NCTI MT1-MT2|130 Questions With
Correct
8.When transmitting broadband signals - ✔ ✔
In a two way hybrid fiber/coax (HFC) network,
two or more individual optical fibers are required
for each optical node location.
64.What location in the network is common path
distortion (CPD) most severe? - ✔ ✔ At the
output of a forward amplifier because the
forward levels are highest and the return levels
are lowest.
65.What distinguishes a micro-reflection from
other types of signal reflections? - ✔ ✔ In
micro-reflections, the echoed signals arrive back
at the source with a time delay relative to the
incident or transmitted signal, ranging from
nanoseconds (ns) to few microseconds (us).
,66.What are the symptoms of hum on an
upstream digital modulation channel? - ✔ ✔
Bit errors occur, similar to impulse noise and
ingress on the upstream path.
67.Why is it imperative to keep all ingress and
impulse noise, even that outside the frequency
range of the RF return carriers, to a minimum? -
✔ ✔ Regardless of the frequency, if the
impulse noise or ingress is high enough, it can
cause laser clipping.
68.When looking at a cable modem's
PreEqualization Tap response, what do you know
if the ninth bar is less than 10 dB below the eighth
bar? - ✔ ✔ That there are high micro-
reflections and that the cause is near the modem,
likely in the drop system.
69.What practice can uncover potential return
path problems in the drop system that can be
,mitigated before entering the network? - ✔ ✔
Prescreening the drop system for ingress or
egress.
70.Why is installing high-pass filters (HPF) at the
tap on drops without two-way services
considered a short-term solution to ingress and
impulse noise migrating into the hybrid fiber/coax
(HFC) network? - ✔ ✔ The HPF will have to be
removed when cable modems and digital set-top
boxes (STB) are activated at the addresses that
have an HPF installed.
71.What should be done before diagnosing a
return path problem in the drop system? - ✔ ✔
Confirm that the hybrid fiber/coax (HFC)
network is working properly.
72.What spectrum analyzer function is
particularly useful as it captures and holds
ingress, impulse noise, and other impairments on
, its display so that they can be viewed and
analyzed? - ✔ ✔ The Max Hold function.
73.What should be done when the location of
electrical interference in the power network is
identified? - ✔ ✔ Notify the power company
with the exact location so the cause of the
interference can be repaired.
74.What can be used with a signal level meter
(SLM) to check the drop system for RF continuity
at sub-band frequencies? - ✔ ✔ A signal
generator
75.What information can be gathered by a return
path monitoring system that captures the
quadrature amplitude modulation (QAM) return
channel from a DOCSIS modem? - ✔ ✔ The
group delay, in-band ripple/tilt, and micro-
reflections on the QAM channel.
Correct
8.When transmitting broadband signals - ✔ ✔
In a two way hybrid fiber/coax (HFC) network,
two or more individual optical fibers are required
for each optical node location.
64.What location in the network is common path
distortion (CPD) most severe? - ✔ ✔ At the
output of a forward amplifier because the
forward levels are highest and the return levels
are lowest.
65.What distinguishes a micro-reflection from
other types of signal reflections? - ✔ ✔ In
micro-reflections, the echoed signals arrive back
at the source with a time delay relative to the
incident or transmitted signal, ranging from
nanoseconds (ns) to few microseconds (us).
,66.What are the symptoms of hum on an
upstream digital modulation channel? - ✔ ✔
Bit errors occur, similar to impulse noise and
ingress on the upstream path.
67.Why is it imperative to keep all ingress and
impulse noise, even that outside the frequency
range of the RF return carriers, to a minimum? -
✔ ✔ Regardless of the frequency, if the
impulse noise or ingress is high enough, it can
cause laser clipping.
68.When looking at a cable modem's
PreEqualization Tap response, what do you know
if the ninth bar is less than 10 dB below the eighth
bar? - ✔ ✔ That there are high micro-
reflections and that the cause is near the modem,
likely in the drop system.
69.What practice can uncover potential return
path problems in the drop system that can be
,mitigated before entering the network? - ✔ ✔
Prescreening the drop system for ingress or
egress.
70.Why is installing high-pass filters (HPF) at the
tap on drops without two-way services
considered a short-term solution to ingress and
impulse noise migrating into the hybrid fiber/coax
(HFC) network? - ✔ ✔ The HPF will have to be
removed when cable modems and digital set-top
boxes (STB) are activated at the addresses that
have an HPF installed.
71.What should be done before diagnosing a
return path problem in the drop system? - ✔ ✔
Confirm that the hybrid fiber/coax (HFC)
network is working properly.
72.What spectrum analyzer function is
particularly useful as it captures and holds
ingress, impulse noise, and other impairments on
, its display so that they can be viewed and
analyzed? - ✔ ✔ The Max Hold function.
73.What should be done when the location of
electrical interference in the power network is
identified? - ✔ ✔ Notify the power company
with the exact location so the cause of the
interference can be repaired.
74.What can be used with a signal level meter
(SLM) to check the drop system for RF continuity
at sub-band frequencies? - ✔ ✔ A signal
generator
75.What information can be gathered by a return
path monitoring system that captures the
quadrature amplitude modulation (QAM) return
channel from a DOCSIS modem? - ✔ ✔ The
group delay, in-band ripple/tilt, and micro-
reflections on the QAM channel.
