A.E. Co. Type 20/50
P.A.B.X.

This system has been recently developed. A single unit that has a capacity of 20 lines and four connecting circuits and contains one ringing and one distributor circuit. It can, however, accommodate as an alternative, 30 lines and four connecting circuits; thus 50 lines and eight connecting circuits are provided by two units bolted together.

Both units are interchangeable. Two-party line service may be provided on certain levels. 31 would be the X line and 41 the Y line. If tie line service is not required, levels 31-30 or 41-40 are left spare. The operator's cordless board provides the facilities indicated earlier for this type of manual board.