Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: What material is used for telephone wires?
The vast majority of houses in the U.S. are wired with 6-position modular jacks with four conductors (6P4C) wired to the house's junction box with copper wires. Those wires may be connected back to two telephone overhead lines at the local telephone exchange, thus making those jacks RJ14 jacks. More often, only two of the wires are connected to the exchange as one telephone line, and the others are unconnected. In that case, the jacks in the house are RJ11.
Telephone hybrids are used in telephone exchanges to convert the 4-wire appearance to the 2-wire last mile connection to the subscriber's telephone. A different kind of hybrid is used in telephone handsets to convert the four wires of the transmitter (earpiece) and receiver (microphhone) to the 2-wire line connection. This kind of hybrid is more commonly called an induction coil due to its derivation from high-voltage induction coils. It does not produce a high voltage, but like the high-voltage variety, it is a step-up transformer in order to impedance match the low-impedance carbon button transmitter to the higher impedance parts of the system. The simple induction coil later evolved into a form of hybrid as a sidetone reduction measure, or volume of microphone output that was fed back to the earpiece. Without this, the phone user's own voice would be louder in the earpiece than the other party's. Today, the transformer version of the hybrid has been replaced by resistor networks and compact IC versions, which use integrated circuit electronics to do the job of the hybrid coil.
Disadvantages of single wire operation such as crosstalk and hum from nearby AC power wires had already led to the use of twisted pairs and, for long distance telephones, four-wire circuits. Users at the beginning of the 20th century did not place long distance calls from their own telephones but made an appointment to use a special soundproofed long distance telephone booth furnished with the latest technology.
Disadvantages of single wire operation such as crosstalk and hum from nearby AC power wires had already led to the use of twisted pairs and, for long distance telephones, four-wire circuits. Users at the beginning of the 20th century did not place long distance calls from their own telephones but made an appointment to use a special sound proofed long distance telephone booth furnished with the latest technology.
The painter Armando Reverón is one of the first to use this technique when using disposable materials such as bamboo, wires, wires or kraft paper. In the thirties he made a skeleton with wings of mucilage, adopting this style years before other artists. Later, Reverón made instruments and set pieces such as a telephone, a sofa, a sewing machine, a piano and even music books with their scores.
In modern times, most telephones are plugged into telephone jacks. The jacks are connected by inside wiring to a drop wire which connects the building to a cable. Cables usually bring a large number of drop wires from all over a district access network to one wire center or telephone exchange. When a telephone user wants to make a telephone call, equipment at the exchange examines the dialed telephone number and connects that telephone line to another in the same wire center, or to a trunk to a distant exchange. Most of the exchanges in the world are interconnected through a system of larger switching systems, forming the public switched telephone network (PSTN).
Troops involved in technical intelligence operations have used knowledge of foreign material to put enemy equipment to use. For example, Army troops used German military telephone wire and medical supplies to aid civilians in France during World War II.
This list covers only single line telephone plugs commonly used in homes and other small installations; there are 44 different variations of plugs, including an Israeli version of BS6312 with different internal wiring of the pins, plus hard wiring to a junction box with no adapter. Special telephone sets use a variety of special plugs, for example micro ribbon for key telephone systems.
Rogers' system was essentially sending one-way telephone signals over his own wires, but he had to use voltages far higher than that used by standard telephone lines, because he was sending not only audio but also the power needed to operate what would become hundreds of loudspeakers. His initial setup output was 2.5 watts, but as the system expanded this was increased in steps over time to 350-400 watts. This occasionally led to issues when his wires ran too close to standard telephone lines, which sometimes picked up the strong grapevine transmissions. Special steps had to be taken to eliminate interference with the telephone company's service.
If it is not practical to run new cables, it is often still possible to split the telephone line at the point of entry in some cases. If Category 3 cable, Category 4 cable, or Category 5 cable was used to wire the premises and at least one pair of wires in the cable is unused, a "whole house" DSL filter can be installed at the point of entry, usually a Network Interface Device (NID) box. Although an in-line filter could be used for this purpose, special whole-house filters are available to make the installation easier. The wire pair that connects to telephones and fax machines is connected to the telephone company feed through the filter, while the wire pair that connects to the DSL modem is connected directly to the telephone company feed, unfiltered. At the wall jack where the DSL modem is installed, a commercial 2-line splitter adapter is used that puts each line of the cable on its own jack port, connected as Line 1. The telephone, if any, is plugged into the Line 1 jack and the DSL modem is plugged into the Line 2 jack of the adapter, but is fed through the Line 1 contacts in that jack location. Due to the self-shielding nature of twisted wire pairs, this cable sharing technique works well for Category 4 and 5 cables. Since old-style Category 3 cables contain four parallel strands of wire, there is crosstalk and ADSL signal degradation between pairs, so cable sharing should be limited to 20 meters (65 ft), or so. This approach saves considerable money and labor, as the only changes to the premise wiring may occur at the NID and the only additional equipment needed is a 2-line splitter adapter. If the Line 2 wire pair was originally not connected at the wall jack where the DSL modem is to be used, it may be necessary to complete this step as well.
Until 1982 the GPO had a monopoly on the provision of all telephone lines and telephones within the UK, other than in Kingston upon Hull, and so the range was limited. Customers (known within the GPO as "subs", being short for 'subscribers') did not buy their telephones, they were rented from the GPO, together with the house wiring and the wiring connecting the house to the local network at a connection point known as a DP (distribution point). The majority of DPs were (and still are) at the top of what are still known in the UK as telegraph poles.
Field telephones operate over wire lines, sometimes commandeering civilian circuits when available, but often using wires strung in combat conditions. At least as of World War II, wire communications were the preferred method for the U.S. Army, with radio use only when needed, e.g. to communicate with mobile units, or until wires could be set up. Field phones could operate point to point or via a switchboard at a command post. A variety of wire types are used, ranging from light weight "assault wire," e.g. W-130 —— with a talking range about , to heavier cable with multiple pairs. Equipment for laying the wire ranges from reels on backpacks to trucks equipped with plows to bury lines.Torture of POWs
In 1876, Alexander Graham Bell achieved the first successful telephone transmission of clear speech. The first telephones had no network, but were in private use, wired together in pairs. Users who wanted to talk to different people had as many telephones as necessary for the purpose. A user who wished to speak, whistled into the transmitter until the other party heard. Soon, however, a bell was added for signalling, and then a switch-hook, and telephones took advantage of the exchange principle already employed in telegraph networks. Each telephone was wired to a local telephone exchange, and the exchanges were wired together with trunks. Networks were connected together in a hierarchical manner until they spanned cities, countries, continents, and oceans.
1960s two-way radio remote control consoles used direct current loops. Users would run ordinary telephone wiring from the remote consoles to the radio base station chassis. In some cases, the base station was located at the same address as the control console. In other cases, the base station was located at a distant site. For distant sites, a dry pair of telephone wires called a "DC loop", "private line-" or "RTO circuit" (Radio Telephone Operation) was leased from the telephone company. Older burglar alarms used the same type of DC wiring from subscriber location to the alarm office.
Strictly speaking, a textbook installation will only actually use pins 2, 5 (for the voice) and 3 (for the ringer). Having said this, most modern telephones no longer require a ringing capacitor may have and 2-wire connections, which means that extension wiring can usually be run with only pins 2 and 5. Often where multi-core cable is used, the remaining cables are used for wiring extensions on additional incoming telephone lines.
In the 1890s and 1900s the Telegraph authorities were faced with the dilemma of modernising the old telegraph systems, then in use for 40 or more years, to new voice telephone systems. The cost to convert the hundreds of kilometers of overhead 'one wire' systems to 'two wire' for telephone would have been enormous. Extra wire, crossarms, and transposition of wires to reduce crosstalk all added to the conversion cost. Where conversion could be justified by high traffic levels, meaning high income from those busy lines, they were quickly converted to two wire telephone circuits, but in many cases the cost could not be justified. A method was invented whereby a telephone circuit could be established using the one wire and earth return method similar to the telegraph circuit method. The telegraph could be retained as this was still accepted as the basic method for transferring simple data someone similar to SMS text messages versus voice calls today.
Telephone wiring is required between the telephone company's service entrance and locations throughout the home. Often a home will have telephone outlets in the kitchen, study, living room or bedrooms for convenience. Telephone company regulations may limit the total number of telephones that can be in use at one time. The telephone cabling typically uses two pair twisted cable terminated onto a telephone plug. The cabling is typically installed as a daisy chain starting from the point where the telephone company connects to the home or outlets may each be wired back to the entrance.
The Feldtelephone 50 (50 FTf) is a field telephone used in the Swiss Army. It takes its name from the year 1950, in which it was produced for the first time.
The field telephone 50 is packed in a rectangular box-shaped protective casing of green canvas on which a strap is secured from the same material. Inside is the actual phone that is powered by a 1.5-volt battery. A standard handset with earpiece and microphone is used (called Mikrotel). The canvas surrounding the phone has a circular opening for the crank, through the actuation of the ring signal is triggered at the other end. The ring signal is generated by a hand crank. Two wire terminals at the upper end of the apparatus are available for attaching the wire ends of telephone lines.
Telegraph lines in rural areas typically used one wire earth return circuits, this is a system whereby one conductor is installed on insulators mounted on telegraph poles. The circuit return current travels back via the earth to the origin battery. One wire on a pole was very economical to build and one wire circuits expanded rapidly to remote rural communities. Telephone circuits as distinct from telegraph circuits ideally use two wires to provide a noise free line. Once telephone communications became more commonplace in big cities there became more interest in voice telephone lines for long distance communications to smaller centers remote from the cities. Voice messages improved the correctness of the information and could allow more messages to be sent including direct person to person communications. Telegraphs typically operated between two telegraph offices and the messages written on a telegraph note and hand delivered to the recipient.
In its role as the demarcation point (dividing line), the NID separates the telephone company's equipment from the customer's wiring and equipment. The telephone company owns the NID itself, and all wiring up to it. Anything past the NID is the customer's responsibility. To facilitate this, there is typically a test jack inside the NID. Accessing the test jack disconnects the customer premises wiring from the public switched telephone network and allows the customer to plug a "known good" telephone into the jack to isolate trouble. If the telephone works at the test jack, the problem is the customer's wiring, and the customer is responsible for repair. If the telephone does not work, the line is faulty and the telephone company is responsible for repair.
Benton finds a hidden telephone, but before he can reach the police, he is seen and the phone is ripped from the wires. Jones leaves and Benton is locked in with the women in the same room. He touches the telephone wires together to simulate dialing 0, but cannot talk to the operator without a telephone. But, noticing a radio in the room, he uses his knowledge of radio to improvise a way to use it as a phone: the loudspeaker will double as a microphone if they swap the right wires back and forth each time he starts or finishes talking.
Wired communication refers to the transmission of data over a wire-based communication technology. Examples include telephone networks, cable television or internet access, and fiber-optic communication. Also waveguide (electromagnetism), used for high-power applications, is considered as wired line. Local telephone networks often form the basis for wired communications that are used by both residential and business customers in the area. Most of the networks today rely on the use of fiber-optic communication technology as a means of providing clear signaling for both inbound and outbound transmissions. Fiber optics are capable of accommodating far more signals than the older copper wiring used in generations past, while still maintaining the integrity of the signal over longer distances.
What was lacking was an inexpensive and lightweight cordless for each wired telephone end instrument, to serve only a modestly improved range than the existing wired cord. When this became technically possible, direct interconnection to telephone subscriber loop wires was still restricted according to the Communications Act of 1934 (see history of CPE, or Customer Premises Equipment). Rules relaxed long before Judge Green's eventual breakup, with some limited permissions granted as early as 1956 (see Hush-A-Phone).
A telephone hybrid is the component at the ends of a subscriber line of the public switched telephone network (PSTN) that converts between two-wire and four-wire forms of bidirectional audio paths. When used in broadcast facilities to enable the airing of telephone callers, the broadcast-quality telephone hybrid is known as a broadcast telephone hybrid or telephone balance unit.
In most cases, two copper wires (tip and ring) for each telephone line run from a home or other small building to a local telephone exchange. There is a central junction box for the building where the wires that go to telephone jacks throughout the building and wires that go to the exchange meet and can be connected in different configurations depending upon the subscribed telephone service. The wires between the junction box and the exchange are known as the local loop, and the network of wires going to an exchange, the access network.