E9A01:

What describes an isotropic antenna?

  1. A grounded antenna used to measure earth conductivity
  2. A horizontally polarized antenna used to compare Yagi antennas
  3. A theoretical antenna used as a reference for antenna gain
  4. A spacecraft antenna used to direct signals toward the earth

E9A02:

What antenna has no gain in any direction?

  1. Quarter-wave vertical
  2. Yagi
  3. Half-wave dipole
  4. Isotropic antenna

E9A03:

Why would one need to know the feed point impedance of an antenna?

  1. To match impedances in order to minimize standing wave ratio on the transmission line
  2. To measure the near-field radiation density from a transmitting antenna
  3. To calculate the front-to-side ratio of the antenna
  4. To calculate the front-to-back ratio of the antenna

E9A04:

Which of the following factors may affect the feed point impedance of an antenna?

  1. Transmission-line length
  2. Antenna height, conductor length/diameter ratio and location of nearby conductive objects
  3. The settings of an antenna tuner at the transmitter
  4. Sunspot activity and time of day

E9A05:

What is included in the total resistance of an antenna system?

  1. Radiation resistance plus space impedance
  2. Radiation resistance plus transmission resistance
  3. Transmission-line resistance plus radiation resistance
  4. Radiation resistance plus ohmic resistance

E9A06:

How does the beamwidth of an antenna vary as the gain is increased?

  1. It increases geometrically
  2. It increases arithmetically
  3. It is essentially unaffected
  4. It decreases

E9A07:

What is meant by antenna gain?

  1. The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna
  2. The ratio of the signal in the forward direction to that in the opposite direction
  3. The ratio of the amount of power radiated by an antenna compared to the transmitter output power
  4. The final amplifier gain minus the transmission line losses

E9A08:

What is meant by antenna bandwidth?

  1. Antenna length divided by the number of elements
  2. The frequency range over which an antenna satisfies a performance requirement
  3. The angle between the half-power radiation points
  4. The angle formed between two imaginary lines drawn through the element ends

E9A09:

How is antenna efficiency calculated?

  1. (radiation resistance / transmission resistance) x 100 percent
  2. (radiation resistance / total resistance) x 100 percent
  3. (total resistance / radiation resistance) x 100 percent
  4. (effective radiated power / transmitter output) x 100 percent

E9A10:

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

  1. Install a good radial system
  2. Isolate the coax shield from ground
  3. Shorten the radiating element
  4. Reduce the diameter of the radiating element

E9A11:

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

  1. The standing wave ratio
  2. Distance from the transmitter
  3. Soil conductivity
  4. Take-off angle

E9A12:

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

  1. 3.85 dB
  2. 6.0 dB
  3. 8.15 dB
  4. 2.79 dB

E9A13:

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 12 dB gain over an isotropic antenna?

  1. 6.17 dB
  2. 9.85 dB
  3. 12.5 dB
  4. 14.15 dB

E9A14:

What is meant by the radiation resistance of an antenna?

  1. The combined losses of the antenna elements and feed line
  2. The specific impedance of the antenna
  3. The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
  4. The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal

E9A15:

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

  1. 1977 watts
  2. 78.7 watts
  3. 420 watts
  4. 286 watts

E9A16:

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

  1. 317 watts
  2. 2000 watts
  3. 126 watts
  4. 300 watts

E9A17:

What is the effective radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

  1. 159 watts
  2. 252 watts
  3. 632 watts
  4. 63.2 watts

E9A18:

What term describes station output, taking into account all gains and losses?

  1. Power factor
  2. Half-power bandwidth
  3. Effective radiated power
  4. Apparent power