A & P Flashcards

1
Q

What is the speed of light in meters per second?

A

300,000,000 mps

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2
Q

What is the civilian HF frequency band?

A

3 MHz to 30 MHz

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3
Q

How many 5khz channels would you get in the UHF bandwidth? (Remember-kilohertz: 1000 hertz, megahertz: 1000, 000)

A

UHF bandwidth is 300-3000Mhz giving 2700 MHz bandwidth; therefore answer should be 2700, 000, 000 divided by 5000 equals: 5400 channels

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4
Q

What is the relationship between Wavelength and Frequency?

A

Higher Frequency shorter wavelength

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5
Q

What is the polarization of a SATCOM antenna?

A

Polarization of a Satcom antenna is circular

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6
Q

Name the three components of a radio wave?

A

Frequency ( f )
Wavelength ( lambda )
Velocity ( v )

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7
Q

How will the ionosphere affect at night effect UHF Tacsat communication?

A

Less resistance and refraction than than during the day time. therefore less interference and potential clearer Tacsat comm

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8
Q

How will the ionosphere affect HF comms at night?

A

Higher frequencies will pass through the ionosphere and less will be reflected back to the surface

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9
Q

Name the three types of radio wave?

A

Skywave
Space wave - Direct wave
- Ground reflected
Surface wave

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10
Q

Give one predictable Ionospheric variation?

A

Geographical
Seasonal
Daily
Sunspot cycle

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11
Q

Give one unpredictable Ionospheric variation?

A

Solar flares
Magnetic storms
Sporadic E

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12
Q

What is the symbol for writing wavelength and its name?

A

LAMBDA

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13
Q

Name 2 factors effecting surface wave?

A
Polarisation
Frequency
Ground
Terrain
Obstacles
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14
Q

Factors effecting space wave?

A

Antenna height
Refraction in lower atmosphere
Obstacles terrain

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15
Q

Name the layers of the ionosphere and what happens at night?

A

F2
F1
E
D

Turn into one F layer at night

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16
Q

Explain skip zone?

A

The zone where surface wave stops and sky wave returns to Earth

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17
Q

Explain skip distance?

A

Distance where the wave leaves antenna to where it first returns to Earth

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18
Q

What does NVIS stand for?

A

Near Vertical Incidence Skywave

19
Q

Name two factors common to all 3 types of propagation?

A

Antenna
Noise
Power output of transmitter
Receiver

20
Q

What is the working out triangle ?

A

V
_________
F | Lambda

21
Q

Name the antenna categories?

A

Resonant
Traveling wave
Wideband/broadband

22
Q

What is the calculation for a ¼ wavelength antenna for a freq of 9 MHz?

A

300,000,000 metres per second divided by 9,000,000 hz equals: 33.3 metres. Divided by four to produce a 1/4λ antenna equals: 8.3 metres

They may also answer: 75/9 which also equals 8.3 metres.

23
Q

What travels faster through Free Space, radio waves, gamma waves or x-rays ?

A

None, they all travel the same speed – the speed of light

24
Q

In what direction do you get the most gain (signal strength) from an HF Dipole Antenna?

A

The HF Dipole is omni-directional at close range, but for highest gain and furthest distance the antenna needs to be orientated broadside on towards the receiving station

25
Q

Name the 5 components of a radio station?

A
power supply
inteligence input and output
transceiver
transmission line
antenna
26
Q

What does EMC stand for?

A

Electromagnetic Capability

27
Q

What do AM and FM stand for?

A
AM = Amplitude modulation
FM = Frequency Modulation
28
Q

What does USB AND LSB stand for?

A

Upper side band

Lower side band

29
Q

Factors effecting surface wave range?

A
height
polarisation
type of ground
frequency
terrain
30
Q

What does the power supply do on a radio station?

A

dc power

drives electronic components

31
Q

What is the transceiver made up of??

A

RF transmitter

RF receiver

32
Q

What does the rRF transmitter do??

A

converts speech into RF

amplifies it into a signal to TX

33
Q

What does the RF receiver do??

A

RF intelligence from antenna

amplifies and convert it back to its original form

34
Q

What is the intelligence input and output made up of?

A

headset or handset microphone

35
Q

What is the transmission line?

A

Coax

36
Q

What capabilities must the transmission line have?

A

Flexible and robust

37
Q

What is the antenna made up of?

A

TX antenna

RX antenna

38
Q

What is the definition of a frequency?

A

Frequency is the number of complete cycles of an alternating radio wave that pass a given point in 1 secondA AND P Q

39
Q

Two materials use in antenna makeup and resistance number??

A

Copper wire - 71.3

Brad - 68.5

40
Q

When does a resonant antenna perform to the best effectiveness?

A

When the length of the antenna corresponds to the wavelength in use

41
Q

What does MEMIC stand for? And what causes it?


A

Mobile Electromagnetic Incompatibility

Vibrating metal objects

42
Q

Surfaces wave range?


A

Ranges up to 100km

43
Q

What is a UNipole half of?

A

A dipole