Monitoring the status of optical nodes
Involves the use of a node transponder that continuously monitors a number of critical functions.
Digital return path transmissions
Use DWDM
Dense wavelength division multiplexing
digital return transmitters in hub-to-headend architectures.
Broadband cable operators provide customers with HSD High-speed data connections to the Internet via their HFC networks using what standard?
DOCSIS
What is MPEG?
A universally accepted standard for digital television, first released in 1992.
Which of the following is true about optical nodes?
They contain four main sections: the optical receiver, the RF amplifier module, the reverse optical transmitter, and the DC power supply.
What product based on the DOCSIS defines the protocols for IP telephony over HFC?
PacketCable
In a centralized server VOD architecture,
The number of servers needed for video content storage is smaller than in the distributed server architecture.
Which of the following statements about local ad insertion is true?
Local ad insertion is performed usually by a video server.
In regard to providing HSD service,
The CMTS
Cable modem termination system
can provide a data transfer rate up to 38 Mbps, using 256-QAM in a single 6 MHz channel.
Which of the following is true about the SONET standard?
SONET is the North American standard used for telephony applications.
Compared to a solid copper center conductor, which property about a copper clad aluminum (CCA) center conductor is correct?
The CCA center conductor has almost equal attenuation at high frequencies.
In hardline coaxial cable, what is the most common dielectric material?
Foamed polyethylene produced by gas injection.
In aerial installations, why do cable manufacturers recommend that expansion loops be formed in hardline coaxial cable?
To allow movement of the cable when lashed to the strand
Why was the impedance for the broadband cable industry standardized at 75 ohms (Ω)?
At 75 Ω characteristic impedance, the coaxial cable has minimal attenuation, with adequate breakdown voltage and power carrying capacity.
What is the coaxial cable velocity of propagation (VoP)?
The rate that radio frequency (RF) signals travel through the coaxial cable versus the speed that RF signals travel in a vacuum or free space.
If the attenuation through a 100 ft. span of 0.750 MC2 coaxial cable is 2.5dB at 75 MHz, what will be the approximate attenuation at 300 MHz?
2 x 2.5 dB, or 5.0 dB.
What is the attenuation through 1,600-feet of 0.750 cable at 600 MHz and 120° F, when at 68° F and 600 MHz the cable attenuation rate is 1.31 decibels (dB)/100 feet? (Be sure to factor in the higher temperature.)
22.05 dB.
What happens when there is an impedance mismatch between the coaxial cable and the load?
Some signal energy is transferred to the load, with the remainder reflected along the coaxial cable back to the source.
What is the return loss in coaxial cable?
The difference in decibels (dB) between the signal power applied to a terminated cable and the reflected signal power.
How can signal leaks (egress) from hardline coaxial cable occur?
Through cracks in the shield where the cable is bent, or tiny holes in the shield.
Why are pin-type hardline connectors the preferred type of connector for attaching hardline coaxial cable to equipment housings in today’s networks?
Over the years, intermittent operation, low-frequency roll-off, and common path distortion (CPD) issues have been attributed to feed-through connectors.
What type of adapter is used for permanent or temporary jumper installation in place of damaged hardline coaxial cable or equipment hookup?
Pin-to-F female adapters.
What should be worn when cutting and preparing hardline coaxial cable for connector attachment?
Leather work gloves.
How should a knife be used when preparing hardline coaxial cable for connector attachment?
To carefully cut the dielectric away before coring the cable.
What is a consequence of cutting hardline coaxial cable with conventional side cutters?
The end of the cable is crushed and deformed, which makes coring the dielectric and sliding connector parts onto the cable difficult.
When using a single-purpose coring tool, what is done before the coring tool can be used to cut and remove the dielectric?
The appropriate length of aluminum shield and dielectric must be removed, to expose the cable center conductor.
If the hardline coaxial cable center conductor is too short after coring the dielectric with a combination coring tool, what should be done?
Clean out any dielectric and aluminum trimmings from the cable and the tool and continue coring to the correct depth.
What is different about preparing QR hardline coaxial cable for connector installation compared to all other types?
QR cable is first cored and the aluminum shield is stripped before the polyethylene jacket is removed to the proper length, the reverse of other cable types.
What can be said about a straight splice connector?
It is essentially two hardline connectors with a common interface.
How far beyond a pin connector should the shrink tubing overlap the coaxial cable?
At least two inches after shrinking.
What do all hardline splitter, directional coupler, power inserter, and distribution tap housings have on the back?
A threaded mounting tap and strand clamp on the back for attachment to the aerial strand or an underground pedestal.
What can be done when installing hardline splitters, directional couplers, power inserters, and distribution taps in tight quarters, such as in a pedestal?
The seizure screw can be removed, and the hardline connecter attached to the side of the housing.
What is on the interior side of the faceplate in a hardline splitter, directional coupler, power inserter, and distribution tap?
The electronic circuitry and male or female faceplate/housing interconnect pins.
In a directional coupler, what is the relationship of the insertion loss between the directional coupler input and through ports, and the amount of signal tapped off from the input?
The insertion loss remains constant regardless of the signal tapped from the input.
What element in a splitter and directional coupler serves, among other functions, to determine to which ports 60/90 alternating current voltage (VAC) is sent?
Plug-in fuses.
What must be done when measuring the port-to-port isolation between the output ports of a splitter or directional coupler?
Terminate the common input port.
How much does a power inserter impact the radio frequency (RF) in a network?
A power inserter should have minimal impact on the RF in both directions.
Which of the following describes a power inserter?
It contains a high-pass filter network that passes radio frequency (RF) signals between the two RF/alternating current (AC) ports and blocks the 60-hertz (Hz) AC voltage between the same two ports.
Which characterizes a feed-through distribution tap?
It has a directional coupler that efficiently routes most of the signal to the output port while removing a small amount of the signal and passing it to the splitter network.
Why is it necessary that feed-through distribution taps pass alternating current (AC)?
To pass AC along to power other amplifiers downstream.
What type of map can be useful for tracking the progress of a network upgrade, or the expanse of a network condition, such as an outage?
A network key map.
Why are many network design maps drawn on a scale in which 1 inch represents 100 feet, a ratio of 1:1,200?
To capture and display the details of the network.
When looking at a design map, what do the small circles with an X connected with a solid line represent?
Joint use poles.
In a network design map, the squares with the number inside are symbols for what devices?
4-port distribution taps.
Which hardline coaxial cable splicing project would be in the repair and/or maintenance category?
Splicing in a short replacement cable with a straight splice connector.
When studying a network map for an upcoming splicing project, how can you identify the high-output port of an unbalanced 3-way splitter ?
The high-output port of an unbalanced 3-way splitter is indicated by a dot on the map symbol.
When splicing equipment into underground hardline coaxial cable, if the construction crew forgets to identify the direction of the cable, what can be done to find which cable attaches to the input and output side of the equipment?
Attach a cable locator to each cable to identify the route that each buried cable follows.
When can a single straight splice connector be used to repair a crack in aerial hardline coaxial cable?
If the crack is small, water migration is minimal, and the crack is in a straight section of cable.
Why would a technician be asked to measure the signal levels on the highest and lowest downstream channels from a specific location when performing a cost payback analysis?
To help the design group determine where to add distribution taps, or to tap into the network for a network extension.
What should be used in place of short coaxial cable jumpers to provide a compact and solid mechanical and electrical connection between the equipment housings?
Housing-to-housing adapters.
What is the typical gain of a line extender in decibels (dB)?
53 to 60 decibels (dB).
Line extenders can be powered from the network or from a 120- volts alternating current (VAC) source. Which of the following statements about line extender power sources is true?
Line extenders powered by the network can pass current to other devices.
How much intermodulation distortion degradation is added when two line extender amplifiers with identical distortion characteristics are in cascade?
6 decibels (dB).
What can cause a resistive type of test to deliver false information?
An impedance mismatch.
Why is it unnecessary to measure the unregulated direct current (DC) voltage on a line extender that has a switching mode power supply (SMPS)?
An SMPS provides DC voltage regulation over a wider alternating current (AC) voltage range than a linear power supply.
As the RF signal travels on the coaxial cable, one portion of the signal may be attenuated more than the others. What term is used to describe a situation where cable attenuation is low, causing signal levels to remain greater at the higher frequencies than at the lower frequencies?
Positive tilt.
When setting up the forward amplifier of a line extender, why must the manual gain control be at a mid-range position at the desired operating level?
For the automatic/thermal control to work effectively.
Why is it a good practice to measure the downstream input signal and compare the measurements to the calculated levels shown on the network maps before attempting to set up the forward amplifier section of a line extender?
Undocumented changes to the network design can affect the designed input to the line extender, or there could be a separate problem that needs to be corrected.
A return path sweep-and-alignment system is used to adjust which of the following?
Signals from a line extender to the headend.
When aligning amplifiers in the return path, what must be achieved and maintained from the customer premises to the headend, or node?
An active return path through all the line extenders.
What is a metallic time domain reflectometer (MTDR)?
A test instrument that measures reflected voltage at discrete moments in time to evaluate the electrical characteristics of metallic cables.
How does a time domain reflectometer (TDR) measure the distance to a reflection from a fault or the end of a cable?
Circuitry within the TDR converts the pulse travel time into distance and displays the information as a waveform with a scale showing the distance to the reflection.
Velocity of propagation (VOP) is the speed of the radio frequency (RF) signals traveling in a coaxial cable relative to the speed of light. What is the range of VOP factors for broadband coaxial cable?
0.78 to 0.93
What presents the biggest electrical shock hazard when operating a time domain reflectometer (TDR) in the network?
The low-frequency alternating current (AC) voltage on the coaxial cable.
What does the decibel return loss (dBRL) displayed on most time domain reflectometers (TDR) indicate?
The relative severity of a cable fault.
Anomalies, such as echoes and blind spots, can hide cable faults or cause a technician to misinterpret the signature of a time domain reflectometer (TDR) waveform. What causes an echo on a waveform TDR?
The extra distance that the TDR pulse travels after initially reflecting off the end of the cable span.
What type of adapter provides a clean transition from the hardline coaxial cable to an F-connector when testing hardline coaxial cable with a time domain reflectometer (TDR)?
The hardline cable-to-F female (or BAFF) adapter.
How is a time domain reflectometer (TDR) used during a tap audit or when investigating a suspicious network connection?
To confirm an illegal connection of customer premises equipment (CPE) based on the signature of the TDR waveform.
When using a cable locator, why is it unnecessary to disconnect the cable from any connections?
Because the locating signal is carried on the cable shield.
What should be done before measuring any distance with a measuring wheel?
Set the measuring wheel distance counter to zero.
In the tree-and-branch architecture, how is the downstream signal from the trunk fed to the distribution branches?
Within each trunk amplifier, a portion of the downstream is fed to a bridger amplifier to boost the signal before being split and routed to the distribution branches.
What is a common solution when congestion from modem activity and traffic becomes unacceptable in a HFC Hybrid fiber/coax network?
Node splitting, the subdividing of serving areas into two or more smaller serving areas.
What technologies are defined in DOCSIS 4.0 to help sustain the HFCHybrid fiber/coax network infrastructure for several more years?
FDX and ESD.
How can a less-experienced technician identify what non-standard symbols on the network design maps represent?
The legend at the bottom of the network design map that defines the map symbols, cable types, and amplifier data.
What is the RF distribution tap value indicated on the tap face plate by a sticker or number stamped into the housing?
The signal loss between the tap downstream input port and the tap ports.
How can a distribution amplifier be identified in the network or on a network design map?
The distribution amplifier has multiple downstream outputs.
What is spliced into the hardline coaxial cable to combine the AC power with the transported RF signal in a HFC Hybrid fiber/coax network?
A power inserter.
What test instrument sends out a test signal and displays any reflections caused by impedance mismatches in the cable that are characteristic of cable faults?
TDR.
What should you be looking for when analyzing the network design maps to troubleshoot a problem?
The device common to those customers affected before traveling to make signal status checks.
What is required for checking the physical network integrity when maintaining the coaxial cable network?
Being observant and performing some minor tasks while engaged in regularly scheduled activities.
A chain trencher
Should be inspected for any loose bolts, broken chain teeth, or any types of fluid leaks before beginning its operation.
When digging the trench,
First confirm that all utilities have located their lines.
What may be required to remove a very large rock from the ground during trenching?
Backhoe.
What is the proper method for removing the coaxial cable from its reel for a direct burial operation?
With the reel on an appropriate stand, pull the cable from the bottom of the reel.
When directly burying coaxial cable,
Avoid reverse bending of the coaxial cable when unreeling the coaxial cable.
How much contraction will 1,200 feet of conduit have if the temperature changes from 94 degrees F to 54 degrees F when the rate of contraction is 1 1/2 inches per 100 feet per 20 degrees F change?
36 inches.
What is the purpose of a portable conduit fishing system?
It is used to blow a pull-line through the conduit.
What are some of the factors in determining the total length of preassembled cable in a conduit for a trench site?
Thermal expansion/contraction allowance.
When backfilling the trench,
Gravel, a soil stabilizer, or a slurry mixture should be used when proper compaction is difficult to obtain with the present trench material.
The boom on a chain trencher
Is usually spring-loaded to create tension on the chain.
Which type of vibratory plow is an attachment to a tractor or trencher and requires a ground person to manually guide the conduit into the feed chute as the plow cuts through the ground?
The modular vibratory plow.
In which areas is the use of a vibratory plow much more economical than trenching?
In undeveloped areas where a large tractor can be maneuvered.
How should coaxial cable be plowed using a plow machine without a cable reel carrier?
Lay the coaxial cable along the bury route and have a helper guide the coaxial cable into the feed chute of the forward-moving plow.
When preparing to plow conduit/cable in conduit (CIC), how long should the starter trench be?
A length that allows the plow blade to be lowered to the burial depth without violating the minimum bend radius of the attached conduit.
What mechanisms do pit dry boring machines utilize to bore through soil and underneath obstacles?
Hydraulic power, a rod pusher, steel rods, and a piercing tool.
When using a surface dry boring machine, what is the preferred forward speed of the machine?
A speed that allows the boring bit to work freely without being forced.
When backfilling a boring pit or trench, what should be done to protect the buried conduit or cable in conduit (CIC)?
Remove accessible rocks and backfill all but the top 12 inches of the pit or trench with sand.
What must all fluid assisted boring machine operators and crew members do in case of an inadvertent utility cut or other unforeseen accident?
Follow all company and equipment manufacturer guidelines and safety procedures.
What do the electrical grid mats that are bonded to a fluid-assisted boring system provide?
Operator protection, in case of contact with electrical lines, the boring equipment and machine operators are at the same electrical potential.
When using a fluid-assisted boring machine, why is the drilling fluid added when pulling the drill string back through the hole?
To help the rotating back-reamer expand the drilled pilot hole diameter and reduce the drag on the conduit that is being pulled into place.
Why are pin-type hardline connectors the preferred type of connector for attaching hardline coaxial cable to equipment housings in today’s networks?
Over the years, intermittent operation, low-frequency roll-off, and common path distortion (CPD) issues have been attributed to feed-through connectors.
What type of adapter is used for permanent or temporary jumper installation in place of damaged hardline coaxial cable or equipment hookup?
Pin-to-F female adapters.
What should be worn when cutting and preparing hardline coaxial cable for connector attachment?
Leather work gloves.
How should a knife be used when preparing hardline coaxial cable for connector attachment?
To score the aluminum shield that must be broken and then removed.
What is a consequence of cutting hardline coaxial cable with conventional side cutters?
The end of the cable is crushed and deformed, which makes coring the dielectric and sliding connector parts onto the cable difficult.
When using a single-purpose coring tool, what is done before the coring tool can be used to cut and remove the dielectric?
The appropriate length of aluminum shield and dielectric must be removed, to expose the cable center conductor.
If the hardline coaxial cable center conductor is too short after coring the dielectric with a combination coring tool, what should be done?
Clean out any dielectric and aluminum trimmings from the cable and the tool and continue coring to the correct depth.
What is different about preparing QR hardline coaxial cable for connector installation compared to all other types?
QR cable is first cored and the aluminum shield is stripped before the polyethylene jacket is removed to the proper length, the reverse of other cable types.
What can be said about a straight splice connector?
It is essentially two hardline connectors with a common interface.
How far beyond a pin connector should the shrink tubing overlap the coaxial cable?
At least eight inches after shrinking.
How can signal leaks (egress) from hardline coaxial cable occur?
Through cracks in the shield where the cable is bent, or tiny holes in the shield.
What is the return loss in coaxial cable?
The difference in decibels (dB) between the signal power applied to a terminated cable and the reflected signal power.
What happens when there is an impedance mismatch between the coaxial cable and the load?
Some signal energy is transferred to the load, with the remainder reflected along the coaxial cable back to the source.
What is the attenuation through 1,600-feet of 0.750 cable at 600 MHz and 120° F, when at 68° F and 600 MHz the cable attenuation rate is 1.31 decibels (dB)/100 feet? (Be sure to factor in the higher temperature.)
22.05 dB.
If the attenuation through a span of coaxial cable at 75 MHz is 2.5 dB, what will be the approximate attenuation at 300 MHz?
??? 4 x 2.5 dB, or 10.0 dB. ???
What is the coaxial cable velocity of propagation (VoP)?
The rate that radio frequency (RF) signals travel through the coaxial cable versus the speed that RF signals travel in a vacuum or free space.
Why was the impedance for the broadband cable industry standardized at 75 ohms (Ω)?
At 75 Ω characteristic impedance, the coaxial cable has minimal attenuation, with adequate breakdown voltage and power carrying capacity.
In aerial installations, why do cable manufacturers recommend that expansion loops be formed in hardline coaxial cable?
To allow movement of the cable when lashed to the strand.
In hardline coaxial cable, what is the most common dielectric material?
Foamed polyethylene produced by gas injection.
Compared to a solid copper center conductor, which property about a copper clad aluminum (CCA) center conductor is correct?
The CCA center conductor has almost equal attenuation at high frequencies.
What do all hardline splitter, directional coupler, power inserter, and distribution tap housings have on the back?
A threaded mounting tap and strand clamp on the back for attachment to the aerial strand or an underground pedestal.
What can be done when installing hardline splitters, directional couplers, power inserters, and distribution taps in tight quarters, such as in a pedestal?
The hardline coaxial cable connectors are is attached to the end of the housing.
What is on the interior side of the faceplate in a hardline splitter, directional coupler, power inserter, and distribution tap?
The electronic circuitry and male or female faceplate/housing interconnect pins.
In a directional coupler, what is the relationship of the insertion loss between the directional coupler input and through ports, and the amount of signal tapped off from the input?
–NOT– “The insertion loss increases as the signal bandwidth increases.” –NOT–
What element in a splitter and directional coupler serves, among other functions, to determine to which ports 60/90 alternating current voltage (VAC) is sent?
Plug-in fuses.
What must be done when measuring the port-to-port isolation between the output ports of a splitter or directional coupler?
Terminate the common input port.
How much does a power inserter impact the radio frequency (RF) in a network?
A power inserter should have minimal impact on the RF in both directions.
Which of the following describes a power inserter?
It contains a high-pass filter network that passes radio frequency (RF) signals between the two RF/alternating current (AC) ports and blocks the 60-hertz (Hz) AC voltage between the same two ports.
Which characterizes a feed-through distribution tap?
It has a directional coupler that efficiently routes most of the signal to the output port while removing a small amount of the signal and passing it to the splitter network.
Why is it necessary that feed-through distribution taps pass alternating current (AC)?
To pass AC along to power other amplifiers downstream.
What type of map can be useful for tracking the progress of a network upgrade, or the expanse of a network condition, such as an outage?
A network key map.
Why are many network design maps drawn on a scale in which 1 inch represents 100 feet, a ratio of 1:1,200?
To capture and display the details of the network.
When looking at a design map, what do the small circles with an X connected with a solid line represent?
Joint use poles.
In a network design map, the squares with the number inside are symbols for what devices?
4-port distribution taps.
Which hardline coaxial cable splicing project would be in the repair and/or maintenance category?
Splicing in a short replacement cable with a straight splice connector.
When studying a network map for an upcoming splicing project, how can you identify the high-output port of an unbalanced 3-way splitter ?
The high-output port of an unbalanced 3-way splitter is indicated by a dot on the map symbol.
When splicing equipment into underground hardline coaxial cable, if the construction crew forgets to identify the direction of the cable, what can be done to find which cable attaches to the input and output side of the equipment?
Attach a cable locator to each cable to identify the route that each buried cable follows.
When can a single straight splice connector be used to repair a crack in aerial hardline coaxial cable?
If the crack is small, water migration is minimal, and the crack is in a straight section of cable.
Why would a technician be asked to measure the signal levels on the highest and lowest downstream channels from a specific location when performing a cost payback analysis?
To help the design group determine where to add distribution taps, or to tap into the network for a network extension.
What should be used in place of short coaxial cable jumpers to provide a compact and solid mechanical and electrical connection between the equipment housings?
Housing-to-housing adapters.
When aligning amplifiers in the return path, what must be achieved and maintained from the customer premises to the headend, or node?
Unity gain.
A return path sweep-and-alignment system is used to adjust which of the following?
Signals from a line extender to the headend.
Why is it a good practice to measure the downstream input signal and compare the measurements to the calculated levels shown on the network maps before attempting to set up the forward amplifier section of a line extender?
Undocumented changes to the network design can affect the designed input to the line extender, or there could be a separate problem that needs to be corrected.
When setting up the forward amplifier of a line extender, why must the manual gain control be at a mid-range position at the desired operating level?
For the automatic/thermal control to work effectively.
As the RF signal travels on the coaxial cable, one portion of the signal may be attenuated more than the others. What term is used to describe a situation where cable attenuation is low, causing signal levels to remain greater at the higher frequencies than at the lower frequencies?
Positive tilt.
Why is it unnecessary to measure the unregulated direct current (DC) voltage on a line extender that has a switching mode power supply (SMPS)?
An SMPS provides DC voltage regulation over a wider alternating current (AC) voltage range than a linear power supply.
What can cause a resistive type of test to deliver false information?
An impedance mismatch.
How much intermodulation distortion degradation is added when two line extender amplifiers with identical distortion characteristics are in cascade?
6 decibels (dB).
Line extenders can be powered from the network or from a 120- volts alternating current (VAC) source. Which of the following statements about line extender power sources is true?
Line extenders powered by the network can pass current to other devices.
What is the typical gain of a line extender in decibels (dB)?
28 to 35 decibels (dB).
What is a metallic time domain reflectometer (MTDR)?
A test instrument that measures reflected voltage at discrete moments in time to evaluate the electrical characteristics of metallic cables.
How does a time domain reflectometer (TDR) measure the distance to a reflection from a fault or the end of a cable?
Circuitry within the TDR converts the pulse travel time into distance and displays the information as a waveform with a scale showing the distance to the reflection.
Velocity of propagation (VOP) is the speed of the radio frequency (RF) signals traveling in a coaxial cable relative to the speed of light. What is the range of VOP factors for broadband coaxial cable?
0.78 to 0.93
What presents the biggest electrical shock hazard when operating a time domain reflectometer (TDR) in the network?
The low-frequency alternating current (AC) voltage on the coaxial cable.
What does the decibel return loss (dBRL) displayed on most time domain reflectometers (TDR) indicate?
The relative severity of a cable fault.
Anomalies, such as echoes and blind spots, can hide cable faults or cause a technician to misinterpret the signature of a time domain reflectometer (TDR) waveform. What causes an echo on a waveform TDR?
The extra distance that the TDR pulse travels after initially reflecting off the end of the cable span.
What type of adapter provides a clean transition from the hardline coaxial cable to an F-connector when testing hardline coaxial cable with a time domain reflectometer (TDR)?
The hardline cable-to-F female (or BAFF) adapter.
How is a time domain reflectometer (TDR) used during a tap audit or when investigating a suspicious network connection?
To confirm an illegal connection of customer premises equipment (CPE) based on the signature of the TDR waveform.
When using a cable locator, why is it unnecessary to disconnect the cable from any connections?
Because the locating signal is carried on the cable shield.
What should be done before measuring any distance with a measuring wheel?
Set the measuring wheel distance counter to zero.
A chain trencher
Should be inspected for any loose bolts, broken chain teeth, or any types of fluid leaks before beginning its operation.
When digging the trench,
First confirm that all utilities have located their lines.
What may be required to remove a very large rock from the ground during trenching?
Backhoe
What is the proper method for removing the coaxial cable from its reel for a direct burial operation?
With the reel on an appropriate stand, pull the cable from the bottom of the reel.
When directly burying coaxial cable,
Avoid reverse bending of the coaxial cable when unreeling the coaxial cable.
How much contraction will 1,200 feet of conduit have if the temperature changes from 94 degrees F to 54 degrees F when the rate of contraction is 1 1/2 inches per 100 feet per 20 degrees F change?
36 inches.
What is the purpose of a portable conduit fishing system?
It is used to blow a pull-line through the conduit.
What are some of the factors in determining the total length of preassembled cable in a conduit for a trench site?
Thermal expansion/contraction allowance.
When backfilling the trench,
Gravel, a soil stabilizer, or a slurry mixture should be used when proper compaction is difficult to obtain with the present trench material.
The boom on a chain trencher
Is usually spring-loaded to create tension on the chain.
Which type of vibratory plow is an attachment to a tractor or trencher and requires a ground person to manually guide the conduit into the feed chute as the plow cuts through the ground?
The modular vibratory plow.
In which areas is the use of a vibratory plow much more economical than trenching?
In undeveloped areas where a large tractor can be maneuvered.
How should coaxial cable be plowed using a plow machine without a cable reel carrier?
Lay the coaxial cable along the bury route and have a helper guide the coaxial cable into the feed chute of the forward-moving plow.
When preparing to plow conduit, how long should the starter trench be?
A length that allows the plow blade to be lowered to the burial depth without violating the minimum bend radius of the attached conduit.
What mechanisms do pit dry boring machines utilize to bore through soil and underneath obstacles?
Hydraulic power, a rod pusher, steel rods, and a piercing tool.
When using a surface dry boring machine, what is the preferred forward speed of the machine?
A speed that allows the boring bit to work freely without being forced.
When backfilling a boring pit or trench, what should be done to protect the buried conduit or cable in conduit (CIC)?
Remove accessible rocks and backfill all but the top 12 inches of the pit or trench with sand.
What must all fluid assisted boring machine operators and crew members do in case of an inadvertent utility cut or other unforeseen accident?
Follow all company and equipment manufacturer guidelines and safety procedures.
What do the electrical grid mats that are bonded to a fluid-assisted boring system provide?
Operator protection, in case of contact with electrical lines, the boring equipment and machine operators are at the same electrical potential.
When using a fluid-assisted boring machine, why is the drilling fluid added when pulling the drill string back through the hole?
To help the rotating back-reamer expand the drilled pilot hole diameter and reduce the drag on the conduit that is being pulled into place.