PMBX No. 1

The BPO P.M.B.X. No. 1 and No. 1A is a lamp calling manual switchboard with lamp supervisories.  The switchboards are bolted together to form a suite.

The number of switchboards was dependant on traffic and extensions.  In addition to the switchboards a power supply, batteries, equipment rack and distribution frame were also supplied.

Introduced in 1940.

See the Ericsson section for a description.

In the picture above - the equipment racks are show centrally behind the switchboard and the distribution frame to the far right.

PMBX 1A suite - unusual in so much as it bends around the room.  Note the filler sections between switchboard positions.


Equipment PMBX No. 1/35a



BACK Home page BT/GPO Telephones Search the Site Glossary of Telecom Terminology Quick Find All Telephone Systems

Last revised: March 27, 2019