GEC PABX 3

GEC 'Series 3' provides an efficient and flexible telephone service to meet the communication needs of any organisation - wherever people, or computers, need to talk to each other.

GEC 'Series 3' can be installed as a PABX, PAX or PMBX-automatic operation to meet the needs of modern business, or manual operation to provide the personal service of a luxury hotel, or a combination of both.

GEC 'Series 3' is built up from a series of standardised equipment racks, low-line operator's switchboards, and high performance GEC telephones. By suitable combination, almost any form of telephone system can be evolved.

GEC 'Series 3' is both extensible and convertible.  A small system can be installed initially and equipment added to match communication growth.

GEC 'Series 3' can be converted at any time to meet changing requirements without having to replace existing equipment and with out recourse to custom-built inflexible units.  The accompanying diagram illustrates this.

GEC 'Series 3' is suitable for systems ranging from 100 extensions upwards.  There is no upper limit except in PMBX form which has a practical limit of 800.  For systems requiring less than 100 extensions which are not expected to reach this level in, say, 5 years one of the smaller GEC cabinet type PAX or PABX systems may be more suitable.

Low-line switchboard
The switchboard is attractively styled in teak with green and black working surfaces.  Its low height - only 1065 mm (3 ft 6 in) - is ideal for areas where the operator is also the receptionist.  Typically, four switchboards would need a floor area of about 3 m x 4 m (10 ft x 13 ft).

Each switchboard section has space for 200 extension lines: as the system expands, sections are added but if the system will never exceed 300 lines, these can be accommodated on a single switchboard.  The operator answers and extends a call by a 'cord circuit' and can handle up to 15 calls at a time.  A pushbutton keysender is fitted.

In systems of up to 800 lines, each extension is identified on the switchboard with individual 'line lamps'; on larger systems, calling extensions are signalled on grouped calling lamps.  The practical maximum for a PMBX system is 800 lines.

Free-line signalling is employed in the exchange-line and interswitchboard line circuits thus saving valuable time in obtaining a free line.

An adaptation of the standard switchboard, approved by the Royal National Institute for the Blind, is available for blind operators.  Both blind and sighted operators can staff these switchboards.

Switching equipment
Switching equipment is mounted on steel frames 2286 mm (7 ft 6 in) high.  A separate room is required with a ceiling height of 2.7 m (9 ft).  A 300-line PABX system could be housed in a room 3.5 m x 5 m (12 ft x 17 ft).

Telephones
GEC746 desk telephones, GEC741 wall telephones, and 'Keyphone' pushbutton telephones are available in a wide colour range.  GEC Loudspeaking telephones enable an executive to carry on a telephone conversation whilst having both hands free.  GEC switching telephone systems enable a secretary to receive an executive's calls and to transfer only those that require his personal attention.

GENERAL FEATURES
Internal calls between staff are fully automatic or (on a PMBX) via the operator.

Incoming calls are controlled by the operator.

Trunk offering
The operator can break into any conversation and offer a waiting public-exchange call.

Outgoing calls
Extensions can either make all calls through the operator or may be allowed to dial their own public-exchange calls.

Trunk call restriction
When direct dialling out is allowed, selected extensions can be automatically restricted to local calls only; trunk calls being made through the operator.

Metering
Extensions with direct-dialling out may be metered at the exchange.  All calls via the operator can be metered at the switchboard.

Enquiry
During a public-exchange call, an extension can ring another extension or the operator to make an enquiry without being disconnected from, or overheard on, the public-exchange line.  Transfer of a call to another extension is normally made via the operator.

Tie lines
Where there are two or more private exchanges within an organisation, they can be interconnected by tie lines independent of the public exchange.  Such calls can be made automatically or via the operator.

ADDITIONAL FEATURES
The following paragraphs describe some of the more usual extra facilities that can be added to the 'Series3' system.  There are many others, and experienced engineers are available to help solve the particular communication problems of any organisation.

Executive's priority
Selected extensions can secure immediate connection, interrupting any telephone that may be engaged.

Direct-access
Keycalling enables executives to 'key' up to 20 selected extensions without dialling.

Message waiting
Messages left for absent staff can be passed on with minimum delay upon their return.  An illuminated 'message waiting' panel, under the control of the receptionist and/or operator, is also coupled to a light on each telephone.  Staff returning to their offices, or passing through Reception, can see the message-waiting lamp and know, if it is lit, that a message has been left for them.

Absent extension transfer
A member of staff can press an 'absent' button on his telephone and calls will be automatically transferred to another predetermined extension.  Alternatively, this transfer can be made automatically after a delay of, say, 30 seconds.

Free-extension search (group hunting)
The switching equipment can be arranged c that should one telephone (in a large office, for example) be engaged, further calls are automatically routed to the nearest 'free' telephone.

Conference
Up to l0 extensions can be connected together via a special circuit for a conference by telephone.  On PABX systems, an exchange line can be included, but with a maximum of five extensions.

Staff location
A special 'locating' number, followed by a personal code is dialled from any extension or by the operator to initiate a visible or audible calling system.  The person called responds by dialling a special 'answering' number from the nearest telephone, connecting him directly to the caller.

Radio paging
An alternative staff-location service uses a radio-paging system under the control of the operator.

Public address
A public address system under the control of the operator can be provided.

Central dictation 
By dialling a specified number, the switching equipment will automatically select the first available machine of a group of dictation machines.  On PMBX systems, the connection is made via the operator.

Data transmission
Any data terminal suitable for operation over normal telephone lines can be used with the exchange to provide data transmission at speeds of up to 1200 baud.  GEC data modems are available.

Emergency
In an emergency, staff can dial an easily-remembered number (for example 666) which activates alarm lights and bells at the switchboard to command the urgent attention of the operator.  The emergency line can accept simultaneous calls so that the line is always available for reporting emergencies.

Night service
At night, exchange lines can be connected direct to selected extensions so that they make and receive calls to and from the public exchange when the switchboard is unstaffed.  Alternatively, an incoming call (signalled by bells at strategic points) can be answered at any telephone by dialling '8'.

Security patrol record
Security staff can dial a designated number from any telephone, and exchange equipment prints out time and calling number.

'Single digit' services
In addition to the normal 'single digit' features (dial '0' for the operator, etc.) certain specialised operational services - such as the Surgery - may be reached by dialling a single digit instead of the normal 3- or 4-digit number.

An 'area service' dialling system can be provided.  By dialling a single digit the call is automatically routed to the nearest representative of the desired service; for example, dialling a common digit for 'maid service' in a hotel, regardless of the floor, will connect the guest to the appropriate floor maid.

Enquiry and transfer
In addition to the standard enquiry facility, provision can be made for the automatic transfer of public-exchange calls to other extensions.

Fire alarm
A further easily-remembered 'non-busy' number can be provided for fire-alarm services.  In addition, zone indicators defining the location of a fire can be provided.

1975

GEC Telecommunications Limited

Last revised: 18 November, 2000