L. M. ERICSSON DIAVOX

L. M. ERICSSON
TELEPHONE - DIAVOX

Diavox

The Dialog telephone set which was produced in early 1960s and was introduced into Televerket's range in 1965. By the middle of the 1970s they become unfashionable, even though it could be equipped with a keypad for pulse or tone and the number of colours increased from three to six.

The original black, grey and white had been supplemented with the new colours red, light yellow and dark green.

The introduction of new exchange systems was one of the motives to construct a new telephone model which from the very beginning was intended for button selection. In 1975, Televerket and LM Ericsson decided to start developing a new phone, jointly with the development company, Ellemtel.

Four different design companies were commissioned to produce proposals for the exterior design of the new phone. The model selected for production was designed by Carl-Arne Breger, whose designs can be seen many Swedish homes, e.g. the Flora package, the ABC-80 computer, the plastic water jug and the Ericofon 700.

L M Ericsson produced the first Diavox 100 phones in 1977 and 1978 and was introduced in 1979 without a keypad or dial. The initial telephones had a with beige cover, black handset, high-resistance adjustable bell, electret microphone and electronic speech circuit with automatic attenuation compensation.

Diavox replaced the Dialog telephone as Televerket's standard telephone.

Diavox's shape means that there is plenty of room for buttons, display etc. The coloured part of the cover is cheap and easily replaceable by the subscriber. For reasons of cost and reliability, Diavox has been allowed to keep the polarized bell as a signaling device although it has actually been replaced by tone ringers in a number of prototypes. Otherwise, electronics have been used to a large extent. The carbon microphone, which began to be used as early as 1888, has been replaced in Diavox by an electret microphone with significantly better sound characteristics.

Unlike the carbon microphone, the new microphone requires an amplifier. This was built into the same capsule as the microphone. Electronic components can be fitted to the circuit board placed directly under the front cover.

The base model is available in two basic versions: the original model and a more modern, the Diavox-II, which unlike the original model has volume control and cords with modular connectors.

In the Diavox-II, the amplifier for the microphone has been moved from the microphone capsule to the circuit board in the device. The microphone cord unlike the older model, which only had two conductors, has four, two to the microphone and two more the earphone.

Diavox is available in a large number of variants. The base model has been manufactured with 10, 12 and 13 buttons. The ten-button model is intended for older switches that can only receive pulse selection. The twelve-button device is an MF tone device without a Recall button and was intended to be used with older switches that have been supplemented with tone receivers. The model with thirteen buttons is an MF tone device with a Recall button, intended for AX switches and modern company switches. Ericsson has also produced devices with 11 buttons where the Recall button does not have it the usual time break function, but instead is used to connect the line to earth. This Recall button has the same function as the regular Recall button but is used with pulse dialing instead of tone dialing.

A Diavox telephone you rarely see is the one equipped with a regular "old fashioned" dial. This is because this model was never used on Televerket's network.

Within the casing there is also room for amplifiers and speakers, as in the Diavox 200, with the Andra models being used in manager-secretary arrangements (by use of two-lines) and a model that is headset compatible.

There have also been produced special models, analogue and digital, for connection to different types of exchanges.

Ericsson produced a total of 6.5 million complete telephones and kits for composition out- abroad. The production continued until 1989. Additionally, a large number of Diavox sets, for the Swedish market, were manufactured by TELI.

Taken from an article by Ove Svensson

Additional Information

The Diavox was produced in three basic variants with 10, 12 or 13 buttons. The 10-button (904) was LD (Dial pulses). The 12 button, 921 model and the 13 button, 901 model were manufactured with tone dialing (MF to international standards). LM Ericsson manufactured 6.5 million devices and many were exported worldwide. The Diavox was available in a large number of different versions, e.g. loudspeaker, manager/secretary, line recorder, cover in precious wood, cover in leather and a small number with a finger plate.

The wooden cased sets were called Royal Wood and were available in Walnut, Mahogany, African Rosewood, Cherry and Birch. As these were made of wood the grain was different on each telephone. Each telephone came with a certificate of authenticity and a serial number.

A Royal 100 was also available and this was available as three different combination sets of three colours. Each set consisted of a Diavox MF telephone with two extra cases, which the customer could change.

A wall type was also produced and these were known as the Diavox 901 and 933, the 933 being the model with a recall button.

Marketing Names
Diavox 100 - Standard telephone or variant with same cover
Diavox 120 - Telephone with headset
Diavox 125 - Telephone with two exchange lines
Diavox 130 - Telephone with abbreviated dialing
Diavox 150 - Executive/secretary working
Diavox 200 - Loudspeaking telephone
Diavox 150 - Loudspeaking base
Diavox 824 - telephone with multiple exchange lines

There were 20 different plastic covers, of different colours, including white, black, blue, red, mustard yellow, green, silver and gold. These covers could be easy changed by releasing the two screws on the base and was advertised as a customer function.

Many were sold in Holland. The Dutch PPT introduced the Diavox S to their consumer market in the colours ivory white, beige and black. The handset was the same colour as the case. By means of interchangeable cases the phones could be obtained in numerous colours as many colour combinations were possible. The colour range was extended later.

In the UK, BT marketed the Diavox telephone as the Astrofon. The engineering designations were Telephone Special Range No. 1003 or 8003.

Variants
DBA 101 - Dial
DBA 102 - LD press button
DBA 103 - MF press button
DBA 180 - press button
DBA 192 - press button - System telephone
DBA 202 - press button

DBA 112 - LD press button wall type
DBA 113 - MF press button wall type

An article from the Ericsson Review Volume 57 1980

Diavox advert

Pictures

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