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technician pool

Subelement T3 question review

All 35 official questions with the exact winning phrase marked.

T3A01T3A

Why do VHF signal strengths sometimes vary greatly when the antenna is moved only a few feet?

CMultipath propagation cancels or reinforces signals
Why this answer

The reason is multipath propagation cancels or reinforces signals. Connect the cause in the question to this direct result instead of memorizing the answer letter.

Memory hook: A half wave dipole is two quarter wave legs.

T3A02T3A

How does vegetation affect UHF and microwave signals?

BAbsorbs signals, leading to poor reception of weak signals
Why this answer

Use this action or method: Absorbs signals, leading to poor reception of weak signals. It is the choice that directly completes the job described in the question.

T3A03T3A

What antenna polarization is normally used for long-distance CW and SSB contacts on the VHF and UHF bands?

CHorizontal
Why this answer

The key fact is Horizontal. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

Memory hook: A half wave dipole is two quarter wave legs.

T3A04T3A

What is the effect of antenna cross-polarization over a line-of-sight VHF or UHF path?

BReceived signal strength is reduced
Why this answer

The key fact is Received signal strength is reduced. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

Memory hook: A half wave dipole is two quarter wave legs.

T3A05T3A

When using a directional antenna, how might your station be able to communicate with a distant repeater if buildings or obstructions are blocking the direct line of sight path?

BTry to find a path that reflects signals to the repeater
Why this answer

The key fact is Try to find a path that reflects signals to the repeater. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

Memory hook: A repeater receives on one frequency and transmits on another.

T3A06T3A

What is the meaning of the term “picket fencing”?

BRapid flutter on mobile signals due to multipath propagation
Why this answer

The key fact is Rapid flutter on mobile signals due to multipath propagation. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3A07T3A

What weather condition might decrease range at microwave frequencies?

CPrecipitation
Why this answer

The key fact is Precipitation. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3A08T3A

What is a likely cause of irregular fading of signals propagated by the ionosphere?

DRandom combining of signals arriving via different paths
Why this answer

The key fact is Random combining of signals arriving via different paths. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3A09T3A

Which of the following results from the fact that signals propagated by the ionosphere are elliptically polarized?

BEither vertically or horizontally polarized antennas may be used for transmission or reception
Why this answer

The key fact is Either vertically or horizontally polarized antennas may be used for transmission or reception. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

Memory hook: A half wave dipole is two quarter wave legs.

T3A10T3A

What effect does multi-path propagation have on data transmissions?

DError rates are likely to increase
Why this answer

The key fact is Error rates are likely to increase. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3A11T3A

Which region of the atmosphere can reflect HF radio waves?

CThe ionosphere
Why this answer

The key fact is The ionosphere. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3A12T3A

What effect does fog or rain have on 10-meter and 6-meter band signals?

BLittle effect
Why this answer

The key fact is Little effect. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3B01T3B

What is the relationship between the electric and magnetic fields of an electromagnetic wave?

DThey are at right angles
Why this answer

The key fact is They are at right angles. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3B02T3B

What property of a radio wave defines its polarization?

AThe orientation of the electric field
Why this answer

The key fact is The orientation of the electric field. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3B03T3B

What are the two components of a radio wave?

CElectric and magnetic fields
Why this answer

The key fact is Electric and magnetic fields. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3B04T3B

What is the velocity of a radio wave traveling through free space?

ASpeed of light
Why this answer

The key fact is Speed of light. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3B05T3B

What is the relationship between wavelength and frequency?

BWavelength gets shorter as frequency increases
Why this answer

The key fact is Wavelength gets shorter as frequency increases. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

Wavelength in meters = 300 ÷ frequency in MHz
T3B06T3B

What is the formula for converting frequency to approximate wavelength in meters?

DWavelength in meters equals 300 divided by frequency in megahertz
Why this answer

The key fact is Wavelength in meters equals 300 divided by frequency in megahertz. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

Wavelength in meters = 300 ÷ frequency in MHz
T3B07T3B

In addition to frequency, which of the following is used to identify amateur radio bands?

AThe approximate wavelength in meters
Why this answer

The key fact is The approximate wavelength in meters. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3B08T3B

What frequency range is referred to as VHF?

B30 MHz to 300 MHz
Why this answer

The key fact is 30 MHz to 300 MHz. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3B09T3B

What frequency range is referred to as UHF?

D300 to 3000 MHz
Why this answer

The key fact is 300 to 3000 MHz. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3B10T3B

What frequency range is referred to as HF?

C3 to 30 MHz
Why this answer

The key fact is 3 to 30 MHz. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3B11T3B

What is the approximate velocity of a radio wave in free space?

B300,000,000 meters per second
Why this answer

The required value is 300,000,000 meters per second. Keep the units with the number so a nearby distractor cannot pull you away from the result.

T3B12T3B

Which of these frequencies travels at the highest velocity in free space?

DAll radio frequencies travel at the same velocity
Why this answer

The key fact is All radio frequencies travel at the same velocity. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C01T3C

Why are simplex UHF signals rarely heard beyond their radio horizon?

CUHF signals are usually not propagated by the ionosphere
Why this answer

The reason is uHF signals are usually not propagated by the ionosphere. Connect the cause in the question to this direct result instead of memorizing the answer letter.

T3C02T3C

What is a characteristic of HF communication compared with communications on VHF and higher frequencies?

CLong-distance ionospheric propagation is far more common on HF
Why this answer

The key fact is Long-distance ionospheric propagation is far more common on HF. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C03T3C

What is one characteristic of VHF signals received via auroral backscatter?

BThey are distorted, with a characteristic raspy sound
Why this answer

The key fact is They are distorted, with a characteristic raspy sound. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C04T3C

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

BSporadic E
Why this answer

The key fact is Sporadic E. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C05T3C

Which of the following effects may allow radio signals to travel beyond obstructions between the transmitting and receiving stations?

AKnife-edge diffraction
Why this answer

The key fact is Knife-edge diffraction. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C06T3C

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

ATropospheric ducting
Why this answer

The key fact is Tropospheric ducting. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C07T3C

What band is best suited for communicating via meteor scatter?

B6 meters
Why this answer

The key fact is 6 meters. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C08T3C

What causes tropospheric ducting?

DTemperature inversions in the atmosphere
Why this answer

The key fact is Temperature inversions in the atmosphere. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C09T3C

What is generally the best time for long-distance 10-meter band propagation via the F region?

AFrom dawn to shortly after sunset during periods of high sunspot activity
Why this answer

The key fact is From dawn to shortly after sunset during periods of high sunspot activity. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C10T3C

Which of the following bands may provide long-distance communications via the ionosphere’s F region during the peak of the sunspot cycle?

A6 and 10 meters
Why this answer

The key fact is 6 and 10 meters. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

T3C11T3C

Why is the radio horizon for VHF and UHF signals more distant than the visual horizon?

CThe atmosphere refracts radio waves slightly
Why this answer

The reason is the atmosphere refracts radio waves slightly. Connect the cause in the question to this direct result instead of memorizing the answer letter.