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Question #421Radio Theory and Communication Principles

The frequency stability of a receiver is its ability to:

  1. stay tuned to the desired signal ✓ Correct answer
  2. track the incoming signal as it drifts
  3. provide a frequency standard
  4. provide a digital readout 233.Of two receivers, the one capable of receiving the weakest signal will have:

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Question #422Radio Theory and Communication Principles

The figure in a receiver's specifications which indicates its sensitivity is the:

  1. bandwidth of the IF in kilohertz
  2. audio output in watts
  3. signal plus noise to noise ratio ✓ Correct answer
  4. number of RF amplifiers

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Question #423Radio Theory and Communication Principles

If two receivers are compared, the more sensitive receiver will produce:

  1. more than one signal
  2. less signal and more noise
  3. more signal and less noise ✓ Correct answer
  4. a steady oscillator drift

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Question #424Radio Theory and Communication Principles

The ability of a receiver to separate signals close in frequency is called its:

  1. noise figure
  2. sensitivity
  3. bandwidth
  4. selectivity ✓ Correct answer
Explanation: Selectivity is a receiver’s ability to separate signals close in frequency. The option text was cleaned of OCR spillover.

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Question #425Radio Theory and Communication Principles

The BFO in a superhet receiver operates on a frequency nearest to that of its:

  1. RF amplifier
  2. audio amplifier
  3. local oscillator
  4. IF amplifier ✓ Correct answer
Explanation: The beat-frequency oscillator is used with the receiver’s intermediate-frequency (IF) signal. The option text was cleaned of OCR spillover.

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Question #426Basic Electricity and Electronics

The AGC circuit in a receiver usually controls the:

  1. audio stage
  2. mixer stage ✓ Correct answer
  3. power supply
  4. RF and IF stages

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Question #427Radio Theory and Communication Principles

The mixer stage of a superhet receiver:

  1. produces spurious signals
  2. produces an intermediate frequency signal ✓ Correct answer
  3. acts as a buffer stage
  4. demodulates SSB signals

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Question #428Radio Theory and Communication Principles

The abbreviation AGC means:

  1. attenuating gain capacitor
  2. automatic gain control ✓ Correct answer
  3. anode-grid capacitor
  4. amplified grid conductance 243.Morse code is usually transmitted by radio as:

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Question #429Radio Theory and Communication Principles

The process of modulation allows:

  1. information to be impressed on to a carrier ✓ Correct answer
  2. information to be removed from a carrier
  3. voice and Morse code to be combined
  4. none of these

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Question #430Basic Electricity and Electronics

The following unit in a DC power supply performs a smoothing operation:

  1. an electrolytic capacitor ✓ Correct answer
  2. a fuse
  3. a crowbar
  4. a full-wave diode bridge

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Question #431Radio Theory and Communication Principles

Radio wave polarisation is defined by the orientation of the radiated:

  1. magnetic field
  2. electric field ✓ Correct answer
  3. inductive field
  4. capacitive field 248.A half-wave antenna is often called a:

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Question #432Radio Theory and Communication Principles

The correct colour coding for the earth wire in a flexible mains lead is:

  1. Black
  2. violet
  3. Red
  4. Green ✓ Correct answer

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Question #433Amateur Radio Regulations and Licensing

The Amateur Service may be briefly defined as:

  1. a private radio service for personal gain and public benefit
  2. a public radio service used for public service communications
  3. a radio communication service for the purpose of self-training, intercommunication and technical investigation ✓ Correct answer
  4. a private radio service intended only for emergency communications

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Question #434Amateur Radio Regulations and Licensing

The organization responsible for the International Radio Regulations is the:

  1. European Radio communications Office
  2. United Nations
  3. International Telecommunication Union ✓ Correct answer
  4. European Telecommunication Standards Institute

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Question #435Amateur Radio Regulations and Licensing

The fundamental regulations controlling the Amateur Service is to be found in:

  1. the International Radio Regulations from the ITU ✓ Correct answer
  2. the Radio Amateur's Handbook
  3. the Ham Call book
  4. on the packet radio bulletin-board 254.All amateur stations, regardless of the mode of transmission used, must be equipped with:

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Question #436Operating Procedures, Morse Code and Phonetics

The Morse code signal SOS is sent by a station:

  1. with an urgent message
  2. in grave and imminent danger and requiring immediate assistance ✓ Correct answer
  3. making a report about a shipping hazard
  4. sending important weather information

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Question #437Amateur Radio Regulations and Licensing

The term "harmful interference" means:

  1. interference which obstructs or repeatedly interrupts radio communication services ✓ Correct answer
  2. an antenna system which accidentally falls on to a neighbor's property
  3. a receiver with the audio volume unacceptably loud
  4. interference caused by a station of a secondary service

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Question #438Amateur Radio Regulations and Licensing

International communications on behalf of third parties may be transmitted by an amateur station only if:

  1. prior remuneration has been received
  2. such communications have been authorized by the countries concerned ✓ Correct answer
  3. the communication is transmitted in secret code
  4. English is used to identify the station at the end of each transmission

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Question #439Amateur Radio Regulations and Licensing

The frequency limits of the “2 metre band” in India are:

  1. 144 to 149 MHz
  2. 144 to 146 MHz ✓ Correct answer
  3. 146 to 148 MHz
  4. 144 to 150 MHz

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Question #440Amateur Radio Regulations and Licensing

The value of bandwidth shown as 3K50 is

  1. 3050 Hz ✓ Correct answer
  2. 3500 Hz
  3. 3600 KHz
  4. 3050 KHz

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