The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 317
s desk.The heat coils are first withdrawn from the arrester springs, andthe test-shoe is slipped over so as to make contact with allfour springs of the arrester. This is rather a slow method of testing, but as only a smallproportion (about 5 per cent.) of the faults need to be tested 288 PRACTICAL… … Fig. 292.—Testing Shoe to the main frame, but need not be quite so large, as it is onlynecessary to provide for the lines actually to be fitted on theswitch-board. It should, however, be built for the full capacityat first, as it is difficult to enlarge after installation. The ter-minal tabs on the…
Telephone
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