chris/Extra-Study
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 1 Activity
Extra-Study/pages/E9A.md
Chris ce979dddb4 Initial checkin
2025-05-01 15:49:18 -05:00

3.5 KiB
Raw Permalink Blame History

E9A Basic antenna parameters: radiation resistance, gain, beamwidth, efficiency; effective radiated power (ERP) and effective isotropic radiated power (EIRP)

  • E9A01 (C) What is an isotropic radiator? #card
    • A. A calibrated, unidirectional antenna used to make precise antenna gain measurements
    • B. An omnidirectional, horizontally polarized, precisely calibrated antenna used to make field measurements of antenna gain
    • C. A hypothetical, lossless antenna having equal radiation intensity in all directions used as a reference for antenna gain
    • D. A spacecraft antenna used to direct signals toward Earth
  • E9A02 (D) What is the effective radiated power (ERP) 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? #card
    • A. 469 watts
    • B. 78.7 watts
    • C. 420 watts
    • D. 286 watts
  • E9A03 (C) What term describing total radiated power takes into account all gains and losses? #card
    • A. Power factor
    • B. Half-power bandwidth
    • C. Effective radiated power
    • D. Apparent power
  • E9A04 (B) Which of the following factors affect the feed point impedance of an antenna? #card
    • A. Transmission line length
    • B. Antenna height
    • C. The settings of an antenna tuner at the transmitter
    • D. The input power level
  • E9A05 (D) What does the term “ground gain” mean? #card
    • A. The change in signal strength caused by grounding the antenna
    • B. The gain of the antenna with respect to a dipole at ground level
    • C. To force net gain to 0 dB by grounding part of the antenna
    • D. An increase in signal strength from ground reflections in the environment of the antenna
  • E9A06 (A) What is the effective radiated power (ERP) 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? #card
    • A. 317 watts
    • B. 2,000 watts
    • C. 126 watts
    • D. 300 watts
  • E9A07 (B) What is the effective isotropic radiated power (EIRP) 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? #card
    • A. 159 watts
    • B. 252 watts
    • C. 632 watts
    • D. 63.2 watts
  • E9A08 (A) Which frequency band has the smallest first Fresnel zone? #card
    • A. 5.8 GHz
    • B. 3.4 GHz
    • C. 2.4 GHz
    • D. 900 MHz
  • E9A09 (B) What is antenna efficiency? #card
    • A. Radiation resistance divided by transmission resistance
    • B. Radiation resistance divided by total resistance
    • C. Total resistance divided by radiation resistance
    • D. Effective radiated power divided by transmitter output
  • E9A10 (A) Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna? #card
    • A. Installing a ground radial system
    • B. Isolating the coax shield from ground
    • C. Shortening the radiating element
    • D. All these choices are correct
  • E9A11 (C) Which of the following determines ground losses for a ground-mounted vertical antenna operating on HF? #card
    • A. The standing wave ratio
    • B. Distance from the transmitter
    • C. Soil conductivity
    • D. Take-off angle
  • E9A12 (A) How much gain does an antenna have compared to a half-wavelength dipole if it has 6 dB gain over an isotropic radiator? #card
    • A. 3.85 dB
    • B. 6.0 dB
    • C. 8.15 dB
    • D. 2.79 dB