NZART Amateur Examination                     page 7          NZARTX07 Security code 268509

  1. To obtain high frequency stability in a transmitter, the VFO should be:
    1. run from a non-regulated AC supply
    2. in a plastic box
    3. powered from a regulated DC supply
    4. able to change frequency with temperature

  2. The fifth harmonic of 7 MHz is:
    1. 12 MHz
    2. 19 MHz
    3. 28 MHz
    4. 35 MHz

  3. Parasitic oscillations in a RF power amplifier can be suppressed by:
    1. pulsing the supply voltage
    2. placing suitable chokes, ferrite beads or resistors within the amplifier
    3. screening all input leads
    4. using split-stator tuning capacitors

  4. Electrolytic capacitors are used in power supplies because:
    1. they are tuned to operate at 50 Hz
    2. they have very low losses compared to other types
    3. they radiate less RF noise than other types
    4. they can be obtained in larger values than other types

  5. The block marked 'Regulator' in the diagram could consist of:
    1. four silicon power diodes in a regulator configuration
    2. two silicon power diodes and a centre-tapped transformer
    3. a three-terminal regulator chip
    4. a single silicon power diode connected as a half-wave rectifier

  6. A signal report of "5 and 1" indicates:
    1. very low intelligibility but good signal strength
    2. perfect intelligibility but very low signal strength
    3. perfect intelligibility, high signal strength
    4. medium intelligibilty and signal strength
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