NAVEDTRA 14193A, NAVY ELECTRICITY AND ELECTRONICS TRAINING SERIES. MODULE 21- TEST METHODS AND PRACTICES Flashcards
In equipment that uses vacuum tubes, faulty tubes are responsible for more than what percent of all electronic equipment failures?
50
If the average receiving vacuum tube is not overdriven or operated continuously at maximum rating, it can have a life of at least how many hours before the filament opens?
2,000
Klystron tubes that remain inoperative for more than how many months may become gassy?
6
How many hours or more of reduced voltage operation may be required for klystrons that have been inoperative for periods in excess of 6 months?
Eight
When the twt is installed, you can usually measure the collector current and voltage and check the power output for various inputs. Any deviation greater than what percent from normal specifications may be considered to be an indication of a defective tube?
10%
Transistor circuits, other than pulse and power amplifier stages, are usually biased so that the emitter current is from 0.5 milliampere to 3 milliamperes and the collector voltage is from 3 to how many volts?
15
A back-to-forward resistance ratio on the order of what or greater should be obtained for the collector-to-base and emitter-to-base measurements?
100 to 1
Many ohmmeters are designed such that on the R x 1 range, how many milliamperes or more can flow through the electronic part under test?
100
Ohmmeter ranges that require a current of more than what in the test circuit are not to be used for testing transistors?
1 milliampere
What should not be used to furnish power for transistor equipment because they have poor voltage regulation and, possibly, high ripple voltage?
Battery eliminators
What is created whenever two substances (solid or fluid) are rubbed together or separated?
Static electricity
An MOS field-effect transistor (MOSFET) can be damaged by a static voltage potential of as little as how many volts?
35
When moving an ESDS device or assembly, always touch (with your bare skin) the surface on which it rests for at least how long before picking it up?
1 second
Transistors are capable of operating in excess of how many hours at maximum ratings without appreciable degradation?
30,000
What is a three-element, solid-state device in which the forward resistance can be controlled?
SCR
What device is designed to switch from a blocking state to a conducting state or either polarity of applied voltages and with either positive or negative gate triggering?
Triac
What is a solid-state, three-terminal semiconductor that exhibits stable open-circuit, negative-resistance characteristics?
Unijunction Transistor (UJT)
What must never be used in testing MOSFETs?
VTVM
What constitutes an area of microelectronics in which many conventional electronic components are combined into high-density modules?
Integrated Circuits (ICs)
The most frequently used ICs are manufactured with either 14 or how many pins?
16
What are spring-loaded devices that are designed to clip onto a dual-in-line package IC while the IC is mounted in its circuit?
Logic clips
What is designed to detect faulty, in-circuit-DIP ICs by comparing them with ICs that are known to be good (reference ICs)?
Logic comparator
What can immediately identify whether a specific point in the circuit is low, high, open, or pulsing?
Logic probes
Some logic probes have a feature that detects and displays high-speed transient pulses as small as how many nanoseconds wide?
5
What provides various functions that can assist you in maintenance, testing, and troubleshooting of equipment using digital circuitry?
Logic analyzer
Most logic analyzers have crt displays that can monitor up to how many timing signals at the same time?
32
A specific gravity reading between 1.275 and what indicates a full-charge condition and assures you that the lead acid type battery is in good condition?
1.300
What series of battery testers incorporate a multiple-range voltmeter, battery-loading resistors, multiplier resistors, and a jack-switching arrangement that connects the load resistors across the voltmeter for a total of 32 different voltmeter-load resistor combinations?
TS-183U
What are the two types of nickel-cadmium batteries?
Vented and Nonvented
The voltage at the terminals of a NICAD will normally be between 1.25 and how many volts in an open-circuit condition?
1.30
What are used to attenuate rf signals in incremental steps?
Decade attenuators
The core of Fiber is usually made of plastic, glass, or what else?
Plastic-Clad Silica (PCS)
What type of fiber optic cores have high attenuation (25 dB/km), require precision tools and connectors, and are extremely susceptible to mechanical damage?
Glass
What injects a short, intense laser pulse into the fiber and monitors reflections caused by breaks, inclusions, microcracks, and discontinuities?
OTDR
What is used with an OTDR to provide visual evidence of fiber faults, connector and splice locations, and attenuation locations?
Oscilloscope
What measures the input versus the output of light in an optical fiber?
Optical ohmmeter
What is test equipment designed to evaluate the operational performance of a piece of equipment or printed circuit board (pcb)?
Automatic Test Equipment (ATE)
What provides on-site screen testing and fault isolation of digital pcb’s and modules?
AN/USM-465
What is a versatile troubleshooting tool used to statically test resistors, capacitors, inductors, diodes, transistors, multiple-component circuits, and integrated circuits?
Huntron Tracker 2000
Testing components by what method is the most preferred method for troubleshooting?
Comparison
What is a term used by technicians and engineers alike that generally signifies dissatisfaction with the shape of the wave processed by an amplifier?
Distortion
Attaining 100% amplitude modulation of an rf carrier with a sine wave requires a modulating power equal to what amount of the rf carrier power?
Half
An increase in the power output of an AM transmitter is indicated by an increase in what?
Antenna current
What is widely used as an amplitude-modulation monitor and measuring instrument?
Oscilloscope
What are the two types of modulation patterns provided by the oscilloscope, depending upon the hookup used?
Wave-envelope and Trapezoidal
What type of modulation is a form of amplitude modulation in which only one sideband is transmitted with a suppressed carrier?
Single-sideband
Deviation in frequency is usually expressed in what?
Kilohertz
Typical accuracies for a modulation analyzer are within what percent?
+/- 1%
What is an analysis of a complex waveform, prepared in terms of a graphic plot of the amplitude versus frequency known as?
Spectrum analysis
What three axes of degree are important when considering varying frequency?
Amplitude, time, and frequency
Present-day spectrum analyzers can measure segments of the frequency spectra from 0 hertz to as high as what when used with waveguide mixers?
300 gigahertz
Complex waveforms are divided into what groups?
Periodic and Nonperiodic
The modulation energy in an amplitude-modulated wave is contained entirely within the what?
Sidebands
The amount by which the frequency departs from the average is controlled by the amplitude of the modulating signal. What is this variation referred to as?
Frequency deviation
What is used to pulse-modulate the constant frequency rf carrier to produce the pulse radar output?
Rectangular wave
What is the term for distinguishing a signal from other signals near it?
Resolving
Modern spectrum analyzers have been refined to the degree that IF bandwidths are less than what?
1 hertz
What is a testing and measurement technique that has found increasing usefulness in testing transmission lines (both metallic and fiber-optic), cables, strip lines, connectors, and other wideband systems or components?
Time-domain reflectometry
What is the ratio between the minimum and maximum swr values is then taken as the system?
Figure of Merit
What testing is used to determine the bandwidth, alignment, frequency response, impedance matching, and attenuation in varius circuits, systems, and components?
Swept-Frequency
What is basically a sweep generator in which the sweep rate is matched to that of the spectrum analyzer?
Tracking generator
Circuit impedance is measured conveniently by using what principle?
Reflectometer
What is one of the more common and useful applications for using the swept-frequency technique?
Antenna system testing
The measured vswr (within the operating frequency range) of any broadband antenna should not exceed a vswr of what?
2.5 to 1
The vswr for any single-tuned antenna should not exceed what at the tuned frequency?
1.5 to 1
