Explains the use of carrier telephoning to increase the number of telephone channels on a single wire without the extra cost of wires etc. Using diagrams it shows how four voices can use the same wires without interference to each user.
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How to watch
Collection
In ACMI's collection
Credits
Collection metadata
ACMI Identifier
312745
Language
English
Subject categories
Communications, Infrastructure, & Transport → Telecommunication systems - History
Communications, Infrastructure, & Transport → Telephone - History
Communications, Infrastructure, & Transport → Telephone cables
Documentary → Documentary films - United States
Education, Instruction, Teaching & Schools → Armed forces - training
Sound/audio
Sound
Colour
Black and White
Holdings
16mm film; Access Print (Section 1)