7/8" EIA Connector for 7/8" Coaxial Cable, Gas stop/ Gas pass, O-Ring Sealing

Rev : 02 | Rev date : 22 Apr 2021
Radio Frequency Systems line of high-performance HELIFLEX® coaxial cable connectors are characterized by excellent gas tightness and extremely low losses. HELIFLEX® connectors can be installed with basic hand tools. Tab flange of outer connection and use of o-ring sealing simplifies installation of the connector.
RFS connectors are fully tested for mechanical and electrical compliance to specifications.
HELIFLEX® connectors have excellent electrical values and provide outstanding performance for the most demanding applications. The RFS connector design provides maximum sealing integrity and gas tightness.


  • Easy installation utilizing only basic hand tools.
  • Tab flare of outer contact attachment means quick and simple installation.
  • No need for sealing compound. The connector is ready for pressurization immediately after installed to the cable.
  • Excellent gas tightness. Overpressure for increased voltage handling is maintained throughout the system.
  • Outstanding VSWR performance improves overall system performance.
  • Totally waterproof, assures safe, long term operation in the harshest of environments. 
  • RoHS (EU) and CRoHS (China) compliant, can be used on a global basis.

78EIA Connector for HCA78 Cable

External Document Links


1) The connector is converted to gas pass by drilling through the pilot hole in the insulator.
2) Connector model with -019KT suffix denote connectors that are supplied with an inner connector and flange hardware.
Connector model -019 does not include an inner connector and flange hardware.

Technical features

General Specifications

Transmission Line TypeCoaxial Cable
Cable Size7/8"
Cable TypeAir Dielectric
Model SeriesHCA78-50 Series
Connector Interface7/8" EIA
Connector Type
Gas stop/ Gas pass - See Note 1)
Sealing Method
O-ring seal
GenderFemale - See Note 2)

Electrical Specifications

Insertion loss dB

< 0.05dB

VSWR, Return LossVSWR (dB)0 to 1 GHz: 1.02 (40)
1 GHz to 2.7 GHz: 1.07 (30)

Mechanical Specifications

Plating Outer/InnerTri Plate/Silver
Length mm (in)115 (4.53)
Outer Diameter mm (in)57.2 (2.25)
Outer Contact AttachmentTab Flare

78EIA-HCA78-019 connector, dimensions in mm