gec.gif (1164 bytes)GEC  PABX No. 3

G.E.C. Series 3 Private Telephone System


  • 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.

The Basic Versions

Inter-Extension Calls

Public-Exchange Calls

PAX Private Automatic Exchange Automatic dialling None
PMBX Private Manual Branch Exchange Via the switchboard operator Via the switchboard operator
PABX Private Automatic Branch Exchange Automatic dialling operator or automatic dialling Via the switchboard

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).

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.

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.

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

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.

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.

Keycalling enables executives to 'key' up to 20 selected extensions without dialling. An LST4D voice switched loudspeaking telephone with an added direct -access key calling unit is shown to the right.

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.

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.

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.

1972 and 1975

GEC Telecommunications Limited


Personal Service- the hallmark of the Good Hotel

In the age of automation and computer-controlled systems GEC have designed and supplied PABX automatic telephone systems to suit the age. Direct dialling in to extensions and dialling out with automatic metering - all accelerate the speed of communication. The PABX operator with her modern cordless board with pushbutton operation and television-like screen is still essential but to a lesser degree.

These automated systems are vital to meet the needs of the modern business world where the tempo of industry and commerce insists on the speed of automatic connexion at the expense of old world charm - but would you, a hotelier, change your first-class restaurant into an automated self-service cafeteria? Of course not, because personal service is still of paramount importance to the good hotel with a reputation to keep - or make. It's the same with the hotel telephone service. The modern cordless switchboard cannot economically match the traditional cord-type switchboard in providing all the facilities that enable the well-trained operator to use her charm and courtesy, her friendliness and eagerness to help - this is personal service.

GEC with a history stretching back to the very beginning of the telephone service, has always recognized the superiority of the cord switchboard for hotel systems. Recently it recognized that the upright design of switchboard, basically unchanged for many years, was not an attractive shape to install in the spacious open-plan reception areas often  provided in new hotels. So a new low-line cord-type switchboard has been introduced for the PABX No. 3 telephone system. The modern teak-finished cabinet is a console that any architect or hotelier will be proud to incorporate into the reception area to emphasize the efficiency, and the personal aspect of the hotel's service.

The Pegasus Hotel, Guyana, the Sheraton-Malta Hotel, the Cavendish Hotel, London and the Intercontinental Hotel, Lusaka, Zambia, are four of the many luxury hotels, recently  built that are using GEC Hotel Telephone Systems to provide PERSONAL SERVICE.

Your Telephone System
GEC design telephone systems with built-in flexibility to meet the specialized and exacting demands of any size or type of hotel. Systems can be custom-built to suit your individual communication needs.

The new PABX 3 is ideal for hotels requiring more than 50 extensions - the capacity of the exchange is unlimited. It has been designed to provide the ultimate in personal service for that very important group of people - your guests. A hotel builds its reputation on service. The GEC PABX 3 is built to provide that service.

Your Guests
All your guests requirements can be obtained by asking the operator. In systems with up to 800 extensions each room is individually identified on the switchboard so that your operator knows immediately who is making the request and doesn't need to ask. This is not possible with a cordless-type switchboard without costly additional equipment.
Alternatively, the following automatic facilities are available:-

Guest to Guest
Guests may call each other by dialling the appropriate number. However, many hotels prefer that these calls are controlled by the operator.

Hotel Services
Guests may call room service, reception, housekeeper and other hotel services by dialling a single ", digit. Dials incorporating symbols denoting the service may be supplied. When services are closed, calls may be automatically transferred to the operator.

In an emergency guests 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.

Outgoing calls
Guests can either ask the operator or may be allowed to dial their own local and trunk calls.

Trunk Call Restriction
When direct-dialling out is allowed this facility can be automatically restricted to local calls only; trunk calls being made through the operator.

All outgoing calls may be automatically recorded by individual metering equipment in the exchange and displayed on a meter panel at the reception desk so that the total telephone charges for each room are always available for preparation of guests' accounts.

Incoming calls
All incoming calls are controlled by the operator.

During an outside call guests can call the operator, for advice or information, by pressing a pushbutton on the telephone.

Message waiting
When guests have been out of the hotel and messages have been left for them a message-waiting facility will help your staff to pass on the message with a minimum of delay - another aspect of personal service.

A message-waiting panel (shown to the right) may be provided at the reception desk which shows all the room numbers. When a message has been left, the telephone operator, or the receptionist, can 'light-up' the appropriate room number so that when the guest returns the staff can see at a glance that there is a message for that guest. Small lamps on each bedroom telephone are coupled with the 'message-waiting' panel and light simultaneously so that guests returning to their rooms, without checking at reception, can see the light and know that a message has been left for them.

Do not disturb
Guests can arrange with the operator that they are not disturbed. Outside calls are already controlled by the operator and internal calls can be switched to hear 'busy' tone or automatically transferred to the operator.

Personal service
All these automatic facilities are optional and are alternatives or complementary to, a fully personal system whereby all your guests requirements can be obtained merely by asking the operator.

Your Hotel Administration
Internal calls
Between staff can be completely automatic or through the operator as required. Staff extensions may be barred from making calls direct to guests.

Incoming calls
Are controlled by the operator.

Outgoing calls
Extensions can make outside calls either through the hotel operator or may be allowed to dial their own local and trunk calls. Selected extensions can be barred from dialling their own outgoing calls and can only obtain them through the operator.

Trunk Call Restriction
Any extension with the direct-dialling-out facility can be automatically restricted to local calls only; trunk calls being made through the operator.

Extensions with direct-dialling-out facilities may be metered, at the exchange, to check usage. A metering panel is shown to the right.

An extension can, during an outside call, ring another extension to make an enquiry without being disconnected from or overheard by the outside line.

Night Service
Various arrangements for night service are available. The flexibility of the system caters for the requirements of most hotels.

More information? If you would like to know more about GEC's Hotel Telephone Systems or if you would like more details of a telephone system designed for your hotel, please write and let us know how many public exchange lines you require, how many extensions you require for guests and for administration, the number of floors in your hotel, the guest room numbering scheme and the facilities you require.

Taken from the GEC AEI Catalogue Leaflet SLB13A - Dated 1970

Click here for more pictures of the PABX 3 at the Cavendish Hotel


Personal Comments
The GEC PABX 3 switchboard was a more compact design than the switchboards produced by the other manufactures.  The wood was Rose wood and jack field was much smaller, making the switchboard light and airy.

Because of it's compactness, the cords were contained in cassettes and when these cords needed changing it was a rather horrible job.

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Last revised: November 30, 2021