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 

     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-

     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 

     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 

     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.