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A telephone magneto is a hand-cranked electrical generator that uses permanent magnets to produce alternating current from a rotating armature. In early telegraphy , magnetos were used to power instruments, while in telephony they were used to generate electrical current to drive electromechanical ringers in telephone sets and activate signals ...
The Tucker Telephone is a torture device designed using parts from a crank telephone.The electric generator of the telephone is wired in sequence to two dry cell batteries so that the instrument can be used to administer electric shocks to another person.
The field telephone 50 is used by all communication troops of the Swiss Army for both point-to-point connections and landlines. For the first variant, two field telephones are connected with telephone wire. In the second version the phone is connected to lines specially reserved for the army. Such a linked phone is accessible from any telephone.
In phones connected to common battery exchanges, the ringer box was installed under a desk, or other out of the way place, since it did not need a battery or magneto. Cradle designs were also used at this time, with a handle with the receiver and transmitter attached, separate from the cradle base that housed the magneto crank and other parts.
Kellogg company logo as used from the 1920s to the 1950s. The Kellogg Switchboard and Supply Company was an American manufacturer of telecommunication equipment. Anticipating the expiration of the earliest, fundamental Bell System patents, Milo G. Kellogg, an electrical engineer, founded the company in 1897 in Chicago to produce telephone exchange equipment and telephone apparatus.
A typical Western Electric hand telephone set of c. 1930. It consists of a handset mounting with the handset held in a cradle, and a subscriber set mounted against a wall or vertical surface in close proximity. Shown is a B1A hand telephone set, also known as the type 102B-3 hand telephone set.
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The TA-57 can be used for induction calls working with 2-wire lines in an OB (local battery) or a ZB (central battery) operation. It can be used to transmit voice messaging in ranges between 0.3 and 3.4 kHz, with a calling frequency of 15 to 45 Hz.