One Flashcards
used to determine the distance of a known fault on the cable plant from a specific locatoin
TDR
a device that assists in testing return ingress at a tap location using an available dust cap cover port
I stop
the most common home theatre connection, with sound broken out into two separate cables, color coded fro left and right audio
composite
typically used for audio, this is a form of modulation in which the amplitude of a signal changes in accordance with the instantaneous value of the modulating signal
AM
in signal processing, this term refers to an effect that causes different signals to become indistinguishable when sampled
aliasing
known as an intra-coded picture
I pic
a design philosophy where the loss of the cable and other passive devices before an amplifier station equals its gain
unity gain
a discontinuous signal whose various states are discrete intervals apart.
digital signal
this type of test requires a reference pattern to be sent in order to interpret if errors are present
closed loop testing
this RF passive device has a loss of 3.01dB, disregarding all other internal circuitry
splitter
the number of bits per symbol transmitted in a 256 QAM channel
8 bits
this theorem states that in order to obtain an accurate recreation of a signal, it must be sampled at a rate of at least twice the highest frequency.
Nyquist’s rule
as the modulation rate increases in a constellation diagram, the symbol regions decrease and are what fraction of the prior region
25% (a quarter)
the minimum heel length for new and used boots
3/4” ; 1/2”
a digital connection that can carry both digital video and up to eight channels of audio on a single cable
HDMI
the maximum volume at 3m of the Xfinity home smoke and or heat detector sounder
85 dBa
this is determined by the ratio between the digital carrier RMS level and the noise floor RMS level
carrier to noise ratio
Distortion components caused by non-linear mixing of carriers in the transmission system
Carrier to Coherent Interference
Generally HUM at low frequency—60Hz from the power system, 120Hz from linear power supplies, < 1 KHz from switching power supplies, and other low frequency sources.
Carrier to Low Frequency Distortion
Continuous unwanted signal within the channel pass band that can affect digital decoding but has minimal adverse effect on analog signals
Carrier to Sustained Impairments (CI)
Digital effect due to power loading on amplifier circuits, generally present in processing equipment.
Spectral Regrowth
– In the analog world, this results in “Ghosting” or “fringing,” also known as “ringing.” These are reflections that, if high enough in level in relation to the carrier, cause digital decoding problems
Multipath and Micro-reflections
Generally has no effect in the analog world, but can cause severe reliability problems in digital carriers. This is usually due to oscillator instability in processing equipment.
Phase Noise
Result of the presence of any of the distortion components listed above that cause an error in the digital decoding
Amplitude and Phase Distortion
a signal deviation typically caused by coax impairments
linear distortion
nominal acceptable C/N for reliable operation is:
QPSK - 12dB
16QAM - 20dB
64QAM - 31dB
256QAM - 38dB
There are numerous factors that contribute to digital carrier stability
Type of programming
Compression ratios
SD vs HD
480nm
blue light
455nm
violet
1310nm in terms of where on the spectrum
infra red
type of voice trunking used by a soft switch
SIP
this is caused by the signal hitting an uneven surface and is reflected in many different directions
scattering
when overlaying access points use the same channel or channels with overlapping frequencies causing connectivity issues for customers
co channel interferences
when an object takes in the signal and retains some or all of it
absorption
a technique used to keep upstream energy separate from downstream energy
frequency division multiplexing
active devices use employ this to establish a clear path between the upstream and downstream energy
diplex filter
48.09
48.09
Function of a sweep meter zeros out the frequency response at a particular location in the network
Normalization
the reference carrier under test for a specification of +-2 dB
ICFR
the boundaries in the coaxial plant that can help to determine where faults, impedance mismatches are located
reflection zone
type of distortion most often caused by external interference or ingress
non linear distortion
measurement of signal amplitude (in ICFR chart) deviating up or down in .75dB increments
ripples
these are samples in time, not physical locations, in the plant
taps
the signal measured at the CMTS from the customers DOCSIS device
upstream receive power
a measurement of the signal level from the DOCSIS device to the CMTS
upstream transmit power
the comparison of the signal received at the headend from the customers DOCSIS device to the noise floor.
upstream SNR
750 nm
red
550 nm
green
ccs
concurrent call sessions
ISDN
integrated services digital network
consists of 23 b-channels and 1 d-channels
pri
known for its standard 1.544 Mbps bandwidth
T1
when a signal passes through an object and the signal is redirected
refraction
when a wireless signal hits a smooth object and bounces off the surface
reflection
Name 3 aerial lift vehicle limits
Max boom lift capacity
Max bucket load capacity
Payload and chassis weight
When it is necessary to raise and lower tools or equipment from the bucket, you would use
a hand line
Examples of some critical welds that warrant special attention on your daily inspection of the aerial lift vehicle are located where
Turret wings are welded to the base plate
Cylinder mounts are welded to the boom
Cylinder mounts are welded to the turret
Welds are on the platform support
The semi-annual maintenance checks for Aerial Lift Vehicles include:
Changing the hydraulic filter
Inspecting the hydraulic oil
Checking all valve pressure settings
Aerial Lift Vehicle Cab inspection requires the check of the following items:
Fire extinguisher
First aid kit and flares
Lights
Wheel chocks
Weekly check of Aerial Lift Vehicles include
Battery condition Fan belt pump Rotation chain Bolt tightness Stabilizers Proper operations
Name the types of decals that you would find in an Aerial Lift
Danger, Warnings, Cautions and operating instructions/notice
Hazards of driving a heavy duty Aerial lift vehicle driving hazards include:
Length, height, width, weight, boom, bucket, turning radius stopping distance
Three common causes of aerial lift accidents
Stability problems, Operator error, Violating OSHA regulations
contain all the information to be transmitted and serve as reference points
I-picture
which only carry information about which pixels change in relation to the i-frame
P-picture
which carry information about which pixels change in relation to the i-frame for transmitted and to-be-transmitted frames
B-picture
Wi-Fi Optimized Home visits (both TC and PRO installs) we have broken them down into 5 major steps.
Arrival and Initial Assessment; Discussion with Customer; Detailed Assessment, Device Placement and Install; Test and Fortify; Demonstration and Customer Education;
The four types of tapers
Shoulder tapers
Shifting tapers
Merging tapers (lane closure tapers)
Downstream tapers
area that separates road users from the work area or an unsafe area.
Buffer spaces, allow for some recovery time from an errant vehicle and some bailout time for workers in the work area.
goal of a traffic control zone
allow work to proceed safely with minimum traffic disruption
This assists customers with visual disabilities with finding tv shows and movies independently
Voice guidance
