Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ELEMENT 3 > FCC Element 3 > Flashcards

FCC Element 3 Flashcards

FCC Exam

1
Q

What is the name of the semiconductor memory IC whose digital data can be written or read, and whose memory word address can be accessed randomly?

A

RAM - Random Access Memory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is facsimile?

A

The transmission of printed pictures for permanent display on paper.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a flip-flop circuit? A binary sequential logic element with ____stable states.

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the definition of detection in a radio receiver?

A

The recovery of intelligence from the modulated RF signal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the purpose of not putting sharp corners on the ground leads within a building?

A

Lightning will jump off the ground lead because it is not able to make sharp bends.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a common use of a hot-carrier diode?

A

VHF and UHF mixers and detectors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What type of antenna is used in an aircraft’s Instrument Landing System (ILS) glideslope Installation?

A

A folded dipole reception antenna.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

A switching electronic voltage regulator:

A

Switches the contol device on or off, with the duty cycle proportional to the line or load conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter?

A

6 watts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of antenna is used in an aircraft’s Very High Frequency Omnidirectional Range (VOR) and Localizer (LOC) installations?

A

Horizontally polariezed omnidirection reception antenna.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What turns ratio does a transformer need in order to match a source impedance of 500 ohms to a load of 10 ohms?

A

7.1 to 1.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

TTL inputs left open develop what logic state?

A

A high-logic state.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the common method for determining the exact sensitivity specifications of a receiver?

A

Measure the recovered audio for 12 dB of SINAD?.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Halving the cross-sectional area of a conductor wil:

A

Double the resistance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which type of oscillator circuit is commonly used in aVFO (variable frequency oscillator)?

A

Colpitts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Compliance with MPE, or Maximum Permissible Exposure to RF levels (as defined in /fcc Part 1, GET Buletin 65) for “controlled” environments, are averaged over _____ minutes, while “uncontrolled” RF environments are averaged over _____minutes.

A

6, 30.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where would you normally find a low-pass filter in a radio receiver?

A

A and C, but not B.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the frequency range of the localizer beam system used by the aircraft to find the centerline of a runway during an Instrument Landing System (ILS) approach to an airport?

A

108.10 MHz to 111.95 MHz.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The ATR box:

A

Prevents the received signal from entering the transmitter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What portion of a microprocessor circuit is the pulse generator?

A

Clock.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the term used to refer to the condition where the signals from a very strong station ae superimposed on other signals being received?

A

Cross-modulation interference.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the name of the condition that occurs when the signals of two transmitters in close proximity mix together in one or both of their final amplifiers, and uwanted signals at the sum and difference frequencies of the original transmissions are generated?

A

Intermodulation interference.

23
Q

The GSM (Global System for Mobile Communications) uses what type of CODEC for digital mobile radio system communications?

A

Regular-Pulse Excited (RPE).

24
Q

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz and accepting a maximum modlation rate of 3.5 kHz?

A

2.14

25
Q

How might an installer verify correcy GPS sentence to marine DSC-VHF display?

A

Look for latitude and longitude, plus s[eed, on VHF display.

26
Q

A TDMA radio uses what to carry the multiple conversations sequentially?

A

Separate time slots.

27
Q

When engaging in voice communications via an INMARSAT-B terminal, what techniques are used?

A

CODECs are used to digitize the voice signal.

28
Q

What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

A

Undesired signals will reach the audio stage.

29
Q

What is the main function of the COSPAS-SARSAT satellite system?

A

Monitor 406 MHz for distress calls from EPIRBs.

30
Q

In a CTSS controlled FM receiver tone is filtered out after the:

A

Discriminator but before the audio section.

31
Q

What is the term used to refer to a reduction in receiver sensitivity caused by unwanted high-level adjacent channel signals?

A

Desensitizing.

32
Q

What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain?

A

126 watts.

33
Q

In an FM-phone signal, what is the term for the maximum deviation from the carrier frequency divided by the maximum audio modulating frequecy?

A

Deviation ratio.

34
Q

In what stage of a VHF receiver would a low noise amplifier be most advantageous?

A

Front end RF stage.

35
Q

What is the best description for the INMARSAT-C system?

A

It is a store-and-forward system that provides routine and distress communications.

36
Q

Which of the following statements about SSB voice ransmissions is correct?

A

They normally use J3E emissions, which consists of one sideband and a suppressed carrier.

37
Q

What is the digital signal processing term for noise subtraction circuitry?

A

Adaptive filtering and autocorrelation.

38
Q

What is the purpose of de-emphasis in the receiver audio stage?

A

When coupled with the transmitter pre-emphasis, flat audio and noise reduction is received.

39
Q

What type of signals are used to conduct an SSB two-tone test?

A

Two non-harmonically related audio signals that are within the modulation band pass of the transmitter.

40
Q

The majority of airborne Distance Measuring Equipment systems automatically tune their transmitter and receiver frequencies to the paired ___/____ channel.

A

VOR/LOC.

41
Q

What VHF Channel is used for Digital Selective Calling and acknowledgement?

A

70

42
Q

What is the normal range of pulse widths?

A

.05 µs to 1.0 µs.

43
Q

What is the purpose of a coupling capacitor?

A

It blocks direct current and passes alternating current.

44
Q

Which of these filters can be used in micro-miniature electronic circuits?

A

Receiver SAW IF filter.

45
Q

A circuit that compares the output of a coltage-controlled oscillator (VCO) to a frequency standard and produces an errr voltage that is then used to adjust the capacitance of a varactor diode used to control frequency in that same VCO is called what?

A

Phase-locked loop.

46
Q

How can selectivity be achieved in the front-end circuitry of a communications receiver?

A

By using a preselector.

47
Q

What is the process of detection in a radio diode detector circuit?

A

Rectification and fitering of RF.

48
Q

Aircraft Emergency Locator Transmitters (ELT) operate on what frequencies?

A

121.5, 243 and 405 MHz.

49
Q

The Distance Measuring Equipment (DME) measures the distance from the aircraft to the DME ground station. This is referred to as:

A

The slant range.

50
Q

Which of the following is a required component of an Instrument Landing System (ILS)?

A

Locallizer shows aircraft deviation horizontally from center of runway.

51
Q

What is a product detector?

A

It uses a mixing process with a locally generated carrier.

52
Q

What is the purpose of a bypass capacitor?

A

It removes alternating current by providing a low impedance path to ground.

53
Q
A

ELEMENT 3 (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions