gec.gif (1164 bytes)GEC 10 Line PAX

A Management Company of
The General Electric Company Limited of England

10 Line Private Automatic Exchange

Maximum capacity
10 extension lines.

Connect circuits
Provision for one conversation at a time.

Numbering scheme
0 to 9.

Executive's priority
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.

Power supply
Built-in AC power unit: input, 100 to 120V or 200 to 250V 50 to 60 Hz single phase.

Line resistance
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.

Dimensions and Weight






Switching equipment PX1211   

31cm (12in)   

61cm (24in)   

20cm (8in)   

17kg (38lb)

Taken from a GEC-AEI brochure SLX8C - dated 1968


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 climate.

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.

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.

Line Circuits Link Circuits Dimensions Weight Catalogue Number
ins cms lb Kgs
10 1 12 x 24 x 8 31 x 61 x 19 38 17.5 PX 1211

Taken from the GEC Catalogue Leaflet No. PXL 06A (Date unknown but later than 1955)

Taken in 1959

10 PAX Tropicalised - Drawing 701060


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Last revised: January 02, 2024