Vol2 URE2 CDC 3D153

1. (214) The abbreviation FOT is derived from the term?

Outbound traffic frequency

Optimum tropospheric frequency

Frequency of optimum transmission

Frequency of outbound frequency

2. (214) In high frequency (HF) communications, the lowest frequency that arrives at the distant receiver on 90 percent of the undisturbed days of the month is called the?

Maximum usable frequency (MUF)

Lowest usable frequency (LUF)

Operating frequency

Critical frequency

3. (213) Radio waves that travel near the earth's surface are called

Earth waves

Global waves

Ground waves

Terrestrial waves

4. (219) Super high frequency (SHF)/extremely high frequency (EHF) range is limited to?

Scattering

Line-of-sight (LOS)

Earth's conductivity

Atmospheric absorption

5. (216) What U.S. government agency divides the radio frequency (RF) spectrum into different bands?

Federal Aviation Agency

American National Standard Institute

Federal Communications Commission

Institute of Electrical & Electronics Engineers, INC

6. (215) Sunspots are disturbances?

In the sun's atmosphere

On the sun's surface

In the ionosphere

Beneath the sun's surface

7. (214) Which gives sky wave propagation its ability to communicate beyond the optical line-ofsight (LOS)?

Refraction

Reflection

Earth's conductivity

Atmospheric change

8. (213) Sky wave transmission is used for which type of communications?

Long distance

Subterrestrial

Atmospheric

Line of sight

9. (214) Frequencies higher than the critical frequency are?

Returned to earth

Passed into space

The most desirable

Refracted by the F2 layer

10. (220) In a move to overcome the limited range of forward propagation by tropospheric scatter (FPTS) without requiring many costly relay systems, what was developed?

Optical horizon radar

Satellite communications

Microwave communications

Line-of-sight (LOS) communication

11. (216) For communications purposes, the usable frequency spectrum ranges from?

3Hz to 300 GHz+

300 Hz to 3000 GHz

3000 Hz to 3000 GHz

30 MHz to 300 MHz

12. (214) Which gives sky wave propagation its ability to communicate beyond the optical line-of sight (LOS)?

Refraction

Reflection

Earth's conductivity

Atmospheric charge

13. (215) What is the recombination process dependent upon?

Season

Time of day

Regular variation

Irregular variations

14. (220) A radio wave originated at a center source in free space. If the field strength at one mile from the source has a field strength of 100 microvolts per meter, what is the field strength at two miles?

25 microvolts per metear

50 microvolts per meter

100 microvolts per meter

200 microvolts per meter

15. (215) Which layer of the ionosphere is most important to high frequency (HF) communications?

D

E

F

Topside

16. (214) Magneton splitting creates two waves called?

Direct and indirect

Ordinary and abnormal

In-phase and out-of-phase

Ordinary and extraordinary

17. (217) What frequency bands doe the MILSTAR satellite system use?

High frequency (HF) and Ultra high Frequency (UHF)

Super-High Frequency (SHF) and Extremely high frequency (EHF)

Very high frequency (VHF) and SHF

VHF and UHF

18. (217) What frequency band is most susceptible to jamming?

Low frequency

Medium frequency

High Frequency

Very High Frequency

19. (215) During what season do we have the wider range of critical frequencies and less absorption of all frequencies?

Fall

Winter

Spring

Summer

20. (213) Direct waves are radio waves that travel

Long distances with few interruptions

From point to point along the earth’s surface

Through the air in a straight line.

No more than 20 miles to the receive antenna

21. (218) The main very high frequency (VHF) Ultra high frequency (UHF) communications emphasis is on?

Long range deployable communications

Short range fixed communications

Emergency communications

Air-ground communications

22. (214) What occurs when a transmitted signal travels over two or more separate paths during transmission?

Skip effects

Modulation

Multipathing

Magneton splitting

23. (217) Near-vertical-incidence sky (NVIS) wave operations are most effective when you're using?

Lower high frequency (HF) frequencies

Higher HF frequencies

Medium HF frequencies

Low takeoff antenna angles

24. (220) When comparing the radio and optical horizons, which one is farther away and by what percent?

Optical; 15

Radio; 15

Optical; 33

Radio; 33

25. (220) When K is greater than 4/3, the radio horizon will?

Decrease, then increase.

Remain the same

Decrease

Increase

26. (220) Why isn't very high frequency (VHF) normally used for satellite communications?

The frequency is too low

The frequency is too high

Ionospheric refraction can occur

The rate of absorption is too great

Vol2 Ure2 CDC 3D153

1. (214) The abbreviation FOT is derived from the term?

2.

What first name or nickname would you like us to use?

2. (214) In high frequency (HF) communications, the lowest frequency that arrives at the distant receiver on 90 percent of the undisturbed days of the month is called the?

3. (213) Radio waves that travel near the earth's surface are called

4. (219) Super high frequency (SHF)/extremely high frequency (EHF) range is limited to?

5. (216) What U.S. government agency divides the radio frequency (RF) spectrum into different bands?

6. (215) Sunspots are disturbances?

7. (214) Which gives sky wave propagation its ability to communicate beyond the optical line-ofsight (LOS)?

8. (213) Sky wave transmission is used for which type of communications?

9. (214) Frequencies higher than the critical frequency are?

10. (220) In a move to overcome the limited range of forward propagation by tropospheric scatter (FPTS) without requiring many costly relay systems, what was developed?

11. (216) For communications purposes, the usable frequency spectrum ranges from?

12. (214) Which gives sky wave propagation its ability to communicate beyond the optical line-of sight (LOS)?

13. (215) What is the recombination process dependent upon?

14. (220) A radio wave originated at a center source in free space. If the field strength at one mile from the source has a field strength of 100 microvolts per meter, what is the field strength at two miles?

15. (215) Which layer of the ionosphere is most important to high frequency (HF) communications?

16. (214) Magneton splitting creates two waves called?

17. (217) What frequency bands doe the MILSTAR satellite system use?

18. (217) What frequency band is most susceptible to jamming?

19. (215) During what season do we have the wider range of critical frequencies and less absorption of all frequencies?

20. (213) Direct waves are radio waves that travel

21. (218) The main very high frequency (VHF) Ultra high frequency (UHF) communications emphasis is on?

22. (214) What occurs when a transmitted signal travels over two or more separate paths during transmission?

23. (217) Near-vertical-incidence sky (NVIS) wave operations are most effective when you're using?

24. (220) When comparing the radio and optical horizons, which one is farther away and by what percent?

25. (220) When K is greater than 4/3, the radio horizon will?

26. (220) Why isn't very high frequency (VHF) normally used for satellite communications?