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Precision Software Appli…tions Silver Collection 1
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Precision Software Applications Silver Collection Volume One (PSM) (1993).iso
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tutor
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arsg10.exe
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ARSGDAT.4AI
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Text File
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1992-10-04
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9KB
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371 lines
;/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\:
; :
; AMATEUR RADIO STUDY GUIDE v1.00 :
; :
; Copyright (c) 1992 David Drzyzga - All Rights Reserved :
; :
; Based on a program coded in BASIC by Russ Revels :
; :
;/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\:
;
; You can include comments an the file anywhere you want
; just like these comments. You cannot put a comment in
; the middle of a line though.
;
; When modifying this file, there are several things you
; must be aware of:
;
; -> Any line of text in this file cannot exceed 65 characters!
; this is the 65th character^
;
; No harm will be done, but nothing over 65 characters will
; be read by the program.
;
; -> Do not make questions more than 20 lines long, or you
; will receive an 'out of memory' error when you execute
; the program.
;
; -> You can add or delete questions as you please, just be
; sure to follow the format of the existing questions.
;
;
;
(4AI-1.1)
What is meant by the term antenna gain?
A. The numerical ratio relating the radiated signal strength of
an antenna to that of another antenna
*
(4AI-1.2)
What is the term for a numerical ratio which relates the
performance of one antenna to that of another real or
theoretical antenna?
B. Antenna gain
*
(4AI-1.3)
What is meant by the term antenna bandwidth?
B. The frequency range over which an antenna can be expected to
perform well
*
(4AI-1.4)
How can the approximate beamwidth of a rotatable beam antenna be
determined?
A. Note the two points where the signal strength of the antenna
is down 3 dB from the maximum signal point and compute the
angular difference
*
(4AI-2.1)
What is a trap antenna?
C. An antenna capable of being used on more than one band
because of the presence of parallel LC networks
*
(4AI-2.2)
What is an advantage of using a trap antenna?
D. It may be used for multiband operation
*
(4AI-2.3)
What is a disadvantage of using a trap antenna?
A. It will radiate harmonics
*
(4AI-2.4)
What is the principle of a trap antenna?
B. The traps form a high impedance to isolate parts of the
antenna
*
(4AI-3.1)
What is a parasitic element of an antenna?
C. An element that receives its excitation from mutual coupling
rather than from a transmission line
*
(4AI-3.2)
How does a parasitic element generate an electromagnetic field?
D. By currents induced into the element from a surrounding
electric field
*
(4AI-3.3)
How does the length of the reflector element of a parasitic
element beam antenna compare with that of the driven element?
A. It is about 5% longer
*
(4AI-3.4)
How does the length of the director element of a parasitic
element beam antenna compare with that of the driven element?
B. It is about 5% shorter
*
(4AI-4.1)
What is meant by the term radiation resistance for an antenna?
C. An equivalent resistance that would dissipate the same amount
of power as that radiated from an antenna
*
(4AI-4.2)
What is the term used for an equivalent resistance which would
dissipate the same amount of energy as that radiated from an
antenna?
D. Radiation resistance
*
(4AI-4.3)
Why is the value of the radiation resistance of an antenna
important?
A. Knowing the radiation resistance makes it possible to match
impedances for maximum power transfer
*
(4AI-4.4)
What are the factors that determine the radiation resistance of
an antenna?
B. The location of the antenna with respect to nearby objects
and the length/diameter ratio of the conductors
*
(4AI-5.1)
What is a driven element of an antenna?
C. The element fed by the transmission line
*
(4AI-5.2)
What is the usual electrical length of a driven element in a HF
beam antenna?
B. 1/2 wavelength
*
(4AI-5.3)
What is the term for an antenna element which is supplied power
from a transmitter through a transmission line?
A. Driven element
*
(4AI-6.1)
What is meant by the term antenna efficiency?
B. Efficiency = (radiation resistance) / (total resistance) X
100%
*
(4AI-6.2)
What is the term for the ratio of the radiation resistance of an
antenna to the total resistance of the system?
C. Antenna efficiency
*
(4AI-6.3)
What is included in the total resistance of an antenna system?
D. Radiation resistance plus ohmic resistance
*
(4AI-6.4)
How can the antenna efficiency of a HF grounded vertical antenna
be made comparable to that of a half-wave antenna?
A. By installing a good ground radial system
*
(4AI-6.5)
Why does a half-wave antenna operate at very high efficiency?
B. Because the conductor resistance is low compared to the
radiation resistance
*
(4AI-7.1)
What is a folded dipole antenna?
C. A dipole whose ends are connected by another one-half
wavelength piece of wire
*
(4AI-7.2)
How does the bandwidth of a folded dipole antenna compare with
that of a simple dipole antenna?
D. It is greater
*
(4AI-7.3)
What is the input terminal impedance at the center of a folded
dipole antenna?
A. 300 ohms
*
(4AI-8.1)
What is the meaning of the term velocity factor of a
transmission line?
D. The velocity of the wave on the transmission line divided by
the velocity of light in a vacuum
*
(4AI-8.2)
What is the term for the ratio of actual velocity at which a
signal travels through a line to the speed of light in a vacuum?
A. Velocity factor
*
(4AI-8.3)
What is the velocity factor for a typical coaxial cable?
B. 0.66
*
(4AI-8.4)
What determines the velocity factor in a transmission line?
C. Dielectrics in the line
*
(4AI-8.5)
Why is the physical length of a coaxial cable transmission line
shorter than its electrical length?
B. RF energy moves slower along the coaxial cable
*
(4AI-9.1)
What would be the physical length of a typical coaxial
transmission line which is electrically one-quarter wavelength
long at 14.1 MHz?
B. 3.55 meters
*
(4AI-9.2)
What would be the physical length of a typical coaxial
transmission line which is electrically one-quarter wavelength
long at 7.2 MHz?
B. 6.88 meters
*
(4AI-9.3)
What is the physical length of a parallel antenna feedline which
is electrically one-half wavelength long at 14.10 MHz? (assume a
velocity factor of 0.82.)
C. 8.7 meters
*
(4AI-9.4)
What is the physical length of a twin lead transmission feedline
at 3.65 MHz? (assume a velocity factor of 0.80.)
A. Electrical length times 0.8
*
(4AI-10.1)
In a half-wave antenna, where are the current nodes?
A. At the ends
*
(4AI-10.2)
In a half-wave antenna, where are the voltage nodes?
B. At the feed point
*
(4AI-10.3)
At the ends of a half-wave antenna, what values of current and
voltage exist compared to the remainder of the antenna?
C. Maximum voltage and minimum current
*
(4AI-10.4)
At the center of a half-wave antenna, what values of voltage and
current exist compared to the remainder of the antenna?
D. Minimum voltage and maximum current
*
(4AI-11.1)
Why is the inductance required for a base loaded HF mobile
antenna less than that for an inductance placed further up the
whip?
A. The capacitance to ground is less farther away from the base
*
(4AI-11.2)
What happens to the base feed point of a fixed length HF mobile
antenna as the frequency of operation is lowered?
B. The resistance decreases and the capacitive reactance
increases
*
(4AI-11.3)
Why should an HF mobile antenna loading coil have a high ratio
of reactance to resistance?
C. To minimize losses
*
(4AI-11.4)
Why is a loading coil often used with an HF mobile antenna?
D. To tune out the capacitive reactance
*
(4AI-12.1)
For a shortened vertical antenna, where should a loading coil be
placed to minimize losses and produce the most effective
performance?
A. Near the center of the vertical radiator
*
(4AI-12.2)
What happens to the bandwidth of an antenna as it is shortened
through the use of loading coils?
B. It is decreased
*
(4AI-12.3)
Why are self-resonant antennas popular in amateur stations?
C. They are the most efficient radiators
*
(4AI-12.4)
What is an advantage of using top loading in a shortened HF
vertical antenna?
D. Improved radiation efficiency
*