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Extra Class Exam Question Pool

effective 7/01/2016 thru 6/29/2020

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2016-E4A: Test equipment: analog and digital instruments; spectrum and network analyzers, antenna analyzers; oscilloscopes; RF measurements; computer aided measurements

2016-E4A01: Which of the following parameter determines the bandwidth of a digital or computer-based oscilloscope?

Sampling rate

Input capacitance

Input impedance

Sample resolution

2016-E4A02: Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

RF amplitude and frequency

RF amplitude and time

SWR and frequency

SWR and time

2016-E4A03: Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

A spectrum analyzer

A wattmeter

A logic analyzer

A time-domain reflectometer

2016-E4A04: What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Analog-to-digital conversion speed of the soundcard

Amount of memory on the soundcard

Q of the interface of the interface circuit

All of these choices are correct

2016-E4A05: What might be an advantage of a digital vs an analog oscilloscope?

All of these choices are correct

Automatic amplitude and frequency numerical readout

Storage of traces for future reference

Manipulation of time base after trace capture

2016-E4A06: What is the effect of aliasing in a digital or computer-based oscilloscope?

False signals are displayed

All signals will have a DC offset

Calibration of the vertical scale is no longer valid

False triggering occurs

2016-E4A07: Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Antenna analyzers do not need an external RF source

Antenna analyzers automatically tune your antenna for resonance

Antenna analyzers display a time-varying representation of the modulation envelope

All of these choices are correct

2016-E4A08: Which of the following instrument would be best for measuring the SWR of a beam antenna?

An antenna analyzer

A spectrum analyzer

A Q meter

An ohmmeter

2016-E4A09: When using a computer's soundcard input to digitize signals, what is the highest frequency signal that can be digitized without aliasing?

One-half the sample rate

The same as the sample rate

One-tenth the sample rate

It depends on how the data is stored internally

2016-E4A10: Which of the following displays multiple digital signal states simultaneously?

Logic analyzer

Network analyzer

Bit error rate tester

Modulation monitor

2016-E4A11: Which of the following is good practice when using an oscilloscope probe?

Keep the signal ground connection of the probe as short as possible

Never use a high impedance probe to measure a low impedance circuit

Never use a DC-coupled probe to measure an AC circuit

All of these choices are correct

2016-E4A12: Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

Attenuate the transmitter output going to the spectrum analyzer

Use high quality double shielded coaxial cables to reduce signal losses

Match the antenna to the load

All of these choices are correct

2016-E4A13: How is the compensation of an oscilloscope probe typically adjusted?

A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible

A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude

A frequency standard is displayed and the probe is adjusted until the deflection time is accurate

A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate

2016-E4A14: What is the purpose of the prescaler function on a frequency counter?

It divides a higher frequency signal so a low-frequency counter can display the input frequency

It amplifies low level signals for more accurate counting

It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency

It prevents oscillation in a low-frequency counter circuit

2016-E4A15: What is an advantage of a period-measuring frequency counter over a direct-count type?

It provides improved resolution of low-frequency signals within a comparable time period

It can run on battery power for remote measurements

It does not require an expensive high-precision time base

It can directly measure the modulation index of an FM transmitter

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2016-E3C: Radio-path horizon; less common propagation modes; propagation prediction techniques and modeling; space weather parameters and amateur radio
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Extra Class Exam Question Pool
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2016-E4B: Measurement technique and limitations: instrument accuracy and performance limitations; probes; techniques to minimize errors; measurement of "Q"; instrument calibration; S parameters; vector network analyzers
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