File:Bell telephone magazine (1922) (14569623718).jpg

Identifier: belltelephonemag12amerrich (find matches)
Title: Bell telephone magazine
Year: 1922 (1920s)
Authors: American Telephone and Telegraph Company American Telephone and Telegraph Company. Information Dept
Subjects: Telephone
Publisher: (New York, American Telephone and Telegraph Co., etc.)
Contributing Library: Prelinger Library
Digitizing Sponsor: Internet Archive

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high grade of service. The transmitter is accordingly speciallydesigned to minimize erratic transmission, carbon noise andcarbon aging. The receiver contains an electromagnet, sup-plied with magnetizing current by the same battery that sup-plies current to the transmitter and the amplifier. After thereceiver has been assembled, the pole piece of this magnet isadjusted to such a position, relative to the receiver diaphragm,that the receiver as a whole will have maximum efficiency andis then sealed in place. The amplifier is the most unique element in the audiphone.As has already been pointed out, it consists of two parts, simi-lar respectively to the receiver and the transmitter. The elec-trical output from the audiphone transmitter passes throughthe winding of the receiver part. This varies the magneticfield in the air gap of the magnetic circuit, whose metallic por-tions are of permalloy, and so causes a permalloy diaphragmto move correspondingly. The permalloy diaphragm drives 254 I
Text Appearing After Image:
Figure 1. Tr-axsmitter (left), Ampllfier, and Rxceiver (right) for the New audiphone.

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