GEC AEI TELECOMMUNICATIONS LIMITED
A Management Company of The General Electric Company Limited of England
10 Line Private Automatic
10 extension lines.
Provision for one conversation at a time.
0 to 9.
One selected executive can have a priority-button
telephone enabling him to break into the existing conversation.
Mode of operation
Fully automatic operation with secrecy using
uniselectors and relays.
Tones and ringing
Mains-supply derived ringing tone and current
Required dial-pulse characteristics: 7 to 14 i.p.s.,
2:1 break to make ratio.
Built-in AC power unit: input, 100 to 120V or 200 to
250V 50 to 60 Hz single phase.
Line-loop resistance to exceed 300 ohms. Line-leakage
resistance should be not less than 130k ohms.
Wired-in equipment on a wall-mounted frame and
contained in a lift-off dust cover painted dark green.
Switching equipment PX1211
Taken from a GEC-AEI brochure SLX8C - dated 1968
PRIVATE AUTOMATIC TELEPHONE EXCHANGE
This compact and completely self-contained telephone exchange provides secret
automatic communication facilities for up to ten extensions. It is ideally
suitable for small organisations, or as a separate auxiliary to the main
telephone system in a large organisation. The single wall-mounting unit,
finished in steel furniture green, incorporates all the automatic-switching
equipment and an all-mains power unit.
The exchange has the, following features:-
Automatic connexion between extensions.
Two-wire lines to each extension.
One connecting link.
Executive right-of-way for one extension.
Operates from single-phase mains supply 50-60c/s, 100-110 or 200-250 volts.
Dial tone and ringing tone returned to a caller.
Extensions numbered from 0 to 9.
The exchange is suitable for operation in either tropical or temperate
Any extension user is connected to any other extension by dialling a single
digit. When the connecting link is free, an extension hears dialling tone on
lifting his receiver, and ringing tone when the wanted extension is being
called. If there is no tone when an extension lifts his receiver, the connecting
link is engaged.
One extension connected to the exchange can have an executive right-of-way
facility. This extension instrument is fitted with a pushbutton, and to break-in
to an established connexion the extension user presses the pushbutton. If
neither of the answering parties is the one required, they are requested to
replace their handsets ; the executive then dials the required number. In this
way the head of a small organisation, or the leader of a group in a larger
organisation, can talk to any member of his organisation at all times.
LINES AND TELEPHONES
Each telephone can be connected to the exchange unit by any insulated twin
conductor having a loop resistance of less than 300 ohms and a line leak greater
than 130,000 ohms. This latter condition means that bare open-wire lines should.
not be used with this exchange. An extension with executive right-of-way
facility must be connected to the exchange by two insulated twin conductors.
Recommended telephones for this exchange are the 'New Gecophone' described in
Catalogue Leaflet STL16 and the "G.E.C. 1000" Telephone and the G.E.C. Muraphone
"K" described in Catalogue Leaflet STL13. When the executive right-of-way
facility is required, the executive telephone must be fitted with a pushbutton.
The ringing current is derived from the mains at 50 or 60c/s, compared with the
normal telephone exchange ringing current of 25c/s, therefore slight adjustment
of the bell is required to give the most satisfactory ring.
The connexions to extension lines are by screw-type terminals, and the only tool
required to install the exchange is a screwdriver. Each exchange is fitted with
10ft of 3-core flex to connect to the mains supply.
This compact, neat, inexpensive telephone exchange is easy to install, and
available for quick delivery.
G.E.C. 10 LINE P.A.X.
||12 x 24 x 8
||31 x 61 x 19
Taken from the GEC Catalogue Leaflet No. PXL 06A (Date unknown but later than
Taken in 1959
10 PAX Tropicalised - Drawing 701060