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CaTV | Grounding and Bonding

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  Metal objects have a tendency to accumulate a charge. If the charges between metal objects are different then an arc or spark could develop. This is called potential difference. If there is no potential difference then there is no current flow and there is no danger of spark. Bonding is a way to fuse together metal parts so there is no potential difference, and usually accomplished with a conductor. The earth has an infinite ability to absorb electrons; so bonded parts are directed to a ground rod at the service entrance. This is called the grounding electrode (GE) which is usually a rod driven into the ground about eight feet. There are also other ways to do this. A GE is driven into the ground where the electric service (think electric meter) enters the home. Grounding is the act of connecting bonded parts to a grounding electrode. Grounding and bonding are important for cable TV (CATV) systems to protect people and equipment from lightning strikes and accidental power line con...

CaTV | What is Signal leakage?

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  Photo Credits | Wikipedia   Cable television systems use radio frequency, or RF, signals to provide television, telephone and broadband Internet services to customers. These RF signals normally do not cause interference when cable systems comply with the rules for limiting interference, but the signals can "leak."  Cable signal leaks occur when the RF signals transmitted within a cable system are not properly contained. Signal leaks can be caused by loose connectors, damaged equipment or cables, or cables that are unterminated (not connected to a device, panel or wall outlet). What is RF leakage? Signal leakage refers to the loss or egress of radio frequency (RF) signals from a cable system when they are not properly contained. This can result from a multitude of causes but is generally the result of shielding defects within the cable network. Cable television systems and licensed broadcasters use many of the same frequencies to transmit programming. Cable s...

CaTV | Technical Operating Parameters

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  Photo Credits | Patrick Campanale Cable television, originally known as Community Antenna Television or CATV, was introduced in the 1940s in areas that could not receive the TV signal without obstruction. The solution was to place an antenna on top of a large utility pole and locally share the signal. CATV, as we now know it, was created when the signal from one master antenna was distributed over a large area using coaxial cable and amplifiers. The key innovations in cable TV are optical feeder links, digital compression techniques, and service integration. The technical operating parameters needs to be followed of a RF signal over the outside plant to ensure the quality of signal at the subscriber terminal. IP based Television (IPTV) standard and Over-The-Top (OTT) service. Analog Cable TV This applies to the performance of a cable television system as measured at the output of the head-end and subscriber terminal with a matching impedance of 75 Ohms at the termination point of...

The Cable Television System

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  Photo Credits | Dina Lynda Starting as a means of receiving broadcast television signals for people at two great distance from a transmitter or blocked by mountains, buildings, and trees, cable TV system has grown to be proliferating television delivery system in cities as well as in remote areas. Cable TV became a true multi-channel medium with basic and premium services from satellites and broadcasting stations. Now, Cable TV is one of the major providers of high speed internet and other value added services in the country because of the broadband facility. To receive cable television at a given location, cable distribution lines must be available on the local utility poles or underground utility lines. Coaxial cable brings the signal to the customer's building through a service drop, an overhead or underground cable. If the subscriber's building does not have a cable service drop, the cable company will install one. The standard cable used in the U.S. is RG-6, which has a...

CaTV | Head-end System

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  Photo Credits | Jim Henderson   In cable television head-end is a facility for receiving television signals which is then process and distributed over a cable television system. The building is typically sturdy and purpose-built to provide security, cooling, and easy access for the electronic equipment used to receive and re-transmit video over the local cable infrastructure. Since the term head-end had evolved, a head-end system (HES) is a facility or equipment that receives, processes, and transmits communication signals. It might be referred to a system that collects and submits meter events and measurement data to an application. The role of a head-end system depends on the context, such as in smart metering or cable television. Smart metering A head-end system can automatically collect meter data, monitor parameters, and schedule data collection. It can also provide secure access to meters for software updates, configuration, and other requests. Cable television A head-...

CaTV | Outside Plant System Design

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In telecommunication, OSP refers to the outside plant. It applies to all of the equipment, cables and infrastructure that are located outside of a building. While the term outside plant can be used when referring to communications networks like telephone or cable, today we’ll dive into OSP fiber networks, the foundation upon which the internet is built. The term "outside plant" (OSP) originated in the late 1800s. As Alexander Graham Bell's invention grew in popularity and the Bell System was formed, the new company needed to organize its operations into manageable areas of responsibility. These areas were defined as "plant departments." "Inside plant" (ISP) encompassed the switchboards that were later replaced by telephone switching machines we now call central offices. OSP referred to the facilities and all related components from the switchboard to the subscriber's telephone set. Let's talk about a quick overview of the general anatomy of a f...

CaTV | The Electromagnetic Interference

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  Photo Credits | Freepik Electromagnetic interference (EMI) is a phenomenon that occurs when the operation of an electronic device is disturbed by an electromagnetic (EM) field and typically occurs when the device is close to an EM field, which disrupts the radio frequency spectrum. EMI is a common issue for electronic components used in various industries, such as military, defense, communication systems, appliances, and aerospace. Electrical noise, also known as electromagnetic interference (EMI), can destroy a clean signal from your measurement instrumentation (such as level sensors and pressure transducers). Protecting your sensors from electrical noise is a top priority. Luckily, this is a fairly simple task in most cases. Also known as radio frequency interference, EMI can adversely impact electronics, causing them to operate poorly, malfunction, or stop working completely. There are three different methods to help reduce or eliminate EMI - filtering, grounding, and shieldin...