PRESS BUTTON UNIT No. 3
This a press button unit that consists of a 12 button keypad marked 1 to 0, # and *.

This unit is designed for use with the DC Code "C" PABX signalling system.  The push buttons are arranged in 3 columns each containing 4 buttons. The 11th and 12th buttons are marked * and # respectively.  The 12th button is used for enquiry and transfer.

The keypad will work with DC Code C signalling systems only.

Variants:-
PBU No. 3A used in Telephones SA4252, 1/SA4252 and 2/SA4252.
PBU No. 3B used in Telephones 3/SA4252.
PBU No. 3C used in Loudspeaking Telephone SA4255.
PBU No. 3D used in Press Button Units 1/SA4259 and 2/SA4259.

Drawing - 93090.

Diagram - SA/SAW 4266 (Mark 2).

Specification - S1121.

 

 
 
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Last revised: April 06, 2025

FM