Inhaltsverzeichnis
Teletypewriter 34
Teletypewriter T. typ. 34; manufactured by Siemens & Halske, Munich.
In the 1930s, a wired teletype service went into operation in Germany in 1933, the telex service was a self-dialling network. The teleprinters communicated with each other via a fixed protocol using the Baudot code with 5 data bits; the usual communication speed was 50 baud (later machines could be converted to 75 baud using special cogwheels).
The „Baudot code“ (CCITT-2) as a transmission protocol is a 5-bit code, it consists of a start bit (20 msec.), five character bits (20 msec. each) and a stop bit (30 msec.), the codes of the first level stand for the 26 letters, to represent numbers, code 11011 was used to switch to a second character set for the numbers, code 11111 sets the machine back to the letter character set; later, with the introduction of page printers, characters for carriage return and line feed were also introduced.
As a successor to the antiquated Morse code printers, the army responsibles decided in 1934 to procure the modern Siemens T. typ. 34 teletypewriter, although the complete material stored in eight wooden crates was heavy and bulky.
Technical data
- Principle: Teletypewriter
- Operation modes: CCITT No.2, Baudot, 50 baud
Power supply
- Mains operation: via power supply
- Batteries: Telegraph battery 60 V, 32 Ah
- Generator: petrol operated, 1 kW
Dimensions
- Total equipment (8 crates, battery, petrol generator) 631 kg
Accessories
System components
The teletypewriter Siemens T. typ. 34 was developed by Siemens & Halske, the motor of the teletypewriter can be operated with 60 V direct current or alternating current 125 V, for the line current 60 V, 40 mA were used.
The teletypewriter works with the telegraph alphabet CCITT No.2, the keyboard with 54 keys includes the 26 letters, the digits and several special characters, the type basket includes 26 type levers with two characters each, a code can be used to switch between the two character sets „digits“ and „numbers“.
The teleprinter had also a paper tape printer for printing on telegram paper strips and an punch to create punched paper tapes from incoming messages.
The entire teleprinter equipment is packed in 8 crates, plus the power supply:
- Crate A: Teletypewriter, 94 kg
- Crate B: converter, 33 kg
- Crate C: Power supply unit, 34 kg
- Crate D: Accessories / spare parts and tools, 25 kg
- Crate E: Paper tape punch, 43 kg
- Crate F: Punch tape dispenser, 33 kg
- Crate G: Single-tone telegraphy unit, 30 kg
- Crate H: Broadcasting unit, 30 kg
- Petrol generator 1 kW, 120 kg
- Telegraph battery 60 V, 32 Ah, 210 kg
The total weight of the system is 631 kg. For field use, the components were transported on a trailer and protected by a canvas cover.
Single-tone telegraphy unit ETT-40
Initially, only double-current operation was used; with the use of improved lines in the public telephone networks, a switch was made to use single-tone telegraphy, for which the single-tone telegraphy unit (Crate G) had to be used. The current termination device (Crate C) also has a switch filter, with which simultaneous telegraphy and telephony operation was possible on lines suitable for dual-current operation. Crate H contains a broadcasting unit, with which a message can be sent simultaneously to different recipients via six different lines.
The Paper tape punch was used to punch the messages on punched paper strips in the office.
Technical principle
Tube assembly
Development
Use
In 1936/38, 52 complete sets of teletypewriter 34 equipment on trailers were procured, and in 1941 a further 30 sets consisting of individual crates. The telegraph equipment could be dismantled and used in the model 46 communication centre truck or in the 48 communication centre trailer.
The T. typ. 34 teletapwriter, or the T. typ. 37 page teletypewriter developed as a successor to it and which was used in command posts, was replaced in 1959 by the Siemens Stg-100 teletypewriter, which came in only two boxes…
Technical documentation
- Die Fernschreibstation, technical description, Albiswerk Zürich AG