Telecoms Home
This section lists the PMBX & PABX systems. The data comes from the Post Office Telephones, Service Instruction manuals TPSI (S.S.479A)

Private Automatic Branch Exchange (PABX)
Private Manual Branch Exchange (PMBX)
PABX No 1
House Exchange Systems
Cordless PMBX (Indicator Signalling
PABX No 2
PABX No 3
Cordless PMBX (Lamp Signalling)
Guidance On  PABX 3 Proposals
25 Line Corded PMBX 5+20 (Indicator Signalling)
Comparison Of The Merits Of PABX 3 & 4
65 Line & 80 Line Corded PMBX (Indicator Signalling)
PABX No 4
PABX No 5
Corded PMBX 4 (Lamp Signalling)
PABX No 6
Corded PMBX 1A & 1B (Lamp Signalling)
Private Meters On PBX's
Corded PMBX CB9 (Indicator Signalling)
Corded PMBX BECB 10 (Lamp Signalling)
Police Telephone & Signal Systems (PA150 & PA450)