PRESS BUTTON UNIT No. 56
This a press button unit that consists of a 12 button keypad marked 1 to 0, * and #.

The keypad is MF (DTMF) only.

Used on Telephone No's 782, 783 & 784.

Model Mark Grey Ivory Introduced PBU No Remarks
Tele 782 & 8782 Mk 1 y y 9/77 7E or F GEC
  Mk 2 y y 6/78 54A STC
  Mk 3 y y 9/80 56A/4 PLESSEY
  Mk 4 y y 2/79 11A PYE/TMC
  Mk 5 y y 9/81 56A/2 GEC
  Mk 6 y y 2/81 56A/3 TMC
  Mk 7 y y 9/81 56A/1 STC
  Mk 8 y y 3/82 56A/5 BTF
  Mk 9 y y   56B/4 PLESSEY
  Mk 10 y y 8/82 56B/3 TMC
  Mk 11 y y 3/82 56B/2 GEC

 

PBU No. 56A/4 - Front

 

PBU No. 56A/4 - Rear

 
 
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Last revised: September 27, 2024

FM