Handset
The Monarch PABX console has two handset sockets, one on the right and one on the left. Handsets use the GPO Plug No. 420
The Monarch PABX console has two handset sockets, one on the right and one on the left. Handsets use the GPO Plug No. 420
Each Plug has the following markings
420 - the GPO type of plug
FOA or AAD - manufactures code AAD = Astralux , FOA = ??????
YY - the year of manufacture
/1 - not sure
"PLUGS, SOCKETS, JACKS -in all sizes and for every purpose - are made by the Special Products Division of Astralux Dynamics Ltd. " Post Office Electrical Engineers' Journal Vol 58 Pt 2 July 1965