Electrical instruments and telephones of the U.S. Signal corps (1911) (14753388291)

Identifier: electricalinstru00unitrich (find matches)

Title: Electrical instruments and telephones of the U.S. Signal corps

Year: 1911 (1910s)

Authors: United States. Army. Signal Corps

Subjects: Military telegraph -- United States Military telephone -- United States

Publisher: Washington, Govt. print. off.

Contributing Library: University of California Libraries

Digitizing Sponsor: MSN

Text Appearing Before Image:

.The receiver circuit is bridged across the springs I and /, and thebattery circuit across the s()rings m and n. When the lever or thelistening key is in the normal position all the contacts are open. Thewiring of the board is on same principle that is used in figure 10-t.explained in following paragra))h. J901 model.—The 1901 model is shown in figure lOli. and is of thesame eeneral construction as the one above described, the difference ELECTRICAL INSTRUMENTS U. S. SIGNAL CORPS, 165 coiisistinii in the rows of ringing and cross-connectig keys. Thereare four rows of keys, the upper row being the ringing keys and theother three rows cross-connecting keys. The method of operation ofthe board is siniihir to that of the 1902 niodeL the only ditference QP QP QP ao

Text Appearing After Image:

Fii;. 104—riiciiits (,f coi-flloss switohhoard. model 1001. being in the fact that the first row of keys in tlie 1002 model corre-sponds to the two upper rows in the 1901 model and the second rowin the 1902 model to the third and fourth rows in the 1901 model.The circuits are indicated in figure 101. 166 ELECTRICAL INSTRUMENTS U. S. SIGNAL CORPS. INSTALLATION OI TELEPHONE SWITCHBOARDS. Care should l)e taken in unpacking switchboard ajiparatus so thatthe aj^paratus will not be injured. Different manufacturers usevarious methods of packiii: material so it will not be injured intransit. Different braces will be found in the i)acking of the appa-ratus, which must be removed as the material is taken out. If theapparatus is found to be in an injured condition, note should be takeninnnediately of this fact and witnesses called in for verification, anda report made inmiediately so that proper action may be taken. The cord weights are usually tied up and fastened. Relays whichhave metal cove

electrical instruments and telephones of the u s signal corps 1911 book illustrations government printing office military united states army high resolution images from internet archive

1911

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