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Uniden Bearcat SR30C Scanner Review: Is It Worth It?

I tested the Uniden Bearcat SR30C scanner for analog frequencies. This honest review covers performance, battery life, and if it is worth the price.

#Analog Communications #Handheld Scanners #Product Testing #Uniden Bearcat SR30C

Futility in action: The search for intelligent life

Don’t get me wrong. I love science fiction. Give me spaceships, planets, alien civilizations, and I’m a happy camper. Tonight, though, I’m watching a documentary about the search for life in the universe, and, well, I don’t see the point. Well, no, I get the point, science for sciences sake. But what I don’t understand is why so many intelligent people would devote their time and resources into…

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Important of Telecommunication Technology.

Telecommunication technology has a long and creative history behind it. In classical and ancient times, this was a very effective means of communication in a smaller, more rural world. Flags, lamps and special towers were uses of optical telecommunication technology. Later development with a more advanced civilization and an industrious society allowed for the creature of telegraphs, radio, television, and eventually the internet.

Telecommunications provides a lot for the world. The commerce that telecommunication technology creates is a nice little chunk of the gross world product. It provides business, money and market stability in the world. Development in telecommunication technology provides helpful research and foundation for other technologies. With the development and enhancements of the radio and understanding how radio waves work, flight has become one of the major benefits of telecommunication technology. Space and sea travel, exploration, and enhanced vehicles have all come from stronger developments in telecommunication technology. The world is an ever growing one, and would not be possible without telecommunication technology. As people moved and countries grew, more and more cities developed across the world. With telecommunication technology, it made it a lot quicker to relay messages from one place to another. This has helped tremendously with such things as war, weather problems, geographic problems, illness and health, and trade.

The impact that telecommunication technology have had on the world is evident. Telecommunication technology promotes a better awareness of society and human life. It helps develop solutions and gather support for causes and problems all over the world, making Earth a little closer and a little safer.

Telecommunication Technology.

Telecommunication Technology is the transmission of information over significant distances to communicate. In earlier times, telecommunication technology involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded drumbeats, lung-blown horns, or sent by loud whistles, for example. In the modern age of electricity and electronics, telecommunication technology now also includes the use of electrical devices such as the telegraph, telephone, and teleprinter, as well as the use of radio and microwave communications, as well as fiber optics and their associated electronics, plus the use of the orbiting satellites and the Internet.

A revolution in wireless telecommunication technology began in the first decade of the 20th century with pioneering developments in wireless radio communications by Nikola Tesla and Guglielmo Marconi. Other highly notable pioneering inventors and developers in the field of electrical and electronic telecommunication technology include Charles Wheatstone and Samuel Morse (telegraph), Alexander Graham Bell (telephone), Edwin Armstrong, and Lee de Forest (radio), as well as John Logie Baird and Philo Farnsworth (television).

The world's effective capacity to exchange information through two-way telecommunication technology networks grew from 281 petabytes of (optimally compressed) information in 1986, to 471 petabytes in 1993, to 2.2 (optimally compressed) exabytes in 2000, and to 65 (optimally compressed) exabytes in 2007.The service revenue of the global telecommunication technology industry was estimated to be $1.7 trillion in 2008, and is expected to touch $2.7 trillion by 2013.

Telecommunication Technology Key concepts.

A number of key concepts reoccur throughout the literature on modern telecommunication technology systems.

Telecommunication Technology - Basic elements.

A transmitter that takes information and converts it to a signal.

A transmission medium, also called the "physical channel" that carries the signal. A receiver that takes the signal from the channel and converts it back into usable information in telecommunication technology.

For example, in a radio broadcasting station the station's large power amplifier is the transmitter; and the broadcasting antenna is the interface between the power amplifier and the "free space channel". The free space channel is the transmission medium; and the receiver's antenna is the interface between the free space channel and the receiver. Telecommunication technology over telephone lines is called point-to-point communication because it is between one transmitter and one receiver. Telecommunication technology through radio broadcasts is called broadcast communication because it is between one powerful transmitter and numerous low-power but sensitive radio receivers.

Telecommunication technology in which multiple transmitters and multiple receivers have been designed to cooperate and to share the same physical channel are called multiplex systems.

Telecommunication Technology - Analog versus digital communications.

Communications signals can be either by analog signals or digital signals. There are analog communication systems and digital communication systems. For an analog signal, the signal is varied continuously with respect to the information in telecommunication technology. During the propagation and reception, the telecommunication technology information contained in analog signals will inevitably be degraded by undesirable physical noise. Commonly, the noise in a communication system can be expressed as adding or subtracting from the desirable signal in a completely random way. This form of noise is called "additive noise", with the understanding that the noise can be negative or positive at different instants of time.

Telecommunication Technology - Telecommunication networks.

A communications network is a collection of transmitters, receivers, and communications channels that send messages to one another. Some digital communications networks contain one or more routers that work together to transmit information to the correct user.

Telecommunication Technology - Communication channels.

The term "channel" has two different meanings. In one meaning, a channel is the physical medium that carries a signal between the transmitter and the receiver. Examples of this include the atmosphere for sound communications, glass optical fibers for some kinds of optical communications, coaxial cables for communications by way of the voltages and electric currents in them, and free space for communications using visible light, infrared waves, ultraviolet light, and radio waves. This last channel is called the "free space channel". For example, one radio station can broadcast radio waves into free space at frequencies in the neighborhood of 94.5 MHz (megahertz) while another radio station can simultaneously broadcast radio waves at frequencies in the neighborhood of 96.1 MHz. Each radio station would transmit radio waves over a frequency bandwidth of about 180 kHz (kilohertz), centered at frequencies such as the above, which are called the "carrier frequencies". In the example above, the "free space channel" has been divided into communications channels according to frequencies, and each channel is assigned a separate frequency bandwidth in which to broadcast radio waves. This system of dividing the medium into channels according to frequency is called "frequency-division multiplexing" (FDM).

Some radio communication systems use TDM within an allocated FDM channel.

Telecommunication Technology - Modulation.

The shaping of a signal to convey information is known as modulation. The "Bluetooth" system, for example, uses phase-shift keying to exchange information between various devices. In addition, there are combinations of phase-shift keying and amplitude-shift keying which is called (in the jargon of the field) "quadrature amplitude modulation" (QAM) that are used in high-capacity digital radio communication systems.

Modulation can also be used to transmit the information of low-frequency analog signals at higher frequencies. This is helpful because low-frequency analog signals cannot be effectively transmitted over free space. Hence the telecommunication technology information from a low-frequency analog signal must be impressed into a higher-frequency signal (known as the "carrier wave") before transmission.

Modern Telecommunication Technology.

Telecommunication Technology - Telephone.

Optical fiber provides cheaper bandwidth for long distance communication.

In an analog telephone network, the caller is connected to the person he wants to talk to by switches at various telephone exchanges. Although short-distance calls may be handled from end-to-end as analog signals, increasingly telephone service providers are transparently converting the signals to digital for transmission before converting them back to analog for reception. Mobile phones have had a significant impact on telephone networks. Assisting communication across many modern optic fibre networks is a protocol known as Asynchronous Transfer Mode (ATM). The ATM protocol allows for the side-by-side data transmission mentioned in the second paragraph. It is suitable for public telephone networks because it establishes a pathway for data through the network and associates a traffic contract with that pathway.

Telecommunication Technology - Radio and television.

Digital television standards and their adoption worldwide.

In a broadcast system, the central high-powered broadcast tower transmits a high-frequency electromagnetic wave to numerous low-powered receivers. The broadcast signal can be either analog (signal is varied continuously with respect to the information) or digital (information is encoded as a set of discrete values).

ATSC uses Dolby Digital AC-3 for audio compression, ISDB uses Advanced Audio Coding (MPEG-2 Part 7) and DVB has no standard for audio compression but typically uses MPEG-1 Part 3 Layer 2. In digital audio broadcasting, standards are much more unified with practically all countries choosing to adopt the Digital Audio Broadcasting standard (also known as the Eureka 147 standard). For analog radio, the switch to digital radio is made more difficult by the fact that analog receivers are sold at a small fraction of the price of digital receivers.

Telecommunication Technology - Internet.

The Internet is a worldwide network of computers and computer networks that can communicate with each other using the Internet Protocol. The Internet is thus an exchange of messages between computers.

The nature of computer network communication lends itself to a layered approach where individual protocols in the protocol stack run more-or-less independently of other protocols. This allows lower-level protocols to be customized for the network situation while not changing the way higher-level protocols operate. For the Internet, the physical medium and data link protocol can vary several times as packets traverse the globe. This is because the Internet places no constraints on what physical medium or data link protocol is used. At the network layer, things become standardized with the Internet Protocol (IP) being adopted for logical addressing. At the transport layer, most communication adopts either the Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP). Because certain application-level protocols use certain ports, network administrators can manipulate traffic to suit particular requirements. Finally, at the application layer, are many of the protocols Internet users would be familiar with such as HTTP (web browsing), POP3 (e-mail), FTP (file transfer), IRC (Internet chat), BitTorrent (file sharing) and OSCAR (instant messaging).

Voice over Internet Protocol (VoIP) allows data packets to be used for synchronous voice communications. That prioritization is fine when the network has sufficient capacity for all the VoIP calls taking place at the same time and the network is enabled for telecommunication technology prioritization i.e. a private corporate style network, but the Internet is not generally managed in this way and so there can be a big difference in the quality of VoIP calls over a private network and over the public Internet.