For home cable TV and broadband internet, use F-Type connectors (75Ω, threaded, up to 1 GHz) with RG-6 cable. For professional CCTV and broadcast video, use BNC connectors (75Ω, bayonet lock, up to 4 GHz) with RG-59 or RG-6. For wireless, cellular, GPS, and RF test equipment, use SMA connectors (50Ω, threaded, up to 18 GHz) with RG-174 or RG-58. For outdoor wireless antennas and mobile communications requiring weatherproofing, use TNC connectors (50Ω, threaded, up to 11 GHz) with LMR-400 or RG-58. For legacy home audio/video connections, use RCA connectors with composite cables. The two critical specifications to match are impedance (50Ω for RF/wireless, 75Ω for video/CATV) and cable compatibility (connector inner diameter must match cable outer conductor diameter).
What Are Coaxial Cable Connectors?
A coaxial cable connector is a precisely engineered electromechanical interface that attaches to the end of a coaxial cable to provide a repeatable, low-loss connection to devices, equipment, or other cables. The connector maintains the coaxial cable’s characteristic impedance through the mating interface, preserving signal integrity from source to destination.
Every coaxial connector consists of four functional elements: a center contact (pin or socket) that carries the signal, a dielectric insulator that separates the center contact from the outer shell, an outer contact (shell or body) that serves as the ground/shield connection, and a coupling mechanism (threaded, bayonet, or push-on) that secures the mating interface.
Key Terms Defined
- Impedance: The measure of a cable or connector’s opposition to alternating current flow, expressed in ohms (Ω). Coaxial systems use either 50Ω (RF, wireless, test equipment) or 75Ω (video, CATV, broadband). Mismatched impedance causes signal reflections and loss.
- Insertion loss: The amount of signal power lost when a connector is inserted into the signal path, measured in decibels (dB). Lower is better. A high-quality F-Type connector has approximately 0.1–0.3 dB insertion loss at 1 GHz.
- VSWR (Voltage Standing Wave Ratio): A measure of impedance matching quality. A perfect match is 1.0:1. Most quality connectors specify VSWR of 1.3:1 or lower across their rated frequency range.
- Mating cycles: The number of times a connector can be connected and disconnected while maintaining specified performance. Ranges from 500 cycles (SMA) to 1,000+ cycles (BNC, F-Type).
- Frequency range: The maximum frequency at which the connector maintains its specified electrical performance. Ranges from ~1 GHz (F-Type) to 18+ GHz (SMA).
What Are the Main Types of Coaxial Cable Connectors?
F-Type Connectors (75Ω) — Cable TV, Satellite, and Broadband
The F-Type connector is the standard interface for residential cable television (CATV), satellite TV, and broadband internet connections worldwide. It uses a 75Ω impedance design optimized for video and data signals. The F-Type connector is specified in the SCTE (Society of Cable Telecommunications Engineers) standards and IEC 61169-24.
Specifications: Impedance: 75Ω. Frequency range: DC to 1 GHz (standard) or up to 3 GHz (precision versions). Typical insertion loss: 0.1–0.3 dB at 1 GHz. Mating cycles: 500–1,000+. Coupling: 7/16-28 UNEF thread (standard) or push-on (quick-connect variant).
Compatible cables: RG-6 (primary — most residential installations), RG-6 Quad Shield (high-EMI environments), RG-59 (legacy, shorter runs), and RG-11 (long trunk runs).
Installation types: Compression (recommended — best weatherproofing and signal performance), crimp, and twist-on (not recommended for permanent installations due to higher insertion loss and lower reliability).
Best for: Home cable TV, satellite dish connections, cable broadband modems, over-the-air antenna connections, MoCA networking.
BNC Connectors (50Ω or 75Ω) — CCTV, Broadcast, and Test Equipment
The BNC (Bayonet Neill–Concelman) connector is the standard for professional video, CCTV surveillance, broadcast equipment, and RF test instrumentation. It is available in both 50Ω (RF/test equipment) and 75Ω (video/CCTV) versions, defined by IEC 61169-8 and MIL-STD-348.
Specifications: Impedance: 50Ω or 75Ω. Frequency range: DC to 4 GHz (standard), up to 11 GHz for precision variants. Typical insertion loss: 0.1–0.2 dB at 1 GHz. Mating cycles: 500–1,000. Coupling: quarter-turn bayonet lock (connect/disconnect in <1 second).
Compatible cables: RG-58 (50Ω systems), RG-59 (75Ω CCTV), RG-6 (75Ω video), and RG-174 (miniature 50Ω applications).
Key advantage: The bayonet locking mechanism allows rapid connection and disconnection without tools—critical in broadcast and surveillance environments where equipment is frequently reconfigured. BNC is used in an estimated 90%+ of professional analog CCTV installations worldwide.
Best for: CCTV/surveillance cameras, broadcast video (SDI), oscilloscopes and test equipment, professional audio (AES-3id digital audio), and network analyzers.
SMA Connectors (50Ω) — Wireless, RF, and Microwave
The SMA (SubMiniature version A) connector is a precision 50Ω interface designed for high-frequency RF and microwave applications. Defined by MIL-STD-348 and IEC 61169-2, it is the most widely used connector in wireless infrastructure, cellular base stations, GPS equipment, and RF test instrumentation.
Specifications: Impedance: 50Ω. Frequency range: DC to 18 GHz (standard), up to 26.5 GHz for precision stainless steel versions. Typical insertion loss: 0.06–0.15 dB at 1 GHz. Mating cycles: 500 (per MIL-STD-348). Coupling: 1/4-36 UNS threaded interface. Body diameter: approximately 6.35 mm (0.25”).
Compatible cables: RG-174 (miniature), RG-58 (standard), RG-316 (PTFE, high-temp), and semi-rigid 0.085” and 0.141” cables.
Variant — RP-SMA (Reverse Polarity SMA): The center pin and socket are swapped compared to standard SMA. RP-SMA is the standard connector on most consumer Wi-Fi routers and access points (originally mandated by FCC to prevent unauthorized antenna modification). When replacing a Wi-Fi antenna, confirm whether your device uses SMA or RP-SMA before purchasing.
Best for: Wi-Fi antennas (RP-SMA), cellular/LTE antennas, GPS receivers, RF test & measurement, microwave links, ISM band equipment.
TNC Connectors (50Ω) — Outdoor Wireless and Mobile Communications
The TNC (Threaded Neill–Concelman) connector is a threaded variant of the BNC, designed for applications requiring a more vibration-resistant and weatherproof connection. It is specified in IEC 61169-17 and MIL-STD-348.
Specifications: Impedance: 50Ω (standard), 75Ω variants available. Frequency range: DC to 11 GHz. Typical insertion loss: 0.1–0.15 dB at 1 GHz. Mating cycles: 500+. Coupling: 7/16-28 UNEF threaded interface.
Compatible cables: RG-58, RG-142, RG-400, LMR-195, LMR-400, and similar 50Ω cables.
Key advantage: The threaded coupling provides superior vibration resistance and a more weatherproof seal compared to BNC’s bayonet mechanism. This makes TNC the preferred choice for outdoor antenna installations, mobile radio equipment, and applications subject to mechanical vibration.
Best for: Outdoor cellular/LTE antennas, mobile two-way radio systems, wireless base stations, military communications, vehicle-mounted antennas.
RCA Connectors — Legacy Home Audio and Video
The RCA connector (also called a phono connector) is a push-on connector historically used for analog audio and composite video connections in home entertainment systems. While not a true RF coaxial connector—it is unshielded and has no defined impedance—it is included here because it is frequently encountered alongside coaxial cables in home AV setups.
Specifications: No defined impedance (nominal ~75Ω for video applications). Frequency range: limited to baseband signals (typically <10 MHz). Coupling: friction-fit push-on (no locking mechanism).
Color coding: Yellow = composite video; White = left audio; Red = right audio. Component video uses Red/Green/Blue for the video channels.
Best for: Connecting legacy DVD players, older gaming consoles, VCRs, and analog audio equipment to TVs and receivers. Being replaced by HDMI for all new installations.
Coaxial Connector Comparison Table
This table summarizes the key specifications and applications for each connector type:
| Connector | Impedance | Freq. Range | Typical Cables | Coupling | Best Applications |
| F-Type | 75Ω | DC–1 GHz (3 GHz precision) | RG-6, RG-59, RG-11 | Threaded (7/16-28) | Cable TV, satellite, broadband internet, OTA antenna |
| BNC | 50Ω or 75Ω | DC–4 GHz (11 GHz precision) | RG-58, RG-59, RG-6 | Bayonet (quarter-turn) | CCTV, broadcast SDI, test equipment, digital audio |
| SMA | 50Ω | DC–18 GHz (26.5 GHz precision) | RG-174, RG-58, RG-316 | Threaded (1/4-36 UNS) | Wi-Fi (RP-SMA), cellular, GPS, RF test, microwave |
| TNC | 50Ω | DC–11 GHz | RG-58, LMR-400, RG-142 | Threaded (7/16-28) | Outdoor antennas, mobile radio, military, base stations |
| RCA | ~75Ω (nominal) | Baseband (<10 MHz) | Composite A/V cable | Push-on (friction) | Legacy audio/video, DVD, gaming consoles |
What Impedance Do You Need — 50 Ohm or 75 Ohm?
This is the most fundamental specification to get right. Using a 50Ω connector on a 75Ω system (or vice versa) creates an impedance mismatch that causes signal reflections, increased VSWR, and measurable signal loss.
Use 75Ω for video and data distribution: Cable TV (CATV), satellite TV, broadcast video (SDI), broadband internet via coax, CCTV surveillance, and MoCA home networking. The 75Ω standard minimizes signal attenuation over long cable runs, which is why it was adopted for video distribution.
Use 50Ω for RF, wireless, and power transfer: Wi-Fi antennas, cellular/LTE antennas, two-way radio, GPS receivers, RF test equipment, radar, and military communications. The 50Ω standard represents the best compromise between power handling capacity and signal attenuation for transmitted RF signals.
| Key Takeaway
The simplest rule: if you are receiving a signal (TV, internet, CCTV), you almost certainly need 75Ω. If you are transmitting or working with wireless/RF equipment, you almost certainly need 50Ω. |
How Do You Match a Coaxial Connector to Your Cable?
Every coaxial connector is designed to fit a specific range of cable outer diameters and constructions. Using the wrong connector-cable combination results in a poor mechanical fit, increased insertion loss, and unreliable connections. Here are the most common pairings:
| Cable Type | Impedance | OD (approx.) | Common Connectors | Typical Applications |
| RG-6 | 75Ω | 6.86 mm | F-Type, BNC (75Ω) | Residential CATV, satellite, broadband internet |
| RG-59 | 75Ω | 6.15 mm | F-Type, BNC (75Ω) | Short-run CCTV, legacy cable TV |
| RG-11 | 75Ω | 10.3 mm | F-Type (RG-11 size) | Long trunk runs, backbone CATV distribution |
| RG-58 | 50Ω | 4.95 mm | BNC (50Ω), TNC, SMA | RF test, two-way radio, CB radio, Wi-Fi pigtails |
| RG-174 | 50Ω | 2.79 mm | SMA, BNC (miniature) | GPS, Wi-Fi, miniature RF jumpers, IoT devices |
| LMR-400 | 50Ω | 10.29 mm | N-Type, TNC | Outdoor cellular antennas, base station feeds, long RF runs |
| RG-316 | 50Ω | 2.49 mm | SMA | High-temperature RF, internal equipment jumpers |
Critical: Always verify the specific connector’s cable compatibility before ordering. Connectors designed for RG-6 will not fit RG-58 (different diameters), even though both may have the same interface type (e.g., both available as BNC). Check the manufacturer’s datasheet for the supported cable group.
How Do You Choose the Right Coaxial Connector? (5-Step Framework)
Step 1: Identify Your Application
The application determines the impedance and frequency requirements:
- Cable TV / satellite / broadband: F-Type, 75Ω
- CCTV surveillance: BNC (75Ω) for analog, F-Type or RJ-45 for IP cameras
- Wi-Fi antenna: RP-SMA (most consumer routers) or SMA (enterprise), 50Ω
- Cellular/LTE antenna: SMA, TNC, or N-Type, 50Ω
- RF test equipment: BNC (50Ω) up to 4 GHz, SMA above 4 GHz
- Broadcast video (SDI): BNC (75Ω)
- Home audio/video (legacy): RCA
Step 2: Match the Cable Type
Identify your cable (RG-6, RG-58, RG-174, LMR-400, etc.) and select a connector specifically rated for that cable. Do not assume that a “BNC connector” will fit any cable—BNC connectors come in variants for RG-58, RG-59, RG-6, RG-174, and other cable types. The connector’s crimp or compression sleeve must match the cable’s outer diameter.
Step 3: Assess the Installation Environment
- Indoor, fixed installation: Standard connectors in nickel or brass finish are sufficient. F-Type compression connectors are the standard for residential CATV.
- Outdoor or weather-exposed: Use connectors with weatherproof boots, silicone seals, or IP-rated housings. TNC connectors are inherently more weatherproof than BNC due to their threaded coupling. Apply weatherproofing tape or heat-shrink over outdoor connections.
- High-vibration (vehicles, industrial): Threaded connectors (SMA, TNC, F-Type) resist vibration far better than bayonet (BNC) or push-on (RCA) types.
- Frequent connect/disconnect: BNC (bayonet lock) is fastest. SMA thread-on is the slowest but most secure. Consider mating cycle ratings if the connection will be made/broken regularly.
Step 4: Prioritize Quality and Brand
Connector quality directly affects insertion loss, VSWR, weatherproofing, and long-term reliability. For critical installations, specify connectors from established manufacturers such as Amphenol, TE Connectivity (formerly Tyco), Molex, Hirose, Huber+Suhner, or Rosenberger. These manufacturers publish full electrical specifications and maintain quality management systems (ISO 9001, IATF 16949, AS9100) that ensure lot-to-lot consistency.
For residential CATV, compression-style F-Type connectors from brands like PPC (Belden), Snap-N-Seal (Thomas & Betts/ABB), or ICM (Holland Electronics) are the industry standard used by major cable operators.
Step 5: Select the Right Installation Method
- Compression (recommended for F-Type): Requires a coaxial compression tool ($15–$50) and cable stripper. Produces the most reliable, weatherproof connection. Standard method used by professional CATV and satellite installers.
- Crimp: Requires a crimp tool matched to the connector. Common for BNC, SMA, and TNC connectors. Produces a permanent, reliable connection when done correctly with calibrated tooling.
- Solder: Used for precision SMA and other RF connectors, especially on semi-rigid cable. Requires soldering skill and provides the lowest insertion loss when executed properly.
- Twist-on (F-Type only): No tools required. Convenient for temporary connections but not recommended for permanent installations due to higher insertion loss and poor weatherproofing.
What Are the Essential Installation and Maintenance Tips?
Installation Best Practices
- Strip the cable to the correct dimensions. Over-stripping exposes too much center conductor (causing impedance discontinuity); under-stripping prevents full contact. Use a coaxial cable stripper set to the connector manufacturer’s specified strip lengths.
- Inspect before mating. Verify that the center pin is straight, the dielectric is undamaged, and no stray shield braid strands are touching the center conductor (which would create a short circuit).
- Hand-tighten threaded connectors, then snug with a wrench. For F-Type: 7/16” wrench to approximately 30 in-lb torque. For SMA: 8 mm wrench to 3–5 in-lb torque (SMA threads are delicate—never overtighten). For TNC: 3/4” wrench to 12–15 in-lb torque.
- Test the connection after installation. Use a cable tester, signal meter, or return loss bridge to verify continuity, impedance match, and signal level. For critical RF systems, measure VSWR across the operating frequency band.
Maintenance Guidelines
- Inspect connectors annually for outdoor installations. Check for corrosion, moisture intrusion, and mechanical damage. Replace weatherproofing tape or boots that have degraded.
- Clean connector interfaces with isopropyl alcohol (IPA) and lint-free swabs before mating precision RF connectors (SMA, TNC, N-Type). Contamination on the mating surfaces increases insertion loss and degrades VSWR.
- Replace damaged connectors immediately. A bent center pin, cracked dielectric, or worn threads will not self-repair and will progressively degrade signal quality.
- Use torque wrenches for SMA connections. SMA connectors are rated for 500 mating cycles when properly torqued. Over-torquing or cross-threading can damage the connector in a single mating, creating a permanent impedance discontinuity.
Frequently Asked Questions About Coaxial Cable Connectors
Q: What is the difference between F-Type and BNC connectors?
A: F-Type connectors are 75Ω threaded connectors designed for residential cable TV, satellite, and broadband internet, typically used with RG-6 cable. BNC connectors use a quarter-turn bayonet lock and are available in both 50Ω (RF/test) and 75Ω (CCTV/broadcast video) versions, typically used with RG-58 or RG-59 cable. F-Type is the standard for home installations; BNC is the standard for professional video and test equipment.
Q: Which coaxial connector is best for home internet and cable TV?
A: The F-Type compression connector on RG-6 cable is the industry standard for home cable TV, satellite TV, and broadband internet. This is the same connector type used by professional cable and satellite installers. Use compression-style connectors (not twist-on) for permanent installations to ensure low insertion loss and good weatherproofing.
Q: What impedance do I need — 50 ohm or 75 ohm?
A: Use 75Ω for video and data reception systems: cable TV, satellite TV, broadcast video, CCTV, and broadband internet. Use 50Ω for RF transmission and wireless systems: Wi-Fi antennas, cellular antennas, two-way radio, GPS, and RF test equipment. Mixing impedances causes signal reflections and loss.
Q: Can I use an SMA connector for TV cable?
A: No. SMA is a 50Ω connector designed for RF frequencies up to 18 GHz, and it is physically incompatible with the RG-6 cable used for TV service. TV cable requires a 75Ω F-Type connector. Using an SMA connector on a TV system would create an impedance mismatch and would not physically fit the cable.
Q: What is the best coaxial connector for outdoor use?
A: TNC connectors are the best general-purpose choice for outdoor RF applications because their threaded coupling provides a weatherproof seal and vibration resistance. For outdoor CATV, use F-Type compression connectors with weatherproof boots and self-amalgamating tape. For any outdoor installation, apply silicone sealant or weatherproofing tape over the connector junction and use UV-rated cable.
Q: How do I know which coaxial connector fits my cable?
A: Check the cable type printed on the jacket (e.g., RG-6, RG-58, RG-174). Then select a connector specifically manufactured for that cable type. For example, an “F-Type for RG-6” fits RG-6 cable; an “F-Type for RG-59” fits RG-59. The connector’s crimp or compression sleeve is sized to match the cable’s outer diameter, so they are not interchangeable between cable types.
Q: What tools do I need to install coaxial connectors?
A: For F-Type compression connectors: a coaxial cable stripper ($10–$20) and a compression tool ($15–$50). For BNC/SMA/TNC crimp connectors: a coaxial cable stripper and a crimp tool with the correct die set for your connector ($30–$100). For SMA solder connectors: a soldering iron (25–40 W), flux, and solder. A 7/16” wrench (F-Type) or 8 mm wrench (SMA) is needed to properly tighten threaded connectors.
Q: How long do coaxial connectors last?
A: A properly installed, high-quality coaxial connector in a protected indoor environment can last 15–25+ years. Outdoor connectors typically last 5–15 years, depending on climate exposure and weatherproofing quality. Mechanically, connectors are rated for a specific number of mating cycles: BNC for 500–1,000 cycles, SMA for 500 cycles, and F-Type compression for 500+ cycles. The limiting factor for outdoor connectors is usually corrosion rather than mechanical wear.
Conclusion: Choosing the Right Coaxial Connector
Selecting the correct coaxial cable connector requires matching three specifications to your application: impedance (50Ω or 75Ω), frequency range (from baseband up to 18+ GHz), and physical cable compatibility (connector must fit your specific cable type). The five connector types covered in this guide—F-Type, BNC, SMA, TNC, and RCA—cover the vast majority of residential, commercial, and professional applications.
For most home users, the answer is straightforward: F-Type compression connectors on RG-6 cable. For professional video and surveillance, BNC is the standard. For wireless and RF applications, SMA and TNC provide the high-frequency performance and environmental durability these systems require. In every case, investing in quality connectors from reputable manufacturers and installing them with the correct tools and techniques pays dividends in signal quality, reliability, and long-term service life.