2-47.
The elements of a broadside
array are spaced one-half
wavelength apart and are
spaced how many wavelengths
away from the reflector?
1.
1.
One–eighth
2.
One-quarter
3.
One–half
4.
Three-quarter
2-48.
What is the advantage, if any,
to offsetting a feedhorn
radiator for a parabolic dish?
1.
A broader beam angle
2.
The elimination of
shadows
3.
A narrower beam angle
4.
No advantage
2-49.
What is the range in nautical
miles of the AN/GPN-27 radar?
1.
55
2.
75
3.
105
4.
155
2-50.
What is the purpose of the
jackscrew on the
AS–3263/SPS–49(V)
antenna?
1.
To adjust the beam width
2.
To vary the antenna feed
horn focal distance
3.
To adjust the beam
elevation angle
4.
To lockdown the antenna
for PM
2-51.
The OE-172/SPS–55 antenna
normally operates in the
linearly polarized mode, for
what reason would you use the
circular polarized mode?
2-52.
Which of the following is NOT
a mode of operation for the
AN/SPN-35A radar set?
Final
2.
Dual
3.
Surveillance
4.
Simultaneous
2-53.
The two primary safety
concerns associated with rf
fields are rf burns and
injuries caused by dielectric
heating.
1.
T
2.
F
2-54.
When a person is standing in
an rf field, power in excess
of what level will cause a
noticeable rise in body
temperature?
1.
5 milliwatts
2.
10 milliwatts
3.
15 milliwatts
4.
20 milliwatts
2-55.
When working aloft, what
safety precaution(s) must be
followed?
1.
Tag out the antenna at
the switchboard to
prevent it from becoming
operational
2.
Secure motor safety
switches for rotating
antennas
3.
Wear the proper oxygen
breathing apparatus when
working near a stack
4.
All the above
1.
To compensate for the
ships pitch and roll
2.
To prevent jamming
3.
To reduce return echoes
from precipitation
4.
To achieve over the
horizon coverage
10
