Connecting a coaxial cable to a BNC (Bayonet Neill–Concelman) connector is a fundamental task in RF and video signal transmission. Whether you’re installing surveillance systems, setting up test equipment, or maintaining broadcasting infrastructure, knowing how to properly terminate a coax cable with a BNC connector ensures signal integrity and equipment compatibility.
In this guide, I’ll walk you through everything you need to know about connecting coax cables to BNC connectors—from choosing the right tools to common mistakes to avoid.
Why This Matters: Ensuring Proper Signal Transmission
Improper termination can lead to:
- Signal loss
- Impedance mismatch
- Unstable performance in video and RF applications
A secure and correct connection is vital for maintaining signal clarity and preventing failure over time.
Understanding the Basics
What Is a Coaxial Cable?
A coaxial cable is a type of electrical cable consisting of an inner conductor, dielectric insulator, shielding (braid and/or foil), and an outer jacket. It’s widely used for:
- RF communication
- CCTV systems
- Test equipment
What Is a BNC Connector?
A BNC connector is a miniature quick connect/disconnect RF connector. It is commonly used with:
- RG58, RG59, RG6 coax cables
- CCTV cameras
- Lab instruments
- Broadcast transmission
It offers a bayonet-style coupling mechanism for secure attachment.
Tools and Materials You’ll Need
| Tool/Item | Purpose |
|---|---|
| Coaxial stripping tool | Strips the coax cable layers to correct lengths |
| Coaxial crimping tool | Secures the BNC connector with the cable |
| BNC connector (crimp/solder type) | Matches your cable type (e.g., RG59, RG6) |
| Utility knife or scissors | For fine trimming or jacket cutting |
| Multimeter (optional) | To test continuity and connection quality |
Step-by-Step: How to Connect a Coax Cable to a BNC Connector
Step 1: Identify the Cable and Connector Type
Check the coaxial cable you are working with (e.g., RG6, RG59). Choose a BNC connector compatible with that specific cable type and impedance (usually 75 ohms for video, 50 ohms for RF test gear).
Step 2: Strip the Cable Correctly
Using a coax stripper:
- Cut the outer jacket (approx. 10 mm from the end)
- Trim the braid/shield to expose the dielectric (approx. 5 mm)
- Expose the center conductor (approx. 2 mm)
Ensure no strands of the shield are touching the center conductor.
Step 3: Insert the Cable into the BNC Connector
- Slide the crimp ring (ferrule) over the cable first
- Insert the prepared cable into the BNC body
- Ensure the center conductor aligns with the pinhole
Step 4: Crimp the Connector
Using the coax crimping tool:
- Crimp the ferrule over the braid
- For crimp-type connectors, also crimp the center pin if required
A firm, even crimp ensures electrical contact and mechanical strength.
Step 5: Test the Connection
Use a multimeter or coaxial tester to verify:
- Continuity between center pin and opposite end
- No short circuit between shield and center conductor
Common Connection Mistakes to Avoid
| Mistake | Consequence |
|---|---|
| Stripping cable too short | Insecure connection or signal drop |
| Shield contacting center pin | Causes short circuit and interference |
| Loose crimp | Intermittent or degraded signal |
| Wrong connector for cable | Impedance mismatch and signal loss |
Interactive Decision Guide
Are You Using the Right BNC Connector?
| Question | If YES | If NO |
|---|---|---|
| Is your cable type RG59 or RG6? | Use matching BNC connector | Select correct connector for cable type |
| Do you have a crimping tool available? | Proceed with crimp-type BNC | Use twist-on or solder type instead |
| Is the application analog video (CCTV)? | Use 75-ohm BNC | Use 50-ohm BNC for RF/test applications |
Use Case Scenarios
CCTV Installation
- Common cable: RG59
- Connector: 75-ohm BNC crimp-on
- Application: Security cameras to DVRs
RF Lab Equipment
- Common cable: RG58
- Connector: 50-ohm BNC solder-on
- Application: Oscilloscopes, signal generators
Video Broadcasting
- Common cable: RG6
- Connector: 75-ohm BNC compression
- Application: HD-SDI signal transmission
-
FAQs: Quick Answers to Common Questions
Q1: Can I reuse BNC connectors?
A: Compression and solder connectors are not reusable. Some crimp connectors may be reused if undamaged, but it’s not recommended.
Q2: Do BNC connectors work on RG6 and RG59 interchangeably?
A: No. Use the connector specifically rated for the cable diameter and impedance.
Q3: What’s the difference between 50-ohm and 75-ohm BNC connectors?
A: 50-ohm connectors are for RF communication and test equipment; 75-ohm are for video and broadcast systems.
Still Not Sure Which Connector or Cable to Use?
If you’re unsure about compatibility, cable type, or installation tools—don’t worry. We’re here to assist.
Try answering this:
Do you need a long-run cable for video signal with minimal loss?
- If yes, go with RG6 and 75-ohm BNC.
- If no, RG59 may suffice for short CCTV runs.
Final Tips Before You Begin
- Always use a proper coax stripper for consistent results.
- Don’t over-tighten twist-on connectors—they can damage the cable.
- Label your cables after termination to simplify maintenance.
Get Expert Help and the Right Supplies
At Bafitop, we specialize in RF and video transmission components for professional integrators and system builders. Whether you need bulk coaxial cable, BNC connectors, or toolkits—we’ve got you covered.
Reach out to our team for samples, pricing, and recommendations tailored to your needs.
Contact Us Now
- Email: sales@bafitop.com
- Phone: +86-15817341810
Let’s make your project seamless and signal-perfect.
