Sara Paxton Emergency Alert System

Duplex Phone

Cordless Phones – Freedom While Talking

A Cordless Phone is commonly a telephone with a wireless handset that can communicate through radio waves with a base station. The base station is connected to a telephone line that is fixed within a limited range of its base station. The base is generally placed on the subscriber premises, and it gets attached to the telephone network the same way a corded telephone does. It is the base station on the subscriber premises that differentiates a cordless telephone from a mobile phone. In the latest model cordless models, the base stations are maintained by a commercial mobile network operator and the users subscribe to the service. Unlike a telephone with cords, a cordless telephone requires the mains electricity to power the base station. The cordless phone is powered by a battery that could be recharged when the handset is placed on the cradle.

It was George Sweigert, an amateur radio operator and inventor from Ohio, who is considered as the father of the cordless phone. He submitted a patent application in 1966 for a "full duplex wireless communications apparatus". The US Patent and Trademark Office awarded him a patent in June of 1969. Sweigert, who was working as a radio operator in World War II, stationed at the South Pacific Islands, developed the full duplex-concept for untrained personnel that would improve battlefield communications for senior commanders. George was also licensed as W8ZIS and N9LC in the amateur radio service. He also held a First Class Radiotelephone Operator's Permit issued by the Federal Communications Commission.

It was in 1980’s that a series of manufacturers including Sony entered in the cordless phone market. Generally the cordless phones used a base station that was connected to a telephone line and a handset with a microphone, speaker, keypad, and telescoping antenna. The handset contained a rechargeable battery, typically NiCd, the base unit was powered by household current, typically through a wall wart. The base included a charging cradle, was generally a form of trickle charger, on which the handset rested when not in use.

About the Author

Raina Kelsey is an expert author, and writes about latest gadgets.
Cheap Cordless Phones
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2-Way Duplex Jack - phone splitter $1.99 Belkin 2-Way Duplex Jack - Phone splitter - RJ-11 (M) - RJ-11 (F) - ivory

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GE/RCA 1 to 2 Line Adapter White (TL) Duplex Adapter $4.99 "1 to 2 Line Adapter White, The GE TL26191 is a duplex adapter that easily converts a single phone jack into a dual jack."

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ITT Full Duplex Conference Telephone. Each $191.54 Manufacturer: ITT. Each. Cortelco Full duplex conference phone LCD with caller ID Hi-fidelity audio amplifier Redial Hold Mute Flash DSP Line echo cancellation >-20dB DSP Acoustic echo cancellation >-50dB Bi-directional noise suppression purifies voice si

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360 Electrical Rotating Duplex Outlet $9.99 The rotating design of this easy-to-install outlet lets you plug in a bulky mobile phone or camera charger in tight spaces.

Jasco Products White Duplex In Line Phone Adapter 76570 $21.57 Adapter. Permits a single line cord to be extended. Creates two jacks for connecting additional devices. 2 connectors. White. Length: 0.9. Width: 4.5. Height: 3.5

AT&T 984 corded phone $177.99 Expandable Base Supported: 16X Conference Call Capability: 3-way Intercom: Yes Caller ID: Yes Call Waiting: Yes Call Transfer: Yes Speakerphone: Digital Duplex Volume Control: Yes

Southwestern Bell duplex jack Pack of 36 $47.3 Turn one outlet into two with this duplex jack convertor. Simply plug two phone lines into the jack and plug the jack into a singlejack outlet instantly converting one jack into two. Works with any singular modular jack. Can work with up to three separate lines. Jack measures 1 x 1 1/2 . Dimensions:. Length: 8. Height: 8. Width: 8

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