and Screening. Knowledge of terms used, principle, operation, characteris- tics, installation and maintenance: Automatic Direction Finder (ADF) Systems. Very High Frequency (VHF) Omni Directional Range System Instrument Landing Systems Weather Radar Systems. Microwave Devices. Air Traffic Control (ATC) Transponder System. Very Low Frequency (VLF) Navigation Systems (WH). Omega Navigation System. Radio Altimeter Systems Cockpit Voice Recorder Distance Measuring Equipment Doppler Navigation System Microwave Landing System Ground Proximity Working Systems. Emergency Locator Transmitters Knowledge of Principle of Satellite Communication and its application to aircraft.