Connecting a BNC connector to a coaxial cable requires precision and attention to detail to ensure a secure, low-loss connection. Below is a step-by-step guide to help you complete this task effectively:
1. Gather Necessary Tools and Materials
Before starting, ensure you have the following items:
BNC connector: Choose the appropriate type (crimp-on, screw-on, or compression) and impedance (50Ω or 75Ω) based on your application.
Coaxial cable: Ensure it matches the impedance requirements of your BNC connector.
Wire strippers: Designed for coaxial cables to avoid damaging the inner conductor or shield.
Crimp tool: If using a crimp-on BNC connector.
Utility knife or box cutter: For carefully trimming the cable jacket (if needed).
Optional: Soldering iron and solder (for solder-type BNC connectors), heat shrink tubing (for insulation and Strain Relief).
2. Prepare the Coaxial Cable
Measure and cut the cable: Use wire cutters to trim the coaxial cable to the desired length. Ensure the cut is clean and perpendicular to the cable's axis.
Strip the outer jacket:
Use a coaxial cable stripper to remove approximately 0.5 to 1 inch (1.27 to 2.54 cm) of the outer jacket, exposing the metal shield beneath.
If you don't have a stripper, carefully use a utility knife to score the jacket around the circumference, then gently peel it back.
Fold back the shield:
Strip the dielectric:
Use the stripper's smaller setting or a sharp blade to remove a small amount (about 0.25 inches or 0.64 cm) of the dielectric material surrounding the center conductor.
Be careful not to nick or damage the center conductor.
3. Attach the BNC Connector
The method of attachment depends on the type of BNC connector you're using:
A. Crimp-On BNC Connector
Slide on the crimp ring: If your connector comes with a separate crimp ring, slide it onto the cable before attaching the connector body.
Insert the center conductor: Gently insert the exposed center conductor into the small hole at the tip of the BNC connector. Ensure it fits snugly without forcing it.
Position the connector: Slide the BNC connector body over the prepared cable end, ensuring the shield makes contact with the connector's metal body.
Crimp the connector:
Place the crimp ring (if used) over the connector's metal sleeve.
Use the crimp tool to apply firm pressure, securing the connector to the cable. The crimp should be tight enough to hold the connector in place but not so tight as to damage the cable.
B. Screw-On BNC Connector
Insert the center conductor: As with the crimp-on type, gently insert the center conductor into the hole at the tip of the connector.
Thread the connector: Screw the BNC connector onto the prepared cable end by hand, ensuring the shield makes contact with the connector's metal body.
Tighten securely: Use pliers or a wrench (if provided with the connector) to gently tighten the connector, ensuring a secure connection without over-tightening.
C. Solder-Type BNC Connector (Less Common)
Tin the center conductor: Apply a small amount of solder to the exposed center conductor to prepare it for soldering to the connector.
Solder the connection: Heat the center conductor and the corresponding pin on the BNC connector with a soldering iron, then apply solder to create a strong electrical bond.
Solder the shield: Similarly, solder the folded-back shield to the metal body of the connector, ensuring good electrical contact.
Insulate (optional): Use heat shrink tubing to cover the soldered connections for insulation and strain relief.
4. Final Checks and Testing
Inspect the connection: Visually check that the center conductor is properly seated in the connector's pin and that the shield is making good contact with the connector body. There should be no exposed wires or loose parts.
Test the connection:
Use a multimeter to check for continuity between the center conductor and the connector's pin, and between the shield and the connector's body.
If possible, perform a signal test by connecting the BNC cable to your equipment and checking for proper signal transmission.
Secure the connection (optional): If the cable will be subject to movement or stress, consider using heat shrink tubing or electrical tape to provide additional strain relief and insulation.
