The use of electronics and electrical equipment requires a variety of cables. Out of them, BNC cables are quite standard as a type of radiofrequency connectors. You can find different configurations of BNC cables and connectors also vary. So how do you choose the right one?
In this guide, we will go into the depths of BNC cable and give you a full course on the topic. We will also tell you how to make your BNC cable. In the end, you will be able to choose the right wire and make your application a success.
Table of Contents
- Chapter 1: What is a BNC Cable
- Chapter 2: Applications of BNC Cable
- Chapter 3: Types of BNC Cable Connectors
- Chapter 4: BNC Cable Connector Formats and Variants
- Chapter 5: How to Make Your Own BNC Cable
- Chapter 6: Helpful BNC Cable Connector Installation Tips
- Chapter 7: Coaxial Cables with BNC Connectors
BNC cables are widely used for RF connections and offer high performance. BNC cables have BNC or Bayonet Neill–Concelman connectors. They come useful when you need a coaxial or screened cable.
BNC cables come with a bayonet fixing to prevent accidental disconnections. The cable has the same characteristic impedance across the whole wire. This results in lower levels of loss and fewer reflections. For this reason, RF applications benefit a great deal from the use of BNC cables.
BNC cables have two bayonet lugs on the female connector. You can secure it to the male connector using the coupling nut.
The BNC cable comes in different specifications depending on the manufacturer. The two basic specifications are-
- 50 ohm
- 75 ohm
The 50-ohm version is more common than the 75-ohm version. You can use the 75-ohm version for frequencies up to 2 GHz. Many HD video applications use this cable specification.
The 50 ohm BNC cable supports frequencies up to 4 GHz and suited for RF and data applications.
You can also find a 95-ohm version of BNC cable. It is suitable for use in the aerospace industry.
Now let’s explore the applications of BNC cables.
BNC cables have widespread use. You can use them for test equipment of:
- Audio generators
- Power meters
- Function generators
75 ohm BNC cables come useful when a low loss of signal is useful. You can use them for:
- HD TVs
- Satellite and cable TV receiver boxes
- AM or FM radio receivers
- Police scanners
- Medical equipment
- CCTV and security cameras
- Audio security systems
BNC cables are generally suited for most video applications. You can also use 75 ohm BNC cables for high-temperature situations.
In the next section, we will take a look at the different BNC cable connectors.
Safe High Voltage (SHV) and Miniature High Voltage (MHV)
You can find a threaded version of BNC cable. It is called TNC or Threaded Neil-councilman connector. It offers better performance compared to BNC connectors at microwave frequencies.
Twin BNC or Twinax Connectors
Twin BNC connectors come with the same bayonet as other BNC cables. However, they have two independent contact points. One of them is male while the other is female. Twinax connectors disallow the mixing of signals.
Triaxial connectors are a form of BNC connectors. They come with a ground connector, a guard and a signal. They are suitable for applications which need maximum RF shielding. You can find triaxial connector cables in sensitive electronic testing systems.
You can come across smaller versions of BNC called Mini BNC and High-Density BNC (HD BNC). They are common in many electronics. Sometimes you may also find LEMO-00 miniature connectors in place of Mini BNC.
Now it’s time to explore the formats and variants of BNC cable.
BNC cables have many formats and variants. You also have various adapters and attenuators. That’s why you need to choose the correct size. Make sure to check the BNC plug to determine which cable you need.
BNC cables have straight and angled variants. Straight connectors are standard and useful for most applications, but you can also use right-angled variants for applications with limited space. The right-angled BNC cables have a higher level of loss than straight connectors.
Some female connectors of BNC cables also differ from one another. You will see four nuts and bolts in some of them. You can also find bulkhead mounting connectors on some wires.
BNC Cable Plug Assembly Variants
Going by the assembly method, there are two types of BNC cables-
- Compression gland type
- Crimp type
The compression gland type BNC cable is compatible with limited sizes of wires. However, you don’t need any special tools to assemble the cable. This type is suited for limited production quantities.
For crimp type BNC cables, you need to choose the correct connector variant. You will also need proper crimping tools for assembly. Crimp type BNC cables are ideal for more massive production as they are fast to assemble.
In the next section, we will teach you how to make your BNC cable.
Things to Arrange
- Wire stripper
- Crimping tool
Take the connector ferrule and slide it over the cable. The bushing is the hollow tube portion of the connector. Slide the ferrule out of the way.
Use the stripper to cut the end of the cable evenly. You will fit the connector here.
Now take the wire stripper and strip the cable. Strip the jacket of the cable about half inch from the end. Now hold the braids and strip them back by 1/4 of an inch. Then strip the inner insulation back by around 3/16 inch.
Take the solid center conductor and insert it into the center pin. Pull the center pin until it covers the inner insulation fully.
Now use the crimping tool and crimp the center pin.
Next, pull the connector body over the center pin. It should also cover the inner insulation. However, don’t let it cross the braided shield. The center pin will take its place once you push the body back.
Now push the ferrule forward so that it touches the connector piece. Use the crimping tool to crimp it in place.
Here’s a video to help you make your BNC cable-
We will discuss a few tips in the next section to make your BNC cable installation a success.
Here are some useful tips to make sure you do the right job-
- Select the right connector size.Never force one connector into another. You can check the manufacturer recommendations for more information.
- Check the impedance of the connectors. Don’t try to differentiate the connectors by looks as it could get challenging. Always go for the right impedance to avoid problems later on.
- Choose the correct bandwidth of your connectors. Different connectors support different bandwidths like 1.5 GHz or 4.5 GHz. Check the rating of the connector if you are installing a 4K coaxial cable.
- Always use a wire stripper to cut the coax.Never use electrical dikes as they can change the structure of the cable. Also, check the size of the stripping tool to make sure they fit the wire.
- Don’t use a dull prep tool.It will make the braid wrap around the center conductor resulting in shorts. Also, stay away from using razors or scissors.
- Never forget to flatten the foil of the cable. Otherwise, the center pin will not fit the front of the cable.
- Don’t pull the connector too hard to test your connection.All cables have a maximum pull tension they can withstand. After that, the connector can break off.
- Make sure the center pin locks appropriately on the cable. Push the pin till it locks in place.
Now we will take a look at a few cables similar to BNC cables.
Some coaxial cables use BNC connectors. We will go over such similar wires and their uses-
RG-59 coaxial cable uses 75 ohm BNC connectors. Applied for transmitting video signals from CCTV cameras to surveillance setups.
RG-58 coaxial cable: A cost-effective cable similar to BNC and uses 50-ohm connectors. It has a wide variety of applications due to high performance.
RG-174 coaxial cable: It’s a thin cable and features 50 ohm BNC connectors. Many GPS navigation antennas of vehicles use this cable.
RG-213 coaxial cable: Ideal for high-power usages and comes with a 50 ohm BNC connector. You can use it for applications of up to 1,000 watts. It is also very thick due to its power-carrying capacity.
Our guide will help you to choose the right BNC cable and also make one yourself. However, if you need custom BNC cables, you will need to choose a reliable manufacturer. We manufacture BNC cables meeting international standards for the highest quality and performance. You can get in touch with us for quality BNC cable matching your design and specifications.