NZART Amateur Examination                     page 9          NZARTX07 Security code 268509

  1. Insulators are used at the end of suspended antenna wires to:
    1. increase the effective antenna length
    2. limit the electrical length of the antenna
    3. make the antenna look more attractive
    4. prevent any loss of radio waves by the antenna

  2. An isotropic antenna is a:
    1. half wave reference dipole
    2. infinitely long piece of wire
    3. dummy load
    4. hypothetical point source

  3. Radio wave energy on frequencies below 4 MHz during daylight hours is almost completely absorbed by this ionospheric layer:
    1. C
    2. D
    3. E
    4. F

  4. Signal fadeouts resulting from an 'ionospheric storm' or 'sudden ionospheric disturbance' are usually attributed to:
    1. heating of the ionised layers
    2. over-use of the signal path
    3. insufficient transmitted power
    4. solar flare activity

  5. Three recognised layers of the ionosphere that affect radio propagation are:
    1. A, E, F
    2. B, D, E
    3. C, E, F
    4. D, E, F

  6. The position of the E layer in the ionosphere is:
    1. above the F layer
    2. below the F layer
    3. below the D layer
    4. sporadic

  7. When a HF transmitted radio signal reaches a receiver, small changes in the ionosphere can cause:
    1. consistently stronger signals
    2. a change in the ground wave signal
    3. variations in signal strength
    4. consistently weaker signals
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