A.E. Co. Type 100/125 Line, P.A.B.X.


A.E. Co. 100/125 line system

The A.E. Co. have also designed P.A.B.X's of larger capacity for "private purchase" subscribers. A typical one employs individual forward hunting extension uniselectors and 200 outlet Final Selectors. This is known as the 100/125 line P.A.B.X. By employing 200 point banks on the final selectors group selectors are saved.

The vertical marking bank in this case discriminates between the 200's groups dialled as well as performing the operations described in the 30/30 line P.A.B.X section.

In all systems a P.G. or "called sub held" condition is supervised by a slow alarm device, generally consisting of a uniselector stepped by impulses from the ringing machine. After a predetermined period this disconnects the automatic equipment from a faulty or P.G. extension holding it and switches the extension to the manual board, where its calling lamp is made to glow. The manual operator is thus able to deal with the faulty or P.G. extension and plug it out of service until the fault or the P.G. condition is removed.

Taken from a paper by the IPOEE dated 1932 (No. 142)


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Last revised: June 16, 2022