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2024 Amateur Extra pool
16 / 602 questions need explanations
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Which of these digital modes has the highest data throughput under clear communication conditions?
  • MFSK16 (0% chose this)
  • 170 Hz shift, 45 baud RTTY (0% chose this)
  • FT8 (0% chose this)
  • PACTOR IV (0% chose this)
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Where is transequatorial propagation (TEP) most likely to occur?
  • Between points separated by 2,000 miles to 3,000 miles over a path perpendicular to the geomagnetic equator (0% chose this)
  • Between points located 1,500 miles to 2,000 miles apart on the geomagnetic equator (0% chose this)
  • Between points located at each other’s antipode (0% chose this)
  • Through the region where the terminator crosses the geographic equator (0% chose this)
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Which of the following can be measured by a two-port vector network analyzer?
  • Phase noise (0% chose this)
  • Filter frequency response (0% chose this)
  • Pulse rise time (0% chose this)
  • Forward power (0% chose this)
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What combines to create the self-resonance of a component?
  • The component’s resistance and reactance (0% chose this)
  • The component’s nominal and parasitic reactance (0% chose this)
  • The component’s inductance and capacitance (0% chose this)
  • The component’s electrical length and impedance (0% chose this)
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What is the primary cause of loss in film capacitors at RF?
  • Inductance (0% chose this)
  • Dielectric loss (0% chose this)
  • Self-discharge (0% chose this)
  • Skin effect (0% chose this)
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Which of the following is a common use of a Schottky diode?
  • In oscillator circuits as the negative resistance element (0% chose this)
  • As a variable capacitance in an automatic frequency control circuit (0% chose this)
  • In power supplies as a constant voltage reference (0% chose this)
  • As a VHF/UHF mixer or detector (0% chose this)
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Which of the following digital logic families has the lowest power consumption?
  • Schottky TTL (0% chose this)
  • ECL (0% chose this)
  • NMOS (0% chose this)
  • CMOS (0% chose this)
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What circuit is required at the output of an RF switching amplifier?
  • A filter to remove harmonic content (0% chose this)
  • A high-pass filter to compensate for low gain at low frequencies (0% chose this)
  • A matched load resistor to prevent damage by switching transients (0% chose this)
  • A temperature compensating load resistor to improve linearity (0% chose this)
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What is characteristic of an emitter follower (or common collector) amplifier?
  • Low input impedance and phase inversion from input to output (0% chose this)
  • Differential inputs and single output (0% chose this)
  • Acts as an OR circuit if one input is grounded (0% chose this)
  • Input and output signals in-phase (0% chose this)
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What is the purpose of feeding an off-center-fed dipole (OCFD) between the center and one end instead of at the midpoint?
  • To create a similar feed point impedance on multiple bands (0% chose this)
  • To suppress off-center lobes at higher frequencies (0% chose this)
  • To resonate the antenna across a wider range of frequencies (0% chose this)
  • To reduce common-mode current coupling on the feed line shield (0% chose this)
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What is the purpose of making a Yagi’s parasitic elements either longer or shorter than resonance?
  • Wind torque cancellation (0% chose this)
  • Mechanical balance (0% chose this)
  • Control of phase shift (0% chose this)
  • Minimize losses (0% chose this)
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What indicates the correct value of terminating resistance for a Beverage antenna?
  • Maximum feed point DC resistance at the center of the desired frequency range (0% chose this)
  • Minimum low-angle front-to-back ratio at the design frequency (0% chose this)
  • Maximum DC current in the terminating resistor (0% chose this)
  • Minimum variation in SWR over the desired frequency range (0% chose this)
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What is the function of a Beverage antenna’s termination resistor?
  • Increase the front-to-side ratio (0% chose this)
  • Absorb signals from the reverse direction (0% chose this)
  • Decrease SWR bandwidth (0% chose this)
  • Eliminate harmonic reception (0% chose this)
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What type of radiation pattern is created by a single-turn, terminated loop such as a pennant antenna?
  • Cardioid (0% chose this)
  • Bidirectional (0% chose this)
  • Omnidirectional (0% chose this)
  • Hyperbolic (0% chose this)
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What is meant by “100% tie-off” regarding tower safety?
  • All loose ropes and guys secured to a fixed structure (0% chose this)
  • At least one lanyard attached to the tower at all times (0% chose this)
  • All tools secured to the climber’s harness (0% chose this)
  • All circuit breakers feeding power to the tower must be tied closed with tape, cable, or ties (0% chose this)
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Which of the following types of equipment are exempt from RF exposure evaluations?
  • Transceivers with less than 7 watts of RF output (0% chose this)
  • Antennas that radiate only in the near field (0% chose this)
  • Hand-held transceivers sold before May 3, 2021 (0% chose this)
  • Dish antennas less than one meter in diameter (0% chose this)
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