TELEPHONE No. 758

TELECOMMUNICATIONS INSTRUCTION
B MARKETING COMMERCIAL
4 Facilities and Apparatus
B0144
Issue 1, Nov 1979

PUSH BUTTON TELEPHONES
SELF CONTAINED (SC) BATTERY-LESS
Four Button Table Model (Telephone No. 758)

DESCRIPTION
This battery-less Push Button Telephone is a four button table instrument which has a 10 button keypad; it supersedes the battery operated Telephone No. 768.  The instrument is available only in ivory.  Each key has a black engraved numeral on a white ground.

The Push Button Telephone contains miniaturised electronic components (integrated circuits) which store the digits as they are keyed and then transmit them to the public exchange in the form of normal dial pulses.

The layout of the numbers conforms to the recommendations of the International Consultative Committee on Telephones and Telegraphs (CCITT).

The number label is located below the keypad.  To remove - push down on one side and then slide sideways, whilst still pushing down..

The instrument will be issued with a 3 metre cord (Cord Connecting No. 4/502 3000mm) but a longer cord can be fitted if required.

FIELD OF USE
This instrument is suitable for those Plan extension arrangements which could be provided by the use of the 4 button dial telephone (Telephone No. 740) on either exclusive or shared service lines or as PBX extensions (with or without recall facilities).  It can also be used as the operators instrument on PBXs - except when a Dial No. 25 is required.

NOTE: Some of the newer types of PABX are designed to have special 12 button PABX Push Button Telephones as described in B14 B0101.

If a Push Button Telephone is provided in association with subscribers automatic group transfer service, a separate dialling unit must be supplied (normally a Plan 1A for which a charge is raised).

For policy and/or technical reasons it cannot be provided:-

• to work on Plan arrangements with obsolescent (ie pre 700 type) telephones

• as the carrier subscriber on the WB900 '1 + 1' subscribers carrier system

Push button telephones can be provided with the following subsidiary equipment:-

• Amplifying Handsets (Handset 14A)

• Answering Sets 1 & 2

• Bells, Buzzers and Hooters

• Callmakers

• Clock type Meters

• Faint Speech Amplifiers

• Key & Lamp Units

• Lamp Signalling Handsets (Handset 7)

• Renters POA Coinbox (CC 700 only)

• Speakers sets 1 & 2

• Subscribers Controlled Transfer Equipment

• Transmitter Cut-out (Handset 6)

• Trimphones

• Watch Receivers

NOTE: In cases where a Push Button Telephone is provided for use in association with a Speakerset 2 with handset control, the Speakerset cannot be switched in until the call has been connected.

For the new plan socket system in the UK the Telephone No.  8758 was introduced.  This telephone was fitted with a Bell No. 59D-1 (high impedance bell coils 4000 ohms) and a Cord Connection No. 4/502 3000mm.

Circuit diagram - N858 (Telephone No. 758) and N8858 (Telephone No. 8758).

Specification - S1203 (Telephone No. 758) and S1492 (Telephone No. 8758).

Additional information

Last revised: April 20, 2023