The antenna efficiency of an HF grounded vertical antenna can be made comparable to that
of a half-wave antenna
A. By installing a good ground radial system
B. By isolating the coax shield from ground
C. By shortening the vertical
D. By lengthening the vertical

1 Answer

Answer :

A. By installing a good ground radial system

Related questions

Description : How can the antenna efficiency of an HF grounded vertical antenna be made comparable to that of a half-wave antenna? A. By lengthening the vertical B. By installing a good ground radial system C. By shortening the vertical D. By isolating the coax shield from ground

Last Answer : B. By installing a good ground radial system

Description : The advantage of using top loading in a shortened HF vertical antenna is A. lower quality factor B. greater structural strength C. higher losses D. improved radiation efficiency

Last Answer : D. improved radiation efficiency

Description : The enzyme systems for lengthening and shortening for saturating and desaturating of fatty acids occur in (A) Intestine (B) Muscle (C) Kidney (D) Liver

Last Answer : Answer : D

Description : Shortening effect of an antenna that makes it appear as if it were 5% longer. A. End effect B. Flywheel effect C. Skin effect D. Capture effect

Last Answer : A. End effect

Description : The vertical dotted line connecting the small circular symbols at coordinates '05L', '09L', '13L', '21L', '25L', etc., shown in the illustration, indicate that all _______________. EL-0100 A. contacts are ... board 'TB2' C. wires are grounded at both ends of the line D. wires have a common shield

Last Answer : Answer: B

Description : What is actual length in feet of a one-half wavelength of a coax with a velocity factor of 0.59 at 26 MHz? A. 11.16 B. 40.29 C. 42.46 D. 46.28

Last Answer : A. 11.16

Description : What is the actual length in feet of a one-half wavelength of a coax with a velocity factor of 0.63 at 28 MHz? A. 44.28 B. 43.46 C. 11.07 D. 46.27

Last Answer : C. 11.07

Description : One of the following is very useful as a multiband HF receiving antenna. A. Parabolic antenna B. Elementary doublet C. Log-periodic D. Square loop

Last Answer : C. Log-periodic

Description : What is the usual electrical length of a driven element in an HF beam antenna? A. ¼ wavelength B. ¾ wavelength C. ½ wavelength D. 1 wavelength

Last Answer : C. ½ wavelength

Description : This is a flexible vertical rod antenna commonly used on mobiles. A. Marconi B. Hertz C. Whip D. Ground plane

Last Answer : C. Whip

Description : Which antenna is not grounded at one end? A. Hertz B. Marconi C. Dipole D. Whip

Last Answer : C. Dipole

Description : One of the following prevents a transmitter from emitting a signal that interferes with other stations on frequency during the test. A. Use of low height antenna B. Use of grounded antenna C. Use of dummy antenna D. Use of shielded antenna radiator

Last Answer : C. Use of dummy antenna

Description : The rhombic antenna is primarily used for A. ground wave propagation B. space wave propagation C. ionosphere scatter propagation D. sky wave propagation

Last Answer : D. sky wave propagation

Description : What is the difference in Coax cable, Cat 5 cable, and Quad shield?

Last Answer : Jeez, frogs and ponies. Apples and oranges would be too close. Coaxial cable has one or more conductors running down the center, separated by an insulator from a tubular foil or mesh conductive sleeve. ... , it is unshielded, which means it's about as different from coax cable as wire can be.

Description : How can intermodulation interference between two transmitters in close proximity reduced or eliminated? A. Through installing a band-pass filter in the antenna feed line B. Through installing terminated circulator ... high driving power D. By installing a low-pass filter in the antenna feed line

Last Answer : A. Through installing a band-pass filter in the antenna feed line

Description : Where are the current nodes in a half-wave antenna? A. At the ends B. At the center C. Three-quarters of the way from the feed point toward the end D. One-half of the way from the feed point toward the end

Last Answer : A. At the ends

Description : Where are the voltage nodes in a half-wave antenna? A. At the ends B. Three-quarters of the way from the feed point toward the end C. One-half of the way from the feed point toward the end D. At the feed point

Last Answer : D. At the feed point

Description : An antenna with unity gain A. Rhombic B. Half-wave dipole C. Isotropic D. Whip

Last Answer : C. Isotropic

Description : _____ is an antenna with a number of half-wave antenna on it. A. Antenna array B. Tower C. Omni-directional D. Rhombic

Last Answer : A. Antenna array

Description : At the ends of a half-wave antenna, what values of current and voltage exist compared to the remainder of the antenna? A. Minimum voltage and minimum current B. Equal voltage and current C. Minimum voltage and maximum current D. Maximum voltage and minimum current.

Last Answer : D. Maximum voltage and minimum current.

Description : Where the voltage node of a half-wave antenna does exists? A. At feed point B. Near the center C. At center D. Near the feed point

Last Answer : A. At feed point

Description : The product of the power supplied to the antenna and its gain relative to a half-wave dipole in a given direction. A. Peak envelope power B. ERP C. Rated power D. Carrier power’

Last Answer : B. ERP

Description : Unity gain antenna A. Isotropic B. Rhombic C. Half-wave dipole D. Dummy

Last Answer : A. Isotropic

Description : A type of array antenna which consists of one half-wave driven dipole, one reflector and one director A. Hertzian dipole B. Yagi-uda C. Broadside collinear D. Log periodic dipole array

Last Answer : B. Yagi-uda

Description : ECE Board Exam March 1996 The standard reference antenna for the directive gain is ___________. A. elementary doublet B. isotropic antenna C. half-wave dipole D. infinitesimal dipole

Last Answer : B. isotropic antenna

Description : A voltmeter located on a control panel has been operating correctly for six months, suddenly burns out. After removing it, it is found that neither side of the meter has been grounded. When ... side and the ground C. installed exactly as the old installation D. grounded to the positive side

Last Answer : Answer: C

Description : What circuit is responsible in activating and deactivating adjacent antenna elements in a mobile satellite array? A. Radial divider B. Divider/combiner C. Radial combiner D. Radial multiplexer

Last Answer : A. Radial divider

Description : When a transmission line uses ground return, it is called a/an __________ line. A. ungrounded B. balanced C. unbalanced D. grounded

Last Answer : C. unbalanced

Description : What is the actual length in feet of a one-quarter wavelength of a coax with a velocity factor of 0.68 to 30 MHz? A. 19.26 B. 5.6 C. 17.82 D. 16.97

Last Answer : B. 5.6

Description : What is the actual length in feet of a one-quarter wavelength of a coax with a velocity factor of 0.695 at 45 MHz? A. 17.82 B. 19.26 C. 16.28 D. 16.97

Last Answer : C. 16.28

Description : Which of the following is and impedance matching ration of coax balun? A. 2:8 B. 1:2 C. 4:1 D. 2:1

Last Answer : C. 4:1

Description : In shipboard satellite dish antennas system, azimuth is referred as the _______. A. 0 to 90 degrees B. Vertical aiming of the antenna C. North to East D. Horizontal aiming of the antenna

Last Answer : D. Horizontal aiming of the antenna

Description : What is the term for the ration of the radiation resistance of an antenna to the total resistance of the system? A. Effective radiated power B. Beamwidth C. Radiation conversion loss D. Antenna efficiency

Last Answer : D. Antenna efficiency

Description : For a shortened vertical antenna, where should a loading coil be placed to minimize losses and produce the most effective performance? A. As low as possible on the vertical radiator B. Near the center of the vertical radiator C. As close to the transmitter as possible D. At a voltage node

Last Answer : B. Near the center of the vertical radiator

Description : In horizontal-dipole antenna, the polarization is A. in the vertical direction B. in the horizontal direction C. circular D. measured at the center of the antenna

Last Answer : B. in the horizontal direction

Description : What antenna radiates equally in all directions? A. Vertical antenna B. isotropic antenna C. Horizontal antenna D. Dipole antenna

Last Answer : B. isotropic antenna

Description : In order to get maximum radiation to all surrounding points in the horizontal plane, the antenna used is a A. vertical loop B. vertical quarter-wavelength rod C. array which includes parasitic elements D. a horizontal Hertz dipole

Last Answer : B. vertical quarter-wavelength rod

Description : A vertical loop antenna has a A. unidirectional radiation pattern in the horizontal plane B. unidirectional radiation pattern in the vertical plane C. omnidirectional radiation pattern in the horizontal plane D. a bidirectional radiation pattern in the horizontal plane

Last Answer : D. a bidirectional radiation pattern in the horizontal plane

Description : A one-quarter wavelength shunt-fed vertical Marconi antenna A. has maximum radiation in a vertical direction B. must have a horizontal receiving antenna for the best reception C. must use a receiving antenna for the best reception D. must have a vertical receiving antenna for the best reception

Last Answer : D. must have a vertical receiving antenna for the best reception

Description : Which of the following antennas receive signals in the horizontal plane equality well from all directions? A. Horizontal Hertz antenna B. Vertical loop antenna C. Vertical Yagi antenna D. A vertical antenna which is a quarter-wavelength long

Last Answer : D. A vertical antenna which is a quarter-wavelength long

Description : Which antenna radiates an omnidirectional pattern in the horizontal plane with vertical polarization? A. Marconi antenna B. Discone antenna C. Horn antenna D. Helical antenna

Last Answer : A. Marconi antenna

Description : Which does not use vertical polarization antenna? A. AM Broadcasting B. FM Broadcasting C. Mobile Communications D. Satellite Communications

Last Answer : B. FM Broadcasting

Description : What is the polarization of a discone antenna? A. Vertical B. Horizontal C. Circular D. Spiral

Last Answer : A. Vertical

Description : Which of the following antennas receives signals equally well from all directions in a horizontal plane? A. Hetz antenna B. Vertical Marconi antenna C. Yagi antenna D. Helical antenna

Last Answer : B. Vertical Marconi antenna

Description : The polarization of a discone antenna is _____. A. Horizontal B. Vertical C. Omni D. Directional

Last Answer : B. Vertical

Description : If the modulation index of an AM wave is doubled, the antenna current is also doubled, the AM system being used is A. A5C B. A3J C. A3H D. A3

Last Answer : B. A3J

Description : An antenna efficiency is computed by using one of the following equations. A. Efficiency = (radiation resistance / transmission resistance) B. Efficiency = (total resistance / radiation resistance) x ... / transmitter output) x 100% D. Efficiency = (radiation resistance / total resistance) x 100%

Last Answer : D. Efficiency = (radiation resistance / total resistance) x 100%

Description : A final amplifier of a radio transmitter draws 250 mA of plate current when the plate supply voltage is 1400 volts. If the plate circuit efficiency is 80% and the transmitter is connected to an antenna having a feed impedance of 70 ohms, ... at the feed-point? A. 4.0 A B. 2.2 A C. 1.25 A D. 2.0 A

Last Answer : D. 2.0 A

Description : _____ of an antenna is a measure of how the antenna concentrates its radiated power in a given direction. A. Efficiency B. Power C. Gain D. Polarization

Last Answer : C. Gain

Description : What is meant by the term antenna efficiency? A. Efficiency = effective radiated power/transmitter output x 100% B. Efficiency = radiation resistance/ transmission resistance C. Efficiency = total resistance/radiation resistance x 100% D. Efficiency = radiation resistance/total resistance x 100%

Last Answer : D. Efficiency = radiation resistance/total resistance x 100%