Hell Feld-Morse machine

[Introduction]
[Model MS 3]
[Model MS 5]
[Model ÜS 3]
[Tape perforator TL 1]
[Model MG 10]
[Model MG 22]
[Model MG 23]
[Model RC 28]
[Model UR 39]
[Patents]
[References]

Latest page update: 13 February 2021 (added Fig. 18 & 19, associated text & ref. 15)

Previous page updates: 29 October 2019 (added section on Hell MG 23, added ref. 13)

INTRODUCTION

Besides Hellschreiber machines, Rudolf Hell's company also developed and manufactured equipment for Morse-telegraphy: tape printers, punch-tape senders, and a special punch-tape perforator:

Morseschreiber printers, such as the military models "MS 3" and MS 5". Note that some other manufacturers also made Morse-printers with an "MS" model designator.
Übungsschreiber and Übungsmorsescheiber Morse-training printers, such as models "ÜS 3" and "Üb.M.Schr."
Morsegeber mechanical tape-senders, such as models "MG 12", "MG 22", and "MG 23". These were also Morse training equipment ("Hell-Morsegeräte für Schulungszwecke")
Electronischer Geber electronic tape-sender, such as model "EG 21"
Recorder single & dual-channel high speed printers, such as models "RC 28" and "RC 30"
Unterricht-Recorder Morse-training printers, such as model "UR 39"
Tastenlocher tape-perforator ("Wheatstone code), model "TL 1". Note that some other manufacturers also had a tape perforator model "TL 1" (though 5-bit Baudot code).

Fig. 1: civil Morse-equipment product brochure of the Rudolf Hell company

(source: ref. 1)

Note that all of the recorders print the "raw" telegraphy signals (i.e., the dots and dashes, dits and dahs) onto paper tape. They do not print decoded characters. The Hell "Schnellmorseschreiber" models (high speed recorders) were suitable for machine-sent speeds of up to 500 words per minute (2500 characters per minute). "Übungsmorseschreiber" models were used in telegraphy training classes.

Some of the Hell-Morseschreiber printers are directly based on Hellschreiber printer technology (see p. 20 in ref. 2A). This is why I decided to expand my Hellschreiber website with this page. In particular, models MS 3 and MS 5 are look-alikes of the ubiquitous WW2 military Hell-Feldfernschreiber ("Feld-Hellschreiber") machine, which is why I refer to them as "Feld-Morseschreiber".

Contrary to other high-speed Morse recorders, the Hell recorder is not a so-called "siphon recorder". The latter type uses a moving-coil galvanometer with an attached ink-filled capillary tube (ref. 3). Instead, the Hell recorder uses the tried-and-true "Hell system": a special, fast electromagnet that taps the paper tape against a continuously spinning printer wheel that is kept wet with ink.

Fig. 2: the Hell-Morse printer system

(source: Fig. 2 in ref. 2A)

However, the printer wheel is not a Hellschreiber helix, but resembles a gearwheel with the teeth set at an angle:

Fig. 3: printer wheel of the Hell Morseschreiber

(source: Fig. 5 in ref. 2A)

Fig. 4: printer wheel of a Hell Morseschreiber model "MS 5"

As soon as - and as long as - a (Morse) tone signal is received, the electro-magnet of the printer is energized, and the paper tape is pushed up against the printer wheel. Unlike the conventional Morse recorders, the signals are not printed as thin line segments on the centerline of the paper tape, but as a heavy hashed wide line (better readability):

Fig. 5: hashed dits & dahs printed with the Hell system - the paper tape moves from right to left

(source: Fig. 5 in ref. 2A)

Fig. 6: print-out of a series of Morse "V" characters on paper tape

(source: Fig. 6 in ref. 2A)

Fig. 7: printer wheel of a Hell Morseschreiber

Fig. 8: printer wheel of a Hell Morseschreiber

This may appear to be similar to the original Morse recorders of the late 1800s, but it is not. First of all, such conventional electro-magnet Morse recorders do not perform well with low signal-to-noise levels. Also, those "ticker" recorders are not suitable for high-speed Morse signals that are sent by machines. Note that a Morse telegraphy speed of 500 words/min implies a shortest pulse duration of a mere 2.5 msec. This means that the armature of the electro-magnet must move up (down) well within 1 msec as soon as the magnet is (de)energized!

HELL MORSESCHREIBER MODEL "MS 3"

As the side-by-side photos below clearly show, the construction of Hell Morseschreiber model MS 3 is similar to that of the Hell Feldfernschreiber (a.k.a. "Feld-Hell") that was developed for the German military several years earlier. Same modular design, similar die-cast electronics box, same printer box and felt ink ring, two paper trays, etc. This is why I'd like to refer to it as the "Hell Feld-Morseschreiber". Model MS 3 can handle speeds from slow hand-sent, up to an average 300 words/min (1500 characters/sec) machine-sent speed. The speed of the paper tape is adjustable between 1.5 and 10 m/min (!) - i.e., 5-33 ft/min.

Fig. 9: Hell Feld-Morseschreiber "MS 3" and Feld-Hellschreiber side-by-side

(source: Fig. 8 in Ref. 2A (left), Fig. 9 in ref. 4)

Fig. 10: Hell "MS 3a" in its carrying case

(original unedited "MS 3a" photos are courtesy Pierre Destexhe; used with permission)

The MS 3 includes a winder for the paper tape ("Papieraufspulvorrichtung") - nice to have when the tape moves at 10 m/min! It is driven by a slip-clutch pulley on the shaft of the paper transport drive, via a belt.

Fig. 11: Hell "MS3 a" in its operating position - with paper tape winder installed

Fig. 12: principle diagram of a Morse and image telegraphy printer

(source: Fig. 1 in the 1937 Hell patent 694437)

Received Morse-signals are passed through a volume-control potentiometer and a band-pass filter. The filter can be switched off, and has two selectable center frequencies: 900 Hz and 1500 Hz. The output of the filter is transformer-coupled to the first tube (valve) amplifier stage, and then transformer-coupled to a solid-state full-wave rectifier (with two Siemens "Sirutor" cuprous-oxide diodes). The rectified signal is filtered and passed to the final amplifier. The anode current of this amplifier drives the printer's electromagnet. Both tubes are of type RV12P4000. See ref. 5 for the detailed schematic. Contrary to the Feld-Hell machine, the required DC anode voltage is not generated with a motor-generator ("dynamoto"), but with a so-called "Wechselrichter" (a.k.a. "Zerhackerpatrone"): an electro-mechanical DC-DC "chopper" converter.

Fig. 13: simplified schematic of the MS3

(source: Fig. 7 in ref. 2A)

Fig. 14: the amplifier box of a Hell "MS 3a" - very similar to that of the Feld-Hell

Fig. 15: top of the amplifier box of a Hell "MS 3a"

(left-to-right: "Zerhacker" DC-DC converter, 2x RV12P4000 tubes, fuse, battery/power supply switch)

Fig. 16: label on the front of the electronics box of a 1939 Hell "MS 3a"

After World War 2, the machine shown in the photos above (serial number 2831) was used in Mexico by an engineer of the Telefunken company, to "phone home".

Fig. 17: the label of a 1940 Hell "MS 3a"

The "Tornister" carrying case of the MS 3 measures 33.6x43.6x22.2 cm (WxHxD; ≈15x17x9 inch). That is slightly smaller than the case of the Feld-Hellschreiber: 39x45.5x24 cm (WxHxD, ≈15x18x9½ inch). Including the case, the MS 3 weighs about 18 kg (≈40 lbs). A 1-page operating manual is provided in ref. 6.

The next photo shows the 1940 communications wagon of the Reichsbahn "Sonderzug" (special trainset) of Mr. Heinrich Himmler, Hitler's Reichsführer-SS:

Fig. 18: "Salon-.Nachrichtenwagen" wagon type "Sal N 6ü 39a", serial number "10 255 Bln"

(source: adapted from ref. 15A, 15B; orignal photo by wagon manufacturer Wegmann & Co.; note: wagon "10 253 Bln had a telescopic mast at both ends)

The telescopic T-antenna was only cranked up while parked. Two antenna wires were strung along the entire top of the wagon. The equipment of the radio operating room ("Funkbetriebsraum") included a Feld-Hell machine and an MS3 Hell Morse-printer:

Fig. 19: Equipment in the radio operations room of "10 255 Bln"

(source: adapted from ref. 15A (also in ref. 15C); orignal photo by wagon manufacturer Wegmann & Co.)

As the Lorenz EO 509 general-coverage receiver (ref. 32D) is located directly next to the Feld-Hell machine and directly below the MS3 Hell Morse printer, it is assumed that the receiver was used with both.

The transmitter was located behind the position of the photographer. The photo was taken towards the left in the diagrams of Fig. 18. The wagon also included a teleprinter room, a telephone exchange (switch board) room, a message cipher/crypto room, a Signals Officer room, and a generator room (12 kW, diesel powered; a second generator was gear-driven by an axle of one of the two triple bogies). The rail wagon was built by Wegmann & Co. in Kassel/Germany.

HELL MORSESCHREIBER MODEL "MS 5"

Model MS 5 is a successor to the MS 3. Again, it is a military system. It is suitable for printing speeds of 20-500 words per minute ( = up to 2500 characters per minute!). The audio bandpass filter is different from that of the MS 3: it has a fixed center frequency of 900 Hz, but the bandwidth is now selectable (±100 Hz "narrow" and ±200 Hz "wide"). The circuitry still comprises two amplifier stages, but now with an RL12P10 and an RV2P2000 tube. Also, the MS 5 can operate off 12 volt DC (again, with a "Zerhacker" DC-DC power-converter for the anode voltage of the vacuum tubes), as well as 220 volt AC power. The printer uses paper tape that is 9.5 mm wide. Tape speed is selectable (two speed ranges, speed manually adjustable within each range). The sand-cast housing of the printer unit is made of Elektronmetall (Elektron-metal): an alloy that consists of ±90% magnesium and ±9% aluminium. The rest is manganese (for corrosion resistance), zinc, and silicon. The carrying case measures 39x46x24.2 cm (WxHxD, ≈15x18x10 inch). The complete set weighs 22 kg (≈49 lbs). Ref. 13.

Fig. 20: Hell "MS 5" in its carrying case

(original unedited "MS 5" photos (this one and the next 3) are courtesy Pierre Destexhe; used with permission)

The two compartments above the printer/electronics module are for "Schreibpapier" (spare rolls of paper tape) and "Ersatzteile" (spare parts such as fuses and ink rollers)

Fig. 21 Hell "MS 5" - in its operating position, with its upper paper cassette pull out

Fig. 22: label on the above 1941 Hell "MS 5 "

Fig. 23: the "Zerhacker", tubes and fuse are easily accessible on top of the printer/electronics module

Fig. 24: printer module of another "MS 5"

Fig. 25: label on the front of the above "MS 5"

Fig. 26: close-up of the printer module of the "MS 5" - note the printer wheel

Fig. 27: close-up of the printer module of the "MS 5" - note the similarity with the Feld-Hell printer

Fig. 28: Print-out from an MS 5 - with strong interference (top) and without interference

(source: Fig. 3 in ref. 13)

Fig. 29: A "Prüfkarte" (acceptance test tag) from the Rudolf Hell factory in Berlin-Dahlem - signed in 1939

HELL ÜBUNGSMORSESCHREIBER "ÜS3"

Fig. 30: Hell Übungsmorseschreiber "ÜS 3" - front & rear view

(source: ref. 7)

As shown in the schematic below, the connectors on the rear of the machine are marked (top to bottom): "Fernhörer", "Taste", "Fremdsummer", "+ 4 Volt -", and "Netz". I.e., "phone", "key", "external tone-oscillator", "+ 4 Volt -" and "mains / AC-power":

Fig. 31: schematic of the Hell Übungsmorseschreiber "ÜS 3"

Fig. 32: a 1938 Hell Übungsmorseschreiber "ÜS 3"

Fig. 33: rear of a "ÜS 3" - cover removed

Fig. 34: "HELL ÜS 3A2" is marked on the chassis casting

Fig. 35: "HELL ÜS 3 A1" is marked on the bottom of the cast base plate

HELL MASCHINENGEBER "MG 12"

Maschinen-Geber MG 12 is a punch-tape Morse sender. Ref. 7, 8.

Punch tape encoding: Wheatstone-code
Output: on-off keyed (relay) or tone pulses
Built-in tone generator frequency: selectable 960, 1540, 2560 Hz
Telegraphy speed: 15-340 characters/min (relay), 15-480 characters/min (tone)

Fig. 36: Hell Maschinengeber "MG 12"

(source original unedited photo: eBay)

Fig. 37: Hell Maschinengeber "MG 12"

(source original unedited photo: eBay)

HELL MORSEGEBER "MG 22"

Morse-Geber MG 22 is a punch-tape Morse sender for training purposes.

Punch tape width: 12 mm
Punch tape encoding: Wheatstone code
Built-in tone generator
Telegraphy speed: 39 - 150 characters/minute
Compatible with the practice recorder UR 39.

Fig. 38: Hell Morsegeber "MG 22"

(source original unedited photo: eBay)

HELL MORSEGEBER "MG 23"

Morse-Geber MG 23 is a punch-tape Morse sender for training purposes. It dates back to 1950. Model MG 23 D/E was also used by the Fernmeldetruppe EloKa ("elektronische Kampfführung" = electronic warfare, EW) of the Bundeswehr (ref. 14).

Fig. 39: Hell Morsegeber "MG 23"

(source original unedited photo: Hell Verein Kiel)

Fig. 40: Equipment label of a Morsegeber "MG 23 D"

HELL DOPPEL-RECORDER "RC 28"

Model RC 28 is a 2-channel Morse printer ("Doppel-Recorder"). It has two separate keying amplifiers, each with a printer system. Both printers print onto the same paper tape. It was specially developed for diversity reception on shortwave. That is: Morse signals were sent with two simultaneous audio tones, and separated upon reception, with narrow audio filters; this improved reception quality during noise and fading. The unit includes circuitry for noise suppression, automatic gain control, and adaptation for signal time constants (fast/medium/slow). Ref. 7, pp. 60-61 in ref. 9.

Paper tape width: 13 mm. Tape speed is continuously variable.
Telegraphy speed: 15 to 480 words/minute (75 - 2400 characters/min!)

Fig. 41: Hell "RC 28"

The RC 28 resembles the recorder drawing in one of Rudolf Hell's US patents:

Fig. 42: Hell "RC 28"

(source: Figure 1 in US patent 2731322)

Fig. 43: Label on the back of a Hell "RC 28"

(original unedited "RC 28" photos below: courtesy J. Fastner, used with permission)

Fig. 44: top view of another "RC 28" - cover removed

Fig. 45: rear view of an "RC 28"- cover removed

Fig. 46: close-up of the connectors on the rear of an "RC 28"

Fig. 47: close-up of the vacuum tubes at the rear of an "RC 28"

HELL DOPPEL-RECORDER "RC 30"

The RC30 is the same as the RC 28 above, but for speeds of 10-200 WPM instead of 15-480 WMP.

Fig. 48: label on a Hell "RC 30"

HELL ÜBUNGSRECORDER "UR 39"

As the name suggests, this is a recorder (printer) for Morse training purposes ("Uebung", "Unterricht"). Model UR 39 C was used by the Fernmeldetruppe EloKa ("elektronische Kampfführung" = electronic warfare, EW) of the Bundeswehr (ref. 14). This model dates back to 1952.

Main characteristics of the UR 39 are:

Speed of the paper tape can be varied between 1 and 3 m/min (3.3-10 ft/min).
Input signal level: 0.25-3 volt (-9.5 to +12dB) at 600 ohm ( = standard phone line)
Frequency of the built-in tone-generator: 1000 Hz.
Output signal level: 2 volt at 600 ohm
Vacuum tubes (valves): ECC91, EL90
Paper tape width: 9.5 mm
Telegraphy speed: up to 300 characters/minute
Size (WxHxD): 29x24x24 cm (≈11.5x9.5x9.5"inch)
Weight: 11 kg (≈24.3 lbs)
110/125/190/220/240 volt AC

Fig. 49: Hell "UR 39"

(source original unedited photo: eBay)

Fig. 50: Hell "UR 39"

(source original unedited photo: eBay)

Fig. 51: Rear view of a Hell "UR 39 C"

(source original unedited photo: eBay)

Fig. 52: Label on a Hell "UR 39 C"

(source original unedited photo: eBay)

HELL TASTENLOCHER "TL 1"

The Hell company also made keyboard punch-tape perforators for Morse telegraphy applications, primarily with Wheatstone encoding rather than Baudot (ref. 5). The keyboard of Hell model TL 1a has 40 keys, whereas general purpose teleprinter keyboards have 50 keys. These perforators were still built in the 1960s. The TL 1 was also used by the Fernmeldetruppe EloKa of the Bundeswehr (ref. 14).

Punch tape width: 12 mm
Punch tape encoding: Wheatstone code
Typing speed: up to 650 characters/minute

Fig. 53: Hell Tastenlocher Typ 1

(source: Fig. 264 in ref. 3)

Fig. 54: Hell Tastenlocher model "TL 1a"

(source: Fig. 43 in ref. 9)

Fig. 55: Hell Tastenlocher model "TL 1a"

(source: Fig.4 in ref. 10)

PATENTS

Patent number	Patent office	Year	Inventor(s)	Patent owner(s)	Title (original)	Title (translated)
682595	RP	1937	Dr.-Ing. Rudolf Hell	Dr.-Ing. Rudolf Hell	Schaltung für Übungsmorseschreiber mit Motorantrieb, die wahlweise aus einem Wechselstrom- oder Gleichstromnetzt gespeist werden können	Circuit for motorized practice Morse recorders, that can be AC or DC powered [tone generated by motor collector]
694437	RP	1937	Dr.-Ing. Rudolf Hell	Dr.-Ing. Rudolf Hell	Schreiber für Morsezeichen und Bildtelegrafenimpulse	printer for Morse characters and image telegraph pulses
718017	RP	1939	Dr.-Ing. Rudolf Hell	Dr.-Ing. Rudolf Hell	Anordnung zur Aufzeichnung mehrerer im absatzweisen Mehrfachbetrieb gleichzeitig gegebener Telegramme	Device for simultaneous recording of multiple telegrams
726257	RP	1939	Dr.-Ing. Rudolf Hell	Dr.-Ing. Rudolf Hell	Anordung für Schreibempfänger mit selbsttätigem Anlassen und verzögertem Stillsetzen des streifens	Device for autonomously starting and stopping paper tape transport of a printer
2731322	US	1950	Rudolf Hell	Rudolf Hell	-	Recording devices [variants of spindle and paper tape]

Patent office abbreviations: RP = Reichspatentamt

Patent source: DEPATISnet, the on-line public database of the Deutsches Patent- und Markenamt (DPMA, German Patent and Trademark Office)

REFERENCES

Ref. 1: "Hell-Morsegeräte", company brochure, Dr.-Ing. Rudolf Hell Co., M-9-7002 (684), 1970, 4 pp.
Ref. 2: "Hell - Technische Mitteilungen der Firma Dr.-Ing. Rudolf Hell - Gerätentwicklungen aus den Jahren 1929-1939", Nr. 1, May 1940
Ref. 2A: pp. 22-28, "Der Schnellmorseschreiber System Hell", G. Ege
Ref. 2B: pp. 28-31, "Der Schnellmorseschreiber als Funkempfangsgerät", H. Haberland
Ref. 2C: pp. 40-44, "Der Uebungsmorseschreiber", Rudolf Hell
Ref. 3: "Der Drehspulschnellschreiber der Siemens & Halske AG", pp. 321 in "Lehrbuch der Fernmeldetechnik – Band 1", C. Brendel, Karl Bergmann Verlag, 1939, 527 pp.
Ref. 4: "Der SH-Feldschreiber", Siemens-Halske AG, Berlin-Siemensstadt, SH 7535. 1.2.39. TT1., 11 pp. (courtesy Siemens Corporate Archives, München)
Ref. 5: MS3a schematic
Ref. 6: MS3a Betriebsanweisung (1-page operating manual)
Ref. 7: "Hell Morsegeräte für den Schnellverkehr", 1962
Ref. 8: "Morseschnellgeber - High-Speed Morse Transmitter MG 12 G/l; Anlagen zur Ersatzteilliste - Appendix to list of spare parts", Dr.-Ing. Rudolf Hell Co., 12 G/l - E3 d/e - 6608, 18 pp.
Ref. 9: p. 55-61 in "Siemens-Hell-Geräte", pp. 61-77 in "Telegrafentechnik", Band 6, Teil 6 of "Der Dienst bei der Deutschen Bundespost - Leitfaden für die Ausbildung", Fritz Schiweck (ed.), R. v. Decker's Verlag, G. Schenck, 1960, 970 pp.
Ref. 10: "Handlocher für Lochstreifenherstellung", Fritz Schiweck, in §9.4 "Apparate für Schnellmorsebetrieb", pp. 352-358 in "Lehrbücher der Feinwerktechnik", Band 9 "Fernmeldetechnik", 4^th ed., C. F. Winter'sche Verlagsbuchandlung, 1962, 894 pp.
Ref. 11: "Ausbildungsanlagen in den Aufbaujahren der Fernmeldetruppen EloKa der Bundeswehr" [pdf], Rudolf Grabau, pp. 22-28 in "Funkgeschichte", Nr. 195, 2011
Ref. 12: "Schnellmorseempfänger", Fritz Schiweck, pp. 145-149 in "Lehrbücher der Feinwerktechnik", Band 9 "Fernmeldetechnik", 1^st ed., 1942, 526 pp.; "Schnellmorseempfänger", Fritz Schiweck, pp. 352-358 in "Lehrbücher der Feinwerktechnik", Band 9 "Fernmeldetechnik", 4^th ed., 1962, 894 pp.
Ref. 13: "Der Schnellmorseschreiber MS 5 (Entwurf)", D. (Luft) T. 9210, 1942, 27 pp; source: cdvandt.org
Ref. 14: "Ausbildungsanlagen in den Aufbaujahren der Fernmeldetruppe EloKa der Bundeswehr", Rudolf Grabau, pp. 23-28 in "Funkgeschichte - Mitteilungen der Gesellschaft der Freunde der Geschichte des Funkwesens (GFGF)", Vol. 34, Nr. 195, February/March 2011. See note 1
Ref. 15: articles about radio equipment used in German WW2 train wagons
Ref. 15A: "Salonnachrichtenwagen Sal N 6ü-39a", Jens Nestvogel, April 2007. Source: "Salonwagen der Deutschen Reichsbahn bis 1945", drg-salonwagen.eu, retrieved 13 February 2021.
Ref. 15B: "Übersichtsskizzen Sal N 6ü-39a - Zustand des 10 255 Bln mit montiertem Sendemast (bei Stillstand des Zuges)", Jens Nestvogel, April 2007. Source: drg-salonwagen.eu, retrieved 13 February 2021.
Ref. 15C: "Die Salonberatungs- und Salonnachrichtenwagen in den Führungszügen der Reichsregierung im Dritten Reich" [], Bruno Rebbelmund, pp. 65-82 in "Jahrbuch für Eisenbahngeschichte 2008/2009", Vol. 40, Deutsche Gesellschaft für Eisenbahngeschichte (DGEG, publ.), 112 pp., ISBN-13: 9783937189352. See note 1
Ref. 15D: "LORENZ Allwellenempfänger Type EO 509", C. Lorenz AG, Beschreibung Nr. 78/43, 4^th ed., 26 pp.

Note 1: due to copyright reasons, this file is in a password-protected directory. Contact me if you need access for research or personal study purposes.

External links last checked: March 2016, unless noted otherwise.