Frequently Asked Questions
Twinax / Triax Cables
What is a twinax cable?
Twinax cables are constructed with a two-conductor twisted balanced wire line at a specific impedance (such as 78 and 124 Ω), surrounded by an outer braided shield with dielectric isolation between the braided shield and the conductors. Twinax cables are protected by a halogen-free, flame-retardant polyolefin outer jacket rated for operating temperatures from -30 to +80ºC.
What is the difference between twinax and coax cables?
Twinax cables use two inner conductors while standard coaxial cables only have one.
What is the advantage of a twinax cable over a coax cable?
Twinax cables provide greater flexibility and less fatigue with bending than coaxial cables, especially for applications requiring short cable runs. Such flexibility translates to much higher reliability for applications with excessive cable movement, along with less degradation in electrical performance from cable bending over time. The use of two copper wires in a braided weave helps to minimize signal loss and the effects of ground loops and protect against low-frequency noise from magnetic (H) fields.
What is the difference between triax, twinax, and coaxial cables?
Triax cables differ from both coaxial and Twinax cables in adding a second dielectric layer around the outer conductor and a second braided outer conductor. As with Twinax cables, Triax cables are protected by a halogen-free, flame-retardant polyolefin outer jacket rated for operating temperatures from -30 to +80ºC.
What is the difference between twinax, triax, and BNC connectors?
Twinax and Triax cables differ from coaxial cables in offering enhanced shielding for improved suppression of noise especially at low signal levels. Twinax connectors, for example, are often referred to as twin BNC connectors since they accommodate dual center conductors with keyway polarization for improved signal integrity (SI) compared to standard BNC connectors.
Can you mate twinax and triax connectors with other connector types?
Yes. Adapters are available to mate Twinax and Triax connectors to most standard coaxial connectors within their operating frequency ranges, including BNC, Type N, TRS, TPS, and TNC coaxial connectors, in various configurations of male and female interconnection combinations for system or test applications.
Can twinax/triax connectors be used in military applications requiring hermetic sealing?
Yes. Twinax and Triax connectors can come with hermetic sealing in various formats, including front-mounted, rear-mounted, feedthrough, and subminiature types with low leakage rates (1 × 10-6 atm-cm3/s or better).
Can twinax/triax connectors be used in CATV systems?
Yes. Triax cables are available with nominal characteristic impedance of 75 Ω for low-loss applications in 75 Ω cable-television (CATV) systems, especially where noise and interference from outside noise sources must be minimized. In addition, for CATV and high-speed data applications, Twinax cables are available in standard models with nominal impedances of 78 and 124 Ω.
How are twinax and triax connectors tested?
Twinax and triax connectors can be tested to the requirements of MIL-C-549192, which include corona voltage testing, 24-hour salt spray, shock, vibration, thermal shock, and hermeticity (where applicable). Connectors are also tested for mechanical specifications, including engage and disengage force, cable retention force, and coupling torque. For particularly demanding applications, they can be manufactured with special plating to meet the 500-hour salt-spray requirements of MIL-STD-1344.