NEETS 17.txt

  1. The usual range of radiotelephone is from ___ to ___ miles.
    20, 25
  2. Successful transmission of hf signals over a long distance is dependent upon refraction of radio waves by layers of the ___________.
  3. Frequencies above ___ megahertz are not normally refracted by the atmosphere and ground-wave range is minimal.
  4. 30
  5. The __________ mode uses a single channel or frequency to exchange information between two or more terminals. Communications is in one direction only.
    simplex (splx)
  6. The _________ mode has one-way flow of information between terminals.
    half-duplex (hdx
  7. The ______________uses an arrangement of equipment where one terminal is simplex configured and the other uses two channels or frequencies in full duplex.
    semiduplex (sdx)
  8. The ________ mode is a method of operation in which telecommunications between stations takes place simultaneously in both directions using two separate frequencies
    full-duplex (fdx)
  9. __________ is the type of operation in which one station transmits information on one or more channels directed to more than one station and/or unit
    Broadcast (bc)
  10. _______ occurs when a transmitted electromagnetic wave passes through the receiver antenna and
  11. induces a voltage in the antenna.
  12. Reception
  13. _________ is the ability of the receiver to select a particular frequency of a station from all other station frequencies appearing at the antenna of the receiver.
  14. Selection
  15. __________ is the action of separating the low (audio) frequency intelligence from the high (radio) frequency carrier. A detector circuit is used to accomplish this action.
  16. Detection
  17. _________ is the action of converting the electrical signals to sound waves, which can then be interpreted by your ear as speech, music, and the like.
  18. The ability of a receiver to reproduce weak signals is a function of the __________ of a receiver
  19. __________ is the degree of distinction made by the receiver between the desired signal and unwanted signals
  20. Selectivity
  21. The ________ of a receiver is its ability to accurately reproduce, in its output, the signal that appears at its input.
  22. fidelity
  23. A typical value of IF for an AM communications receiver is _____ kilohertz
  24. The overwhelming danger to date appears to be the hazard from thermal effects, which are a function of intensity of radiation and frequency. This is particularly true in the range of ___ to __ gigahertz.
    1, 3
  25. The distance of one hop for a line-of-sight system is between _____ and ____miles.
    31, 95
  26. HF has a hop distance (skywave) of about ________miles;
Card Set
NEETS 17.txt