CommScope Trunk & Distribution Cable User Manual

Page 51

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Industry Standards

To assure a cable’s performance for the user, the industry has adopted standardized test methods and

minimum specifications for defining the bond characteristics of coaxial cable.

As a starting point, the SCTE in its “Specification for Trunk, Feeder and Distribution Coaxial Cable” [ANSI/SCTE

15 2001] specifies minimum bond strength between the dielectric and the center conductor defined as “Dielectric

Shear Adhesion”. The bond strength values vary with cable size, with larger cables having higher bond strength

requirements then smaller cables.

As an example, a P3 500 cable size has a minimum
bond strength requirement of 60 lbs, while a P3 750
cable size has a requirement of 90 lbs.

Additional important attributes of the bond are
identified in this specification. First, a “Dielectric
Shrinkback” requirement in which the shrinkback of
the dielectric shall shrink no more than 0.250 inches
(6.35 mm) from both ends of the sample following
test procedure ASTM D 4565. Second, is the “Cable
Static Minimum Bend” tested following ANSI/SCTE
39 2001.

Bond Strength

Cable Type

Miminum Pound Force

P3

500

60

625

80

750

90

875

86

QR

540

68

715

90

860

96

ANSI/SCTE 15 2001 - Table 10.0

Typical bond strengths of today’s cables well exceed these minimum requirements, being as much as 100% above

that specified by ANSI/SCTE. Such a conservative approach is understandable given that there was no cost

penalty to create a bond that performed at such a high level, and that operating at that level eliminated any

potential for poor performance due to low bond strength. With excessively high bond strengths, controlling the

consistency of the cable’s quality is less demanding. The negative impact of this for the cable’s user is a difficult

preparation and connectorization process.

At the other end of the spectrum are poorly bonded cables that do not meet the specified ANSI/SCTE

requirements. The typical cause of low bond strength is attributed to the inability to control a consistent

manufacturing process. The negative impact of this for the cable’s user is poor core retention, moisture migration,

and poor bend performance (kinks easily).

Connectorization 6.2

ACT

®

- Advanced Coring Technology

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