Telephones used by the GPO & Post Office Telephones 1960-1980
When the 706 telephone was first introduced in 1959 it was known as the Modern Telephone. It was made in two versions, the Mk. I version was conventionally wired, whilst the Mk. II version used a printed circuit board. The Mk. I had a plastic base on which all the components are mounted and the interconnections made by conventional wiring. Mk. II and IIA had a metal base on which a printed wiring board is mounted with most of the components soldered directly on to it. All electrical components other than the gravity switch, spring sets and bell mechanisms are identical in each version. Each instrument is supplied with an extensible coiled hand-set cord which extends from 200mm to about 1524mm. Line cords were available in lengths of 3.00m, 5.0m and 8.0m. The telephone handset weighs 255g and the complete instrument weighs approximately 1.6kg. The 706 was available in seven standard colours: black, light ivory, concord blue, lacquer red, topaz yellow, two-tone green and two-tone grey.
The 706 Mark II version telephone uses conventional wiring with a plastic base
The 706 Mark II version telephone uses a printed circuit board with a metal base
The 710 telephone was first introduced in 1959 and was based on the 706 telephone. The case was been adapted to take up to four push buttons and one or two lamps. Push in dummy buttons are fitted when no switches are used.
The 710 was available in three colours: ivory, grey and black.
The 711 telephone was first introduced in 1961 and was a wall mounted telephone based on the 706. The telephone is mounted onto the wall with a ‘T’ shaped bracket. It has provision for up to four press buttons and two lamp opals. The 711 was available in four colours: ivory, grey, black and red. The orange 711 was made for Saudi Arabia and was not standard GPO issue, nor is the transparent version shown below.
The 746 was first introduced in 1967 and was available to all subscribers by 1970. It was a lightweight plastic instrument which incorporated a balanced armature receiver. All the components, including the gravity switch, were soldered onto a printed wiring board which was mounted on either metal or plastic base. One or two optional switches such as the 5A-4 (used for recall) or the 23A-1 (used for bell on/off) could be added.
The 746 was available in seven standard colours, see the bottom of this page for further information. With the advent of new style wiring the 746 was renumbered the 8746 and was fitted with a 4000 ohm high impedance bell and a new style line cord fitted with a 431A plug. This model was also available in Brown.
The 746 table telephone measures 121mm high x 146mm wide x 229mm deep.
At first glance the two 746 telephones pictured below look identical …
… but look again at the same telephones pictured from the side
The original 746 design, shown on the left, was released in 1967, however the recess for the handset to sit on the top of the phone was too broad. This enabled either the handset to be carelessly placed or to slip out of position off the switch hooks, which took the telephone off-hook. As can be seen from the picture on the right, in around 1971, the top of the 746 case was redesigned with a narrower recess to prevent the handset from sliding off the switch hooks.