advanced technician

1. A transmission line

D

2. The twisted-pair line

B

3. The coaxial line

A

4. Short Transmission lines

E

5. The characteristic impedance of a transmission line

C

6. Which of the following statements about traveling waves is not true?

A

7. A resonate line

C

8. The standing wave

A

9. A nonresonant line

D

10. Copper loss

B

Test Title: 435-60-02 Radio Wave Propagation

Question #1: Multiple Choice - choose 1 answer

Frequencies

(A) Refer to the number of seconds that elapse during one cycle of a sine wave.

(B) In general practice are expressed in meters.

(C) That are harmonics of the original frequency progressively increase in radiated energy level.

(D) That fall between 3k Hz and 300 GHz are called radio frequencies since they are commonly used in radio communications.

(E) Refer to the combination of one positive and one negative alternation of a sine wave.


A radio wave's velocity

(A) Is determined by the direction of the electric field of the wave with respect to Earth.

(B) Varies inside free space as the wave is affected by factors such as barometric pressure, humidity, and molecular content.

(C) Divided by the wavelength is equal to its frequency, and divided by its frequency is equal to its wavelength.

(D) Generally decreases as the wave's frequency increases.

(E) Refers to the distance that the wave travels as it is radiated into space.


Which of the following statements about ground and space wave propagation is not true?

(A) A ground wave is more effectively absorbed by hills, mountains, trees, and buildings as the wave's frequency increases.

(B) The range of space wave propagation can be increased by increasing the height of either or both the transmitting and receiving antennas.

(C) At frequencies of or above 4 to 5 MHz, signals can be transmitted farther with space wave rather than ground wave propagation.

(D) Ground wave coverage can be greatly improved by using horizontal polarization.

(E) Ground waves are the primary mode of propagation in the low and medium frequency bands.


To calculate the radio horizon of an antenna,

(A) Take the square root of the antenna height and multiply it by four.

(B) Take the square root of each of the transmitting and receiving antennas, multiply each by four, and add the two products.

(C) Subtract the square root of the height of the transmitting antenna multiplied by four from the radio horizon distance, divide by four, then square the result.

(D) Take the square root of the antenna height and divide by four.

(E) Take the optical horizon distance and multiply by one-third.


Sky wave propagation

(A) Occurs when all the energy radiated upward travels in a straight line off into space.

(B) Occurs within ionized layers in the atmosphere between 10 and 20 kilometers above the surface of the Earth.

(C) Is the least useful for carrier frequencies in the medium (300 kHz-3 MHz) and high frequency (3-30 MHz) bands.

(D) Is influenced by the amount of refraction, which depends on wave frequency, ionized layer density, and wave's entry angle into the ionosphere.

(E) Is the most useful technique in transmitting carrier frequencies in the ultra-high frequency (UHF) and super high frequency (SHF) bands.


The ionospheric

(A) Layer known as F2 is at its greatest height during the winter, stretching from 180 to 250 miles above the surface of the Earth.

(B) Variation of the aurora borealis makes continuous wave (CW) the best means of communications.

(C) Disturbance known as the sporadic E-layer completely absorbs low frequencies and causes a radio blackout for weeks.

(D) Disturbances caused by solar flares weaken signal levels in the VHF band and may

cause signals to disappear completely.

(E) Cyclical variations are caused by a 13-year sun spot cycle.


The distance

(A) Between the end of the usable ground wave and the reappearance of the reflected sky wave is called the critical angle zone.

(B) Of a single-hop transmission is about 2,000 meters maximum under the best conditions.

(C) That multiple-hop signals can travel is determined by the combined attenuation of the signal from the ionoshpere and ground reflection points.

(D) That a wave travels over the Earth (the skip distance) increases as the wave's radiation angle increases.

(E) That sky waves at the multifrequency (MF) band travel over the Earth does not differ between day and night.


Which of the following statements about usable frequencies is true?

(A) Usable frequencies rarely change from hour, day, or month.

(B) Below the lowest usable frequency, the RF signal is only partially absorbed by the ionosphere.

(C) The optimum usable frequency is above the maximum usable frequency but below the lowest usable frequency.

(D) The maximum usable frequency is the highest frequency at which a signal will be refracted from the ionosphere to Earth with usable strength.

(E) At the optimum usable frequency, the signal is significantly affected by constant atmospheric changes.


Signal fading

(A) As a result of receiving both direct and reflected waves has little effect on TV sets.

(B) Occurs most often when ground and sky waves arrive at the receiver in phase with each other.

(C) From multipath can be minimized by stagger stacking of antennas, providing a 10-20 dB decrease in the front-to-back ratio and a substantial increase in forward gain.

(D) Can occur in frequency modulation, where the carrier fades at different rates and times in either sideband.

(E) Results from multipath, when reflected versions of a signal take multiple paths to the receiver causing variations in signal strength.


Troposcatter

(A) Reflects all of an ultra-high frequency (UHF) signal and sends it in the direction of the

receiving antenna.

(B) Fading can be overcome with diversity reception methods that use two or more receive antennas and receivers.

(C) Systems use very inexpensive high-power transmitters, high-gain receivers, and elaborate antenna arrays.

(D) Eliminates the problem of signal fading caused by multipath because the troposphere loses much of the energy.

(E) Systems are most widely used when the distance that must be covered is 60 miles or less.

Test Title: 435-70-02 Examining Antenna Principles


The reciprocity theorem

(A) States that the different principles that apply to transmitting and receiving antennas are completely dissimilar.

(B) Refers to the capability of interchanging an antenna's functional use between transmitting and receiving.

(C) Can be used to determine currents and voltages only in simplified, single-branch networks.

(D) Is in direct conflict with Kirchhoff's and Ohm's laws.

(E) States that the transmitted power must be the reciprocal of the receiving power.


A vertically polarized antenna

(A) Has the strongest radiation intensity sent out in the vertical plane.

(B) Is also known as a bidirectional antenna because it can radiate to and receive from only two directions equally well.

(C) Picks up more man-made noise than a horizontally polarized antenna.

(D) Usually produces an electromagnetic wave with different field strengths when it is measured in different directions at the same distance from the antenna.

(E) Is not as effective in low frequency (LF) and very low frequency (VLF) bands because their surface-wave propagation requires a horizontally polarized field.


A horizontally polarized antenna

(A) Has better noise immunity and less fading than a vertically polarized antenna in the VHF and UHF bands.

(B) That is unidirectional cannot help mitigate the effects of some interfering signals.

(C) Offers maximum radiation at the ends of the antenna and minimum radiation in the directions broadside to the antenna.

(D) Has its electric lines of flux oriented so that they are perpendicular to the surface of the Earth.

(E) Is less effective than a vertically polarized antenna for sky-wave signal propagation.


Elliptical polarization

(A) Can be used to allow the reception of signals having unpredictable or changing polarization, although with a maximum of fading and signal loss.

(B) For satellite transmission increases the probability that the satellite will receive a poor signal for retransmission.

(C) Is the same as circular polarization, except that the orientation of elliptically polarized electrical field lines of flux completes one rotation for every cycle of the wave.

(D) Of the transmitting antenna must not be opposite that of the receiving antenna, or there will be considerable signal loss.

(E) Is a condition in which the orientation of the electrical lines of flux complete one clockwise rotation for every cycle of the wave and uniformly rotate in that direction.


The dBd specification

(A) Refers to the strength of a signal, in decibels, compared to 1 milliwatt with a load impedance of 600 ohms.

(B) Uses the reference direction of the antenna under test as the direction in which it radiates the least power.

(C) Is the most common way of expressing antenna power gain.

(D) Refers to the power gain of the antenna, in decibels, relative to an isotropic antenna.

(E) Stands for adjusted decibels, expressing relative levels of noise.


Antenna loading

(A) By changing the antenna's physical length is the most practical approach if an antenna is to be used to radiate at different frequencies.

(B) Requires using guy wires whose individual lengths are resonant to the transmitted frequency.

(C) Refers to the connection of the RF output of a transmitter to the transmitting antenna.

(D) Refers to tuning the antenna to bring it into exact resonance with the transmitter's output frequency.

(E) For an antenna radiating at different frequencies can be achieved by removing the discrete coil or capacitor in series with the antenna.


A dummy antenna

(A) Should be used when making adjustments to the transmitter in order to avoid interference to other signals on the same frequency.

(B) Consists of resonant tank circuit in which a known value of series current has been placed.

(C) Normally is constructed with a capacitive reactance value greater than the reactance of the coupling coil used.

(D) Enables the transmitter to operate at increased power to allow for inadvertent overloads during tuning.

(E) Converts the RF power that is supplied to it into heat in addition to radio waves.


Which of the following statements about antenna radiation is true?

(A) Isotropic antennas, which radiate electromagnetic energy equally well in all directions, have been deployed in the field more than any other types of antennas.

(B) There are different radiation patterns for transmitting and receiving antennas.

(C) The antenna radiation pattern is a graphical plot of the field strength radiated by the antenna in different angular directions.

(D) The polar plot of an antenna pattern views radiation from the ground plane.

(E) Effective radiated power is a minor factor in determining a transmitting station's effectiveness.


Antenna power gain is

(A) Significantly different between reception and transmission of signals.

(B) The ratio of the power required to produce a given field strength at a given location using a reference antenna, compared to the power required to produce the same field strength with a directional antenna.

(C) Calculated by adding the effective radiated power and the actual RF power applied to the feed point.

(D) Calculated by choosing a reference antenna with a gain assumed to be unity.

(E) Seldom measured in the favored direction of an antenna, which is the azimuth direction in which the antenna performs the best.


Which of the following statements about improving receive antenna signal-to-noise (S/N) ratio is false?

(A) If a signal is transmitted from a horizontal antenna, the best reception will be obtained by using a horizontal receiving antenna.

(B) An antenna should be physically isolated from objects that may interfere with reception of desired signals.

(C) A Yagi antenna is an example of using both frequency and polarization discrimination at the same time.

(D) A high signal-to-noise (S/N) ratio is best achieved when the antenna is resonant at the received frequency.

(E) When using a transmission line, both the pure resistance and the current in the line must be low.

Test Title: 435-75-02 Investigating Antenna Types


An antenna that is entirely above ground is said to be used in “free space,” meaning that it is not connected to the ground. The shortest antenna that can be used in free space is a half-wavelength antenna, also called what?

(A) A Marconi antenna.

(B) A Hertz antenna.

(C) A Yagi antenna.


When vertical polarization is required, the antenna must be vertical. What is the physical height of the antenna dependent on?

(A) The frequency.

(B) The location and clearance above obstacles.

(C) The current.


In a parasitic array, the dipole is connected to the transmission line, which directly excites the antenna. Since it is the element that is excited by the transmission line, the dipole is referred to as what?

(A) The driven element.

(B) The parasitic element.

(C) The reflector element.


A parasitic element may be used to increase radiation in both the forward and the backward directions. However, if only forward gain is desired, what type of parasitic element can be used?

(A) A reflector.

(B) A director.

(C) A driver.


Phased arrays can be very simple, consisting of only two elements, but more complicated arrangements are sometimes used by radio transmitting stations. What is one reason a radio station may use phased arrays?

(A) To reduce radiation to areas where unlimited reception is likely, such as large cities.

(B) To transmit a signal to a small geographic area at lower power.

(C) To avoid interference with other broadcast stations on the same channel.


Wide-bandwidth antennas are capable of receiving or transmitting signals over a wide band of frequencies. When is an antenna considered to be wide bandwidth?

(A) When its upper frequency divided by its lower frequency is greater than two.

(B) When its upper frequency divided by its lower frequency is less than two.

(C) When its lower frequency divided by its upper frequency is greater than two.


A biconical antenna is a balanced wide-bandwidth antenna that consists of two metal cones arranged so they meet at or near the vertices. If a ground plane replaces the lower cone, what does the antenna become?

(A) A discone antenna.

(B) A folded dipole antenna.

(C) A conical monopole antenna.


The bow-tie antenna is a two-dimensional form of the biconical antenna. What bands is the bow-tie antenna often used at?

(A) The low frequency (LF) and very low frequency (VLF) bands.

(B) The very high frequency (VHF) and ultra-high frequency (UHF) bands.

(C) The ultra-high frequency (UHF) and super high frequency (SHF) bands.


A narrow-bandwidth antenna is a highly directional antenna that is capable of transmitting and receiving signals over great distances. In a narrow-bandwidth antenna; the narrower the bandwidth, the higher the what?

(A) Gain.

(B) Phase.

(C) Amplitude.


Receiving antennas don’t need not be as sophisticated or as large as transmitting antennas to function at varying frequencies. What type of antenna is used for receiving applications at low frequency (LF), medium frequency (MF), and high frequency (HF) bands, up to about 20 megahertz (MHz)?

(A) The whip antenna.

(B) The ferrite rod antenna.

(C) The quarter-wavelength antenna.

Test Title: 435-81-01 Examining Microwave Applications


Which of the following is a true statement?

(A) Microwaves are defined as the portion of the electromagnetic spectrum containing wavelengths between 30 cm and 100 cm.

(B) Heating from microwave radiation is not hazardous to humans even when the radiation level is intense.

(C) Microwaves have a shorter wavelength than infrared (light) energy.

(D) Microwaves are used for command and control of orbiting satellites and the transmission of video signals via communications satellites.

(E) The microwave region contains a small amount of spectrum space and therefore cannot hold many wideband signals.


For radio waves, the velocity of propagation in a vacuum is

(A) The speed of sound.

(B) Symbolized by the Greek letter lambda.

(C) 186,280 miles per second, which is the speed of light in a vacuum.

(D) One full cycle at any given instant.

(E) 300 meters per second, the speed of light in a vacuum.


Line-of-sight (LOS)

(A) Range of communications depends on the nature of the terrain before the transmitting antenna and after the receiving antenna.

(B) Range is limitless, extending far below and above the radio horizon.

(C) Range of communications depends on the height of the transmitting and receiving antennas above the ground.

(D) Seldom is necessary in propagation at microwave frequencies.

(E) Range of communications is unaffected by weather.


Atmospheric attenuation

(A) Becomes a consideration at all microwave frequencies.

(B) Will not be particularly severe under heavy rain conditions.

(C) Should rarely be considered by a communications system designer when working in microwave bands.

(D) Is caused by water and oxygen in the air increasing electromagnetic energy.

(E) Is affected by rain and fog as a signal's wavelength approaches the same size as the rain drops.


Single link and multi-microwave systems

(A) That go beyond the line-of-sight (LOS) threshold employ repeaters to extend or redirect the signal.

(B) Use antennas with signal gain, meaning much less signal strength is obtained at the receiver.

(C) Require right-of-way acquisition between towers.

(D) Must use unreasonably sized antennas because the wavelength of the transmitted signal is short.

(E) Require purchase or lease of about one square mile for the installation of each tower.


Cable antenna relay service (CARS) bands

(A) Primarily carry digital signals, although a few systems carry analog signals.

(B) Include channelization schemes for frequency modulation (FM) and amplitude modulation (AM).

(C) All operate in only one microwave frequency.

(D) Transmit signals from a source microwave antenna underground to several receive antennas simultaneously.

(E) ) Only transport signals within large cities serviced by broadcast TV providers.


An amplitude modulated link (AML)

(A) Is a modulated/demodulation system for transporting microwave signals.

(B) Uses a free-running oscillator at the receiver so that it can always be in phase with transmitter.

(C) Is a relay service using 25 MHz channelization schemes.

(D) Block converts the entire cable channel frequency spectrum (54 to 552 MHz) to the cable antenna relay service (CARS) frequency band for transmission.

(E) Is resistant to rain fade because of its high-powered transmission and line-of-sight (LOS) between the antennas.


Waveguides

(A) Are pressurized with dry air or nitrogen to reduce the impedance and displace moisture.

(B) Of the rectangular type, can transmit much higher frequencies than the circular type.

(C) Require a center conductor to increase the skin effect at high frequencies.

(D) May be constructed of glass, copper, or nickel.

(E) Can transmit greater amounts of power than coaxial cable, but with more energy loss.


Microwave system performance

(A) Is rarely compromised by anything except rain fade.

(B) Can be optimized by obstacles in the Fresnel zone that filter out multipath interference.

(C) Can be compromised by highly reflective surfaces, such as smooth flat ground or bodies of calm water, which can cause multipath interference.

(D) Is always best when antennas are in line-of-sight (LOS).

(E) Is calculated using azimuth settings relative to magnetic north on a compass.


Which of the following is a true statement about wave propagation in a waveguide?

(A) If all of the electric lines of flux are parallel to the axis of a waveguide, the propagation mode is called transverse electric.

(B) The wave propagates by reflecting off the walls of the waveguide, so the total distance from end to end of the waveguide is greater than its length.

(C) If all of the magnetic lines of flux are perpendicular to the axis, the mode is called transverse electric.

(D) An antenna's resistance should be matched to the characteristic impedance of the waveguide to produce standing waves on the line.

(E) The electromagnetic field can be coupled into the waveguide only through its magnetic components.

Test Title: 435-86-01 Examining Microwave Components


The electron beam tube

(A) Is a vacuum tube that uses an electron beam generator instead of a typical cathode.

(B) Operates using an unfocused and diffuse beam of electrons.

(C) Cannot control the paths of the beams.

(D) Uses only electric fields to control the paths of the beams.

(E) Includes types such as voltage beam, klystron, gyrotron, cathode ray, and photo reducer tubes.


The klystron

(A) Experiences greater signal fluctuations in the input cavity than at the second cavity.

(B) Is a linear-beam tube that incorporates an electron gun, one or more cavities, and a modulating apparatus.

(C) Contains one or more cavities between the input and output cavities and has its input terminated.

(D) Is used at high power levels, as high as 1 megawatt in some cases.

(E) Uses a phase reversal process that allows only a tiny amount of energy to be drawn from the electrons.


The traveling wave tube

(A) Includes types such as the angled-beam reverse wave tube, the crossed-field backward wave tube, and the crossed-field angled wave tube.

(B) Houses a glass helix with 50 thin wire tubes inside.

(C) That provides useful amplification of signals at frequencies of the order of several gigahertz, is called a wave amplifier.

(D) Requires multiple power supplies, including a 7.5 VAC heater supply, a 0-450 VDC anode supply, and a variable high-voltage (300 VDC-33 kVDC) supply for the helix.

(E) In which the electrons travel in a direction opposite to that in which the wave is propagated, is called a crossed-field forward wave tube.


In the magnetron,

(A) A magnetic field is applied in a latitudinal direction that causes electrons to travel outward in spiral, rather than straight, paths.

(B) The cathode is connected to the positive terminal of a high-voltage source, and the

anode is connected to the negative terminal.

(C) Electrons tend to travel in bundles because there is no interaction between the electric and magnetic fields.

(D) The output power increases as the frequency increases.

(E) The RF output is taken from a waveguide opening in the anode.


A cavity resonator

(A) Operates as a tuned circuit and is practical at frequencies below about 200 MHz.

(B) Has a resonant frequency that cannot be affected by temperature and humidity variations.

(C) Is a piece of waveguide closed off at only one end with a metallic plate.

(D) That is tunable has a wavelength at resonance directly proportional to the physical length of the cavity.

(E) Has a fundamental frequency and, theoretically, just two harmonic frequencies.


Directional waveguide couplers

(A) Are rated in microwatts, which specify the fraction of the input signal appearing at the secondary output port.

(B) With holes one-half wavelength apart, the propagation is such that most of the energy is induced in the primary section in the reverse direction.

(C) Are produced by welding together two pieces of waveguide and opening one or more holes between them.

(D) With fewer and smaller holes have greater power transfer from the primary waveguide section to the secondary waveguide section.

(E) Use a dummy load in the forward-direction end to absorb any reflected power.


Which of the following is not true about microwave diode types?

(A) Only a small fraction of the consumed power in a Gunn diode results in RF power.

(B) Varactor diodes are designed to provide an electronically variable capacitance.

(C) IMPATT diodes tend to complement Gunn diodes in many continuous wave, and in a few pulsed, applications.

(D) Gunn diodes are very efficient, as only a small amount of energy results in RF power.

(E) Tunnel diodes depend on a voltage-controlled negative resistance effect for amplification at microwave frequencies.


Which of the following is not true about passive diodes?

(A) The point contact diode is limited to low-power applications because the point contact junction cannot carry much power.

(B) In a Schottky barrier diode, the forward resistance and noise are lower because of a large contact area between the metal and semiconductor.

(C) PIN diodes have low power capabilities that are limited to 5 amps maximum, with voltages less than 200 V.

(D) PIN diodes are capable of switching times faster than 100 nanoseconds in low-power switching and pulse modulation.

(E) Passive diodes are used for power control, not power generation or amplification.


Field-effect transistors

(A) Are the only transistors that can provide useful gain with low noise at frequencies through the J-band.

(B) Are exactly similar to bipolar junction transistors in both structure and material.

(C) Are unpopular devices and have largely been overtaken by bipolar junction transistors for frequencies above 8 GHz.

(D) Have higher usable gain, higher transconductance, and consistently lower noise than bipolar junction transistors below 2 GHz.

(E) Are almost always silicon NPN type due to the inherent stability of silicon monoxide.


Waveguides

(A) Must be straight with no turns.

(B) Have three methods for injecting or removing energy: the loop, the probe, and the slot.

(C) Are efficient only at frequencies below 10 GHz.

(D) That are rectangular or square are better suited for long distances higher frequencies than round waveguide.

(E) Have a maximum frequency of 0.7 of the wavelength.

Test Title: 435-90-02 Satellite Communications


Which satellite orbit enables two-way communications from fixed locations?

(A) Low Earth orbit (LEO).

(B) Medium Earth orbit (MEO).

(C) Geosynchronous Earth orbit (GEO).


What characteristic in a standard star configuration, using very small aperture terminals (VSAT) causes excessive delays and disrupts voice communications?

(A) The small size of the VSAT antenna does not support the bandwidth required for voice

service so it “piles up” until in a buffer.

(B) The network management system used for VSAT in a standard star configuration does not meet the quality of service (QOS) requirements for voice communications.

(C) The hops from the origination point to the satellite and down to the hub, and a second hop from the hub to the satellite and down to the destination.


Which global positioning system (GPS) service has its carrier signal calibrated with GPS to sub-hertz levels?

(A) High-Accuracy NDGPS (HA-NDGPS).

(B) Nationwide Differential GPS (NDGPS).

(C) Differential GPS (DGPS).


What advancement in satellite communications has increased the usable frequencies available for new communications satellites?

(A) Increases in the number of transponders from 24 to 50.

(B) The addition of Ka- and V-band frequencies.

(C) Advancements in beam forming.


What is the result of increases in effective isotropic radiated power (EIRP).

(A) Increased spatial separation of satellites.

(B) Reduced antenna size.

(C) Increased numbers of spot beams.


What technique is used in satellite transmission which enables the use of the same downlink frequencies without interference?

(A) Polarization.

(B) Spot beams.

(C) Multiplexing.


Which multiplexing scheme has the advantage of using a single frequency for a site connection?

(A) Frequency division multiplexing (FDM).

(B) Single channel per carrier (SCPC).

(C) Time division multiplexing (TDM).


What can be done to achieve the goal of smaller, less expensive downlink antennas?

(A) Use smaller antennas on satellites to focus the beam.

(B) Use larger antennas for uplink and satellite transmissions.

(C) Increase satellite spacing to reduce noise.


Space diversity is used to overcome which of the following conditions?

(A) Rain fade.

(B) Limitations on frequency availability.

(C) Decreased satellite spacing.


In reference to satellite communications, what is the meaning of the term “bent pipe”?

(A) Bent pipe satellites change the modulation of received signals.

(B) Bent pipe satellites receive signals at one frequency and retransmit at another.

(C) Bent pipe satellites have switchable transponders to redirect signals to other satellites.

Test Title: 529-21-02 Analyzing Analog TV Signals


Horizontal sync pulses in the National Television System Committee (NTSC) color system

(A) Occur in groups of six before and after each equalizing pulse.

(B) Maintain uninterrupted horizontal synchronization throughout the vertical blanking pulse period.

(C) Occur at intervals of 63.5 microseconds.

(D) Have a duration of 3 H.

(E) Maintain synchronization of the horizontal scanning circuits in the TV receiver with its trailing edge.


The vertical blanking pulse

(A) Duration is sufficient to extinguish the scanning beam at the TV receiver during horizontal retrace time.

(B) Duration is considerably shorter than the horizontal blanking pulse duration.

(C) Synchronizes the camera scanning circuits.

(D) Ensures that the scanning beam is properly positioned both vertically and horizontally in the TV receiver when video information is applied.

(E) Is not part of the transmitted composite video signal.


The color sync burst in the National Television System Committee (NTSC) color system

(A) Is not part of the transmitted composite color video signal.

(B) Is transmitted at the end of each horizontal scanning line.

(C) Consists of eight to eleven cycles of the 3.58 MHz signal.

(D) Is placed on the front porch of the horizontal sync pulse.

(E) Keeps the receiver 3.58 MHz oscillator out of phase with the equivalent transmitter oscillator.


The transmitted composite National Television System Committee (NTSC) color video signal

(A) Polarity of modulation is negative.

(B) Lowest camera signal amplitudes correspond to the darkest parts of the scene scanned by the camera.

(C) Carrier output power is increased with an increase in the luminance of a color picture.

(D) Black level is reached at an amplitude equivalent to 25% of the maximum transmitted signal.

(E) Contains a color burst that is transmitted at a frequency of 3.579545 MHz in the lower portion of the video pass band.


In an analog video waveform, what is the purpose of the vertical and horizontal synchronization pulses?

(A) To synchronize alternate lines within the video fields of a video frame.

(B) To maintain horizontal synchronization during the vertical blanking interval (VBI).

(C) To synchronize the elements of the composite video and route them to the appropriate processing circuitry.

(D) To synchronize the scanning motion in the television display with the respective scanning motion of the electronically recorded image.

(E) To synchronize all the elements of the video waveform to each other.


The vertical interval reference signal

(A) Is used for system testing.

(B) Is used at the receiving station as a reference to assure the correct transmitted hue and saturation of the color signal.

(C) Is transmitted in fields 1 and 2 on line 18 of the vertical blanking interval (VBI).

(D) Does not enable correction of video gain, chrominance-to-luminance gain ratio, black level, chroma phase, color-burst amplitude, and sync amplitude errors.

(E) Is used for in-line signal correction.


The vertical interval test signal that can be used to examine amplitude/frequency response errors is the ___________ test signal.

(A) Color bar

(B) Modulated staircase composite

(C) Multiburst

(D) Pulse and bar

(E) White reference burst


What are the three elements of the composite video signal?

(A) Luminance, chrominance, and picture information.

(B) Chrominance, synchronization signals, and picture information.

(C) Luminance, synchronization signals, and chrominance.

(D) Luminance, synchronization signals, and color burst.

(E) Luminance, synchronization signals, and blanking information.


A(n) _________ circuit extracts the leading-edge component from the combined sync waveform input signal.

(A) Sync pulse separator

(B) Differentiator

(C) Integrator

(D) Low pass filter

(E) Clipper


Equalizing pulses

(A) Create problems of non-uniform spacing of the scanning lines as successive fields are scanned.

(B) Occur in groups of four before and after each vertical sync pulse.

(C) Are spaced at periods of 3 H.

(D) Equalize the time difference that occurs between horizontal sync signals as alternate

fields are scanned.

(E) Maintain uninterrupted horizontal synchronization throughout the vertical blanking pulse period.

Test Title: 536-20-01 Equipment Connection Protocols


The broadband cable headend consists of connection protocols developed by different organizations and manufacturers for specific applications. Who developed the serial data interface (SDI) protocol?

(A) The Institute of Electrical and Electronics Engineers (IEEE).

(B) The Society of Motion Picture and Television Engineers (SMPTE).

(C) General Instrument (GI).


Transporting data between headend devices requires the use of standard communications protocols. Which protocol uses non-return to zero inverted (NRZI) coding, making it resistant to noise and low frequency components such as hum?

(A) The serial data interface (SDI) protocol.

(B) The digital headend expansion interface (DHEI) protocol.

(C) The Gigabit Ethernet (GigE) protocol.


The digital headend expansion interface (DHEI) protocol is a common connection protocol in the headend. What was the original application of the proprietary DHEI protocol?

(A) To enable the transport of MPEG-2 Transport Streams between devices from other hardware suppliers, such as Motorola.

(B) To distribute Emergency Alert System (EAS) messages from national, state, and local authorities.

(C) To chain multiple General Instrument integrated receiver/transcoders together to function as a single unit.


The Digital Video Broadcasting-Asynchronous Serial Interface (DVB-ASI) protocol is more commonly known as the ASI protocol. Why was the ASI protocol developed?

(A) To transport the MPEG-2 Transport Stream data between devices.

(B) To transport uncompressed digital video throughout a broadcast facility.

(C) To transport compressed digital video and audio throughout a broadcast facility.


Video-on-demand (VOD), Switched Digital Video (SDV), and Internet protocol television (IPTV) are examples of switched services deployed in many cable systems. Which common networking protocol is being used as cable services transition from broadcast to these types of switched services?

(A) The serial data transport interface (SDTI) protocol.

(B) The program and system information (PSIP) protocol.

(C) The Gigabit Ethernet (GigE) protocol.


There are multiple hardware options and configuration possibilities when utilizing Gigabit Ethernet (GigE) in the headend. What can be used for GigE connections over short distances?

(A) A 75-ohm coaxial cable with a BNC interface.

(B) An RJ-45 connector on unshielded twisted-pair (UTP) Ethernet cable.

(C) Twisted-pair cables with a 15-pin or 26-pin connector.


The patch panel is a demarcation point between the output from a source and the input to another device or destination. In the headend, the serial data interface (SDI) patch panel is used to route the SDI signal from a local origination studio to what?

(A) A satellite receiver/decoder.

(B) An MPEG-2 encoder.

(C) A quadrature amplitude modulation (QAM) transcoder.


Video, audio, asynchronous serial interface (ASI), and serial data interface (SDI) patch panel jacks are available in three modes: full-normal, half-normal, and non-normal. Which jack mode uses a looping plug to provide the connection between the top and bottom jacks?

(A) Full-normal.

(B) Half-normal.

(C) Non-normal.


A patch panel contains a series of jacks or ports with multiple cable connections. In a half-normal patch panel jack connection, when will the connection break?

(A) When a patch cable is plugged into the bottom jack.

(B) When a patch cable is plugged into the top jack.

(C) When a patch cable is plugged into ether the top or bottom jack.


Routing switchers are used in television broadcast production facilities, where loss of synchronization during a switch from one program to another can be disastrous. Why were routing switchers developed?

(A) To route individual signals to multiple destinations using electronic switching.

(B) To switch from digital television (DTV) content to local advertisements.

(C) To digitally insert one MPEG-2 program, typically a commercial, into another.

Test Title: 535-23-02 Understanding Signal Processors


The heterodyne process used to perform channel and frequency conversions is an essential process used in radio communications. When is heterodyning used?

(A) In the processor intermediate frequency (IF) stage.

(B) To eliminate any undesired signals before being amplified.

(C) In the processor input stage.


During the heterodyne process, the signal from an internally generated carrier is combined with the original signal to create a sum and difference signal. What signal usually becomes the intermediate frequency (IF)?

(A) The sum signal.

(B) The difference signal.

(C) The original signal.


The input converter of a Channel 2 processor has a local oscillator frequency of 101 megahertz (MHz), a video frequency of 55.25 MHz, and an audio frequency of 59.75 MHz. What is the video intermediate frequency (IF) for Channel 2?

(A) 41.25 MHz

(B) 4.50 MHz

(C) 45.75 MHz


There are many applications that convert an entire frequency band or block of channels to a higher or lower frequency band. In the low-noise block (LNB) application, what are satellite microwave frequencies converted to?

(A) L-band frequencies of 950 to 1,450 megahertz (MHz).

(B) KU-band frequencies of 11.7 to 12.2 gigahertz (GHz).

(C) C-band frequencies of 3.7 to 4.2 gigahertz (GHz).


During the input stage of an analog channel processor, the signal at the output of the channel filter is amplified in the radio frequency (RF) amplifier. Where does the output of the RF amplifier go?

(A) Into a mixer stage along with the signal from the local oscillator (LO).

(B) Into an intermediate frequency (IF) port of the signal processor.

(C) Into the RF output carrier level signal control to adjust the signal.


In an analog channel processor, the output of the intermediate frequency (IF) amplifier is split and sent to the IF filter and the IF detector. What does the IF filter contain to remove adjacent carriers other than the video and audio IF?

(A) A low-noise block (LNB) application.

(B) Scramblers.

(C) Notch filters.


A signal processor normally has three stages: the input stage, or input converter; the intermediate frequency (IF) stage; and the output stage, or output converter. What is the specific function of the output converter?

(A) To convert the composite intermediate frequency (IF) to an analog television channel.

(B) To convert the incoming analog television channel to composite intermediate frequency (IF).

(C) To receive the intermediate frequency (IF) signal from the mixer output of the input converter.


The use of a common intermediate frequency (IF) enables the insertion of alternate IF signals into the IF input of an output converter. Which of the following uses is an example of an alternate IF connection?

(A) Using a suitcase jumper or toggle switch for phase lock selection.

(B) Routing a composite intermediate frequency (IF) signal to a scrambler.

(C) Switching an Emergency Alert Message (EAS) into a processor.


In a frequency agile processor, the first local oscillator (LO) varies in frequency. At what point are all other signal frequencies filtered out so channel selection can be achieved?

(A) When the composite intermediate frequency (IF) is created.

(B) When the output from the mixer is equal to the intermediate frequency (IF).

(C) When the video intermediate frequency (IF) is higher than the audio IF.


Frequency agile processors can be used to convert over-the-air (OTA) channels to channels on a broadband cable system. When there is no input filtering in an agile processor, what is the solution to filter out spurious input carriers?

(A) Complete a double frequency conversion and use a surface acoustic wave (SAW) filter.

(B) Phase lock the output converter to the input converter.

(C) Match the processor’s output frequency to an OTA video carrier of the same frequency.

Test Title: 535-12-02 Modulating and Demodulating Analog TV Signals


Baseband signals occupy bandwidth—a measure of the information-carrying capacity of a communications channel. What is another characteristic of all baseband signals, whether they come from a video camera, microphone, or computer?

(A) They can easily be transmitted long distances.

(B) They can be in the form of analog or digital signals.

(C) They extract information from modulated carriers.


Early television filters were not good enough to filter out the lower sideband without filtering some of the upper sideband, so part of the lower sideband remains in the transmitted channel. What is the term applied to filtering the lower sideband, but leaving a portion so that the upper sideband is transmitted intact?

(A) Vestigial sideband (VSB) transmission.

(B) Negative sideband transmission.

(C) Double-sideband transmission.


In video, the brightness or luminance level of a scene represents the amount of light in a scene. In a transmission using negative-polarity modulation, what effect does a dark scene have?

(A) It increases the modulation and increases the output power.

(B) It decreases the modulation and reduces the output power.

(C) It increases the modulation and reduces the output power.


During frequency modulation of a television signal’s audio, the amount by which the signal

frequency varies above and below the center of the main carrier is called the deviation. The amount of deviation is determined by what?

(A) The amplitude of the sidebands.

(B) The amplitude of the modulating signal.

(C) The amplitude of the carrier.


An imperfect clamp circuit is likely to cause low-modulation percentage (black compression). Which of the following can black compression result in?

(A) Excessive tilt.

(B) Washed out pictures during bright scenes.

(C) A loss of resolution of dark scene information and receiver synchronization problems.


The process of frequency conversion to a desired channel is similar to modulation in that a local oscillator (LO) signal is mixed with the intermediate frequency (IF) to produce difference and sum signals. During this frequency conversion, what is the difference signal?

(A) The image.

(B) The audio.

(C) The output channel.


Phase lock is used with the harmonically related carrier (HRC) and incrementally related carrier (IRC) plans. Which of the following is an example of when phase lock should occur?

(A) When direct pick-up problems with local over-the-air broadcast transmissions on the same channel need to be eliminated.

(B) When the output level in the combining network is too high, even when set to the lowest permissible value.

(C) When carrier frequencies need to be shifted slightly to avoid aeronautical frequencies.


An analog demodulator is the reciprocal of a modulator; its design is very similar with circuitry performing functions opposite to those of a modulator. In a fixed channel demodulator, what type of input interface is always used?

(A) A BNC connector.

(B) An RCA connector.

(C) An F-type connector.


The block diagram of a single analog channel demodulator can be divided into three sections: the radio frequency/intermediate frequency (RF/IF) section, the video section, and the audio section. During the RF/IF section, the output of the input mixer goes through an IF filter which removes all other carriers except for what?

(A) The audio IF.

(B) The composite IF.

(C) The modulated video IF.


A video detector separates modulated video from the carrier to provide a baseband signal. When a modulator is used for testing a received video signal, what method of video detection is preferred?

(A) Envelope detection.

(B) Synchronous detection.

(C) Diode rectifier detection.

Test Title: 580-10-01 Digital Integrated Receiver/Decoders


At the downlink site of a C-band communications system, a feedhorn collects a satellite signal and directs it to an amplifier inside a device called a low-noise block (LNB). What function does the LNB perform?

(A) It splits the C-band signal and routes it to the appropriate transponder channel.

(B) It amplifies the C-band signal then converts it to the lower L-band frequency range.

(C) It receives the uplink channel, then amplifies and converts it to the receive frequency.


An integrated receiver/decoder (IRD) can be tuned to select individual satellite transponder channels or frequencies that have been block-converted. Why do the transponders alternate between the satellite antenna’s vertical and horizontal polarity?

(A) To enable the receiver to be used for any satellite band.

(B) To minimize the amount of signal loss between the dish and the receiver.

(C) To minimize adjacent transponder interference.


In the Ku-band there are downlink allocations for fixed satellite services (FSS) and broadcast satellite services (BSS). FSS includes the uplink frequencies used for what?

(A) Non-mobile satellite terminals, like those used for television programming distribution.

(B) Direct broadcast satellite (DBS) services received directly at a customer’s home.

(C) Commercial distribution of television programming via satellite.


The tuning of C-band or Ku-band at the integrated receiver/decoder (IRD) is identical except that the satellite transponder channel assignments are reversed. How is the L-band frequency of a C-band transponder calculated?

(A) By subtracting the C-band range from the local oscillator (LO) frequency.

(B) By subtracting the local oscillator (LO) frequency from the C-band range.

(C) By subtracting the Ku-band range from the local oscillator (LO) frequency.


The digital modulation systems used for satellite transmission, quadrature phase shift keying (QPSK), offset quadrature phase shift keying (OQPSK), and 8-phase shift keying (8-PSK), present digital information as different states of signal phase. Which modulation uses two continuous wave (CW) carriers, 90° out of phase with one another?

(A) OQPSK

(B) QPSK

(C) 8-PSK


To receive a satellite service, all systems require a compatible integrated receiver/decoder (IRD) that decodes the MPEG-2 Transport Steam. Which protocol is the next generation of its standard which uses coding that can be uplinked in a tiered approach?

(A) The Digital Video Broadcasting-Second Generation (DVB-S2) protocol.

(B) The Digicipher II (DCII) protocol.

(C) The Asynchronous Serial Transfer (ASI) protocol.


Digital content that is encrypted at the uplink must be received and decoded by an integrated receiver/decoder (IRD). What is the purpose of a transcoder integrated receiver/decoder (IRD)?

(A) To decode and decrypt multiple services on a single multiplex using a single IRD.

(B) To adjust a satellite dish antenna’s low-noise block (LNB) to receive a horizontal or vertical polarity signal transmission.

(C) To convert MPEG-4 advanced video compression (AVC) to an MPEG-2 compression protocol.


Conditional access (CA) is the term used to describe how the distribution of television content is controlled. In a CA system, when is the decryption key sent?

(A) Before the integrated receiver/decoder (IRD) at the downlink is installed and receiving the encrypted signal.

(B) As soon as the programmer sends the authorized decryption key to the uplink it is sent to the integrated receiver/decoder (IRD).

(C) After the integrated receiver/decoder (IRD) at the downlink is installed and receiving the encrypted signal.


The rate that the data bits in a digital modulated satellite carrier change states is called the symbol rate, stated as mega-symbols per second (MS/s). What is the symbol rate of a 60 megabits per second (Mbps), 8-phase shift keying (8-PSK) modulated transmission containing three bits per symbol?

(A) 20 MS/s

(B) 30 MS/s

(C) 15 MS/s


The Digicipher II (DCII) and the Digital Video Broadcasting-Second Generation (DVB-S2) protocol systems differ in how their respective system information (SI) is placed into configuration tables by the decoder. What table does the DCII system have that includes satellite, modulation, and tuning information?

(A) A program association table (PAT).

(B) A network information table (NIT).

(C) A virtual channel table (VCT).

Test Title: 580-20-01 Transcoding Digital Broadcast Channels


The Advanced Television Systems Committee (ATSC) standards cover HDTV, SDTV, and DBS. Which of the following is also covered?

(A) Multichannel audio.

(B) Phase alternating line encoding.

(C) Quadrature amplitude modulation (QAM).


What are the two modulation formats for the transmission of digital data streams that are covered in ATSC A/53 Part 1?

(A) A 16-VSB high data rate terrestrial mode and a 24-VSB ultra-high broadcast mode.

(B) A 16-VSB terrestrial transmission mode and a 16-VSB broadcast data mode.

(C) An 8-VSB terrestrial broadcast mode and a 16-VSB high data rate mode.


When converting an HDTV transmission to an SDTV or analog transmission, which system imbeds instructions from the broadcaster for picture reconstruction?

(A) Active format description (AFD).

(B) Program and System Information Protocol (PSIP).

(C) Statistical multiplexer.


HDTV signals are broadcast at 19.39 Mbps using 8-VSB. Why must conversion of this signal be done at the headend?

(A) The quadrature amplitude modulation (QAM) format used by the cable industry has insufficient bandwidth capacity to transport the 8-VSB format.

(B) The quadrature amplitude modulation (QAM) format used by the cable industry is not compatible to the 8-VSB format.

(C) No conversion is necessary as the cable industry has adopted the 8-VSB carrier format.


When an HDTV signal is transcoded to an SDTV MPEG-2 signal, what is the change in data rate?

(A) The data rate changes from 19.39 Mbps up to 256 Mbps.

(B) The data rate changes from 2.39 Mbps up to 19.39 Mbps.

(C) The data rate changes from 19.39 Mbps down to 2-4 Mbps.


When converting an HDTV signal to an SDTV display using the center cut option, what portion of the picture is cropped?

(A) Typically, 16.5% from each side of the picture.

(B) Typically, 16% from both sides and the top and bottom of the picture.

(C) Nothing is cropped, the picture is just made smaller to fit.


Why did the Society of Motion Picture and Television Engineers (SMPTE) develop active format description (AFD)?

(A) To prevent postage stamp displays on HDTV commercials.

(B) To prevent the pillar box and postage stamp condition from appearing in SDTV displays.

(C) To prevent pillar box video stretching on HDTV displays.


Each DTV-to-analog decoder must convert the ATSC digital audio signal into an analog television signal, which includes compensating for program loudness adjustments and dynamic range compression (DRC). What is the third feature the decoder must adjust?

(A) Up mixing to a multi-audio signal.

(B) Selecting out the major audio components for enhancement.

(C) Down mixing to a single audio signal.


If closed captioning data that is present on a DTV signal is converted to analog, how does the decoder include the closed captioning data?

(A) The closed captioning data stream is converted along with rest of the digital signal, then removed and sent as a separate signal simultaneously with the original signal.

(B) The closed captioning data stream is extracted from the digital stream and reconstructed onto line 21 of the vertical blanking interval (VBI).

(C) All closed captioning data can be converted along with rest of the digital signal and displayed normally without any other conversion processing.


For content advisory data to work after conversion from digital to analog, what must the analog television receiver do after decoding the signal?

(A) Decode the content advisory from the vertical blanking interval (VBI) and compare it to the V-chip setting, blocking the display of the program if the program rating exceeds the selected rating level.

(B) Decode the content advisory from the vertical blanking interval (VBI) and compare it to the V-chip setting, blocking the display of the program if the program rating extends below the selected rating level.

(C) Decode the content advisory from the horizontal sync pulse and compare it to the V-chip setting, blocking the display of the program if the program rating exceeds the selected rating level.

Test Title: 580-30-01 Digital Modulators


In a system offering interactive services such as video-on-demand (VOD), what determines the amount of data going into the QAM modulator that is connected to the VOD server?

(A) The amount of data is dependent upon the number of orders being fulfilled by the VOD server.

(B) The amount of data is dependent upon the length of the MPEG-2 programs being supplied by the server.

(C) The amount of data is determined by whether the content is standard definition television (SDTV) or high definition television (HDTV).


What is the usable data rate for 256-QAM?

(A) The usable data rate for 256-QAM is 26.97 Mbps.

(B) The usable data rate for 256-QAM is 42.88 Mbps.

(C) The usable data rate for 256-QAM is 38.8 Mbps.


How is the usable data rate for a quadrature amplitude modulation (QAM) signal calculated?

(A) The symbol rate times the number of bits per symbol equals the usable data rate.

(B) The number of symbol combinations (64 or 256) times the number of bits per symbol equals the usable data rate.

(C) The symbol rate times the number of bits per symbol minus overhead equals the usable data rate.


What role does the out-of-band (OOB) modulator play in the scrambling/descrambling of signals?

(A) The OOB modulator receives the control word used to decrypt the content and designates which programs in the multiprogram transport stream (MPTS) are scrambled.

(B) The OOB modulator receives set-top box (STB) authorization from the conditional access controller (CAC) and distributes the authorizations via the forward data channel (FDC).

(C) The OOB modulator distributes the scrambled packet headers to receivers so they can use the proprietary algorithms generated by the conditional access controller (CAC).


Which device in a conditional access (CA) system populates the scrambling control (SC) field on programs that are to be scrambled?

(A) The multiplexer populates the SC field on programs that are to be scrambled by the QAM modulator.

(B) The QAM modulator populates the SC field on programs that are to be scrambled by the conditional access controller (CAC).

(C) The conditional access controller (CAC) populates the SC field on programs that are to be scrambled by the QAM modulator.


What must the entitlement management message (EMM) receive from the conditional access (CA) controller before it can decrypt the entitlement control message?

(A) The control word.

(B) The user key.

(C) The service key.


Within the packet identifier (PID) assignments there are three tables. Which table lists all of the programming/services that have assigned PIDs of scrambled programs on that transport stream?

(A) The program association table (PAT).

(B) The program map table (PMT).

(C) The conditional access table (CAT).


Which modulator receives its data from a headend controller or from a satellite receiver that has extracted the data that is embedded in a satellite program?

(A) The edge QAM (EQAM) modulator.

(B) The out-of-band (OOB) modulator.

(C) The video-on-demand (VOD) modulator.


What are the primary differences between the transmission protocols used on the return data channel, ALOHA, and time division multiple access (TDMA)?

(A) ALOHA is a channel-based protocol; time slots are allocated for the reliable and orderly transmission of upstream data with no collisions. Time division multiple access (TDMA) is a collision recovery protocol; if a collision occurs, the data is resent.

(B) ALOHA is a collision recovery protocol; if a collision occurs, the data is resent. Time division multiple access (TDMA) is a channel-based protocol; time slots are allocated for the reliable and orderly transmission of upstream data with no collisions.

(C) ALOHA is a collision recovery protocol; if a collision occurs, the data is resent only after all other transmissions have been completed. Time division multiple access (TDMA) is a channel-based protocol; time slots are allocated for fast, reliable, and orderly transmission of upstream data with no collisions.


The edge QAM (EQAM) communicates with a session manager and a resource manager, which

are two content management devices that can be integrated within the EQAM. What is the purpose of the resource manager?

(A) The resource manager administers the delivery of content between the headend and the customer.

(B) The resource manager determines which EQAM is being used for the delivery of content.

(C) The resource manager re-packetizes the data into a new transport stream.

Test Title: 536-12-02 Combining Broadband Signals


What device should you use to combine two forward RF carriers of unequal amplitude if the goal after combining is for the carriers to be the same approximate amplitude?

(A) A splitter with an in-line attenuator placed on its common (or input) port.

(B) A directional coupler (DC) having a value approximately the same as the difference between the carrier levels.

(C) A directional coupler (DC) with its tap port connected to the lower of the two carriers.


Why would an apartment tap be used as a combiner?

(A) Some cable operators use terminating apartment taps to combine headend carriers because of their low insertion loss, cabling simplicity, isolation specifications, and bandpassing ability.

(B) Some cable operators use terminating apartment taps to combine headend carriers because of their size, cabling simplicity, high isolation specifications, and bandpassing ability.

(C) Some cable operators use terminating apartment taps to combine headend carriers because of their size, cabling simplicity, low isolation specifications, and bandpassing ability.


What components are used to create headend combiners?

(A) Headend combiners are comprised of combinations of quality splitters and directional couplers, used to achieve high port-to-port isolation (typically greater than 30 dB, some as high as 40 dB) with integral test points.

(B) Headend combiners are comprised of combinations of quality amplifiers having multiple inputs to achieve high port-to-port isolation (typically greater than 30 dB, some as high as 40 dB) with integral test points.

(C) Headend combiners are comprised of combinations of directional couplers configured in the forward direction to achieve high port-to-port isolation (typically greater than 30 dB, some as high as 40 dB) with integral test points.


If the device used as a headend combiner (splitter, apartment tap, etc.) has no test point, what can be done to create a test point?

(A) If the device used as a headend combiner (splitter, apartment tap, etc.) has no test point, a splitter can be installed in the forward direction to function as a test point.

(B) If the device used as a headend combiner (splitter, apartment tap, etc.) has no test point, a directional coupler can be installed in the forward direction to function as a test point.

(C) If the device used as a headend combiner (splitter, apartment tap, etc.) has no test point, a directional coupler can be installed in the reverse direction to function as a test point.


What component should be used to insert the output from modulators of the same frequency, but different content, directed to specific service areas?

(A) Directional couplers (DC) should be used to insert the output from each modulator into the signal after it has been split for each service area.

(B) Splitters should be used to insert the output from each modulator into the signal after it has been split for each service area.

(C) Dedicated combiners or apartment taps should be used to insert the output from each modulator into the signal after it has been split for each service area.


When is carrier isolation a factor in a combining scheme?

(A) When carriers are distributed to different service areas, there is the possibility of interference between carriers of different frequencies.

(B) When carriers are distributed to one service area, there is the possibility of interference between carriers of different frequencies.

(C) When different modulators on the same frequency carrier are serving different service areas, the possibility of interference between modulators exists.


Isolation amplifiers are effective at increasing the carrier isolation. What must be considered when utilizing isolation amplifiers?

(A) The manufacturer suggestions for input and output carrier levels and the number of input carriers.

(B) The manufacturer suggestions for output carrier levels and the number of output carriers.

(C) The manufacturer suggestions for input and output carrier levels, the number of input carriers, and external feedback loops for redundancy in case of a power outage.


What should be considered when choosing between the use of an active combiner or an isolation amplifier?

(A) Isolation: Active combiners amplify after combining and do not increase the port-to-port isolation of the combiner.

(B) Gain: Active combiners have more gain than launch amplifiers, making them a better choice in the headend to overcome the losses in the combiner system.

(C) The number of carriers: Nonlinear distortions (composite triple beats, etc.) may occur in active combiners if a minimum number of carriers is not maintained.


What controls and manages the upstream transmissions of the customer premises equipment (CPE)?

(A) The return carrier demodulator (RCD) for each associated CPE.

(B) The CPE transmissions are self-managed using a specific upstream transmission protocol.

(C) The headend controller (HC) such as the cable modem termination system (CMTS) for cable modems.


What is the best way to maintain return carrier isolation in the headend?

(A) Combine the service areas before splitting the signals and directing to each return carrier demodulator (RCD).

(B) Split the service areas before combining signals for specific services.

(C) Install an isolation amplifier at the input of every return carrier demodulator (RCD).

Test Title: 538-15-01 Analog Video Measurements and Testing


The Institute of Radio Engineers (IRE) developed a 140-unit scale to express video signal component values. What IRE value represents the picture black level?

(A) 100 IRE

(B) 7.5 IRE

(C) -40 IRE


Carrier demodulation and modulation in the headend can cause chrominance-to-luminance delay inequality (CLDI), differential gain, and differential phase distortion. What is a symptom of differential gain?

(A) An overall lack of sharpness in a picture.

(B) Different shades of the same color on a television screen.

(C) Smearing or bleeding at the edges of objects in a picture.


Problems in the headend can cause poor television pictures at home. What problem occurs if the high-frequency information is not consistently processed at all luminance levels?

(A) Differential gain.

(B) Chrominance-to-luminance delay inequality (CLDI).

(C) Differential phase.


Video signal generators are used to measure video levels, linearity, phase response, chrominance noise, picture monitor alignment, and frequency response. When using a video signal generator, what enables the measurement of video quality without interrupting programming?

(A) Tunable down converters.

(B) Vertical interval test signals (VITS).

(C) Video filters.


Test signals are used to enable the set up and measurement of specific video parameters. What is the multiburst test signal used for?

(A) To test the frequency response of an individual television channel.

(B) To enable the alignment and measurement of several video parameters.

(C) To balance the color circuitry in video equipment.


Negative-polarity modulation is used to reduce the amount of power required to transmit a video signal. How is the depth of modulation measured?

(A) From the zero carrier to the horizontal sync tip.

(B) From the black level to the zero carrier.

(C) From the horizontal sync tip to the peak white level.


The depth of modulation for standard broadcast television is 87.5%. What is the result of a depth of modulation that is too low?

(A) Degraded signal-to-noise (S/N).

(B) Washed out picture.

(C) Differential phase distortion.


Differential gain can be measured on both a vectorscope and a waveform monitor. When using a waveform monitor, which of the following indicates differential gain?

(A) Any difference in the amplitude of the chrominance packets.

(B) Any elongation of the dot representing the staircase’s chrominance peak.

(C) Any widening of the chrominance vector.


Modulation linearity is a measure of a video signal’s amplitude at different luminance levels. What should be measured on a waveform monitor to determine if modulation linearity error exists?

(A) The zero carrier reference pulse.

(B) The amplitude of the left and right lobes.

(C) The height of each step in the staircase.


Video measurement sets and spectrum analyzers automate the process of measuring baseband video and provide accurate and repeatable results. Which of the following is necessary for use with a video measurement set, but not with an automatic spectrum analyzer?

(A) An external precision demodulator.

(B) Automated measurement software.

(C) Gated video functionality.

Test Title: 537-35-01 Planning and Executing FCC Proof-of-Performance Tests


The testing of standard performance parameters to prove Federal Communications Commission (FCC) compliance is called FCC proof-of-performance (POP) testing. Where are the broadband cable system technical standards, required for FCC compliance, described?

(A) In the Code of Federal Regulations 47 Part 76.605(a).

(B) In the Code of Federal Regulations 76 Part 60.475(a).

(C) In the Code of Federal Regulations 60 Part 47.765(a).


The Federal Communications Commission (FCC) requires that systems with 1,000 to 12,500 customers have six test points that are balanced to represent all geographic areas served by the system. How many test points are required in a system with 37,501 to 50,000 customers?

(A) 8

(B) 9

(C) 10


Successful execution of proof-of-performance (POP) tests requires knowledge of many aspects of a system that apply to the testing requirements. During POP tests, signal level, carrier-to-noise (C/N), beat products, and hum measurements should be taken at field locations at the end of what length drop cable?

(A) 6 feet

(B) 30 feet

(C) 100 feet


Test equipment used in proof-of-performance (POP) tests must be properly identified for training and field measurements. Performance measurement specifications of a signal level meter (SLM), though adequate for field measurements, are not as good as those of what type of test equipment?

(A) A vectorscope.

(B) A precision tunable demodulator.

(C) A spectrum analyzer.


Choosing the channels for proof-of-performance (POP) testing requires knowledge of a system’s past, current, and projected lineup. Which of the following POP tests is measured on

one channel only?

(A) Terminal isolation.

(B) Hum.

(C) Audio signal level.


Calculating total beat products at the output of a set top box (STB) is similar to calculating carrier-to-noise (C/N) at the STB output. However, since beats are the voltage measurement, what is the multiplier/divider when calculating total beat products at the STB output?

(A) 10

(B) 20

(C) 50


The hum from a system is added to that from a set-top box (STB) data sheet to provide a worst-case measurement. If both the system hum and the set-top box (STB) hum are .10%, or -60 decibels (dB), what is the total hum?

(A) .20%

(B) -120 dB

(C) 0%


Gathering all the measurement results, support data, and documentation is the final step toward complying with the Federal Communications Commission’s (FCC) proof-of-performance (POP) tests. For which of the following POP tests is it permissible to incorporate the manufacturer’s specifications in the test document in lieu of testing?

(A) Terminal isolation.

(B) Differential gain.

(C) Chrominance-to-luminance delay.


After all of the Federal Communications Commission’s (FCC) proof-of-performance (POP) tests are completed, it is necessary to compile and file a test report. Which of the following is a requirement of the FCC when compiling and filing measurement data?

(A) The test report must include a summary sheet listing, each test location, and the worst-case measurement for each parameter.

(B) The test report must group measurement results by test point or measurement type.

(C) The test report must identify the test equipment used, serial numbers, and calibration information.


Proof-of-performance (POP) test data must be made available for inspection by the Federal Communications Commission (FCC) or the local franchiser, upon request. How long must POP tests be maintained on file at the operator’s local business office?

(A) For at least two years.

(B) For at least five years.

(C) For at least seven years.

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