DEH 1010 and DEH 1020 (replaces HA 270/10 and HA 270/20)
These devices have a black Bakelite cover and are equipped with line selector and signal button.  If you want to talk to someone else from one device of the devices, the selector is set to the one in question the number of the device, the microphone was lifted off and the signal button is pressed. If the called device is free, both devices' bells will ring. If it is busy, none of the bells ring. On an incoming call, the called bell will operate no matter on the position of the devices selector switch. Several calls can be made at the same time. There is no secrecy.

One battery is required for each device microphone battery consisting of two dry cells BKA 1002 or BKA 2002.  For signalling, one is required for the whole facility common battery, which should placed as close to the centre of the facility as possible. The number of elements is adapted to the size of the facility and the length of the wires. At least four elements BKA 1002 or BKA 2002 should be included in the signal battery. For the batteries there are suitable battery boxes BKY 1001, each with space for two elements.

The cables are connected directly to the device's junction box, whereby construction costs are reduced. Cable requirements are: 22 and 42 conductors for facilities with 10 and 20 devices respectively. These devices can also be used for single-wire management.

By means of a DYY1012 shelf, the devices can be mounted on the wall.

Parts:
Microphone RLF1020 made of black Bakelite with microphone capsule RLA 1004, 40ohms, and string TRS 1404, 1250mm.
Transformer RCL 10201.
Direct current ringer KLD 1003, 100ohms.
Wall mounting cable, 2 m.
Junction box.

Dimensions:
Height 139mm, width 233mm, depth 178mm

Taken from the L. M. Ericsson Catalogue No. 610 (1939) - Swedish Translation
 

Last revised: March 23, 2024