GEC-AEI TELECOMMUNICATIONS LIMITED
A Management Company of The General Electric Company
Limited of England
10+98/16+97 Line Private Automatic Branch Exchange
10 public exchange lines and 98 extension lines; can be
extended to 16 public exchange lines in which case the number of extension lines
is reduced to 97.
Provision for 10 simultaneous inter-extension calls in
addition to a maximum of 10 or 16 public exchange calls.
Within the range 200 to 299 for extensions; 7 for
tie-line access; 8 for night service; 9 for public exchange access; 0 for
operator switchboard access.
Public exchange service
Outgoing: direct access from extensions, or through
operator's switchboard. Individual
extensions can be prevented from dialling public-exchange calls.
Incoming: through operator's switchboard.
Enquiry and transfer
Telephones with a pushbutton can be supplied to all or
selected extensions to enable a public exchange call to be held while the user
calls another extension with an enquiry. When
the enquiry is complete, the original extension returns to the public-exchange
call, or can transfer it to another extension or to the operator.
Incoming public-exchange calls can be answered from any
extension by dialling '8'; alternatively, the feature can be restricted to one
extension only*. Calls can then be
transferred to other extensions by the enquiry and transfer method.
The operator can offer a public-exchange call to an
extension already engaged.
A maximum of 10 selected executives can break into an
existing conversation by dialling an extra digit '1'.
Up to 4 on one route only.
Designated extensions can be connected together via a
Various procedures are available to suit individual
requirements and local fire regulations.
Staff absent from their offices may be called by
dialling a special locating number and a personal code, to operate lamps or
A secretarial switching telephone enables secretaries
to filter calls to an executive.
Individual extensions may be permitted to dial local
but not long-distance calls.
Public exchange lines can be automatically connected to
designated extensions in the event of an AC mains supply failure.
Mode of operation
Fully automatic operation using 2-motion selectors,
uniselectors and relays. All
conversations secret from each other.
Tones and ringing
All-electronic tone generator provides dial tone, ring
tone and current, busy tone, number-unobtainable tone and operator/executive
Required dial-pulse characteristics: 7 to 14 i.p.s.,
2:1 break to make ratio.
Lamp indication at switchboard.
Urgent: release alarm, ring fail and blown fuse.
Deferred: failure to replace receiver (PG condition).
AC power unit: input, 100 to 120V or 200 to 250V 50 to
60Hz single phase; 50V d.c., output 10A for 10+98 line, 15A for 16+97 line.
Battery: 50V 48 AH; with float charger, input as for AC
power unit, 50V d.c., output 5A for 10+98 line, 10A for 16+97 line.
Not to exceed 900 ohms.
Switching equipment: Plug-in and wired-in units on a
steel framework. Optional
rack-enclosing cabinets (painted grey) with lift-off dust-proof panels front and
rear can be provided.
Switchboard: dual grey desk-mounting console.
Dimensions and weight
|10+98 line switching equipment
|16+97 line switching equipment
|AC mains units
||SU3204 & SU3205
|| 38cm (15in)
||SU4203 & SU4204
Taken from a GEC-AEI brochure SLX11B - dated 1968