Volume 2 2
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- Where are the explicit operating instructions for test equipment, and which TO tells you where to find further information?
- Applicable technical orders & 0-1-33-1
- Repair and calibration of test equipment is the responsibility of the
- PMEL
- When can a shop standard be used for routine maintenance functions?
- If an emergency condition exists and like test equipment is inoperative
- To eliminate moisture, most complex items of electronic test equipment use
- build-in heaters
- Which test equipqment item is most likely to be tropicallized and fungus-proofed?
- Laminated circuit boards
- Which of these is usually not affected by storing test equipment accessories improperly
- Maintenance procedures
- Of what should you be aware in taking voltage measurements?
- A voltmeter of low sensitivity used on a low range may render circuits inoperable
- Before measuring a resistance, you must sometimes unsolder one side of a resistor in order to
- prevent erroneous readings
- In troubleshooting equipment, which of these measurements are not commonly taken?
- Current
- What is the problem in measuring current with a multimeter with handheld probes?
- High risk of electrical shock
- Which test set can you use to check the frequency of a transmitter?
- Frequency counter
- Which component is not a troubleshooting aid?
- System and unit programs
- What is the most important step in the troubleshooting effort?
- Think before you act
- In the established general troubleshooting procedures, steps 1 through 4 are used in
- locating the trouble
- What are functional inspections?
- Inspections done through periodic tests
- It's important to document periodic maintenance inspections because they reveal
- slow progressive drifts that may be too small to show up in any one test
- What troubleshooting technique would be used to isolate a circuit card or module failure?
- Internal diagnostic checks
- What type of tests would you you do to isolate a defective component?
- Resistance measurement, voltage measurment, and waveform comparisons
- The resistance values provided in TO resistance charts are normally measured between
- the indicated point and ground
- What safety practices do you observe before making resistance checks?
- Ensure the power is turned off and set the meter to the highest range
- Regardless of the size of the circuit you are troubleshooting, you can immediately isolate the defective half of a unit by which troubleshooting technique?
- Half-split method
- Which control on the analog multimeter calibrates the meter's pointer to zero for a resistance measurement?
- Zero ohms switch
- Which analog multimeter control must you depress to remove an overload condition and return meter to its normal operation?
- Reset button
- When you make a resistance measurements, how do you electronically isolate a resistor from the circuit?
- Disconnect one side of the resistor
- How do you place multimeter tests leads in a circuit to measure voltage?
- Parallel
- In which type of circuit would you measure the AC component of an output voltage where both AC and DC voltage levels exist?
- Amplifier
- Which feature of the Fluke 8025A multimeter do you use to select various measurments functions?
- Rotary switch
- Which part of the Fluke 8025A's display section indicates the absolute value of the input?
- Analog bar graph
- Which feature of the Fluke 8025A locks the measurements into the display for viewing and automatically updates the display when you take a new measurement?
- Touch-hold push button
- When you use the Fluke 8025A, which voltage range do you select to measure 50 volts DC?
- Volts DC
- Which current range on the Fluke 8025A do you select to measure 250 milliamps AC?
- Milliamps/amp AC
- Which Fluke 8025A multimeter function displays "OL" with the leads connected in one direction while reversing them produces a continuous audible one?
- Diode Test
- How are voltage, time, and depth represented on the oscilloscope display?
- Voltage = vertical axis, time = horizontal axis, depth = intensity
- Which mode of triggering an oscilloscope causes a trace to be drawn on the screen at all times, whether there is an input signal or not?
- Auto
- Which triggering source would be used to look for power line hum?
- Line
- Where should the volts/cm (volts/div) control be set to begin with?
- Maximum setting
- Which control should you adjust if the display is too tall (extents off screen)?
- Volts/cm
- Which oscilloscope probe is essentially just a shielded piece of wire?
- Passive 1:1 probe
- Which probe lets you use the oscilloscope to measure higher voltage levels, raises the input impedance, does not require a bias voltage, and attenuates noise?
- Passive divider, 10:1 probe
- Which probe does not need to actually make contact with the circuit under test?
- Current probe
- In which of these situations is probe compensation not necessary?
- Any time you have changed test points
- Rise time is measured between
- 10% and 90% amplitude points on the leading or trailing edge of the pulse
- If a sine wave signal's positive alternation covers 2.5 divisions and the TIME/DIV is set to 20 nS, what is the singal's frequency?
- 10 MHZ f=1/t
- In using an oscilloscope to compare two signals, if the Lissajous pattern has 3 bumps on one axis and 4 on the other
- the signals have different frequencies
- What digital storage oscilloscope circuit compensates for high sampling rates of high-frequency signals?
- Charged coupled device
- Sampled data points are stored in the memory of a digital storage oscilloscope as
- waveform points
- Wheat area of a digital storage oscilloscope takes digitized samples and performs numerous manipulations on the data including measuring rise and fall times, periods, time intervals, and math computations
- Microprocessor
- What type of sampling does a digital storage oscilloscope normally use on a single-shot or seldom-occuring signals?
- Real-time
- What type of interpolation does a digital storage oscilloscope use the measure pulse waves?
- Linear
- What are the three types of digital storage oscilloscope acquistion modes, and which is the standard operationg mode?
- Sample, peak detect, averaging | sample
- Which digital storage oscilloscope button controls all waveforms displayed in the STORE mode?
- CURSORS control
- In acquiring a 4K record length on a digital storage oscilloscope, how many samples can you view at one time?
- 1,000
- What is the purpose of the bit error rate test set?
- Provide an error detection system to determine the quality of received data
- What test equipment item provides a patterned digital test signal for loop testing and compares an identical pattern to determine the loop data quality?
- BERTS
- Which of these is a major section of the typical bit error test set?
- Internal clock generator
- In the internal clock generator section of a typical bit error rate test set, what generates the basic clock that provides all clock phases, and is periodically frequency calibrated by a crystal-controlled oscillator in the automatic calibration section?
- VCO
- Which pattern simulator section of a bit error rate test set controls the clock selector and selects either the external clock or the internal clock for processing?
- Data/clock select encoder
- What pattern simulator section of the bit error rate test set accepts a 48-bit parallel word and generates an serial pattern?
- 48-bit transmitter only
- What pattern simulator section of the bit error test set converts the NRZ-L data into the desired coding, such as NRZ-m?
- Code converter
- What pattern synchronizer and error counter section of the bit error rate rest set internally generates its own pattern to compare with the received data from the data/clock receivers?
- PRN pattern synchronizer/comparator
- When will the pattern synchronizer and error counter err/IN SYNC section of the bit error rate test set provide an output to the front panel display, and what interrupts this output?
- At the end of the count cycle or when the reset switch is pushed, reset pulse
- Which of these are the primary means of measuring the quality of transmitted digital information, and how is this means derived?
- Bit error rate (BER), the ratio ofthe number of bits in error to total number of bits transmitted
- What is the first step in the basic bit error rate testing procedure?
- A known bit pattern, usually pseudo-random, is generated at the sending end of the data channel or equipment under test and is transmitted through the channel
- During a basic bit error rate testing procedure, an error signal is generated when
- any bit in the recieved signal is not the same as the generated bit
- Which of these data circuit speeds would normally use the shorter generated bit error rate (BER) test pattern lengths, and what is data circuit bit rate
- Low to intermediate, 1200 to 9600 bps
- Which of these bit rates should you use for a bit error rate test on a 64 Kbps data circuit?
- 64 Kbps
- On the bit error rate test set, the 25-pin connectors are designed to operate with data modems to
- simplify connection of test equipment to themodem under test and to carry the necessary
- The primary use of a signal generator is to
- align frequency sensitive or tuned circuits
- What is the frequency range of an audio signal generator?
- 20 Hz to 20 kHz
- What components make up the frequency determining device in a signal generator, and which of these elements is usually chosen as the variable element?
- A inductor and capacitor (Lc cirucit) with the capacitor as the variable element
- Which of these is not an application of a radio frequency generator?
- Aligning galvanometers
- A radio frequency generator is used to
- align telemtry receivers
- What is the variable voltage range of signals output from the HP3325B synthesizer/function generator?
- 1 mV to 10 V peak-to-peak
- The output of the HP 3325B function generator may generate only DC voltages, to an maximum of
- ±5V
- In using the phase modulation controls of the HOP 3325B function generator, an input of a ±5V peak would result in what approximate phase deviation?
- -+425 degrees per volt for square wave
- The 10:1 power ratio represented by 1 bel can also be represented by how many decibels (dB)?
- 10 dB
- A power reading that uses the abbreviation dBm indicates the
- ratio of decibels relative to a 1-milliwatt standard
- The measureable frequency and power ranges of the HP 436A power meter are determined by the
- power sensor
- The most efficient power sensor for converting RF energy to the DC voltage measured the HP 436A power meter is the
- detecting diode
- When you connect a new or different power sensor to the HP 436A power meter, you should
- immediately calibrate the units together
- You are using an HP 436A power meter to troubleshoot a transmitter. You are trying to determine which stage is causing a low power output from the transmitter. To find out how well each transmitter stage is amplifying, which power meter mode should you s
- Relative power
- Which on e of these measurements is not made with a spectrum analyzer?
- Peak-peak voltage
- Which of these measurements do you make with a spectrum analyzer?
- Subcarrier oscillator output
- Which trigger control on a spectrum analyzer lets the sweep be triggered by an AC power source at a rate equal to the frequency of the power source?
- LINE
- Which sweep control on a spectrum analyzer do you select to run the sweep only once after triggering, with a READY light indication each time it is run?
- Single
- Besides the per division mode, what are the other two scan modes available through the FREQUENCY SPAN/DIV control on a spectrum analyzer?
- Maximum and 0 Hz
- On a spectrum analyzer, you select LIN (linear) VERTICAL DISPLAY mode. The VERTICAL DISPLAY reads "5.00/mV," and there is a signal peak six divisions above the CRT bottom line. What will the amplitude readout display?
- 30 mV
- Which spectrum analyzer control selects the maximum input level of the analyzer and reduces input signals to an optimum level?
- MIN RF ATTEN dB
- Which electronic counter measurement represents the average bit-to-bit time of an input signal?
- Period
- Which electronic counter measurement counts the number of bits in a pulse train?
- Totalize
- When the display section of a frequency counter receives the first 10 pulses passes from the signal gate, what is sent from the first decimal counting unit to the second decimal counting unit?
- A carry pulse
- Which of these is not an application of a frequency counter?
- Monitoring transducer outputs
- A time domain reflectometer will not detect cable
- ground
- What principle does the time domain reflectometer use to test cables?
- Rader
- Which push-button(s) would you select to get 125 Ohms impedance on the time domain reflectometer?
- 50 Ohms and 75 Ohms
- What type of deflection return on the TDR CRT would indicate a cable "short?"
- Negative "pip"
- What do we call the power that is reflected back?
- Backscatter
- How is the signal loss represented in on optical time domain reflectometer display?
- Decibels
- Which mode is first used to analyze the fiber after fiber insertion?
- REAL-TIME mode