1A2 Multiline Phone Control Board - REV-J5a

The revision J5 adds two small improvements to the previous boards: The newer J5a has minor improvements that affect assembly only.
[Update 11/27/2021] Received the REV-J5 boards from the printer, and soldered one up:

Fully assembled REV-J5 board

Raw REV-J5 boards from PCB printer


This revision offers the same features as previous releases:

When combining two boards to provide a total of 4 CO lines / 8 extensions, each extension can be uniquely dialed on the intercom line via Touch-Tone or Rotary. This page shows how to interlink two boards.

Closeup of cable management for interlinked boards

Slots between amphenols (new in REV-J3 and up) allow Velcro cable straps
(optional) to be added to retain connectors for permanent installations.

Eight 1A2 phones Interlinked with two KSU boards for a total of 5 active lines (4 CO and 1 Intercom) with two PowerDSINE Ring Generators.


History of Board Revisions



Board Layout And Schematics

Schematics + Wiring Diagrams