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48 Cards in this Set
- Front
- Back
3-74L1
What is a 1/2 digit on a DMM? |
Partial extended accuracy on lower part of the range
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3-74L2
A 50 microampere meter movement has an internal resistance of 2,000 ohms. What applied voltage is required to indicate half-scale deflection? |
0.05 volts
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3-74L3
What is the purpose of a series multiplier resistor used with a voltmeter? |
It is used to increase the voltage-indicating range of the voltmeter
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3-74L4
What is the purpose of a shunt resistor used with an ammeter? |
It is used to increase the ampere indicating range of the ammeter
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3-74L5
What instrument is used to indicate high and low digital voltage states? |
Logic probe
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3-74L6
What instrument may be used to verify proper radio antenna functioning? |
An SWR meter
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3-75L1
How is a frequency counter used? |
To measure the time between events, or the frequency, which is the reciprocal of the time
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3-75L2
What is a frequency standard? |
A device used to produce a highly accurate reference frequency
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3-75L3
What equipment may be useful to track down EMI aboard a ship or aircraft? |
Portable AM receiver
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3-75L4
On an analog wattmeter, what part of the scale is most accurate and how much does that accuracy extend to the rest of the reading scale? |
The accuracy is only at full scale, and that absolute number reading is carried through to the rest of the range. The upper 1/3 of the meter is the only truly calibrated part
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3-75L5
Which of the following frequency standards is used as a time base standard by field technicians? |
Rubidium Standard
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3-75L6
Which of the following contains a multirange AF voltmeter calibrated in dB and a sharp, internal 1000 Hz bandstop filter, both used in conjunction with each other to perform quieting tests? |
SINAD meter
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3-76L1
What is used to decrease circuit loading when using an oscilloscope? |
10:1 divider probe
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3-76L2
How does a spectrum analyzer differ from a conventional oscilloscope? |
The oscilloscope is used to display electrical signals in the time domain while the spectrum analyzer is used to display electrical signals in the frequency domain
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3-76L3
What stage determines the maximum frequency responce of an oscilloscope? |
Vertical amplifier
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3-76L4
What factors limit the accuracy, frequency response, and stability of an oscilloscope? |
Sweep oscillator quality and deflection amplifier bandwidth
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3-76L5
An oscilloscope can be used to accomplish all of the following except: |
Measure velocity of light with the aid of a light emitting diode.
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3-76L6
What instrument is used to check the signal quality of a single-sideband radio transmission? |
Oscilloscope
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3-77L1
A(n) ____ and ____ can be combined to measure the characteristics of transmission lines. Such an arrangement is known as a time-domain reflectometer (TDR). |
Oscilloscope, pulse generator
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3-77L2
What does the horizontal axis of a spectrum analyzer display? |
Frequency
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3-77L3
What does the vertical axis of a spectrum analyzer display? |
Amplitude
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3-77L4
What instrument is most accurate when checking antennas and transmission lines at the operating frequency of the antenna? |
Frequency domain reflectometer
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3-77L5
What test instrument can be used to display spurious signals in the output of a radio transmitter? |
A spectrum analyzer
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3-77L6
What instrument is commonly used by radio service technicians to monitor frequency, modulation, check receiver sensitivity, distortion, and to generate audio tones? |
Service monitor
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3-78L1
Can a P25 radio system be monitored with a scanner? |
Yes, if the scanner has P25 decoding
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3-78L2
Which of the following answers is true? |
The RF Power reading on a CDMA radio is not accurate on an analog power meter
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3-78L3
What is a common method used to program radios without using a “wired” connection? |
Infra-red communication
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3-78L4
What is the common method for determining the exact sensitivity specification of a receiver? |
Measure the recovered audio for 12 dB of SINAD
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3-78L5
A communications technician would perform a modulation-acceptance bandwidth test in order to: |
Determine the effective bandwidth of a communications receiver
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3-78L6
What is the maximum FM deviation for voice operation of a normal wideband channel on VHF and UHF? |
5.0 kHz
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3-79L1
When soldering or working with CMOS electronics products or equipment, a wrist strap: |
Must have less than 100,000 ohms of resistance to prevent static electricity
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3-79L2
Which of the following is the preferred method of cleaning solder from plated-through circuit-board holes? |
Use a vacuum device
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3-79L3
What is the proper way to cut plastic wire ties? |
With flush-cut diagonal pliers and cut flush
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3-79L4
The ideal method of removing insulation from wire is: |
The thermal stripper
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3-79L5
A “hot gas bonder” is used: |
For non-contact melting of solder
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3-79L6
When repairing circuit board assemblies it is most important to: |
Wear safety glasses
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3-80L1
What color is the binder for pairs 51-75 in a 100-pair cable? |
Green
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3-80L2
What is most important when routing cables in a mobile unit? |
Assuring radio or electronics cables do not interfere with the normal operation of the vehicle
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3-80L3
Why should you not use white or translucent plastic tie wraps on a radio tower? |
UV radiation from the Sun deteriorates the plastic very quickly
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3-80L4
What is the 6th pair color code in a 25 pair switchboard cable as is found in building telecommunications interconnections? |
Red/Blue, Blue/Red
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3-80L5
What tolerance off of plumb should a single base station radio rack be installed? |
Just inside the bubble on a level
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3-80L6
What type of wire would connect an SSB automatic tuner to an insulated backstay? |
GTO-15 high-voltage cable
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3-81L1
On a 150 watt marine SSB HF transceiver, what would be indicated by a steady output of 75 watts when keying the transmitter on? |
There is probably a defect in the system causing the carrier to be transmitted
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3-81L2
The tachometer of a building’s elevator circuit experiences interference caused by the radio system nearby. What is a common potential “fix” for the problem? |
Add a .01 µF capacitor across the motor/tachometer leads
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3-81L3
A common method of programming portable or mobile radios is to use a: |
A laptop computer
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3-81L4
In a software-defined transceiver, what would be the best way for a technician to make a quick overall evaluation of the radio’s operational condition? |
Use the built-in self-test feature
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3-81L
How might an installer verify correct GPS sentence to marine DSC VHF radio? |
Look for latitude and longitude on the display
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3-81L6
What steps must be taken to activate the DSC emergency signaling function on a marine VHF? |
Input of registered 9-digit MMSI
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