Last page update: 14 January 2017
During the early-mid 1950s, Hell and Siemens developed several Siemens-Hell-Schreiber models for start-stop operation:
- printer T.empf.39 "L"
- sender/printers T.typ.72 "GL" and T.typ.73 "AGL" with an integrated keyboard, and with a punch-tape reader (T.empf.73 "AGL" only)
These models were intended for broadcast- and command/control-networks over existing telephone lines, and over radio channels with "phone-line equivalent" audio quality (interference pulses shorter than 3 msec). The latter is required to ensure dependable functioning of the start-stop mechanism, as with "telex" teleprinters. The Hell-font used by these start-stop model is basically the same as the 7x14 pixel font of the Presse-Hell system, but with a start-pulse hidden in the first (blank) column:
7x14 Hell-font with start-pulse hidden in the first column
Broadcast-networks targeted by Siemens were those of stock markets, financial markets, international shipping departure & arrival information, and police (e.g., "wanted" warrants). Command/control networks were those of railway systems, fire departments, electrical power nets. Ref. 1.
Starting 1955/56, the Deutsche Bahn (DB, German national railway system) began to replace their 6000 Morse-telegraphy stations with 1300 Hellschreibers model T.typ.72 "GL", T.typ.73 "AGL", and printer-only model T.empf.39 "L". This allowed DB to reduce the workforce of their teleprinter service ("Fernschreibdienst") by 400, and save 80 thousand Morse-code training days per year - combined about 1 million Deutsche Mark (DM) per year (ref. 2, 3). Based on the development of the German consumer price index since 1955, this is equivalent to an estimated 2.16 million Euros in 2012 (ref. 4, 5). Note that teleprinter equipment prices do not necessarily follow the general cost of living inflation.
In 1954, DB paid 1000 DM for Hellschreiber printers (ref. 6A) - about 2600 Euros (2012). Regular "telex" sheet -teleprinters were much more expensive, and only used at head-offices ("Direktionssitze", "Ämtersitze") and a few major railway stations (ref. 6B). In 1967, DB consumed about 60000 rolls of Hellschreiber paper tape (ref. 6C). In 1968, DB owned 1440 Hellschreiber machines (ref. 6D).
Hellschreiber communication was done via the existing private, automated telephone network of the DB: the Bahnselbstanschluß-Netz. The BASA-Netz was in established in the mid-1930s by the Reichsbahn, the predecessor of the DB. It connected all railway stations, controls posts, and offices. Over the decades this network grew to some 120 thousand phone and teleprinter terminals. The DB used Hellschreibers throughout the 1980s (ref. 6E). These machines were used by the German railroad system in the Neanderthal region (i.e., near Düsseldorf) until ca. 1995 (ref. 7). The last DB service regulations that mention Hellschreiber are from 1983 (ref. 8).
MODEL T.EMPF.39 "L"
The equipment label of a T.empf.39b
(source: eBay; 1945 was Siemens year "A"; the serial-number on the label is from year "J" = 1954)
The photos below are of model T.empf.39b and T.empf.39d. I presume there were also model 39a and 39c. I do not have any information about the differences between these model variants.
T.empf.39d - the housing has rounded corners
(source: ref. 1)
The main characteristics of the T.empf.39 are:
- Transmission rate: 6.1 characters per second
- Telegraphy speed: 300 Bd
- Hell-font: 7x14 pixel matrix with start-pulse in the first column
- Start-stop synchronization: start-pulse in the first column of the Hell-font.
- Tone-detector/printer amplifier:
- Input bandpass filter: center frequency selectable 1000 Hz / 3000 Hz.
- Line impedance: 600 ohm (standard POTS telephone land-line)
- Minimum input signal level: -30 dB into 600 ohm
- Headset output (marked "Mh" = "Mithören"): 4000 ohm
- Vacuum tubes: EF80 pentode (pre-amplifier), EL83 pentode (printer-driver amplifier)
- Printer helix: 1-turn
- Size of printed characters: 2.5 x 4.5 mm (WxH).
- Paper tape width: 9.5 mm (as only a single line of text is printed, the paper tape can be narrower than the 15 mm paper tape of the Feld-Hell, Presse-Hell, and model T.empf.40 "F".
- Motor: 2100 rpm brushless AC type with centrifugal regulator. The speed control knob is located under the lid of the unit, next to the roll of paper tape. The start-stop synchronization accommodates up to 2% speed difference between sender and receiver/printer. The speed can be checked visually with a strobe disk on the motor shaft, and a 125 Hz tuning fork ("Stimmgabel", ref. 9).
- Paper tape speed: 1.1 m per minute
- Power: 220 volt AC, 40-60 Hz, 50 VA
- Remote control: tone pulse of 180 msec (minimum) to 1 sec (nominal) to turn the motor on, and 4 sec (minimum) to 6 sec (nominal) to turn the motor off. ("off"). This is the same as in the Presse-Hell printers. Control-tone frequency could be 25, 1000, or 3000 Hz, or DC.
- Size: 32x26x20 cm (WxDxH, ≈12¾ x 10¼ x 8 inch)
- Weight: 11 kg (≈24.3 lbs)
Front of a T.empf.39b - cover removed
Rear of a T.empf.39b - cover removed
Inside of the printer-module of a T.empf.39 "L"
(source: F. Sonnenrein; used with permission)
Gearing of a T.empf.39d "L"
(source: F. Sonnenrein; used with permission)
The following Hellschreiber telegram (note: from 1991 !!!) is a "Bahndienstfernschreiben", i.e., a telegram of the national German railway company ("Deutsche Bundesbahn"). It was printed with a T typ 72, T typ 73, or a "printer-only" T empf 39 (cf. Bild 3 in ref. 12).
1991 Hellgram of the Deutsche Bahn
(source: courtesy B. Rothe; used with permission)
1965 Hell-Bahnfernschreiben received at Jünkerath Railway Station
(source: Eisenbahnmuseum Jünkerath; used with permission)
1969 Hell-Bahnfernschreiben received at Jünkerath Railway Station
(source: Eisenbahnmuseum Jünkerath, used with permission)
1954 message of the Seewetterdienst des Deutschen Wetterdienstes (DWD; Marine Weather Service) in Hamburg
(source: ref. 10)
Several examples of telegrams printed with a 1935-45 Hell Feldfernschreiber are on this page.
- Ref. 1: "Siemens-Hell-Schreiber "L" - T empf 39 d", Siemens Fernschreib Technik, Siemens & Halske AG, Wernerwerk für Telegrafen- und Signaltechnik, Beschreibung St Bs 1223/11 [incl. schematic], July 1957, 32 pp. (courtesy Heinz Blumberg, DC4GL)
- Ref. 2: "Die Fernmeldetechnik als Hilfe bei der Rationalisierung der Eisenbahn", W. Leitenberger [Hellschreiber use in German railroad system is described in Section 3: "Modernisierung des Eisenbahnbetriebes"], in "ETR: Eisenbahntechnische Rundschau", Nr. 4, April 1966, pp. 139-146
- Ref. 3: "Rationalisierung im Bauwesen der Deutschen Bundesbahn", Albert Dobmaier, pp. 58 in "Jahrbuch des Eisenbahnwesens", W. Teigeler, 1958
- Ref. 4: personal correspondence with the Deutsche Bundesbank, February/March 2012
- Ref. 5: "Das Ausmaß der Geldentwertung seit 1950 und die weitere Entwicklung des Geldwertes. Gutachten der Deutschen Bundesbank vom 21. Juli 1965, erstattet auf Wunsch des Bundesfinanzhofs", in "Bundesbank-Monatsbericht", Vol. 20, Nr. 3, March 1968, pp. 3-19
- Ref. 6: "Signal + Draht: Zeitschrift für das Signal- und Fernmeldewesen der Eisenbahnen"
- Ref. 6A: Nr. 11, November, 1954, p. 7
- Ref. 6B: Nr. 7, July 1962, p. 10
- Ref. 6C: Nr. 9, September 1967, p. 11
- Ref. 6D: Nr. 11/12, November 1968, p. 1
- Ref. 6E: p. 46 "Hundert Jahre Bahn-Telekommunikation", Rainer Knewitz, Vol. 98, Nr. 1 + 2, 2006, pp. 38-54
- Ref. 7: "Wann wurde eigentlich der letzte Hellschreiber außer Betrieb genommen??" ["When was the last Hellschreiber taken out of service??"], 2008 thread in the "Historische Bahn" forum of "Drehscheibe" ("Turntable") website of railroad enthousiasts.
- Ref. 8: "Vorläufige ergänzende Bestimmungen zur Fernschreibvorschrift (für den Wählbetrieb, den Betrieb von Hellschreibern und das fernmündliche Zustellen und Aufgeben von Fernschreiben)", Deutsche Bahn, Dienstvorschrift 476 b, 1 February 1953 (addendum to DV 476); reprinted 1983.
- Ref. 9: "Der Stimmgabelgenerator", Funk-Technik - Zeitschrift für das gesamte Elektro- Radio- und Musikwarenfach, Nr. 5, March 1948, p. 114
- Ref. 10: "Einleitung", p. 5 of "Das Hell-Jahrhundert: Lothar Deckert berichtet über Dr.-Ing. Rudolf Hell und seine eigenen Tätigkeiten in der Firma", Lothar Deckert, Verlags- und Druckhaus Schmidt & Klaunig KG, 2007, 180 pp.
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