Radio Part 3
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50 terms
Terms | Definitions |
|---|---|
 d | What is the preamble in a formal traffic message? A. The first paragraph of the message text B. The message number C. The priority handling indicator for the message D. The information needed to track the message as it passes through the amateur radio traffic handling system |
| a | What is meant by the term "check" in reference to a formal traffic message? A. The check is a count of the number of words or word equivalents in the text portion of the message B. The check is the value of a money order attached to the message C. The check is a list of stations that have relayed the message D. The check is a box on the message form that tells you the message was received |
| d | What should you do if another operator reports that your station's 2 meter signals were strong just a moment ago, but now they are weak or distorted? A. Change the batteries in your radio to a different type B. Turn on the CTCSS tone C. Ask the other operator to adjust his squelch control D. Try moving a few feet, as random reflections may be causing multi-path distortion |
| b | Why are UHF signals often more effective from inside buildings than VHF signals? A. VHF signals lose power faster over distance B. The shorter wavelength allows them to more easily penetrate the structure of buildings C. This is incorrect; VHF works better than UHF inside buildings D. UHF antennas are more efficient than VHF antennas |
| c | What antenna polarization is normally used for long-distance weak-signal CW and SSB contacts using the VHF and UHF bands? A. Right-hand circular B. Left-hand circular C. Horizontal D. Vertical |
| b | What can happen if the antennas at opposite ends of a VHF or UHF line of sight radio link are not using the same polarization? A. The modulation sidebands might become inverted B. Signals could be significantly weaker C. Signals have an echo effect on voices D. Nothing significant will happen |
| b | When using a directional antenna, how might your station be able to access a distant repeater if buildings or obstructions are blocking the direct line of sight path? A. Change from vertical to horizontal polarization B. Try to find a path that reflects signals to the repeater C. Try the long path D. Increase the antenna SWR |
| b | What term is commonly used to describe the rapid fluttering sound sometimes heard from mobile stations that are moving while transmitting? A. Flip-flopping B. Picket fencing C. Frequency shifting D. Pulsing |
| a | What type of wave carries radio signals between transmitting and receiving stations? A. Electromagnetic B. Electrostatic C. Surface acoustic D. Magnetostrictive |
| c | What is the cause of irregular fading of signals from distant stations during times of generally good reception? A. Absorption of signals by the "D" layer of the ionosphere B. Absorption of signals by the "E" layer of the ionosphere C. Random combining of signals arriving via different path lengths D. Intermodulation distortion in the local receiver |
| b | Which of the following is a common effect of "skip" reflections between the Earth and the ionosphere? A. The sidebands become reversed at each reflection B. The polarization of the original signal is randomized C. The apparent frequency of the received signal is shifted by a random amount D. Signals at frequencies above 30 MHz become stronger with each reflection |
| d | What may occur if VHF or UHF data signals propagate over multiple paths? A. Transmission rates can be increased by a factor equal to the number of separate paths observed B. Transmission rates must be decreased by a factor equal to the number of separate paths observed C. No significant changes will occur if the signals are transmitting using FM D. Error rates are likely to increase |
| c | Which part of the atmosphere enables the propagation of radio signals around the world? A. The stratosphere B. The troposphere C. The ionosphere D. The magnetosphere |
| c | What is the name for the distance a radio wave travels during one complete cycle? A. Wave speed B. Waveform C. Wavelength D. Wave spread |
| d | What term describes the number of times per second that an alternating current reverses direction? A. Pulse rate B. Speed C. Wavelength D. Frequency |
| c | What are the two components of a radio wave? A. AC and DC B. Voltage and current C. Electric and magnetic fields D. Ionizing and non-ionizing radiation |
| a | How fast does a radio wave travel through free space? A. At the speed of light B. At the speed of sound C. Its speed is inversely proportional to its wavelength D. Its speed increases as the frequency increases |
| b | How does the wavelength of a radio wave relate to its frequency? A. The wavelength gets longer as the frequency increases B. The wavelength gets shorter as the frequency increases C. There is no relationship between wavelength and frequency D. The wavelength depends on the bandwidth of the signal |
| d | What is the formula for converting frequency to wavelength in meters? A. Wavelength in meters equals frequency in hertz multiplied by 300 B. Wavelength in meters equals frequency in hertz divided by 300 C. Wavelength in meters equals frequency in megahertz divided by 300 D. Wavelength in meters equals 300 divided by frequency in megahertz |
| a | What property of radio waves is often used to identify the different frequency bands? A. The approximate wavelength B. The magnetic intensity of waves C. The time it takes for waves to travel one mile D. The voltage standing wave ratio of waves |
| b | What are the frequency limits of the VHF spectrum? A. 30 to 300 kHz B. 30 to 300 MHz C. 300 to 3000 kHz D. 300 to 3000 MHz |
| d | What are the frequency limits of the UHF spectrum? A. 30 to 300 kHz B. 30 to 300 MHz C. 300 to 3000 kHz D. 300 to 3000 MHz |
| c | What frequency range is referred to as HF? A. 300 to 3000 MHz B. 30 to 300 MHz C. 3 to 30 MHz D. 300 to 3000 kHz |
| b | What is the approximate velocity of a radio wave as it travels through free space? A. 3000 kilometers per second B. 300,000,000 meters per second C. 300,000 miles per hour D. 186,000 miles per hour |
| c | Why are "direct" (not via a repeater) UHF signals rarely heard from stations outside your local coverage area? A. They are too weak to go very far B. FCC regulations prohibit them from going more than 50 miles C. UHF signals are usually not reflected by the ionosphere D. They collide with trees and shrubbery and fade out |
| d | Which of the following might be happening when VHF signals are being received from long distances? A. Signals are being reflected from outer space B. Signals are arriving by sub-surface ducting C. Signals are being reflected by lightning storms in your area D. Signals are being refracted from a sporadic E layer |
| b | What is a characteristic of VHF signals received via auroral reflection? A. Signals from distances of 10,000 or more miles are common B. The signals exhibit rapid fluctuations of strength and often sound distorted C. These types of signals occur only during winter nighttime hours D. These types of signals are generally strongest when your antenna is aimed to the south (for stations in the Northern Hemisphere) |
| b | Which of the following propagation types is most commonly associated with occasional strong over-the-horizon signals on the 10, 6, and 2 meter bands? A. Backscatter B. Sporadic E C. D layer absorption D. Gray-line propagation |
| c | What is meant by the term "knife-edge" propagation? A. Signals are reflected back toward the originating station at acute angles B. Signals are sliced into several discrete beams and arrive via different paths C. Signals are partially refracted around solid objects exhibiting sharp edges D. Signals propagated close to the band edge exhibiting a sharp cutoff |
| a | What mode is responsible for allowing over-the-horizon VHF and UHF communications to ranges of approximately 300 miles on a regular basis? A. Tropospheric scatter B. D layer refraction C. F2 layer refraction D. Faraday rotation |
| b | What band is best suited to communicating via meteor scatter? A. 10 meters B. 6 meters C. 2 meters D. 70 cm |
| d | What causes "tropospheric ducting"? A. Discharges of lightning during electrical storms B. Sunspots and solar flares C. Updrafts from hurricanes and tornadoes D. Temperature inversions in the atmosphere |
| a | What is generally the best time for long-distance 10 meter band propagation? A. During daylight hours B. During nighttime hours C. When there are coronal mass ejections D. Whenever the solar flux is low |
| a | What is the radio horizon? A. The distance at which radio signals between two points are effectively blocked by the curvature of the Earth B. The distance from the ground to a horizontally mounted antenna C. The farthest point you can see when standing at the base of your antenna tower D. The shortest distance between two points on the Earth's surface |
| c | Why do VHF and UHF radio signals usually travel somewhat farther than the visual line of sight distance between two stations? A. Radio signals move somewhat faster than the speed of light B. Radio waves are not blocked by dust particles C. The Earth seems less curved to radio waves than to light D. Radio waves are blocked by dust particles |
| b | Which of the following is true concerning the microphone connectors on amateur transceivers? A. All transceivers use the same microphone connector type B. Some connectors include push-to-talk and voltages for powering the microphone C. All transceivers using the same connector type are wired identically D. Un-keyed connectors allow any microphone to be connected |
| c | What could be used in place of a regular speaker to help you copy signals in a noisy area? A. A video display B. A low pass filter C. A set of headphones D. A boom microphone |
| a | Which is a good reason to use a regulated power supply for communications equipment? A. It prevents voltage fluctuations from reaching sensitive circuits B. A regulated power supply has FCC approval C. A fuse or circuit breaker regulates the power D. Power consumption is independent of load |
| a | Where must a filter be installed to reduce harmonic emissions? A. Between the transmitter and the antenna B. Between the receiver and the transmitter C. At the station power supply D. At the microphone |
| d | What type of filter should be connected to a TV receiver as the first step in trying to prevent RF overload from a nearby 2 meter transmitter? A. Low-pass filter B. High-pass filter C. Band-pass filter D. Band-reject filter |
| c | Which of the following would be connected between a transceiver and computer in a packet radio station? A. Transmatch B. Mixer C. Terminal node controller D. Antenna |
| c | How is the computer's sound card used when conducting digital communications using a computer? A. The sound card communicates between the computer CPU and the video display B. The sound card records the audio frequency for video display C. The sound card provides audio to the microphone input and converts received audio to digital form D. All of these choices are correct |
| d | Which type of conductor is best to use for RF grounding? A. Round stranded wire B. Round copper-clad steel wire C. Twisted-pair cable D. Flat strap |
| d | Which would you use to reduce RF current flowing on the shield of an audio cable? A. Band-pass filter B. Low-pass filter C. Preamplifier D. Ferrite choke |
| b | What is the source of a high-pitched whine that varies with engine speed in a mobile transceiver's receive audio? A. The ignition system B. The alternator C. The electric fuel pump D. Anti-lock braking system controllers |
| a | Where should a mobile transceiver's power negative connection be made? A. At the battery or engine block ground strap B. At the antenna mount C. To any metal part of the vehicle D. Through the transceiver's mounting bracket |
| b | What may happen if a transmitter is operated with the microphone gain set too high? A. The output power might be too high B. The output signal might become distorted C. The frequency might vary D. The SWR might increase |
| a | Which of the following can be used to enter the operating frequency on a modern transceiver? A. The keypad or VFO knob B. The CTCSS or DTMF encoder C. The Automatic Frequency Control D. All of these choices are correct |
| d | What is the purpose of the squelch control on a transceiver? A. To set the highest level of volume desired B. To set the transmitter power level C. To adjust the automatic gain control D. To mute receiver output noise when no signal is being received |
| b | What is a way to enable quick access to a favorite frequency on your transceiver? A. Enable the CTCSS tones B. Store the frequency in a memory channel C. Disable the CTCSS tones D. Use the scan mode to select the desired frequency |
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