Ringing Siemens&Halske Telephone Telephone exchange

Automatic telephone exchange – operating

A step-by-step automatic telephone exchange brought into operation in 1921 at a post office in Ljubljana, which was the first automatic exchange in the then Kingdom of Serbs, Croats and Slovenes (later Yugoslavia). Originally it connected 500 users, but the facilities were later upgraded. Before being donated to the Museum of Post & Telecommunications in 1981, it had a total of 2000 subscribers.
Two automatic telephones are connected to the exchange; the first is a Siemens & Halske and the other Telefongyar R. T. Budapest.

Sound: Operation of a step-by-step automatic telephone exchange Strowger and sound of telephones ringing

Sound level: 68 dB

Sound recordist: Boštjan Troha
Photographer: Veronika Štampfl
Video recordist: Barbara Grilc


6.7 MB
34 s
2 (Stereo)
Sample rate:
Bit rate:
Bit depth:
48 kHz
1536 kb/s
16 bit
68 dB

Recorded on April 17, 2014
Museum of Post and Telecommunications
Polhov Gradec, SLOVENIA
Creative Commons License