Terrestrial television is a term which refers to modes of television broadcasting which do not involve satellite transmission or via underground cables. Terrestrial television broadcasting dates back to the very beginnings of television as a medium itself and there was virtually no other method of television delivery until the s with the beginnings of cable television, or community antenna television CATV. The first non-terrestrial method of delivering television signals that in no way depended on a signal originating from a traditional terrestrial source began with the use of communications satellites during the s and s of the twentieth century. The analogue television picture is "drawn" several times on the screen 25 in PAL system as a whole each time, as in a motion picture film, regardless of the content of the image.
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- Golden Age of Radio in the US
- China CN: Radio & Television Receiving Equipment & Device: YoY: Financial Expense: ytd
- Basics of Designing a Digital Radio Receiver (Radio 101)
- Radio technology
- What Is the Difference Between AM and FM Radio?
- radio: Transmission and Reception of Radio Waves
- Visual radio production for sport events
- Classifying audio and video equipment for import and export
Golden Age of Radio in the USVIDEO ON THE TOPIC: Electromagnetic Spectrum: Radio Waves
At the heart of any studio is the audio console sometimes called a radio panel, sound panel, or sound desk. The fader slider attenuates or amplifies the incoming signal. A microphone captures sounds from the studio and turn it into electrical impulses. Studio microphones are often mounted on a special arm that keeps the microphone at the correct height. The computer system that plays back music, spots ads, promos, etc. These are specially designed computer programs that allow for continuous playback of audio, with a lot of granular control for Announcers and Programme Directors.
All music played on a commercial radio station will be pre-programmed by the Music Director and loaded into the log. A separate person will often load all advertisements into the same log.
Most automation systems also contain a music database, hot keys to play ad-hoc audio , an audio editor, segue editor to change the mix between different elements , interfaces for website and RDS data, and a lot more.
To ensure output of a station is somewhat consistent, radio studios contain different Level Meters. These allow the announcer or panel operator to see if their audio is too loud or too quiet at any given time. Some radio stations also provide phase meters along side level meters.
Often, these are very high quality speakers so any abnormalities in sound quality can be detected. Studio Monitor Speakers are automatically muted whenever a microphone is turned on.
As a result, anyone in a studio needs headphones to hear what is going to air. Headphone selection is often a very personal decision based on your preferences in comfort and frequency response. These panels are generally mounted in front of each guest microphone, usually recessed into the table.
Most panels include a headphone jack, and some also contain an XLR connector for the microphone. How do you know a mic in the studio is live? Sometimes you need to control settings not available from the audio console itself. This is why many consoles can have at least one row of configurable buttons. These can be physically wired to other equipment in analog audio consoles , or configured via software in digital audio consoles.
These buttons will often control studio delegation which studio goes to air , phone systems, automation systems, or even remote triggering for networked radio stations.
This is a software program or physical controller that shows you every call coming in on each line, and allows you to send this caller to a specific studio or audio channel. How do you communicate easily between studios? An intercom system. Some radio stations use a dedicated microphone audio processor for each microphone. This keeps the levels consistent, and helps tailor the sound. This is where most equipment lives. The most common piece of equipment in any radio station is by far the computer.
These come in many shapes and sizes, and can perform a whole range of broadcast functions. They have become popular, in part, because they are commoditised and thus much cheaper than broadcast-specific boxes.
Computers in a rack room will often be in rack-mounted server form factor, even for studios workstations. This is typically achieved by a pair of proprietary boxes communicating over a dedicated un-switched Cat6 cable. These days, a Mix Engine usually has two plugs: network and power. As the digital controls protocols are proprietary, you almost always need to purchase your Mix Engine from the same company that makes your Audio Console.
Older facilities are likely to have an Audio Router different from a Network Router. This expensive box receives all audio inputs from your entire facility, and switches them to the correct outputs. The advantage of having a router at the heart of your facility is that you can send any audio source, to any destination, at any time. Some routers are card-based, and allow you to mix and match formats Analog, AES, etc. Most nodes have a number of inputs and outputs, with a web-based configuration interface allowing you to configure the routing.
A huge advantage of StudioHub is that you can run analog audio over regular network cable, using ordinary network patch bays. Older facilities use a lot of Multipair Audio Cable, from cable giants such as Belden. This will be terminated to punch-down blocks in every room and rack.
Krone is a popular punch-down brand in Australia. Most facilities will still have them somewhere. All audio and control signalling can be punched down to a Krone block and then interconnected with special patch wire loosely wound pairs of copper cable. For IDC to work, you generally need solid core cable rather than stranded cable. If you have a digital audio network, check with your equipment vendor to ensure your switch will be compatible.
Any time you need to route IP packets across subnets, you need a router. If you have a IP Audio network, you may wish to use a multicast-enabled router, although most vendors recommend against multicast routing for IP Audio as it adds a lot of complexity to the setup. Most stations want to be the loudest, and the big Audio Processor manufacturers all claim to be the loudest and clearest. If you have a lot of money to spend and want a dedicated box, look at Orban and Omnia. It encodes a Stations use RDS to encode the station name, song data, program guide and traffic information.
If you want to take phone calls on-air, you need a Phone Hybrid. In simple terms, a Hybrid is an interface to connect two-wire phone lines into input and output XLRs. Many hybrids also contain echo cancellation and an automatic equaliser. A Modulation Monitor or FM Analyser is a special radio receiver designed for engineers to monitor specific transmission characteristics.
This includes modulation power, pilot tone, phase, frequency deviation, signal strength, RDS, and more. To ensure accurate time-keeping, you may wish to use a GPS-locked clock system. The master unit connects to a GPS antenna on your roof, and then distributes time code to all compatible clocks in the facility.
Some stations now opt for NTP-enabled clocks. A nifty solution for the budget conscious! This is compatible with standard server racks. With servers, air flows front to back using special vents and plastic air guides within the equipment.
Thus, server racks with in-built cooling may not be suitable. The whole piece of equipment needs to be cooled, rather than forcing air in through the front. Speciality Audio Codecs allow you to transport audio between locations. They are often bi-directional, low-latency, and incorporate lossy encoding algorithms. These devices take your analog or AES audio and wrap it up in the correct transport protocol ready to be pulled into the multiplexer.
If you have a predominantly analog facility, perhaps without a central router, you may need a audio patch bay to interconnect and re-route audio. Many silence detectors have a built-in audio player than can play off mediums such as Compact Flash Cards. Delegation Switchers provide a way to switch between studios and other audio sources, selecting what goes to air. Otherwise, you can use an external switcher. Some delay units will then fill this time with a pre-recorded ID, but high-end units will stretch the incoming audio so there is no break in program.
The Profanity Delay can be located in a studio controlled directly , or in a rack room controlled via remote control. If you have multiple studios, it makes sense to locate it in the central rack room. Analog links perhaps in the Mhz or Mhz bands are popular. These RF links need line-of-sight antennas and licensed frequencies in order to operate.
Typically a station would have multiple links in different formats to ensure there is never a break in transmission. Often the Stereo Generation will be done in the Audio Processor, and sometimes in smaller FM transmitters it can also be done directly in the transmitter. A Composite Switcher allows you to switch between multiple Stereo generators.
FM Exciters generally output a few Watts of power, and can be used without a separate Power Amp on low power stations. This means more power without buying a bigger transmitter sort of.
To prevent damage to your equipment, antenna switchers have interlocks with the input transmitters. Generally the power output is muted while the switch takes place.
Regulations have been relaxed over the years. A Transmitter Remote Control can be used to monitor all transmission systems and provide alarms if readings are outside their acceptable tolerance. This ensures impurities are kept out of the cable. The pressurisation can be done with an air compressor, or a bottle of nitrogen. Coaxial cable manufacturers such as Andrew Helix have specific recommendations based on the type of cable, power output and environmental factors.
An offline UPS simply switches to battery power when there is an outage. A UPS can only last so long. To run for extended periods of time during an outage, you need a generator with a decent fuel supply. Typically a generator for a broadcast facility is permanently connected with an automatic transfer switch — this allows it to start up automatically when mains power is lost.
The generator should be connected to the input of the UPS in the event of a mains failure. This keeps power filtered, and the batteries charged. This will allow allow you to shut down the generator while you refuel in the event of an extended outage.
Coinchon, M. Most modern radio receiving devices but also cars, smartphones include a colour screen and integrate digital, hybrid or web radio. With these features, pictures can be transmitted alongside the audio. The content provided consists of an international signal with live sport results, photos from the events and quotes that broadcasters can use on their radio or web platforms. In this paper, we describe briefly how the project for sports was set in place, the workflow and how it has been distributed and used.
China CN: Radio & Television Receiving Equipment & Device: YoY: Financial Expense: ytd
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Basics of Designing a Digital Radio Receiver (Radio 101)
Italian inventor and engineer Guglielmo Marconi developed, demonstrated and marketed the first successful long-distance wireless telegraph and in broadcast the first transatlantic radio signal. In he shared the Nobel Prize in Physics for his radio work. Guglielmo Marconi was born in in Bologna, Italy. After failing to interest the Italian government in his work, Marconi decided to try his luck in London. The year-old Marconi and his mother arrived in England in and quickly found interested backers, including the British Post Office. Within a year Marconi was broadcasting up to 12 miles and had applied for his first patents.SEE VIDEO BY TOPIC: How to make FM Radio receiver at home
Last updated: April 21, I magine holding out your hand and catching words, pictures, and information passing by. That's more or less what an antenna sometimes called an aerial does: it's the metal rod or dish that catches radio waves and turns them into electrical signals feeding into something like a radio or television or a telephone system. Antennas like this are sometimes called receivers. A transmitter is a different kind of antenna that does the opposite job to a receiver: it turns electrical signals into radio waves so they can travel sometimes thousands of kilometers around the Earth or even into space and back. Antennas and transmitters are the key to virtually all forms of modern telecommunication. Let's take a closer look at what they are and how they work! Photo: The enormous 70m ft Canberra deep dish satellite antenna in Australia.
For the propagation and interception of radio waves, a transmitter and receiver are employed. A radio wave acts as a carrier of information-bearing signals; the information may be encoded directly on the wave by periodically interrupting its transmission as in dot-and-dash telegraphy or impressed on it by a process called modulation. The actual information in a modulated signal is contained in its sidebands , or frequencies added to the carrier wave, rather than in the carrier wave itself.
Radio is the technology of signaling and communicating using radio waves. They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by a radio receiver connected to another antenna. Radio is very widely used in modern technology, in radio communication, radar , radio navigation , remote control , remote sensing and other applications. In radio communication , used in radio and television broadcasting , cell phones , two-way radios , wireless networking and satellite communication among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal impressing an information signal on the radio wave by varying some aspect of the wave in the transmitter. In radar , used to locate and track objects like aircraft, ships, spacecraft and missiles, a beam of radio waves emitted by a radar transmitter reflects off the target object, and the reflected waves reveal the object's location. In radio navigation systems such as GPS and VOR , a mobile receiver receives radio signals from navigational radio beacons whose position is known, and by precisely measuring the arrival time of the radio waves the receiver can calculate its position on Earth. In wireless radio remote control devices like drones , garage door openers , and keyless entry systems , radio signals transmitted from a controller device control the actions of a remote device. Applications of radio waves which do not involve transmitting the waves significant distances, such as RF heating used in industrial processes and microwave ovens , and medical uses such as diathermy and MRI machines , are not usually called radio.
What Is the Difference Between AM and FM Radio?
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radio: Transmission and Reception of Radio Waves
At its most basic level, radio Communication through the use of radio waves. This includes radio used for person-to-person communication as well as radio used for mass communication. Both of these functions are still practiced today. Although most people associate the term radio with radio stations that broadcast to the general public, radio wave technology is used in everything from television to cell phones, making it a primary conduit for person-to-person communication. Guglielmo Marconi is often credited as the inventor of radio. As a young man living in Italy, Marconi read a biography of Hienrich Hertz, who had written and experimented with early forms of wireless transmission.
Visual radio production for sport events
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Classifying audio and video equipment for import and export
At the heart of any studio is the audio console sometimes called a radio panel, sound panel, or sound desk. The fader slider attenuates or amplifies the incoming signal. A microphone captures sounds from the studio and turn it into electrical impulses. Studio microphones are often mounted on a special arm that keeps the microphone at the correct height.
This paper introduces the basics of designing a digital radio receiver. With many new advances in data converter and radio technology, complex receiver design has been greatly simplified. This paper attempts to explain how to calculate sensitivity and selectivity of such a receiver.