N-Type Female Connector For RG8U / RG213 / LMR400 / LMR400UF / RFC400 / RFC400DB / RFC400UF cables

N-Type Female Connector designed for RG8U, RG213, LMR400, LMR400UF, RFC400, RFC400DB, and RFC400UF cables is a robust, threaded 50 Ohm coaxial connector primarily used as a panel mount, bulkhead, or inline adapter in high-frequency applications such as cellular base stations, broadcast equipment, and industrial RF systems. This female connector (jack or receptacle) is specifically engineered to interface with the larger diameter and low-loss characteristics of these 50 Ohm impedance cables. It features an internal threaded coupling for secure mating with an N-Type male connector and a recessed center socket to receive the male’s pin. The termination method for these heavy-duty cables typically involves either soldering the center conductor and using a clamp mechanism for the outer braid/jacket or employing a dedicated crimp ferrule, ensuring a highly reliable electrical connection with minimal signal degradation and excellent mechanical strength, crucial for the demanding environments where these cables and connectors are deployed.

Technical Specification

1. Electrical Characteristics:

Impedance: 50 Ohms ( $Ω$ )
Frequency Range: DC to 6 GHz (standard), often rated up to 11 GHz or 18 GHz for precision versions. The practical limit for reliable low-loss operation with these cables is typically up to 6 GHz.
VSWR (Voltage Standing Wave Ratio):
- Typically $\leq 1.25 : 1$ up to 3 GHz
- $\leq 1.35 : 1$ up to 6 GHz
- $\leq 1.50 : 1$ up to 11 GHz (for higher frequency designs)
Insertion Loss: Low, typically $\leq 0.1$ dB at 3 GHz
Return Loss: High, typically $\geq 20$ dB at 3 GHz
Working Voltage: 1000 V RMS (at sea level)
Dielectric Withstanding Voltage: 2500 V RMS (at sea level)
Insulation Resistance: $\geq 5000$ M$\Omega$
Contact Resistance:
- Center Contact: $\leq 1.0$ m$\Omega$ (initial)
- Outer Contact: $\leq 0.2$ m$\Omega$ (initial)
RF Leakage: Typically $\geq - 90$ dB at 3 GHz (for well-designed versions)

2. Mechanical Characteristics:

Connector Type: N-Type Female (Jack / Receptacle)
Mating Interface: N-Type (Per MIL-STD-348B/304 or IEC 61169-16)
Mounting Styles (Common for Female):
- Panel Mount (e.g., 2-hole, 4-hole flange mount, bulkhead)
- Chassis Mount
- Inline / Cable End
Cable Compatibility: Specifically designed for larger diameter 50 Ohm coaxial cables:
- RG-8/U
- RG-213/U
- LMR®-400 (and equivalents like RFC®-400)
- LMR®-400-UF (UltraFlex) / RFC®-400UF
- RFC®-400DB (Direct Burial)
Cable Attachment Method:
- Center Contact: Solder (most common for reliability with these larger conductors)
- Outer Braid/Jacket:
  - Clamp Type: The cable’s jacket and braid are secured by a threaded clamping nut and compression washer(s).
  - Crimp Type: A crimp ferrule is used over the cable’s braid and jacket, compressed with a specific hex crimp die (e.g., 0.429″ or 0.475″).
Coupling Mechanism: Internal Threaded Coupling (to mate with 5/8″-24 UNEF-2B thread of male connector)
Cable Retention (Axial Force): $\geq 80$ lbs (356 N) for LMR-400/RG213 (varies by termination method and connector design)
Durability (Mating Cycles): $\geq 500$ cycles

3. Materials and Finishes:

Body: Brass, Nickel Plated (typically 100 µin min for corrosion resistance)
Center Contact: Beryllium Copper or Phosphor Bronze, Gold Plated (typically 3-50 µin over Nickel for optimal conductivity and wear resistance)
Insulator: PTFE (Polytetrafluoroethylene / Teflon) for excellent electrical properties and high temperature performance.
Gasket (if weatherproof): Silicone Rubber (for panel mount or inline versions designed for environmental sealing)
Crimp Ferrule (for crimp types): Annealed Copper or Brass, Nickel Plated

4. Environmental Characteristics:

Operating Temperature Range: $- 6 5^{\circ}$ C to $+ 16 5^{\circ}$ C (with PTFE insulator)
Thermal Shock: MIL-STD-202, Method 107, Condition B
Vibration: MIL-STD-202, Method 204, Condition D
Mechanical Shock: MIL-STD-202, Method 213, Condition I
Moisture Resistance: MIL-STD-202, Method 106
Corrosion (Salt Spray): MIL-STD-202, Method 101, Condition B (48 hours)
Weatherproofing: When properly assembled, often provides excellent ingress protection (e.g., IP67 or greater), making them suitable for harsh outdoor environments.