General Exam-Amateur Radio Practices

Card Set Information

Author:
rledwith
ID:
225013
Filename:
General Exam-Amateur Radio Practices
Updated:
2013-07-15 11:49:01
Tags:
rdl gen exam g4
Folders:

Description:
Amateur Radio General Exam - G1 Question Set - Amateur Radio Practices
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user rledwith on FreezingBlue Flashcards. What would you like to do?


  1. G4A01 What is the purpose of the "notch filter" found on many HF transceivers?
    A. To restrict the transmitter voice bandwidth
    B. To reduce interference from carriers in the receiver passband
    C. To eliminate receiver interference from impulse noise sources
    D. To enhance the reception of a specific frequency on a crowded band
    • (B)
    • A notch filter removes a very narrow band of frequencies - the "notch" - from its input. This allows the notch filter to get rid of an interfering tone, such as from an unmodulated carrier, while maintaining the intelligibility of the desired signal. An automatic notch filter can detect tones and remove them without operator intervention.
  2. G4A02 What is one advantage of selecting the opposite or "reverse" sideband when receiving CW signals on a typical HF transceiver?
    A. Interference from impulse noise will be eliminated
    B. More stations can be accommodated within a given signal passband
    C. It may be possible to reduce or eliminate interference from other signals
    D. Accidental out of band operation can be prevented
    • (C)
    • Interference from nearby signals can often be avoided by moving the receiver's carrier frequency to the "other side" of the desired signal, without changing its audio pitch. This won't work on SSB because it also inverts the spectrum of the speech, rendering it unintelligible.
  3. G4A03 What is normally meant by operating a transceiver in "split" mode?
    A. The radio is operating at half power
    B. The transceiver is operating from an external power source
    C. The transceiver is set to different transmit and receive frequencies
    D. The
    transmitter is emitting a SSB signal, as opposed to DSB operation
    • (C)
    • Operating split means using one VFO for transmitting and another for receiving. This is often used when a rare DX station is on the air with many callers. Operating simplex – transmitting and receiving on the same frequency – can result in a lot of confusion with stations trying to hear the DX station while others transmit. By transmitting on one frequency and having callers transmit somewhere else (usually on adjacent frequencies) everyone can hear the DX station and keep “in sync” for more orderly, effective operating.
  4. G4A04 What reading on the plate current meter of a vacuum tube RF power amplifier indicates correct adjustment of the plate tuning control?
    A. A pronounced peak
    B. A pronounced dip
    C. No change will be observed
    D. A slow, rhythmic oscillation
    • (B)
    • Operating split means using one VFO for transmitting and another for receiving. This is often used when a rare DX station is on the air with many callers. Operating simplex – transmitting and receiving on the same frequency – can result in a lot of confusion with stations trying to hear the DX station while others transmit. By transmitting on one frequency and having callers transmit somewhere else (usually on adjacent frequencies) everyone can hear the DX station and keep “in sync” for more orderly, effective operating.
  5. G4A05 What is a purpose of using Automatic Level Control (ALC) with a RF power amplifier?
    A. To balance the transmitter audio frequency response
    B. To reduce harmonic radiation
    C. To reduce distortion due to excessive drive
    D. To increase overall efficiency
    • (C)
    • The ALC circuit of an amplifier senses the amount of input power and generates a feedback voltage to keep a driver stage or transmitter from generating too much power for linear operation. This helps prevent distortion in the amplifier that would cause spurious emissions and interference to other stations.
  6. G4A06 What type of device is often used to enable matching the transmitter output to an impedance other than 50 ohms?
    A. Balanced modulator
    B. SWR Bridge
    C. Antenna coupler
    D. Q Multiplier
    • (C)
    • There are many names for devices that use LC circuits to convert one impedance to another; antenna coupler, impedance matching unit, transmatch, and antenna tuner are common.
  7. G4A07 What condition can lead to permanent damage when using a solid-state RF power amplifier?
    A. Exceeding the Maximum Usable Frequency
    B. Low input SWR
    C. Shorting the input signal to ground
    D. Excessive drive power
    • (D)
    • Transistors are more sensitive to input drive levels than the more rugged vacuum tubes and can be damaged very quickly if too much power is applied. Fast-acting control circuits are required to protect the transistors from excessive drive.
  8. G4A08 What is the correct adjustment for the load or coupling control of a vacuum tube RF power amplifier?
    A. Minimum SWR on the antenna
    B. Minimum plate current without exceeding maximum allowable grid current
    C. Highest plate voltage while minimizing grid current
    D. Maximum power output without exceeding maximum allowable plate current
    • (D)
    • The Tune control of a vacuum tube RF amplifier--either of a standalone amplifier or of a transmitter output stage--adjusts the impedance matching circuit at the frequency of operation. Adjusting the Tune control for a pronounced “dip” in plate current indicates that the circuit is set for the right frequency. The Load or Coupling control is then used to adjust the amount of output power. The Tune and Load controls are alternately adjusted until the required amount of output power is obtained without exceeding the tube’s plate current rating.
  9. G4A09 Why is a time delay sometimes included in a transmitter keying circuit?
    A. To prevent stations from talking over each other
    B. To allow the transmitter power regulators to charge properly
    C. To allow time for transmit-receive changeover operations to complete properly before RF output is allowed
    D. To allow time for a warning signal to be sent to other stations
    • (C)
    • If a relay switches while RF is present in the circuit, that is called “hot switching”. At high power levels hot switching can damage the relay and so it is important to let the relay complete switching before energizing the circuit. Similarly, it is important to disconnect sensitive receive circuits before transmitter RF is enabled. A controlled time -delay, called “sequencing” is used to ensure that all relay and switching operations are completed before enabling the transmitter.
  10. G4A10 What is the purpose of an electronic keyer?
    A. Automatic transmit/receive switching
    B. Automatic generation of strings of dots and dashes for CW operation
    C. VOX operation
    D. Computer interface for PSK and RTTY operation
    • (B)
    • Electronic keyers eliminate a lot of the manual work involved in operating a straight key and insure that each dot or dash has the right length and spacing. This allows comfortable high-speed Morse operation even for extended periods of time.
  11. G4A11 Which of the following is a use for the IF shift control on a receiver?
    A. To avoid interference from stations very close to the receive frequency
    B. To change frequency rapidly
    C. To permit listening on a different frequency from that on which you are transmitting
    D. To tune in stations that are slightly off frequency without changing your transmit frequency
    • (A)
    • Passband or IF shift adjusts the receiver’s passband above or below the displayed carrier frequency to avoid interfering signals. This results in a shift in tone of the received signal, but often improves intelligibility.
  12. G4A12 Which of the following is a common use for the dual VFO feature on a transceiver?
    A. To allow transmitting on two frequencies at once
    B. To permit full duplex operation, that is transmitting and receiving at the same time
    C. To permit ease of monitoring the transmit and receive frequencies when they are not the same
    D. To facilitate computer interface
    • (C)
    • Dual VFOs are used for split operation. Operating split means using one VFO for transmitting and another for receiving. This is often used when a rare DX station is on the air with many callers. Operating simplex – transmitting and receiving on the same frequency – can result in a lot of confusion with stations trying to hear the DX station while others transmit. By transmitting on one frequency and having callers transmit somewhere else (usually on adjacent frequencies) everyone can hear the DX station and keep “in sync” for more orderly, effective operating.
  13. G4A13 What is one reason to use the attenuator function that is present on many HF transceivers?
    A. To reduce signal overload due to strong incoming signals
    B. To reduce the transmitter power when driving a linear amplifier
    C. To reduce power consumption when operating from batteries
    D. To slow down received CW signals for better copy
    • (A)
    • Too strong an input signal can overload a receiver, creating distortion products that interfere with reception of the desired signal. Using an attenuator reduces the input signal level and the possibility of overload.
  14. G4A14 How should the transceiver audio input be adjusted when transmitting PSK31 data signals?
    A. So that the transceiver is at maximum rated output power
    B. So that the transceiver ALC system does not activate
    C. So that the transceiver operates at no more than 25% of rated power
    D. So that the transceiver ALC indicator shows half scale
    • (B)
    • For PSK31 operation, it is important that the output waveform be undistorted. By setting the transmitter output power so that the internal ALC circuit does not activate, that insures the output amplifier is operating with maximum linearity.
  15. G4B01 What item of test equipment contains horizontal and vertical channel amplifiers?
    A. An ohmmeter
    B. A signal generator
    C. An ammeter
    D. An oscilloscope
    • (D)
    • An oscilloscope visually displays a signal waveform, using one signal to deflect a beam of electrons horizontally across the face of the screen and a second signal to deflect them vertically. The electron beam causes a phosphor coating on the inside of the screen to glow so that the beam’s position can be observed. The horizontal and vertical channel amplifiers in the oscilloscope increase the voltage of the two input signals for the desired amount of deflection. Most oscilloscopes have a built-in oscillator circuit, called a sweep generator, designed to repeatedly deflect the electron beam horizontally across the screen at a fixed rate. With an external signal applied to the vertical amplifier, the sweep generator frequency is adjusted to produce a stable pattern on the screen. Some oscilloscopes also allow a second input signal to be applied to a separate horizontal channel amplifier. This allows two signals to be compared to each other with respect to time.
  16. G4B02 Which of the following is an advantage of an oscilloscope versus a digital voltmeter?
    A. An oscilloscope uses less power
    B. Complex impedances can be easily measured
    C. Input impedance is much lower
    D. Complex waveforms can be measured
    • (D)
    • Digital voltmeters display measured values of voltage with excellent precision but they can not measure a complex signal waveform’s time-related parameters, such as its frequency, period, or how it reacts to other signals.
  17. G4B03 Which of the following is the best instrument to use when checking the keying waveform of a CW transmitter?
    A. An oscilloscope
    B. A field-strength meter
    C. A sidetone monitor
    D. A wavemeter
    • (A)
    • An oscilloscope visually displays a signal waveform. This allows you to observe the shape of the CW signal (referred to as the CW envelope) noting, for example, the rise and fall time of the signal. It also allows you to observe problems such as flat-topping (caused by overmodulation) on your SSB signal.
  18. G4B04 What signal source is connected to the vertical input of an oscilloscope when checking the RF envelope pattern of a transmitted signal?
    A. The local oscillator of the transmitter
    B. An external RF oscillator
    C. The transmitter balanced mixer output
    D. The attenuated RF output of the transmitter
    • (D)
    • An oscilloscope visually displays a signal waveform. This allows you to observe the shape of the CW signal (referred to as the CW envelope) noting, for example, the rise and fall time of the signal. It also allows you to observe problems such as flat-topping (caused by over-modulation) on your SSB signal.
  19. G4B05 Why is high input impedance desirable for a voltmeter?
    A. It improves the frequency response
    B. It decreases battery consumption in the meter
    C. It improves the resolution of the readings
    D. It decreases the loading on circuits being measured
    • (D)
    • The higher the impedance of a voltmeter, the smaller the amount of current drawn from the circuit being tested. This allows the voltmeter to make an accurate measurement of voltage while disturbing the circuit as little as possible.
  20. G4B06 What is an advantage of a digital voltmeter as compared to an analog voltmeter?
    A. Better for measuring computer circuits
    B. Better for RF measurements
    C. Better precision for most uses
    D. Faster response
    • (C)
    • A digital voltmeter displays measurements of voltage, current and resistance in numeric form instead of using a moving needle and a fixed scale. That results in significantly better precision than an analog meter. Analog meters, however, may be a better choice for adjusting a circuit for peak and minimum values because the needle movement is easier to see than it is to read changes on a numeric display.
  21. G4B07 Which of the following might be a use for a field strength meter?
    A. Close-in radio direction-finding
    B. A modulation monitor for a frequency or phase modulation transmitter
    C. An overmodulation indicator for a SSB transmitter
    D. A keying indicator for a RTTY or packet transmitter
    • (A)
    • A field-strength meter makes a relative measurement of the intensity of the field being radiated from an antenna. If you are doing some radio direction finding (RDF), you may find that a field-strength meter is a handy piece of equipment to use as you get close to the transmitter source. A strong signal may drive the S-meter off scale, requiring a variable attenuator to be used between the directional antenna and receiver as you get closer to the transmitter. A field-strength meter could replace the normal RDF equipment under those conditions, and you can use your body to shield the field-strength meter to indicate the direction to the transmitter.
  22. G4B08 Which of the following instruments may be used to monitor relative RF output when making antenna and transmitter adjustments?
    A. A field-strength meter
    B. An antenna noise bridge
    C. A multimeter
    D. A Q meter
    • (A)
    • A field-strength meter makes a relative measurement of the intensity of the field being radiated from an antenna. Some amateurs keep a field-strength meter in their shack to monitor the relative RF output from their station. This can be especially handy when you are making antenna or transmitter adjustments
  23. G4B09 Which of the following can be determined with a field strength meter?
    A. The radiation resistance of an antenna
    B. The radiation pattern of an antenna
    C. The presence and amount of phase distortion of a transmitter
    D. The presence and amount of amplitude distortion of a transmitter
    • (B)
    • A field-strength meter makes a relative measurement of the intensity of the field being radiated from an antenna. By placing the field-strength meter in different locations around the antenna, you can determine the relative field pattern of the antenna.
  24. G4B10 Which of the following can be determined with a directional wattmeter?
    A. Standing wave ratio
    B. Antenna front-to-back ratio
    C. RF interference
    D. Radio wave propagation
  25. G4B11 Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements?
    A. Receiver
    B. Transmitter
    C. Antenna and feed line
    D. All of these choices are correct
    • (C)
    • An antenna analyzer is the equivalent of a very low-power, adjustable-frequency transmitter and SWR bridge. The antenna and feed line are connected to the analyzer and SWR measurements are made directly from the analyzer’s meter or display while the analyzer frequency is adjusted. This is much more convenient than using a transmitter and wattmeter and also minimizes the potential for interfering with other signals.
  26. G4B12 What problem can occur when making measurements on an antenna system with an antenna analyzer?
    A. SWR readings may be incorrect if the antenna is too close to the Earth
    B. Strong signals from nearby transmitters can affect the accuracy of measurements
    C. The analyzer can be damaged if measurements outside the ham bands are attempted
    D. Connecting the analyzer to an antenna can cause it to absorb harmonics
    • (B)
    • An antenna analyzer is the equivalent of a very low-power, adjustable-frequency transmitter and SWR bridge. Because the SWR bridge must be sensitive enough to work with the low-power transmitter, it is also sensitive to RF that the antenna may pick up. This is a particular problem when using the analyzer near broadcast stations with their high-powered transmitters. Symptoms might include SWR readings that change with station programming and excessively high or low SWR that does not change with frequency as expected.
  27. G4B13 What is a use for an antenna analyzer other than measuring the SWR of an antenna system?
    A. Measuring the front to back ratio of an antenna
    B. Measuring the turns ratio of a power transformer
    C. Determining the impedance of an unknown or unmarked coaxial cable
    D. Determining the gain of a directional antenna
    • (C)
    • An antenna analyzer's manual will show how to make many useful measurements such as feed line characteristic impedance, velocity of propagation, electrical length, and so on. These are very flexible test instruments.
  28. G4B14 What is an instance in which the use of an instrument with analog readout may be preferred over an instrument with a numerical digital readout?
    A. When testing logic circuits
    B. When high precision is desired
    C. When measuring the frequency of an oscillator
    D. When adjusting tuned circuits
    • (D)
    • The analog meter's moving needle across calibrated scales on the meter face is much easier to adjust for a maximum or minimum value than a numeric display.
  29. G4B15 What type of transmitter performance does a two-tone test analyze?
    A. Linearity
    B. Carrier and undesired sideband suppression
    C. Percentage of frequency modulation
    D. Percentage of carrier phase shift
    • (A)
    • It is common to test the amplitude linearity of a single-sideband transmitter by injecting two audio tones of equal level into the microphone jack, then observing the pattern made on an oscilloscope. In order to get meaningful results, the two tones must not be harmonically related to each other (such as 1 and 2 kHz). Of course, in order for the audio frequencies to display on the oscilloscope, they must be within the audio passband of the transmitter. The ARRL Lab uses 700 Hz and 1900 Hz tones to perform this test.
  30. G4B16 What signals are used to conduct a two-tone test?
    A. Two audio signals of the same frequency shifted 90-degrees
    B. Two non-harmonically related audio signals
    C. Two swept frequency tones
    D. Two audio frequency range square wave signals of equal amplitude
    • (B)
    • It is common to test the amplitude linearity of a single-sideband transmitter by injecting two audio tones of equal level into the microphone jack, then observing the pattern made on an oscilloscope. In order to get meaningful results, the two tones must not be harmonically related to each other (such as 1 and 2 kHz). Of course, in order for the audio frequencies to display on the oscilloscope, they must be within the audio passband of the transmitter. The ARRL Lab uses 700 Hz and 1900 Hz tones to perform this test.
  31. G4C01 Which of the following might be useful in reducing RF interference to audio-frequency devices?
    A. Bypass inductor
    B. Bypass capacitor
    C. Forward-biased diode
    D. Reverse-biased diode
    • (B)
    • If radio frequency interference is entering a home audio system through external control cables or power leads, a bypass capacitor can be effective at keeping the unwanted RF signal out of the equipment. With transistor or integrated circuit audio amplifiers you may need to use RF chokes in series with the speaker leads instead of a bypass capacitor. See the ARRL Handbook and The ARRL RFI Book for more information on finding and fixing RFI problems.
  32. G4C02 Which of the following could be a cause of interference covering a wide range of frequencies?
    A. Not using a balun or line isolator to feed balanced antennas
    B. Lack of rectification of the transmitter's signal in power conductors
    C. Arcing at a poor electrical connection
    D. The use of horizontal rather than vertical antennas
    • (C)
    • An arc, such as in motors or at the contacts of electrical equipment, is rich in harmonic energy, even though the primary current may be dc or 60 Hz ac. The resulting RF harmonics can be radiated by the power wiring as broadband noise heard by nearby receivers. Broadband noise can also be caused by intermittent or poor contacts in RF grounds, such as those in your own station.
  33. G4C03 What sound is heard from an audio device or telephone if there is interference from a nearby single-sideband phone transmitter?
    A. A steady hum whenever the transmitter is on the air
    B. On-and-off humming or clicking
    C. Distorted speech
    D. Clearly audible speech
    • (C)
    • An audio device or telephone can sometimes rectify and detect RF signals in much the same way that a radio does. The audio signal is then amplified resulting in interference. The amateur’s voice will be heard but it will be highly distorted.
  34. G4C04 What is the effect on an audio device or telephone system if there is interference from a nearby CW transmitter?
    A. On-and-off humming or clicking
    B. A CW signal at a nearly pure audio frequency
    C. A chirpy CW signal
    D. Severely distorted audio
    • (A)
    • An audio device or telephone can sometimes rectify and detect RF signals in much the same way that a radio does. The audio signal is then amplified resulting in interference. An amateur’s CW transmission will be heard as on-and-off humming or clicking.
  35. G4C05 What might be the problem if you receive an RF burn when touching your equipment while transmitting on an HF band, assuming the equipment is connected to a ground rod?
    A. Flat braid rather than round wire has been used for the ground wire
    B. Insulated wire has been used for the ground wire
    C. The ground rod is resonant
    D. The ground wire has high impedance on that frequency
    • (D)  
    • One purpose of an amateur station’s RF ground system is to make sure that unwanted signals, such as those picked up from your own transmissions, are directed to ground instead of flowing on or between pieces of equipment. If the ground wire is long enough to be resonant on one or more bands, however, it will present a high impedance, which can enable high RF voltages to be present on the chassis of your equipment or microphone. This can cause an RF burn if the “hot spot” is touched when you are transmitting.  
  36. G4C06 What effect can be caused by a resonant ground connection?
    A. Overheating of ground straps
    B. Corrosion of the ground rod
    C. High RF voltages on the enclosures of station equipment
    D. A ground loop
    • (C)
    • One purpose of an amateur station’s RF ground system is to make sure that unwanted signals, such as those picked up from your own transmissions, are directed to ground instead of flowing on or between pieces of equipment. If the ground wire is long enough to be resonant on one or more bands, however, it will present a high impedance, which can enable high RF voltages to be present on the chassis of your equipment or microphone. This can cause an RF burn if the “hot spot” is touched when you are transmitting.  

  37. G4C07 What is one good way to avoid unwanted effects of stray RF energy in an amateur station?
    A. Connect all equipment grounds together
    B. Install an RF filter in series with the ground wire
    C. Use a ground loop for best conductivity
    D. Install a few ferrite beads on the ground wire where it connects to your station
    • (A)
    • By keeping all of your equipment at the same potential, RF "hot spots" (high voltages) won't be present and RF current that can cause distortion or improper operation won't flow between the enclosures. This is a particularly good strategy when the connection to your ground rod is long enough to be resonant on one or more bands.
  38. G4C08 Which of the following would reduce RF interference caused by common-mode current on an audio cable?
    A. Placing a ferrite bead around the cable
    B. Adding series capacitors to the conductors
    C. Adding shunt inductors to the conductors
    D. Adding an additional insulating jacket to the cable
    • (A)
    • The best solution to many types of interference caused by proximity to an amateur station is to keep the RF signals from entering the equipment in the first place. If filters can be used, they are generally the most effective and least troublesome to install. The next approach is to prevent RF current flow by placing inductance or resistance in its path. This is done by forming the conductor carrying the RF current into an RF choke by winding it around or through a ferrite core. Ferrite beads and cores can also be placed on cables to prevent RF common-mode current from flowing on the outside of cable braids or shields (“common-mode” interference).
  39. G4C09 How can a ground loop be avoided?
    A. Connect all ground conductors in series
    B. Connect the AC neutral conductor to the ground wire
    C. Avoid using lock washers and star washers when making ground connections
    D. Connect all ground conductors to a single point
    • (D)
    • Ground loops are created when a continuous current path (the loop) exists around a series of equipment enclosures. This loop acts as a single-turn inductor that picks up voltages from magnetic fields generated by power transformers, ac wiring, and other low-frequency currents. The result is a “hum” or “buzz” in audio signals or an ac signal that interferes with control or data signals. Less frequently, the loop can pick up transmitted RF and cause distortion in audio signals. Ground loops can be avoided by using a star-ground or ground bus system where all grounds share a common, low-impedance connection. If interconnections make it impossible to avoid loops, minimize the loop’s area and inductance by bundling cables together.
  40. G4C10 What could be a symptom of a ground loop somewhere in your station?
    A. You receive reports of "hum" on your station's transmitted signal
    B. The SWR reading for one or more antennas is suddenly very high
    C. An item of station equipment starts to draw excessive amounts of current
    D. You receive reports of harmonic interference from your station
    • (A)
    • A ground loop can pick up magnetic fields from transformers or ac wiring that result in a “hum” or “buzz” in audio signals or an ac signal that interferes with control or data signals. Less frequently, the loop can pick up transmitted RF and cause distortion in audio signals.
  41. G4C11 Which of the following is one use for a Digital Signal Processor in an amateur station?
    A. To provide adequate grounding
    B. To remove noise from received signals
    C. To increase antenna gain
    D. To increase antenna bandwidth
    • (B)
    • Digital Signal Processing (DSP) is the process of converting analog signals to digital data, processing them with software programs, then converting the signals back to analog form. Digital noise reduction is but one application--filtering, demodulation, and decoding are also commonly performed by DSP circuits.
  42. G4C12 Which of the following is an advantage of a receiver Digital Signal Processor IF filter as compared to an analog filter?
    A. A wide range of filter bandwidths and shapes can be created
    B. Fewer digital components are required
    C. Mixing products are greatly reduced
    D. The DSP filter is much more effective at VHF frequencies
    • (A)
    • Because DSP circuits use software to process the digitized signal, the number of different functions that can be performed is only limited by the amount of memory and processing speed. In addition, unlike most analog filters, parameters such as bandwidth and the shape of the response can be made adjustable by the operator. This provides a great deal of flexibility in receiver operation.
  43. G4C13 Which of the following can perform automatic notching of interfering carriers?
    A. Band-pass tuning
    B. A Digital Signal Processor (DSP) filter
    C. Balanced mixing
    D. A noise limiter
    • (B)
    • The software program that controls a DSP notch filter may also operate automatically. In this type of operation, the software searches for the steady tones of an interfering carrier, such as from a shortwave broadcast signal, and then adjusts the frequency of the notch until the amplitude of the carrier’s tone is minimized.
  44. G4D01 What is the purpose of a speech processor as used in a modern transceiver?
    A. Increase the intelligibility of transmitted phone signals during poor conditions
    B. Increase transmitter bass response for more natural sounding SSB signals
    C. Prevent distortion of voice signals
    D. Decrease high-frequency voice output to prevent out of band operation
    • (A)
    • A speech processor can improve signal intelligibility by raising average power without increasing peak envelope power (PEP). It does this by bringing up low signal levels while not increasing high signal levels. As a result, the average signal level is higher. A speech processor does not increase the transmitter output PEP.
  45. G4D02 Which of the following describes how a speech processor affects a transmitted single sideband phone signal?
    A. It increases peak power
    B. It increases average power
    C. It reduces harmonic distortion
    D. It reduces intermodulation distortion
    • (B)
    • A speech processor can improve signal intelligibility by raising average power without increasing peak envelope power (PEP). It does this by bringing up low signal levels while not increasing high signal levels. As a result, the average signal level is higher.
  46. G4D03 Which of the following can be the result of an incorrectly adjusted speech processor?
    A. Distorted speech
    B. Splatter
    C. Excessive background pickup
    D. All of these choices are correct
    • (D)
    • Proper adjustment of a speech processor is important to insure your transmitted signal is not distorted and is free of spurious signals. Increasing the amount of processing too far causes your speech to be distorted. Processors that amplify softer speech components more than loud ones will also pick up background noise from fans and other radios and combine them with your desired speech. Another common result of too much processing is overdriving the transmitter output stages, causing interference (“splatter”) to signals on nearby frequencies. Read the owner’s manual for your radio and learn to operate its speech processor correctly.
  47. G4D04 What does an S meter measure?
    A. Conductance
    B. Impedance
    C. Received signal strength
    D. Transmitter power output
    • (C)
    • An S meter measures received signal strength in S-units.
  48. G4D05 How does an S meter reading of 20 dB over S-9 compare to an S-9 signal, assuming a properly calibrated S meter?
    A. It is 10 times weaker
    B. It is 20 times weaker
    C. It is 20 times stronger
    D. It is 100 times stronger
    • (D)
    • An ideal S meter operates on a logarithmic scale, indicating one S unit of change for a four-times increase or decrease in power. (This is a 6-dB change in power.) In real life, S meters are only calibrated to this standard in the middle of their range (if at all). Above S9, theoretically corresponding to a 50 µV input signal, S meters are calibrated in dB. In the example of this question, a signal 20 dB stronger than S9 is 100 times stronger than S9.
  49. G4D06 Where is an S meter found?
    A. In a receiver
    B. In an SWR bridge
    C. In a transmitter
    D. In a conductance bridge
    • (A)
    • An S meter measures received signal strength and so is found in a receiver or the receive circuits of a transceiver.
  50. G4D07How much must the power output of a transmitter be raised to change the S- meter reading on a distant receiver from S8 to S9?
    A. Approximately 1.5 times
    B. Approximately 2 times
    C. Approximately 4 times
    D. Approximately 8 times
    • (C)
    • An ideal S meter operates on a logarithmic scale, indicating one S unit of change for a four-times increase or decrease in power. This is a 6 dB change in power.
  51. G4D08 What frequency range is occupied by a 3 kHz LSB signal when the displayed carrier frequency is set to 7.178 MHz?
    A. 7.178 to 7.181 MHz
    B. 7.178 to 7.184 MHz
    C. 7.175 to 7.178 MHz
    D. 7.1765 to 7.1795 MHz
    • (C)
    • Nearly all radios display the carrier frequency of a SSB transmission. That means your actual signal lies entirely above (USB) or below (LSB) the displayed frequency. If the sidebands occupy 3 kHz of spectrum, you’ll need to stay far enough from the edge of your frequency privileges to avoid transmitting a signal outside them. For example, Generals are permitted to use up to 14.350 MHz, so the displayed carrier frequency of a USB signal should be no less than 3 kHz from the band edge – 14.347 MHz – and the signal occupy 14.347 to 14.350 MHz. If you transmit higher than that, the sidebands begin to extend into the non-amateur frequencies above 14.350 MHz!. Similarly, using LSB on 40 meters, Generals should operate with the carrier frequency no less than 3 kHz from the band edge -- 7.178 MHz – thus occupying the range of 7.175 to 7.178 MHz.
  52. G4D09 What frequency range is occupied by a 3 kHz USB signal with the displayed carrier frequency set to 14.347 MHz?
    A. 14.347 to 14.647 MHz
    B. 14.347 to 14.350 MHz
    C. 14.344 to 14.347 MHz
    D. 14.3455 to 14.3485 MHz
    • (B)
    • Nearly all radios display the carrier frequency of a SSB transmission. That means your actual signal lies entirely above (USB) or below (LSB) the displayed frequency. If the sidebands occupy 3 kHz of spectrum, you’ll need to stay far enough from the edge of your frequency privileges to avoid transmitting a signal outside them. For example, Generals are permitted to use up to 14.350 MHz, so the displayed carrier frequency of a USB signal should be no less than 3 kHz from the band edge – 14.347 MHz – and the signal occupy 14.347 to 14.350 MHz. If you transmit higher than that, the sidebands begin to extend into the non-amateur frequencies above 14.350 MHz!. Similarly, using LSB on 40 meters, Generals should operate with the carrier frequency no less than 3 kHz from the band edge -- 7.178 MHz – thus occupying the range of 7.175 to 7.178 MHz.
  53. G4D10 How close to the lower edge of the 40 meter General Class phone segment should your displayed carrier frequency be when using 3 kHz wide LSB?
    A. 3 kHz above the edge of the segment
    B. 3 kHz below the edge of the segment
    C. Your displayed carrier frequency may be set at the edge of the segment
    D. Center your signal on the edge of the segment
    • (A)
    • Nearly all radios display the carrier frequency of a SSB transmission. That means your actual signal lies entirely above (USB) or below (LSB) the displayed frequency. If the sidebands occupy 3 kHz of spectrum, you’ll need to stay far enough from the edge of your frequency privileges to avoid transmitting a signal outside them. For example, Generals are permitted to use up to 14.350 MHz, so the displayed carrier frequency of a USB signal should be no less than 3 kHz from the band edge – 14.347 MHz – and the signal occupy 14.347 to 14.350 MHz. If you transmit higher than that, the sidebands begin to extend into the non-amateur frequencies above 14.350 MHz!. Similarly, using LSB on 40 meters, Generals should operate with the carrier frequency no less than 3 kHz from the band edge -- 7.178 MHz – thus occupying the range of 7.175 to 7.178 MHz.
  54. G4D11 How close to the upper edge of the 20 meter General Class band should your displayed carrier frequency be when using 3 kHz wide USB?
    A. 3 kHz above the edge of the band
    B. 3 kHz below the edge of the band
    C. Your displayed carrier frequency may be set at the edge of the band
    D. Center your signal on the edge of the band
    • (B)
    • Nearly all radios display the carrier frequency of a SSB transmission. That means your actual signal lies entirely above (USB) or below (LSB) the displayed frequency. If the sidebands occupy 3 kHz of spectrum, you’ll need to stay far enough from the edge of your frequency privileges to avoid transmitting a signal outside them. For example, Generals are permitted to use up to 14.350 MHz, so the displayed carrier frequency of a USB signal should be no less than 3 kHz from the band edge – 14.347 MHz – and the signal occupy 14.347 to 14.350 MHz. If you transmit higher than that, the sidebands begin to extend into the non-amateur frequencies above 14.350 MHz!. Similarly, using LSB on 40 meters, Generals should operate with the carrier frequency no less than 3 kHz from the band edge -- 7.178 MHz – thus occupying the range of 7.175 to 7.178 MHz.
  55. G4E01 What is a "capacitance hat", when referring to a mobile antenna?
    A. A device to increase the power handling capacity of a mobile whip antenna
    B. A device that allows automatic band-changing for a mobile antenna
    C. A device to electrically lengthen a physically short antenna
    D. A device that allows remote tuning of a mobile antenna
    • (C)
    • To increase the capacitance of a mobile antenna and electrically lengthen it, a structure of rods and possibly a ring is added at or near the top of the antenna. This is called a "capacitance hat" or "capacity hat".
  56. G4E02 What is the purpose of a "corona ball" on a HF mobile antenna?
    A. To narrow the operating bandwidth of the antenna
    B. To increase the "Q" of the antenna
    C. To reduce the chance of damage if the antenna should strike an object
    D. To reduce high voltage discharge from the tip of the antenna
    • (D)
    • The sharp tip of mobile whip can cause corona discharge even at moderate power levels. By adding a smooth ball, the tendency for corona to form is reduced.
  57. G4E03 Which of the following direct, fused power connections would be the best for a 100-watt HF mobile installation?
    A. To the battery using heavy gauge wire
    B. To the alternator or generator using heavy gauge wire
    C. To the battery using resistor wire
    D. To the alternator or generator using resistor wire
    • (A)
    • When you are making the power connections for your 100-watt HF radio for mobile operation, you should connect heavy-gauge wires directly to the battery terminals. Remember that both leads should have fuses, placed as close to the battery as possible
  58. G4E04 Why is it best NOT to draw the DC power for a 100-watt HF transceiver from an automobile's auxiliary power socket?
    A. The socket is not wired with an RF-shielded power cable
    B. The socket's wiring may be inadequate for the current being drawn by thetransceiver
    C. The DC polarity of the socket is reversed from the polarity of modern HFtransceivers
    D. Drawing more than 50 watts from this socket could cause the engine to overheat
    • (B)
    • The auxiliary socket wiring is adequate for a low-power hand-held radio but probably not for a full-power HF rig drawing 20 amps or more when transmitting. Use a direct connection to the battery using heavy-gauge wire, with both leads fused at the battery.
  59. G4E05 Which of the following most limits the effectiveness of an HF mobile transceiver operating in the 75 meter band?
    A. “Picket Fencing” signal variation
    B. The wire gauge of the DC power line to the transceiver
    C. The antenna system
    D. FCC rules limiting mobile output power on the 75 meter band
    • (C)
    • HF mobile antenna systems are the most limiting factor for effective operation of your station. Placing even an 8-foot vertical antenna on top of a small car makes a dangerously tall system. If you have a taller vehicle, this kind of antenna is almost out of the question. Some type of inductive loading to shorten the length is then required. For operation on the 75 meter band this compromise results in a relatively inefficient antenna system.
  60. G4E06 What is one disadvantage of using a shortened mobile antenna as opposed to a full size antenna?
    A. Short antennas are more likely to cause distortion of transmitted signals
    B. Short antennas can only receive vertically polarized signals
    C. Operating bandwidth may be very limited
    D. Harmonic radiation may increase
    • (C)
    • Electrically short antennas have a very low impedance at the feed point. This causes the frequency range to be very narrow over which a matching network presents a 50-ohm impedance to the transmitter.
  61. G4E07 Which of the following is the most likely to cause interfering signals to be heard in the receiver of an HF mobile installation in a recent model vehicle?
    A. The battery charging system
    B. The anti-lock braking system
    C. The anti-theft circuitry
    D. The vehicle control computer
    • (D)
    • Digital signals internal and external to the vehicle's control computer system can radiate from the vehicle's electrical wiring and be picked up by a mobile radio.
  62. G4E08 What is the name of the process by which sunlight is changed directly into electricity?
    A. Photovoltaic conversion
    B. Photon emission
    C. Photosynthesis
    D. Photon decomposition
    • (A)
    • Natural sources of energy are becoming more economical and more practical as a way to power your station. Photovoltaic conversion by solar cells and panels converts sunlight into dc electricity.
  63. G4E09 What is the approximate open-circuit voltage from a modern, well-illuminated photovoltaic cell?
    A. 0.02 VDC
    B. 0.5 VDC
    C. 0.2 VDC
    D. 1.38 VDC
    • (B)
    • Each photovoltaic cell produces about 0.5 volt in full sunlight if there is no load connected to the cell. The size or surface area of the cell determines the maximum current that the cell can supply.
  64. G4E10 What is the reason a series diode is connected between a solar panel and a storage battery that is being charged by the panel?
    A. The diode serves to regulate the charging voltage to prevent overcharge
    B. The diode prevents self discharge of the battery though the panel during times of low or no illumination
    C. The diode limits the current flowing from the panel to a safe value
    D. The diode greatly increases the efficiency during times of high illumination
    • (B)
    • If connected directly to a battery, during periods of low or no illumination, the battery voltage will be higher than that from the panel, allowing the battery to discharge back through the panel.
  65. G4E11 Which of the following is a disadvantage of using wind as the primary source of power for an emergency station?
    A. The conversion efficiency from mechanical energy to electrical energy is less than 2 percent
    B. The voltage and current ratings of such systems are not compatible with amateur equipment
    C. A large energy storage system is needed to supply power when the wind is not blowing
    D. All of these choices are correct
    • (C)
    • Wind-powered systems provide free energy after the initial cost of installation, but just like solar-powered systems, wind systems need to have a storage battery to supply electricity when the wind is not blowing.

What would you like to do?

Home > Flashcards > Print Preview