IEC BNCT BNC ‘T’ Female to Female to Female Coax Connector

An IEC BNCT BNC ‘T’ Female to Female to Female Coax Connector, more accurately referred to as an In-Series BNC ‘T’ Adapter with Three Female Ports, is a specialized coaxial connector designed for splitting or combining BNC-terminated signals. Unlike the common BNC ‘T’ adapter which typically has one male and two female ports, this specific configuration features three BNC female connectors, all arranged in a ‘T’ shape. This makes it ideal for situations where you need to connect three BNC male-terminated cables or devices together. For instance, it can be used to connect two input signals to one output, split one input signal into two outputs, or act as a common junction point for multiple BNC cables. These adapters maintain the secure and quick-connect/disconnect bayonet coupling mechanism of standard BNC connectors and are commonly available in both 50-ohm and 75-ohm impedance versions to suit various RF, video, or data communication applications. They provide a compact and efficient solution for creating branching connections within BNC cabling infrastructures.

Technical Specification

1. Impedance:

50 Ohm: Most common for general RF, data communication (e.g., older Ethernet networks), and test & measurement applications. Designed to maintain the 50-ohm impedance of the connected coaxial cables and equipment.
75 Ohm: Used specifically for video applications (e.g., CCTV, broadcast video, SDI signals) to match the impedance of 75-ohm coaxial cables (RG-59, RG-6).
- It is crucial to select the correct impedance to avoid signal degradation.

2. Frequency Range:

For 50 Ohm versions: Typically from DC (Direct Current) up to 4 GHz. Performance may slightly degrade at the highest frequencies due to the internal geometry of the ‘T’ connection.
For 75 Ohm versions: Generally from DC up to 1 GHz or 2 GHz. High-quality versions for HD/3G/6G-SDI applications might extend to 3 GHz, 6 GHz, or even 12 GHz, but precise performance specifications for such high frequencies are vital.

3. Electrical Performance:

Voltage Rating (Working Voltage): Typically 500 V RMS (Root Mean Square) maximum.
Dielectric Withstanding Voltage: Approximately 1500 V RMS (at sea level).
VSWR (Voltage Standing Wave Ratio): A critical measure of signal reflections; lower values indicate better impedance matching and less signal loss.
- For 50 Ohm: Typically ≤ 1.3:1 maximum up to 4 GHz.
- For 75 Ohm: Typically ≤ 1.25:1 to 1.5:1 maximum up to 3 GHz.
- Note: VSWR performance can be sensitive to the load conditions on all three ports. Proper termination of unused ports (e.g., with 50-ohm or 75-ohm terminators) is often necessary for optimal performance.
Insertion Loss: Measures signal power lost through the adapter. Due to being a passive splitter, there will be inherent signal division and some material loss.
- Typically < 0.5 dB to 1.0 dB at lower frequencies (e.g., 1 GHz), increasing with frequency. This is in addition to the theoretical power division loss (e.g., if splitting one signal into two, there’s a -3dB power division per output).
Insulation Resistance: Minimum 5000 Megohms.
Contact Resistance:
- Center contact: Typically ≤ 1.5 milliohm.
- Outer contact: Typically ≤ 1.0 milliohm.
RF Leakage: Typically -55 dB minimum at 3 GHz.

4. Mechanical Specifications:

Mating Cycles (Durability): Designed for a minimum of 500 insertion/extraction cycles per port.
Coupling Mechanism: All three ports utilize the standard BNC bayonet lock (quarter-turn) for quick and secure connection.
Configuration: One male pin, with three female receptacle bodies arranged in a ‘T’ shape. All ports are BNC female.
Interface Specification: Compliant with standards like MIL-STD-348A for physical dimensions and mating interface.
Dimensions: Compact, ‘T’-shaped form factor. Specific dimensions vary by manufacturer.

5. Material Specifications:

Body/Outer Shell: Most commonly made of brass with nickel plating. Nickel provides good corrosion resistance, durability, and shielding.
Center Contact (Pin): Typically brass or beryllium copper, with gold or silver plating (e.g., 30 µ-in minimum gold plating) for excellent conductivity and resistance to oxidation.
Insulator/Dielectric: Often PTFE (Polytetrafluoroethylene, or Teflon) for superior high-frequency performance and temperature stability, or Delrin (Acetal resin) for less demanding, more cost-effective options.

6. Environmental Specifications:

Operating Temperature Range: Common range is -40°C to +85°C (with Delrin insulators) or -55°C to +165°C (with PTFE insulators).
Moisture Resistance: Designed to withstand specified levels of humidity and moisture.
Corrosion Resistance: Often tested against salt spray.
Shock and Vibration: Engineered to withstand typical levels of mechanical stress and vibration.