Miller, Kempster Blanchard, 1870-1933 · New York : McGraw publishing company · leaf 645
(J22 DISTRIBUTING FRAMES. 623 In modern exchanges of sufficient size to employ multiple switch-boards an intermediate distributing frame should be provided, andthe circuits leading from the switch-board side of the main frameshould lead through this before passing to the switch-board proper. The…
Telephone
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
