T9A: Antenna types - vertical, horizontal, concept of gain, common portable and mobile antennas, losses with short antennas, relationships between antenna length and frequency, dummy loads
T9A01:
What is a beam antenna?
An antenna that concentrates signals in one direction
An antenna built from metal I-beams
An antenna that transmits and receives equally well in all directions
An antenna that reverses the phase of received signals
T9A02:
What is an antenna that consists of a single element mounted perpendicular to the Earth's surface?
A vertical antenna
A conical monopole
A horizontal antenna
A traveling wave antenna
T9A03:
What type of antenna is a simple dipole mounted so the elements are parallel to the Earth's surface?
A horizontal antenna
A ground wave antenna
A rhombic antenna
A vertical antenna
T9A04:
What is a disadvantage of the "rubber duck" antenna supplied with most hand held radio transceivers?
It does not transmit or receive as effectively as a full sized antenna
It is much more expensive than a standard antenna
If the rubber end cap is lost it will unravel very quickly
It transmits a circular polarized signal
T9A05:
How does the physical size of half-wave dipole antenna change with operating frequency?
It becomes shorter as the frequency increases
It becomes longer as the frequency increases
It must be made larger because it has to handle more power
It becomes shorter as the frequency decreases
T9A06:
What is the advantage of 5/8 wavelength over 1/4 wavelength vertical antennas?
Their radiation pattern concentrates energy at lower angles
They are easier to match to the feed line than other types
They pick up less noise
Their radiation pattern concentrates energy at higher angles
T9A07:
What is the primary purpose of a dummy load?
It does not radiate interfering signals when making tests
It will prevent over-modulation of your transmitter
It keeps you from making mistakes while on the air
It is used for close in work to prevent overloads
T9A08:
What type of antennas are the quad, Yagi, and dish?
Directional or beam antennas
Antennas invented after 1985
Loop antennas
Antennas that are not permitted for amateur radio stations
T9A09:
What is one type of antenna that offers good efficiency when operating mobile and can be easily installed or removed?
A magnet mount vertical antenna
A microwave antenna
A quad antenna
A traveling wave antenna
T9A10:
What is a good reason not to use a "rubber duck" antenna inside your car?
Signals can be 10 to 20 times weaker than when you are outside of the vehicle
RF energy trapped inside the vehicle can distort your signal
You might cause a fire in the vehicle upholstery
The SWR might increase
T9A11:
What is the approximate length, in inches, of a quarter-wavelength vertical antenna for 146 MHz?
19 inches
112 inches
50 inches
12 inches
T9A12:
What is the approximate length, in inches, of a 6-meter 1/2 wavelength wire dipole antenna?
112 inches
6 inches
50 inches
236 inches
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