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T3Edit

The T3 section of the Technician test contains information on radio wave characteristics, radio and electromagnetic properties, propagation modes.

T3AEdit

The T3A section covers radio wave characteristics; how a radio signal travels; distinctions of HF, VHF and UHF; fading, multipath; wavelength vs. penetration; antenna orientation.
Click "Expand" to reveal the questions.

T3A01

What should you do if another operator reports that your station’s 2 meter signals were strong just a moment ago, but now they are weak or distorted?
Try moving a few feet, as random reflections may be causing multi-path distortion

T3A02

Why are UHF signals often more effective from inside buildings than VHF signals?
The shorter wavelength allows them to more easily penetrate the structure of buildings

T3A03

What antenna polarization is normally used for long-distance weak-signal CW and SSB contacts using the VHF and UHF bands?
Horizontal

T3A04

What can happen if the antennas at opposite ends of a VHF or UHF line of sight radio link are not using the same polarization?
Signals could be significantly weaker

T3A05

When using a directional antenna, how might your station be able to access a distant repeater if buildings or obstructions are blocking the direct line of sight path?
Try to find a path that reflects signals to the repeater

T3A06

What term is commonly used to describe the rapid fluttering sound sometimes heard from mobile stations that are moving while transmitting?
Picket fencing

T3A07

What type of wave carries radio signals between transmitting and receiving stations?
Electromagnetic

T3A08

What is the cause of irregular fading of signals from distant stations during times of generally good reception?
Random combining of signals arriving via different path lengths

T3A09

Which of the following is a common effect of "skip" reflections between the Earth and the ionosphere?
The polarization of the original signal is randomized

T3A10

What may occur if VHF or UHF data signals propagate over multiple paths?
Error rates are likely to increase

T3A11

Which part of the atmosphere enables the propagation of radio signals around the world?
The ionosphere

T3BEdit

The T3B section covers radio and electromagnetic wave properties; the electromagnetic spectrum, wavelength vs. frequency, velocity of electromagnetic waves.
Click "Expand" to reveal the questions.

T3B01

What is the name for the distance a radio wave travels during one complete cycle?
Wavelength

T3B02

What term describes the number of times per second that an alternating current reverses direction?
Frequency

T3B03

What are the two components of a radio wave?
Electric and magnetic fields

T3B04

How fast does a radio wave travel through free space?
At the speed of light

T3B05

How does the wavelength of a radio wave relate to its frequency?
The wavelength gets shorter as the frequency increases

T3B06

What is the formula for converting frequency to wavelength in meters?
Wavelength in meters equals 300 divided by frequency in megahertz

T3B07

What property of radio waves is often used to identify the different frequency bands?
The approximate wavelength

T3B08

What are the frequency limits of the VHF spectrum?
30 to 300 MHz

T3B09

What are the frequency limits of the UHF spectrum?
300 to 3000 MHz

T3B10

What frequency range is referred to as HF?
3 to 30 MHz

T3B11

What is the approximate velocity of a radio wave as it travels through free space?
300,000,000 meters per second

T3CEdit

The T3C section covers Propagation modes; line of sight, sporadic E, meteor, aurora scatter, tropospheric ducting, F layer skip, radio horizon.
Click "Expand" to reveal the questions.

T3C01

Why are "direct" (not via a repeater) UHF signals rarely heard from stations outside your local coverage area?
UHF signals are usually not reflected by the ionosphere

T3C02

Which of the following might be happening when VHF signals are being received from long distances?
Signals are being refracted from a sporadic E layer

T3C03

What is a characteristic of VHF signals received via auroral reflection?
The signals exhibit rapid fluctuations of strength and often sound distorted

T3C04

Which of the following propagation types is most commonly associated with occasional strong over-the-horizon signals on the 10, 6, and 2 meter bands?
Sporadic E

T3C05

What is meant by the term "knife-edge" propagation?
Signals are partially refracted around solid objects exhibiting sharp edges

T3C06

What mode is responsible for allowing over-the-horizon VHF and UHF communications to ranges of approximately 300 miles on a regular basis?
Tropospheric scatter

T3C07

What band is best suited to communicating via meteor scatter?
6 meters

T3C08

What causes "tropospheric ducting"?
Temperature inversions in the atmosphere

T3C09

What is generally the best time for long-distance 10 meter band propagation?
During nighttime hours

T3C10

What is the radio horizon?
The distance at which radio signals between two points are effectively blocked by the curvature of the Earth

T3C11

Why do VHF and UHF radio signals usually travel somewhat farther than the visual line of sight distance between two stations?
The Earth seems less curved to radio waves than to light

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