HFC (Hybrid Fiber-Coax)
Network architecture combining fiber trunk with coax distribution.
Headend
Central facility where signals originate and are combined for distribution.
Node (Optical Node)
Fiber-to-coax conversion point serving a neighborhood service area.
Hardline Coax
Large-diameter outdoor coax used for mainline and distribution plant.
.500 Hardline
Smallest common hardline size; used on shorter spans and laterals.
.625 Hardline
Mid-size hardline common on distribution and many bridger runs.
.750 Hardline
Heavy hardline for longer trunk and high-traffic distribution routes.
.875 Hardline
Largest standard hardline; used on primary trunk and super-trunk.
Pin Connector
Hardline connector joining center conductor to the connector pin.
Seizure Screw
Set screw that clamps the center conductor inside the pin body.
Pad (Attenuator Pad)
Fixed RF attenuator used to balance levels across ports and paths.
EQ (Equalization)
Frequency-dependent compensation matching cable slope.
Cable Simulator (SCS)
Module that emulates coax loss for amplifier EQ and pad selection.
ALC (Automatic Level Control)
Amplifier mode that automatically maintains output level.
MAN (Manual Gain Mode)
Amplifier mode where gain is set manually without automatic correction.
Forward Path (Downstream)
RF flow from headend/node toward subscribers (≈54–1002 MHz).
Return Path (Reverse / Upstream)
RF flow from subscribers back toward the headend (≈5–42 or 5–85 MHz).
dBmV
Decibels relative to 1 millivolt—the standard RF level unit in HFC.
Tilt / Slope
Change in signal level across frequency due to cable loss characteristics.
Tap
Passive device feeding subscriber drops while passing mainline signal.
Splitter
Passive dividing RF among multiple output legs with defined loss.
Directional Coupler
Passive coupling signal in one direction with minimal reverse leakage.
Line Extender
Small amplifier extending reach on a distribution leg.
Bridger Amplifier
Distribution amplifier bridging trunk/node feed into multiple legs.
Trunk
Primary high-capacity coax route between hub and node or major junction.
Power Inserter
Device injecting AC/RF power onto coax for amplifier chains.
Heat Shrink
Weatherproof sleeve applied over splices and connectors.
Block Splice
Housing-based splice joining two hardline runs with pin connectors.
Inline Splice
Direct inline repair or extension using connectors and heat shrink.
Strand Map
Construction drawing showing aerial strand and cable routing.
Leakage (RF Leakage)
Unintentional radiated RF from plant defects.
Ingress
External RF noise entering the plant through shield breaches.
Egress
RF energy leaving the coax plant into free space.
Coring
Removing cable dielectric to expose center conductor for connectorization.
Center Conductor
Inner copper conductor carrying RF on coax.
Dielectric
Insulating material between center conductor and shield.
Flooding Compound
Gel or grease filling cable to block moisture migration.
Torque
Specified tightening force for hardware and seizure screws.
LO/TO (Lockout / Tagout)
Procedure isolating energy sources before hazardous work.
PPE (Personal Protective Equipment)
Required protective gear for field and lab work.
TP (Test Point)
Monitoring port for RF level and alignment measurements.
Hybrid
Internal amplifier component splitting/combining forward and return paths.
Diplex Filter
Filter separating low-frequency return from high-frequency forward.
DOCSIS
Standard for high-speed data over coax plant.
CMTS
Headend equipment terminating DOCSIS upstream from the plant.
Pilot Carrier
Reference signal used by ALC to stabilize amplifier output.
Bridger Pad
Pad controlling level on the bridger distribution output leg.
Distribution Port
Amplifier output feeding a customer distribution leg.
Module Hold-Down
Mechanical clamp securing RF module in amplifier housing.
Port Reverse Pad
Return-path pad at an individual amplifier output port.
Passive Device
RF component that does not amplify (tap, splitter, coupler, filter).
Amplifier (Amp)
Active device boosting forward and return RF on coax plant.
Bonding / Grounding
Electrical connection of strand, shield, and ground blocks.
Ground Block
Device bonding drop shield to premises ground electrode.
High-Split
Plant upgrade that expands upstream RF spectrum for higher upload capacity.
Diplex Filter (Diplexer)
Filter set that separates forward and reverse frequency bands in an amp.
AOI QuantumLink
Modern AOI system amp / LE platform used on high-split upgrades.
Mini Bridger / Bridger Amp
Multi-output distribution amplifier feeding multiple hardline legs.
Symmetrical Speeds
Service goal where upload capacity approaches download capacity.
Single-Mode Fiber (SMF)
Fiber type used for HFC node transport; tiny core, long reach.
APC Connector
Angled Physical Contact fiber connector common in CATV optics.
OTDR
Optical Time Domain Reflectometer — maps fiber events and loss.
RPD / Remote PHY
Distributed Access Architecture device that moves PHY to the node.
DAA (Distributed Access Architecture)
Architecture that distributes access PHY/MAC functions toward the field.
Booster Amplifier
Compact amp used to recover level on a short distribution span.
dBmV
RF level unit used on 75Ω coax plant (0 dBmV = 1 mV across 75Ω).
