DF 250

This telephone can be connected with one line (white button) to the loudspeaking conference telephone system and one line (red button) to a CB telephone exchange. Calls from the master station will ring the bell in the telephone and calls from the exchange line the bell in the bell box. The signals will arrive independent of whether one of the lines is engaged or not. The lines cans not be joined up.

Calls from the master station are received by lifting the micros telephone and pressing the white button, and calls from the exchange line by pressing the red button. When the micro-telephone is replaced the press buttons return to home position. The master station is called by lifting the micro-telephone and then pressing the white button. The corresponding indicator on the switchboard will then be actuated. If the white button is pressed in bottom position the bell of the master station will ring.

Calls to or from the CB exchange are handled by lifting the micro-telephone and pressing the red button, after which the station will be in communication with the CB exchange.

Parts:
Dial RG 112, dial cord RS 5062, DC bell RA 610/4.5, 40 ohm, condenser RI 260, 1 uF, micro-telephone RE 1042 of black Bakelite with removable capsule transmitter RC 4000/40, 40 ohm, and cord RS 6162, 2 press buttons, 1 red and 1 white, case of black Bakelite, bell box with condenser RI 260, 1 uF, instrument cord RS 9951, 1000 ohm bell, cover of black enamelled sheet iron.

Dimensions:
Height 140 mm, width 233 mm, depth 175 mm, weight inc. bell box 3.6 kg.

Taken from the L. M. Ericsson Telephones and Signalling Material Catalogue No. 188 (1934)

Last revised: February 07, 2021