Topic G4E Quick Review Audio


What is the purpose of a capacitance hat on a mobile antenna?

  1. To increase the power handling capacity of a whip antenna
  2. To allow automatic band changing
  3. To electrically lengthen a physically short antenna
  4. To allow remote tuning


What is the purpose of a corona ball on an HF mobile antenna?

  1. To narrow the operating bandwidth of the antenna
  2. To increase the "Q" of the antenna
  3. To reduce the chance of damage if the antenna should strike an object
  4. To reduce RF voltage discharge from the tip of the antenna while transmitting


Which of the following direct, fused power connections would be the best for a 100 watt HF mobile installation?

  1. To the battery using heavy-gauge wire
  2. To the alternator or generator using heavy-gauge wire
  3. To the battery using resistor wire
  4. To the alternator or generator using resistor wire


Why is it best NOT to draw the DC power for a 100 watt HF transceiver from a vehicle's auxiliary power socket?

  1. The socket is not wired with an RF-shielded power cable
  2. The socket's wiring may be inadequate for the current drawn by the transceiver
  3. The DC polarity of the socket is reversed from the polarity of modern HF transceivers
  4. Drawing more than 50 watts from this socket could cause the engine to overheat


Which of the following most limits an HF mobile installation?

  1. Picket fencing
  2. The wire gauge of the DC power line to the transceiver
  3. Efficiency of the electrically short antenna
  4. FCC rules limiting mobile output power on the 75-meter band


What is one disadvantage of using a shortened mobile antenna as opposed to a full-size antenna?

  1. Short antennas are more likely to cause distortion of transmitted signals
  2. Short antennas can only receive circularly polarized signals
  3. Operating bandwidth may be very limited
  4. Harmonic radiation may increase


Which of the following may cause receive interference in a radio installed in a vehicle?

  1. The battery charging system
  2. The fuel delivery system
  3. The vehicle control computer
  4. All these choices are correct


What is the name of the process by which sunlight is changed directly into electricity?

  1. Photovoltaic conversion
  2. Photon emission
  3. Photosynthesis
  4. Photon decomposition


What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell?

  1. 0.02 VDC
  2. 0.5 VDC
  3. 0.2 VDC
  4. 1.38 VDC


What is the reason that a series diode is connected between a solar panel and a storage battery that is being charged by the panel?

  1. The diode serves to regulate the charging voltage to prevent overcharge
  2. The diode prevents self-discharge of the battery through the panel during times of low or no illumination
  3. The diode limits the current flowing from the panel to a safe value
  4. The diode greatly increases the efficiency during times of high illumination


Which of the following is a disadvantage of using wind as the primary source of power for an emergency station?

  1. The conversion efficiency from mechanical energy to electrical energy is less than 2 percent
  2. The voltage and current ratings of such systems are not compatible with amateur equipment
  3. A large energy storage system is needed to supply power when the wind is not blowing
  4. All these choices are correct