75 Ohm vs. 50 Ohm - Coaxial Comparison

September 21, 2017 at 8:00 AM

 

Ohm may look like something you’d say while meditating, but when it comes to coaxial cables, it is actually a unit of resistance. Ohms measure the impedance within the cable. Impedance is resistance to the flow of electrical current through a circuit.

 

A smaller Ohm measurement equals less impedance. This means that a 50 Ohm cable has less resistance to the electrical current than a 75 Ohm cable. Though there really isn’t a "good" or "bad" level of impedance, it just depends on what is right for your application.

 

75 Ohm cables are the standard coaxial cables used throughout the home, they are often pre-wired into many homes and businesses. The primary application for 75 Ohm cables is transmitting video and audio signals. They are used to connect televisions to cable and satellite receivers and internet routers. These cables are ideal for smaller applications where a signal is transmitted up to 50 feet before the signal is repeated by an active device.

 

50 Ohm coaxial cables are mainly utilized in wired and wireless networks to relay data signals. Low-loss 50 Ohm cables are used for transferring RF signals in wireless networks. For commercial installations, 50 Ohm cables typically have the advantage over 75 Ohm because they perform better (less attenuation than 75 Ohm) over longer distances of more than 100 feet and over larger areas. The disadvantage of 50 Ohm cables is that they are much thicker and use larger connectors. Typical applications for 50 Ohm cables include GPS, cellular and test and measurement applications.

 

To recap, for the lowest impedance of electrical current, 50 Ohm is the best bet. 75 Ohm cables lose almost two times the amount of dB gain every 10 feet when compared to 50 Ohm cables.

 

Also, keep in mind that the 50 Ohm and 75 Ohm ratings only refer to the cables themselves and they can be mixed and matched with cables and connectors in any other system.

 

Posted in: Wired

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Wired and Wireless Networks for the Energy Industry

September 14, 2017 at 8:00 AM

 

The energy industry is getting a lot of attention these days with more people talking about how we can better harness and use energy. Here, we’ll look at the energy industry and how all sectors, including oil, gas and renewable sources, are using wired and wireless networks to connect their operations.

 

Oil and Gas

 

Offshore oil platforms are exposed to water, salt, vibration and extreme temperatures. Although in many cases the communications equipment used on these rigs are housed in protective enclosures some equipment must be located in exposed areas where they are subject to environmental extremes. This includes IP cameras used for surveillance of the platform, plus the cabling and converters that link back to the central control room on the rig. Wireless sensors and controllers are also located throughout the platform and are linked by outdoor antennas, amplifiers and access points used to operate the rig.

 

In petroleum refineries, wired and wireless sensors are used to monitor and control process applications and provide real-time data that can warn of system issues. Many valves and controllers are linked to a serial or IP network, as well as security and surveillance equipment that are critical to operations.

 

Natural gas pipelines depend on communications networks to monitor the safety and efficiency of the pipeline, which can span hundreds of miles over harsh terrain and in remote areas. These networks allow for real-time data to be sent to the control room that can detect leaks and issues with pressure and temperature. IP based surveillance systems along the pipeline also require network connectivity to provide added protection.

 

Renewable Energy

 

Solar energy networks use wired and wireless connectivity for long distance control and monitoring of solar panel arrays. For example, serial data cables connect to the power meters on the panel, theses power meters are then connected to the Ethernet network via a device server and antennas wirelessly connect the power meters back to the control center for monitoring and control.

 

Hydroelectric power has modernized operations by implementing automated systems in hydroelectric plants. Many of these systems use Programmable Logic Controllers (PLCs) to control valves, motor starters, sensors and flood gate control systems that are critical to operations. Other systems use wireless networks to monitor and control the plant. Surveillance and security systems are also important in these plants to not only monitor for intruders, but also to visually analyze the dam and plant and watch for structural breakdown.

 

Monitoring wind turbines also requires wired and wireless networks. An industrial Ethernet switch allows signals to be sent to the turbine that change its speed and angle. Fiber optic cables connect the control center to multiple turbines over long distances for complete control of the wind farm and antennas are used to connect the local control center to a main control network.  

 

For more details on how wired and wireless technology is powering the energy industry, and how L-com’s products are being used, download our energy industry overview.

 

Counterfeit Cables 101

September 7, 2017 at 8:00 AM

 

Have you ever wondered how some cables are able to be sold at such dramatically low prices? In some cases, it’s because the cables aren’t exactly what they appear to be. Counterfeit cables are more common than you might think.  In fact, we found that cables can be counterfeit from both large and small manufacturers and domestic or overseas sources.

 

A counterfeit cable is any cable that is sold under false pretenses, where the cable specification doesn’t match the actual product construction. Implying that a cable meets a certain performance standard when it doesn’t, such as Cat6a, is also considered counterfeiting. In most cases, the cables are made with inferior materials so they can be offered at a cheaper price.

 

One major factor in avoiding counterfeit cables is ensuring that your supplier or manufacturer is consistently checking cable assemblies, proving UL compliance, testing cables and ensuring standards are met.

 

Here are some things you should be aware of to avoid getting stuck with counterfeit cables:

·  Substituting steel or aluminum for pure copper conductors – This cost saving method also causes the signal strength to drop below noise and cross-talk levels which will lead to problems in a high-speed network.

 

·  Cable jacket material – If a jacket is CMP or CMR-rated, a legitimate business will offer a signed Certificate of Conformance (CoC) for their products. If there’s no CoC offered, the jacket might not meet rating standards.

 

·  Selective electrical performance testing – Some manufacturers claim their products were “fluke tested” but don’t run the full patch testing because it’s not easy to pass and it’s more expensive. Legitimate manufacturers will run the full performance testing to ensure their cable meets standards and provide you with the test result documentation.

 

·  Misleading cable markings – Cables sold in the U.S. have a variety of markings that can be used to look them up on the UL’s database, but that doesn’t always guarantee that the cable is worthy of its markings. A signed CoC is the best way to make sure that you’re not getting a counterfeit cable.

 

·  Deceiving connector construction – Using cheaper materials will lower the combustion rating for a plastic connector and cause metal connectors to eventually corrode and fail when mated.

 

·  Wire gauge changes – 25 AWG and 26 AWG cables are often mislabeled as 24 AWG. They best way to test the gauge is to request a sample, cut it open, remove the insulation and measure the conductors.

 

·  The Golden Sample – Manufacturers may create a golden sample to send to the customer, but cut corners when manufacturing the rest of the order to save money. Creating a quality control system to test the cables in each shipment, unbeknownst to the manufacturer, is your best bet to test for consistency in quality.

 

5 Things You Need to Know About the Cloud

August 31, 2017 at 8:00 AM

 

If you’re like most people, you probably have pictures or some other type of files stored in the cloud, but do you really understand what the cloud is? For many people, the cloud remains a mystical place that they still can’t quite comprehend. Here are 5 things you need to know about the cloud:

 

1.  When something is stored in the cloud, it is actually in a physical place. The cloud is like a giant IT data center, it is a massive infrastructure of thousands of servers that are connected by cables, switches, connectors and patch panels. All of these parts work together to store data, provide virtual desktops, global data access and more.

 

2.  Cloud computing relies on many geographically dispersed servers that provide millions of people with reliable and limitless access to their library of and images, video, audio and data files through the Internet. This frees up local RAM and hard drive space, but it also means that the interconnect components that make up the cloud need to be fast and dependable to keep up with user demand.

 

3.  The consumer cloud is different than a cloud for business. Consumer cloud computing is for those using cloud Internet services casually at home or in small offices. When it comes to business, there are several cloud models being used:

 

-  Software-as-a-Service (SaaS) – businesses subscribe to an application that is accessed using the Internet

-  Platform-as-a-Service (PaaS) – businesses create their own custom application for everyone in the company      to use

-  Infrastructure-as-a-Service (IaaS) – the big names in tech (Amazon, Google, Microsoft, etc.) provide a              backbone that can be used or “rented” for use by other companies

 

4.  The cloud is big business and is having a big impact on business. Worldwide public cloud services are anticipated to grow 18% this year to reach $246.8 billion. Cloud computing is also expected to be the most measurable factor impacting businesses in 2017. Cloud platforms allow for more complex business models and coordination of globally integrated networks – more so than many experts predicted. Cloud services are also increasingly being used by small and medium businesses, which is also increasing the revenue forecast.

 

5.  The Internet of Things (IoT) continues to grow, and with the IoT has come increased use of cloud computing technology. Eventually, IoT devices may become extensions of cloud data centers.  The cloud is a powerful force in the technology industry and a global trend that doesn’t seem to be slowing down.

 

Posted in: Wireless

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How to Protect Your Equipment During Lightning Season

August 24, 2017 at 8:00 AM

 

No matter how lucky you are, the thought of lightning striking your expensive communications equipment can be a scary thought. Depending on your location, the time of year and your proximity to other buildings, the chances of a lightning strike can be higher or lower, but any lightning strike can be debilitating for sensitive electronic equipment. Both direct and indirect strikes can cause extensive damage that includes loss of data, downtime and the cost of replacement.

 

Electromagnetic fields and earth-voltage spikes caused by lightning can also wreak havoc on electronic power and signal circuits. This can damage the Ethernet, coaxial and telephone lines, or anything connected to the circuits. Even entire campuses can experience long-range voltage spikes that can ruin all electronics connected by the above-ground and below-ground cabling systems that run throughout the campus.

 

There’s no single cure-all method, but lightning protectors are an inexpensive way to help protect equipment in the event of a lightning strike. Here are some of the best solutions to give your equipment a fighting chance:

 

 

Coaxial Protectors – These lightning protectors use gas-filled tubes to discharge electrical spikes before they can cause damage. They are used in both wired and wireless networks to protect radios, communications equipment and anything else attached to coaxial cable, which becomes a target for lightning. They feature popular connector types including N, TNC, RP-BNC and F.

 

Low-PIM Coaxial Protectors – Theses are ideal for use with Distributed Antenna Systems (DAS) because of their low-PIM performance of -150dBc. They feature bi-directional protection and there are no gas tubes to replace.

 

Cat5/5e/6 and PoE Protectors – These protectors ground-out and discharge spikes that can permanently blackout security cameras, switches routers and other critical equipment. They are ideal for 10/100/1000 Base-T Ethernet networks. Some models even feature integral PoE injectors that can deliver remote power to access points, access servers, outdoor routers and other Ethernet IP enabled devices.

 

Telephone/DSL/T1 Protectors – They protectors can prevent your POTS or other telephone system from expensive downtime and are perfect for indoor or outdoor installations. These protectors are available in multiple styles including screw terminal 

and RJ11 options.

 

RS232/422/485 Protectors – These are ideal for protecting RS-232, RS-422 and RS-485 lines. They can also save sensors, control lines and AISG lines from lightning’s damaging effects.

 

To see all the products L-com offers to protect your equipment from lightning, click here.

 

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