.500
Smallest common trunk. Short spans, laterals, legacy plant. Highest loss per 100 ft — limits unrepeated distance.
HFC Foundations & Hardline Craft
Hardline Cable Sizes & Construction
Hardline coax construction from center conductor through flooding compound and jacket; velocity and attenuation; size tradeoffs; messenger wire; bend radius; reading jacket print; and matching connectors to verified cable series.
Est. 50 minutes · 2 pages · 12 quiz questions
Objectives
- Identify .500, .625, .750, and .875 hardline and typical deployment scenarios
- Describe each construction layer and its role in RF performance and moisture protection
- Relate cable diameter to attenuation per 100 feet at key frequencies
- Apply bend radius limits and recognize kink or flat-spot damage
- Read jacket printing to verify size, manufacturer, and date code
- Match verified cable size to coring tools and pin connector families
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Hardline Sizes & Field Identification
Hardline in the Cascade
Hardline coax is the trunk medium between node, amplifiers, taps, and major passives. Unlike flexible drop cable, hardline uses a solid or semi-solid center conductor, foam dielectric, corrugated outer conductor, and thick PE jacket — built for decades of aerial or underground service with flooding against moisture.
Designers pick size based on span length, amp spacing, tap loading, and frequency plan. Larger cable = lower attenuation but higher cost, weight, and minimum bend radius. Wrong size identification leads to wrong tools — and destroyed cable ends.
Hardline size comparison
Common hardline series
.625
Workhorse distribution size. Good balance of weight, bend radius, and loss on typical suburban cascades.
.750
Heavier trunk for longer spans between amps. Common on main feeders from node outward.
.875
Large feeder hardline; lowest attenuation per foot. Justified where long unrepeated runs offset material cost.
Match cable size to tools and connectors
Select a material, then its definition. Mis-ID in the bin becomes a bad splice on strand.
Attenuation trend (use manufacturer charts)
- .500 @ ~750 MHz
- Often ~4–5 dB / 100 ft
- .625 @ ~750 MHz
- Often ~3.5–4 dB / 100 ft
- .750 @ ~750 MHz
- Often ~3–3.5 dB / 100 ft
- .875 @ ~750 MHz
- Often ~2.5–3 dB / 100 ft
- Frequency effect
- Loss increases with frequency — high-split plans stress upper band edges
Reading Jacket Print
Jacket is printed with manufacturer, series, impedance, date code, and footage marks. Sun-faded print may require cleaner or reading the next leg. If print is gone, measure outer diameter with calipers — .625 and .750 are not reliably distinguished by eye alone.
Never guess size to save a trip for the correct mandrel. One wrong core ruins the end and wastes trunk length. Document cable type on splice tags per job standard.
Size verification is mandatory
Using .625 tools on .750 cable tears dielectric and leaves an oversized seizure zone that will never seal. Verify size from print, caliper, or known reel tag before cutting.
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