• [Introduction]
• [Germany 1931-45]
• [British propaganda]
• [Kriegsmarine]
• [Post-war Germany]
• [Around the world]
• [Hell Commune & World Service]
• [Early "Presse Hell" printer models]
• [printer model "T.empf.12"]
• [printer model "T.empf.14"]
• [References]

©2004-2023 F. Dörenberg, unless stated otherwise. All rights reserved worldwide. No part of this publication may be used without permission from the author.

Latest page update: February 2023 (added ref. 75B).

Previous updates: Agust 2022 (added ref. 278A-278E, 286 and associated text in the "British propaganda" section; inserted Fig. 5, added Fig. 48B, 48C, ref. 285); 10 April 2022 (added Fig. 57, ref. 196); 8 March 2022 (added ref. 195, inserted Figures 18A, 18B, 19A, 19B, and text); September-October 2021 (added ref. 271, 274, 275); 4 May 2021 (added ref. 272 and text), September 2020 (added Tempf12b photos and started Tempf12c section, added Fig. 48, ref. 132B); 9 June 2020 (added ref. 194A/B and text), December 2019 (expanded "Kriegsmarine" section with submarines, added ref. 258A-258C), 21 October 2019 (uploaded ref. 49), September 2019 (added ref. 190, 191, 192, 193, and expanded associated text, figures).

Note: radio receivers that were used with Presse-Hell printers are discussed on this page.

HELLSCHREIBER - PERFECT FOR NEWS AGENCIES

Rudolf Hell invented and developed the Hellschreiber with the objective of creating a very simple teleprinter system for use by news agencies via wireless communication (Rudolf Hell, ref. 1):

"Das Entwicklungsziel, ein für Presseempfang brauchbares Gerät zu schaffen, konnte nur mit einem denkbar einfachen Schreibgerät erreicht werden." "Die Entwicklung des Hell-Schreibers erfolgte speziell im Hinblick auf die drahtlose Übertragungstechnik"

"The objective of the development was a practical device for the reception of messages from news agencies. This could only be achieved with a very simple teleprinter." "The development of the Hell-printer was specifically done for wireless communication."

This particular form of Hellschreiber is generally referred to as "Presse Hell", "Presse" being the German word for press news media.

Indeed, "Presse Hell" revolutionized the telecommunication of news agencies world-wide (and, by the way, news paper and magazine printing as well). This was basically unequalled until the next revolution some forty years later: the introduction of computer-supported telecommunication. Hellschreiber "Schreibfunk" (or "Presseschreibfunk") competed with Morse code telegraphy, start-stop teletype/teleprinters (typically with 5-bit character encoding), and "Pressefunk" (also referred to as "Presse-Sprechfunk", is "spoken voice" radio-transmission of news messages). "Presse Hell" went into service with news agencies and news media in 1932.

The Hellschreiber system had a number of compelling advantages over the prevailing competition (in particular Morse telegraphy):

• No need for Morse telegraphy stenographers, who had to be trained (ref. 119), could make copy mistakes, and had to be paid a salary.
• No highly trained staff was required to operate and supervise running of the system - a typist/transcriber could do the job, at half the salary of a Morse operator (ref. 33D). Also, reception could be unattended for hours of continuous printing, other than for occasional exchange of the paper roll (e.g., 10 thousand words = 50 thousand characters, ref. 163B).
• The Hellschreiber produced a printed copy of received messages (not traces on a Morse undulator-recorder), enabling a more objective check of reception of the printed material.
• Compared to Sprechfunk, again, stenographers were no longer needed. Like their Morse counterparts, they could make hearing mistakes, and multiple words or entire sentences in a message could be lost due to atmospheric and other interference (ref. 3).
• Also, Morse and Sprechfunk required fixed transmission schedules. However, the Hellschreiber system was suitable for unattended operation (printer models equipped for remote on/off control signaling), and minimized delays between the occurrence of news events, and their reporting.
• The Hell system had a 50% higher transfer rate than Sprechfunk and Morse (ref. 2, 4 , 5, 33D). This made transmission schedules more flexible, which reduced staffing in the field. At the same time, transmission time ( = cost) was cut in half. E.g., for the London Press Service, this represented about 10% of the annual operating budget of the entire service (ref. 160A, 160D, 163B, 167).
• Hell-equipment, esp. printers, were significantly less expensive than conventional teletype/teleprinter equipment, by about a factor of 2-3. The Hell printers did not require a high standard of maintenance and skilled mechanics.
• In the 1930s, conventional teletype/teleprinter systems used expensive dedicated teleprinter lines, networks, and switchboards. So they were basically limited to point-to-point communication. Hellschreiber could be used for wireless broadcasts, with world-wide coverage (VLF/LF/HF), thereby bypassing the wired teleprinter networks. This too gave Hellschreiber a very significant cost advantage (ref. 2). Note that conventional teleprinters were not very usable on long distance radio links: they transmit each character as a 5-bit code with a start bit, and distortion of any bit causes a wrong chracter to be printed, or no character. Such distortion is easily caused by radio propagation effects (fading, atmospheric noise, multi-path "echoes", etc.) and man-made interference. Teleprinter via radio broadcast became popular and dominant after WW2, for several reasons:
• Large numbers of (primarily US) surplus military teleprinters were dumped on the market.
• New radio modulation schemes (in particlar Frequency Shift Keying, FSK, ref. 183B) improved the signal-to-noise ratio, making teleprinter-via-radio sufficiently dependable.
• Both Hell and teleprinter provide hard copy of the received messages, but teleprinters could produce several carbon-copies at once. Standard teleprinters were slightly faster than the Hell-system. Ref. 160A.
• Conventional teleprinters printed on page-wide rolls of paper, and did not require manual glueing of sections of paper tape onto a telegram form. Hell did develop a "Blattschreiber" page printer, which entered the market around 1949.

Fig. 1: print-outs of April 1938 long-distance Hellschreiber tests

(50 kW transmitter station DL0 at Rehmate (near Berlin) and receiver at Santiago de Chile; source: ref. 183A)

In 1947/48, London Press Service (LPS) assessed the Hellschreiber system for worldwide broadcast, and concluded (ref. 157):

The Wolff'sche Telegraphische Büro (WTB, ref. 42) was Germany's oldest news agency, founded in 1849. It tested the Hellschreiber in 1931. In 1932, it was the first agency to put the Hellschreiber into service: between its head office in Berlin, and its branch offices (ref. 6). In December of 1933, WTB and the Telegraphen-Union (TU, ref. 7) news agency were nationalized and merged into the Deutsches Nachrichtenbüro (DNB). DNB was the official news agency of national-socialist Germany (ref. 8). By 1934, the "Presse Hell" was considered mature enough to be tested and evaluated by DNB on the wireless links to their foreign offices (see pp. 239, 241 in ref. 9C, ref. 10). It entered into service on August 1 of that same year (ref. 3, 4). By 1935, all DNB offices abroad had a "Presse Hell" printer for receiving messages from the head-office in Berlin; possibly the domestic offices as well (ref. 2). From March 1940 on, DNB had the exclusive right to sell the Siemens-Halske "Presse Hell" machines. Per ref. 9C (p. 239), the 1940 price charged by DNB for such a printer was 875 Reichsmark (about 2-3 months wages of a male white-collar worker). Note that a Siemens-Halske publication from 1937 (ref. 11) quotes a price of 1257 Reichsmark... General pricing information about Hellschreiber equipment is provided on this page. In 1938, DNB offered a matching radio receiver, the E38, at 470 Reichsmark (ref. 10). Eventually, over 700 German newspapers subscribed to DNB's Hell-Funk "Hellcast" service (ref. 18, 19, 154). Broadcasting was primarily done on long-wave frequencies, to get continental coverage (ref. 12).

Figure 2: Fragment of a DNB Hellcast

(source: ref. 10)

The Transocean G.m.b.H (TO) was a German press agency founded in 1915 for the purpose of providing news from and about Germany to journalists abroad. TO may have evaluated the Hellschreiber system as early as 1932 (ref. 13). Rudolf Hell himself stated that both TO and DNB tested early models in 1934 (page 4 in ref. 1). By 1939, TO had at least 19 offices outside Germany (p. 263 in ref. 17C, ref. 118). It was the world's first news agency with wireless broadcast. TO initially used the high-power LF/VLF transmitter facilities at Großfunkstation Nauen (ref. 14), about 35 km west of Berlin. In 1935/36 they changed over to the Rehmate facilities near Oranienburg (about 30 km north of Berlin). The latter facilities comprised several 10-100 kW transmitters and a large antenna "farm". TO had Hellcasts of up to 18 hours a day from Rehmate, primarily to South-America, Africa, and the Dutch East-Indies (see §10 in ref. 1).

Figure 3A: Map of the wireless Hellschreiber-network of the German DNB press agency ca. 1939

(source: ref. 12, 17C, 119; note that the intra-German network was still fully wired at that time)

Figure 3B: Overseas DNB offices - 1938/39 - covered by Hellcasts from DNB/Berlin

(source: ref. 17C)

By April of 1939, 27 foreign press agencies subscribed to the DNB Hellcasts (ref. 15, 187). From 1939 to 1945, TO, DNB, and EP (Europapress) were controlled and financed by the German propaganda ministry ("Reichsministerium für Volksaufklärung und Propaganda"). Obviously, German embassies, incl. the one in Washington DC/USA, were equipped with Hellschreiber (ref. 16, 1940). In 1938, during the Spanish Civil War, Germany had a special staff in San Sebastián to support General Franco's Falange. The staff's office was equipped with Hellschreiber printers for the DNB service, as well as shortwave receivers and transmitters (ref. 115). During 1942, TO broadcast Morse and Hellschreiber messages in German, French, English, and Spanish, for a combined 72 hours a day, and an average 85000 words a day (ref. 17). Germany stepped up its international propaganda effort in 1942, at which time the Propagandaministerium made two additional transmitters available to the DNB. Starting in 1942, the "Hell Presse-Schreibfunk" [ = teleprinter news broadcast] began to gradually replace the "Presse-Sprechfunk" [ = voice news broadcast, typically spoken at dictation speed]. By the time the Pressefunk was terminated (February 1944, ref. 3, p. 240 in ref. 9C), over 700 of the 980 German newspapers were equipped with a "Presse Hell" printer, and connected to the Hellschreiber-broadcasts of the DNB (ref. 18, 19).

Note that DNB provided an advance service to the German press: the broadcast before they were published in printed press (esp. daily newspapers) and re-broadcast via state-controlled radio. DNB also broadcast "Wehrmachtberichte". These were daily mass-media communiqués of the Wehrmacht High Command (OKW), prepared by the OKW propaganda dept. They were broadcast via the DNB, hours before they appeared in, e.g., German radio announcements. This made the DNB an important source of news to the British government, via the BBC Monitoring Service. Ref. 286.

Fig. 4: "The girl at the Hellschreiber" - cartoon in the Litzmannstädter Zeitung newspaper (1943)

(source: ref. 20, Litzmannstadt in former Germany's Eastern Prussia, now Łódź in Poland)

Note that the "Presse Hell" system was not only used by news organizations. It was, e.g., also used via shortwave radio by the Reichsbahn (the state railway system in Germany), in particular with their counterparts in Romania and Hungary (ref. 179). The Hungarian railway system also used the Hell system via longwave radio (1940-1957, ref. 21; also see this page).

During the war, Presse-Hell printers were also made available to large ethnic German communities outside Germany ("größere reichsdeutsche Gruppen", ref. 53). The German national police also made extensive use of Hellschreiber (ref. 54), as did German embassies and consulates. E.g., those in Zürich/Switzerland (ref. 55), and Washington DC/USA (ref. 16) were equipped with Hellschreibers. During WW2, King Boris of Bulgaria and King Mihai of Romania used German-controlled Hellschreibers to secretly print Hellcasts from Reuters/London (ref. 150).

There are statements in the media, literature and internet - perpetuated to this day - claiming that at the beginning of World War 2, British intelligence services stumbled upon the "strange" Hellschreiber signals, and cleverly managed to reverse-engineer a printer so that they could read the signals. This is all pure and total British propaganda nonsense. Of course, it may very well be true that the UK "intelligence" services were fully unaware of the existence of Hellschreibers. For example, the radio intercept station of the British Foreign Office observed "non-Morse" transmissions during the second half of 1940 and early 1941, "at which point in time, no special apparatus existed to directly print any of these transmissions". Mid-1941, an RAF VHF station intercepted an "unknown type of communication" from across the Channel, which turned out to be Hellschreiber. Ref. 165.

However, Hellschreiber printers had already been used in Britain for many years, so a number of private and government organizations were familiar with Hell-signals. E.g.:

• The London Metropolitan Police evaluated a Siemens-Halske Hellschreiber (model T.empf.12A) in 1935, and concluded "There appear to be definite possibilities for Police work in apparatus of this nature" (ref. 28).
• The London-based Reuters news agency had prepared the introduction of Hellcasts with the General Post Office (GPO; i.e., the British government) since 1933. In 1935, an experimental supplementary Hellcast service to Europe was started via the GPO 43.2 kHz longwave transmitter at Leafield (ref. 75A, 75B). Reuters and all of its customers (in the UK and around the world) had German Hellschreiber printers.
• Given the Post Office's monopoly, Reuters did not own radio transmitters but leased time on Post Office transmitters, in particular at Leafield and Rugby (ref. 22, 23, 26). The Post Office Engineering Dept. performed reception tests for Reuters European Hell service in 1936 and 1939, and investigated effects of noise and propagation fading on Hell transmissions in 1944. Ref. 172A-172F.
• The London offices of other news agencies (e.g. AP, ref. 24, 25), subscribed to Hellschreiber services from Reuters and other news agencies. Hence, they had Hellschreiber printers - probably licensed by the General Post Office (who had full telecommunications monopoly).
• The Marconi company already negotiated Hellschreiber patent licenses in 1935 with Siemens & Halske via Telefunken Gesellschaft für drahtlose Telegraphie m.b.H. ("Telefunken" for short). Ref. 169. Siemens was 50% owner of Telefunken, until bought out by joint-venture partner Allgemeine Elektricitäts Gesellschaft (AEG) in 1941. Marconi and Telefunken had general "exclusive territory" agreements.
• Hellschreibers were also used at certain British airports (e.g., at Croydon, as early as 1937, ref. 27), probably for weather reporting services.
• Around 1938/39, the Cable & Wireless Ltd. company in the UK (probably through its Communications Division of Marconi's Wireless Telegraph Company Ltd.) performed Hellschreiber transmission/reception experiments and signal bandwidth measurements (ref. 166).
• During 1940, the Research Branch of the Engineering Department of the General Post Office (GPO) at Dollis Hill, north London, constructed a "Hell type helix printer". The results were "as good as normally obtained with the standard Siemens Hell printer". Starting in 1940, the GPO also developed a "modified form of the Siemens Hell-Schreiber equipment", with electro-chemical printing. The resulting portable printer/keyboard-sender entered into British Army service, and was referred to as the "Telewriter". Ref. 278A-278E (1940-1944 GPO War Diaries).

Also, the British telegraph/teleprinter technical community was fully aware of the Hellschreiber and its principles (e.g., ref. 29, 30). Moreover, British government representatives approved Hellschreiber-telegraphy at the International Radiocommunications Conference held in Cairo in 1938, for use of frequencies reserved for A1-modulated telegraphy (ref. 31A-31C). Furthermore, the Wireless Committee of the International Criminal Organization (INTERPOL, founded in 1923) adopted Hell-Schreiber for international police communications (via longwave radio, 83.4 kHz), at their annual meeting in 1935 (ref. 32, 175). Also, during 1938/39, the British High Commissioner for Palestine (which was under direct British rule from 1917 to 1948), negotiated a license with the German and Italian Consuls-General for the installation of Hellschreiber equipment in their consulates (ref. 33A, 33B, 34A, 34B).

Yes, one or more Presse Hell printers were surely abandoned by German DNB "agents", who left Britain in a hurry when the war broke out. Their machines were neither secret nor otherwise particularly valuable or of strategic importance. Hellschreiber technology was definitely not secret (contrary to claims in some British reports, e.g., ref. 35, 36). Hellschreiber signals as such, absolutely do not have some "secret" form of encoding: a very simple no-brains printer can print the signals as perfectly legible text. Also, the signals are not at all encrypted - though, of course, messages sent in Hellschreiber format may have been encrypted (and sometimes were - but never for news broadcasts, as that would obviously defeat their purpose).

Military Feld-Hellschreibers used by the code-breakers at Bletchley Park (BP), included captured German units. BP also obtained Hellschreibers from the US (configurable for both 7-line and older 12-line Hell-fonts; ref. 114. Possibly Teletype model 17). Martin Esslin was a so-called "roving monitor" at BBC Monitoring Service (BBCMS), whose operation started late summer of 1939 (ref. 36, 37, 38, 39, 116, 174, 274; he was Head of BBC Radio Drama dept. in the 1960s and 70s). Mid-1940, he "discovered" DNB voice broadcasts ("Presse-Sprechfunk", including communiqués from the German High Command) in the LF frequency band. He caught the announcement that the voice broadcast service was about to switch over to Hellschreiber format. The BBCMS added a special Hellschreiber-section to its M-unit: the H-unit (to be confirmed). This is where Stanley Cook (G5XB) worked. It started coverage of the DNB Hell-broadcasts on 23 October of 1941, at its listening post in Evesham/Worcestershire (ref. 40, 43, 275). Reception of strong signals (voice, Morse, Hellschreiber, teletype) was primarily done Caversham Park in Reading/Berkshire (due to local interference noise levels and lack of space for large antenna installations), whereas Crowsley Park (located about 5 km north of Caversham) concentrated on weak, long-distance signals (ref. 44, 45, 177). BBCMS also intercepted shortwave Hell-messages of the Reichsbahn (German national railways), ref. 46, 120. The recorded and translated "open source intelligence" (OSINT, using data obtained from publicly available sources) was exchanged with monitoring services in the USA (ref. 47). The monitoring and transcription of German Hellcasts at BBCMS was terminated in July of 1945 (ref. 48). However, post-war, the BBCMS monitored world-wide Hellcasts at least into the 1950s (ref. 191).

Fig. 5: War-time Hellschreiber monitoring at the BBC Monitoring Service

(source: ref. 37)

General ignorance in British intelligence circles persisted after the war: "The Hell system of teleprinting was apparently well known before the war, being used throughout Germany for Press communications and also in America. A small portable model was developed for the Wehrmacht" (ref. 170, September 1945).

Some ships of the Kriegsmarine (the German navy, 1935-45) also carried a Presse-Hell printer on board. E.g., the "Prinz Eugen" (a heavy cruiser of the Hipper Class) had one in the Gefechtsnachrichtenzentrale (GNZ, battle communications room, i.e., not in one of the ship's three radio rooms!), ref. 49. It was used in combination with a Lorenz Lo6L39 long-wave receiver.

The signal intelligence service of the Kriegsmarine also had Presse-Hell printers (as well as Feld-Hell machines), e.g., at the monitoring and D/F station ("Marine Peil Haupt Stelle", MHPS) near Neumünster, 35 km south of Kiel, in the far north of Germany (ref. 50). Note that the OKW/Chi (Oberkommando der Wehrmacht / Chiffrierabteilung = Cypher/Crypto Dept. of the Supreme Command Armed Forces) had two distinct intercept systems, one of which concentrated on monitoring of "in clear" (not encrypted) foreign broadcasts, principally news broadcasts, and correspondents' report of news agencies such as Reuters and Dōmei Tsūshinsha (Federal Japanese News Agency, predecessor of Kyodo News Agency). This intercept system had its main station at Ludwigsfelde (≈38 km, 23 miles south of Berlin), and branch stations at Königsberg, Gleiwitz, Münster, and Husum; ref. 51. Section 2 of Group I of the German OKH/GdNA (Oberkommando des Heeres - Army High Command / General der Nachrichtenaufklärung - Signal Intelligence (SigInt, cypher/crypto) Agency) had a sub/section for monitoring of clear text (not encrypted) Helldienst broadcasts of foreign press agencies. Ref. 52

The Kriegsmarine also used a number of LF and VLF transmitters in Germany, France, The Netherlands, and Poland, to communicate with its submarines. Most impressive was the 1 megawatt transmitter station, aptly named "Goliath". It was used to broadcast command and guidance instructions to submerged U-boats around the globe, both in Morse and Hellschreiber format. It is not 100% certain whether submarines that did have a Hell-printer, were equipped with a compact Presse-Hell printer, or a military Feld-Hell printer/sender. Clearly, for broadcast reception, only the printer function was required. Obviously, the broadcasts to submerged subs were uni-directionally, as they did not have an equivalent transmitter station on board.

Towards the end of the war, submarine "Type XXVIIB5" (a.k.a., "Type 127" and "Seehund" ) was also equipped with a Hell-printer. This was a 2-person midget submarine ("Kleinst-U-Boot") with a length of 12 m (≈39 ft), for depths up to 45 m (≈150 ft). It entered operational service on 31 December of 1944 but had no significant military impact. Ref. 258A suggests that it had an integrated longwave-receiver/Hell-printer that worked "satisfactorily". It had a dedicated antenna, as did the Luftwaffe FuG 29 / E29 "LW/KW-Reportageempfangsgerät" receiver, that was also installed in the "Seehund". The latter receiver had 6 adjustable channels in the 150 kHz - 6 MHz frequency range (not low enough for under water reception), but does not appear to have ever been produced in series. Ref. 258B-258C.

During 1945 bombing raids on Berlin, DNB Hellcasts were sometimes interrupted (ref. 57). The activities of the DNB ended on May 2, 1945 (ref. 3). The Psychological Warfare Division (PWD) of the US/British Supreme Headquarters Allied Expeditionary Force (SHAEF), put plans in place by the end of 1944, to use Hellschreiber for propaganda broadcasts. Ref. 58. This was primarily so-called "white" propaganda: tactical psychological warfare, with clear indication of the source. Fake Presse Hell newscasts were made via "Radio 1212", using the Radio Luxemburg transmitter with reduced power and re-tuned to a wavelength of 1212 m / 248 kHz (ref. 272). The Political Intelligence Department (PID) of the British Foreign Office started test-Hellcasts early June 1945, and regular Hellcast news service for the Joint Allied Press Services (APS) by mid June.

On 29 June 1945, the German News Service (GNS) started its operation in the US-controlled zone of occupied Germany. On 5 September 1945, GNS was changed to Deutsche Allgemeine Nachrichtenagentur (DANA; General German Press Agency; ref. 59, 60), headquartered in Bad Nauheim, some 30 km north of Frankfurt. Initially, DANA operated under the direction of Brigadier General Robert A. McClure. On 26 October 1946, DANA was handed over to a German association ("Genossenschaft") of 41 newspaper publishers (see list on p. 12/13 in ref. 190), with a license to operate as a news agency in the American occupation zone, the American sector of Berlin, and the American enclave of Bremen. Ref. 61. On 1 January 1947, the name was changed to Deutsche Nachrichtenagentur (DENA).

Figure 6: DENA inventory label on a T empf 14 "Presse Hell" printer

(source: eBay)

Initially, DANA used a mobile 20 kW long-wave transmitter "P" (Paul/Paula) of the Wehrmacht. DANA Hellschreiber transmissions started on September 6, 1945 (see p. 272 & 281 in ref. 17C, ref. 62, ref. 153). The transmitter burned down in November of 1946, because of a short circuit. Hellschreiber transmissions were interrupted for several days, until replacement transmitters were brought on line. In July of 1947, DENA started using a new, 30 kW transmitter installation near Frankfurt/Main (in the area called the Seckbacher Streuobstwiesen "Am Heiligenstock" at Bad Vilbel); ref. 63, p.284 in ref. 17. With support from the US military government, DENA successfully opposed efforts by the Deutsche Post (the German national PTT) to take over all Hellschreiber communication systems (as part of their claim to the monopoly in all matters of broadcast, ref. 64) - as this could have implied German government influence on the press (ref. 61). DPA used domestic Hellcasts from 1949 until March of 1956 (long wave), at which time it switched over to telex teleprinters (ref. 65); DPA's international newscasts did not switch over until 1961 (ref. 6).

Fig. 7: The 60 meters tall antenna mast, 12000 volt rectifiers and final-stage tubes (valves) of the 20 kW transmitter at Bad Vilbel

(source: ref. 190)

Fig. 8: T.empf.14 "Presse Hell" printer at DANA with E38 receiver - printed tape is transcribed with a typewriter

(source: Bundesarchiv, "Ein Jahr DANA", in "Welt im Film" of 18-Sept-1946, 1min30-1min40 into the clip)

Equivalent to GNS in the US-occupied zone, was the Sowjetisches Nachrichtenbüro (SNB) in the Soviet-occupied zone. It started 18 July 1945. It was transformed into the Allgemeine Deutsche Nachrichtendienst (ADN) in October of 1946. Similar agencies were founded in the French-zone (Rheinische Nachrichtenagentur RHEINA, which became Süddeutsche Nachrichtenagentur SUEDENA, until 1949) and the British-occupied Zone (GNS-BZ). The latter was headed up by Editor-in-Chief Sefton Delmer. During the war, he managed British black propaganda radio broadcasts and radio stations (e.g., "Soldatensender Calais", "Deutsche Kurzwellensender Atlantik", primarily directed at the German armed forces; ref. 66). Initially, Delmer did not want the new German press agency to use Hellschreiber, though DNB equipment was readily available. GNS-BZ was transformed into the Deutscher Presse-Dienst (DPD) in 1947.

Fig. 9: Row of T.empf.14 "Presse Hell" printers and LN21021 receivers in Hellschreiber-room of the DPD in Hamburg - 1948

(source: ref. 65 and ref. 67)

DPD used Hellschreiber over wireless channels, and regular teleprinters for its wired services. DPD used British military wired telecom network, until DPD got its own teleprinter network in April of 1946. DPD used Hellschreiber at least until well into 1947. In August of 1945, Hellschreiber trials between Germany and London were conducted in the British Zone, with two 20 kW shortwave transmitters at the site of "Norddeich Radio". From 1905 through 1998, this was a maritime coastal radio station on the North Sea shore in the far northwest of Germany (ref. 68). After these 1945 trials, the transmitters were moved to Hamburg, for news broadcasts (including Hell-Funk, ref. 6) to London and newspapers in the British-occupied zone.

DPA (Deutsche Presse-Agentur) was founded 18 August 1949 by merging DPD and DENA. Ref. 65, 69, 152. DPA used Hellschreibers (ref. 70) for its wireless services. Their Hellcasts were done via the DENA 60 kW longwave (110 kHz) transmitter at "Heiligenstock" (near Frankfurt): 19 hours/day = 25-30 thousand words/day.

Figure 10: Part of the first DPA press release - a Hellcast at 06:00 o'clock on September 1^st, 1949

(source: p. 18 in ref. 65)

Newspapers such as the Telegraf in Berlin subscribed to Hellcasts from DANA, DENA, as well as DPD, in addition to teletype services from other German and international agencies (ref. 71). Presse-Hell was also used by many magazine and newspaper publishing companies, e.g., "Südost-Echo" in Austria (1939-1945, ref. 72), "Fränkische Presse" newspaper of Verlagshaus Steeger (Hellschreiber used 1946-1955, ref. 51). When the Deutscher Sportverlag (DSV, German Sports Publishing Co.) resumed its operation after the war, it also used Hellschreiber. An associated betting office in Frankfurt/Main is known to have used them at least until 1982 (based on 1981 maintenance records of the machines, and ref. 73), to receive dog and horse racing results from the UK and elsewhere. The post-war Sport-Informations-Dienst (SID) operated a Helslchreiber network until it switched over to regular teleprinters in 1952.

ADN also used Hellcasts (ref. 70), primarily to other socialist news agencies (ref. 181). Hellcasts were on shortwave in German and Russian, and in parallel on long wave in German, in total 16 hours a day. The transmitters were located on the north side of the village of Weesow (about 25 km northwest of down-town Berlin). During 1959/1960, they transitioned from the Hell system to conventional teleprinters. Ref. 181.

As described above, DNB was the world's first news agency to use the Hell system.

Foreign ( = non-German) press agencies also had a "Presse Hell" printer, e.g., the Berlin office of United Press Associations (UP) in 1939 (ref. 74).

Reuters started its own Hellschreiber broadcast service to Europe (i.e., "the continent") in 1935 (ref. 75, 76; 1934 per ref. 77), after evaluation testing in 1934. Initial service was via the General Post Office's VLF transmitter (43.2 kHz) at Leafield (about 100 km northwest of London), later (1939) around 7 and 11 MHz. The Hell-sender was located at Reuters' offices in London. When Hellschreiber equipment was no longer available from Germany, Reuters used other suppliers to build Hellschreibers (ref. 75, 78, 79). This was primarily by subcontractors to the British GPO (see here), but also the Italian company FIApT in Milan (not to be confused with the automobile manufacturer FIAT from Turin). In 1954, Reuters entered into an agreement with Tass News Agency whereby Reuters obtained exclusive copyrights in the United Kingdom to the TASS Russian and English Hellschreiber services, for the annual sum of 10 thousand pound sterling (equivalent to ≈£266 thousand in 2018 ≈€300k ≈US$345k, based on general inflation rates). Reuters would be willing to share these rights (e.g., with the BBC), for a compensation (ref. 182).

Starting 1939/40, some of the broadcasts of Italy's first press agency, Agenzia Stefani (founded 1853), were in Hellschreiber format (in Italian, English, and French). Around the same time, the Spanish press (ref. 80) and the French news agency Havas also started using the Hell system. In 1938, Havas sent an engineer to Siemens in Berlin, "to improve the system" (ref. 81), though there is no evidence of any contributions he may have made.

In 1940, the Reuters and Havas agencies cancelled their contracts with DNB, followed in 1941 by Associated Press (and UP (see p. 242 in ref. 17C). UP maintained several listening posts worldwide during and after the war, capable of printing Hell-casts (e.g., at Valhalla/NY and San Francisco/CA; ref. 47). AP also used Reuter's listening post at Barnet/England (ref. 82, 83).

Here is an overview of non-German news agencies around the world that provided and/or used Hellcasts (ref. 84, status of 1952/1953):

• AA (Anadolu Ajansi (D: Agentur Anatolien, Agentolie); Turkey): subscribed to Hellcasts from Reuters/London, for which it had four Hellschreiber printers. (p. 99 in ref. 84); they also subscribed to DNB Hellcast services (ref. 85).
• AA (Agencia Avalla; Yugoslavia, absorbed into Tanjug in 1943): used Hell-printers starting in 1937.
• AAP (Australian Associated Press); Hellschreiber printers (though it was formally forbidden in Australia at the time for non-government entities to own telecom equipment!) to receive AAP service from London.
• AF (Agencia Fabra; Spain; dissolved in 1938): used Hellschreiber printers since 1934 for HAVAS Hellcasts.
• AFP (Agence France Presse; partly continued as HAVAS in 1940, reemerged as AFP in September of 1944): received Hellcasts from other agencies; had conventional teleprinter link to Frankfurt, and Hellcasts from there (via DENA transmitter) to German customers 30k words/day.
• AGERPRESS (established 1949; Romanian News Agency; frmr. Agentie de Informatii Telegrafice (AIT, see below); own Hellcasts (ref. 155); starting 1950, Hellcast reception limited to TASS.
• AIT (Agentie de Informatii Telegrafice RADOR ("Radio Orient"); Romania): received Hellcasts.
• ANA (Athens News Agency): received Hellcasts.
• ANETA (Algemeen Nieuws- en Telegraaf-Agentschap ("General News and Telegraph Agency"); The Netherlands). The ANETA office in New York also used Siemens printers (ref. 86). Also see P.I.-Aneta below.
• ANP (Algemeen Nederlandsch Persbureau; The Netherlands, established December 1934):
• Received Hellcasts from NTB, DPA, TASS; had its own Hellcasts to Indonesia (incl. PIA in Jakarta), and Surinam. Also see ref. 171b-171e.
• The first successful Hellcast trials between ANP in The Netherlands and ANP in Batavia (Jakarta/Indonesia) took place early March of 1939 (ref. 171a, p. 6 in ref. 194A):
  

  Fig. 11: Print-out of a Hell massage received by ANP in The Netherlands via shortwave from ANP in Jakarta/Indonesia

• The transmission/reception station in the Netherlands was "Holland Radio" (a.k.a. "Radio Kootwijk") at Kootwijk, ca. 85 km southeast of down-town Amsterdam. It had multiple transmitter and antenna systems, ref. 194A-194E. Additional Hell test transmisisons were done in November of that year, with transmitter "PEW", ref. 194F (10 kW, 4637 m longwave, ≈64.7 kHz; ref. 194A-194E). Official Hell transmissions for ANP started in February of 1940, with the transmitter "PDK" (10410-10420 kHz, wavelength about ≈28.8 m). Transmissions were interrupted upon the German invasion of The Netherlands on 10 May 1940. During October - December 1940, Hell test transmissions were done on German "request", on behalf of DNB. Ref. 194F.
• During the winter of 1944/45, the general manager of the ANP made several of the ANP's Hell-printers available to the "underground/resistance" press (ref. 87).
• ANP was founding member of the "Hell Commune".
• ANSA (Agenzia Nazionale Stampa Italiana; post-war replacement of the Stefani agency) receives Reuters' and TASS Hellcasts; no Hellcasts of its own. (1948; p. 58, 62 in ref. 88 ).
• ANTARA (Kantorberita Antara; Indonesia): subscribed to Reuters' Hellschreiber transmissions; used one Siemens Presse-Hell printer on loan from Reuters.
• AP (Associated Press, USA): teleprinter transmission from the USA to London and Frankfurt, and Hell transmission from Frankfurt to Europe (e.g., Hungary, Greece), Middle East (e.g., Turkey, Egypt, Iran, Israel), Asia (e.g., Malaysia, Birma). Hell printer at their radio listening post in Hayward (near San Francisco), New York (2 printers, ref. 147), and Europe (ref. 89). Ref. 146. Hellcasts from Berlin, Rome, London, Moscow (1941, ref. 147). Ref. 151.

Fig. 12: AP's extensive worldwide network centers & links, including for Hellschreiber transmissions - 1948

(source: ref. 146)

• APA (Austria Presse Agentur; 1946 post-war successor of ANA): owns Hellschreiber printers (pre-owned by DNB; 11 printers in 1946 per ref. 90), but not allowed to Hellcast (though ref. 145 states that APA distributed news to domestic media via Hell). No spares/replacement parts were available from Germany, as no trade was allowed between Germany and Austria (1948; p. 3 in ref. 88).
• AR (Agenția de Presă RADOR ("Radio Orient"); Romania): used Hellschreiber printers since 1936.
• ATA (Agence Télégraphique Albanaise, Albanian Telegraph Agency); own Hellcasts, and starting 1950, Hellcast reception limited to TASS.
• ATS / SDA/ ATS / STA (Agence Télégraphique Suisse / Schweizerische Depeschenagentur / Agenzia Telegrafica Svizzera / Swiss Telegraphic Agency; Switzerland); used Hell printers as backup. This agency was part of the "Hell Commune".
• BELGA (Belgisch Perstelegraaf Agentschap, "Agence télégraphique belge de presse"; Belgium): occasional reception of foreign Hellcasts. Starting in June of 1935, BELGA subscribed to German domestic service and the international service of DNB. Starting March of 1937, BELGA received Reuters Hellscasts. Ref. 192. BELGA was part of the "Hell Commune".
• BPS (Burma Press Syndicate): subscribed to Reuters' Hellschreiber transmissions; Hell apparatus provided by Reuters. (p. 76 in ref. 84); Hellschreibers installed and operated in Rangoon by Reuters. (1948; p. 3 in ref. 56).
• BTA (Bulgarski Telegrafitscheka Agentzia, Bulgarian News Agency); own Hellcasts, and starting 1950, Hellcast reception limited to TASS.
• CNA (Central News Agency, Taiwan): Hellcasts to Japan, Philippines, and southeast Asia.
• CTK (Čska Tiskova Kancelar, Czech News Agency; a.k.a. CETEKA): receives TASS Helcasts, and Hellcasts to foreign subscribers. Ref. 271.
• DOMEI (Dōmei Tsūshin Sha - United News Agency): subscribed to DNB and Transocean Hellcast services (ref. 91). Domei cooperated closely with DNB, and used a telephone line through the Soviet Union until June of 1941, including for Hellschreiber communication (ref. 189).
• EFE (Agencia Efe; Spain): Hellcasts to subscribers in the Balearic and Canary Islands and Spanish Morocco. Subscribed to Hell transmissions from other agencies (FP, Reuters, UP). EFE was founded in 1939 as a merger of three other Spanish agencies: Fabra, Faro, and Febus; "efe" is the letter "f" in Spanish, referring to the initial of the three founding agencies. Agencia Fabra in Madrid had 3 printers (model T.empf.12a) in 1935 (ref. 92).
• ITIM Agency (Itonout Israel Meouguedet; Israel): subscribed to Hellschreiber transmissions from Reuters; had three Hellschreiber printers.
• JP (Jiji Tsushin-Sha / Jiji Press Ltd, Tokyo/Japan): domestic Hellcasts with 3 transmitters of the Ministry of Telecommunications.
• KCNA (Korean Central News Agency; North Korea): used Hellschreiber transmissions at least into 1989 (ref. 143).
• KYODO (Japan): subscribed to Hellcasts from Reuters/London (6100 words/day); two Hellschreiber printers in the Tokyo office, more were added in 1952. The Kyodo news service used Hellschreiber transmissions until 1960, when it changed over to kanji script (ideographic, phonetic, and pictographic characters that were primarily developed in China, based on the "han" iconic characters) via telefax (ref. 93, 94).
• LPS (London Press Service, LPS; post-war/cold-war successor to the British Official Wireless, and one of the "gray" propaganda services operated by the Overseas Press & Radio Division of the Central Office of Information (COI), ref. 158. Subscribers were British colonial and diplomatic posts around the world.
• Extensive tests were done between various Post Office transmitters in Britain, and receiving stations on the Indian subcontinent and in the Americas (ref. 164F, 168A). From 1946 until at least 1956, the LPS and the British Information Services maintained Hellcasts via longwave and shortwave transmitters of the British Post Office (78 kHz, 7-20 MHz in 1950, 4-14 MHz in 1953, 5-20 MHz in 1956; ref 9A-9C, 159A, 160C, 164A).
• A general technical problem at various British overseas post was interference with radio reception, caused by many local sources of electrical noise (and some poor antenna placement), ref. 164B - 164E. E.g., at the offices of the British Information Services in New Delhi - "India is probably the worst country in the world for radio!" - heavy automobile traffic [ = ignition noise] within 20 yards of Hell sets; high levels of radio interference from ca. 300 ceiling fans, several copying machines, several air conditioners, a dozen refrigerators, a teleprinter, as well as ca. 800 fans in the nearby palace of the Nizam of Hyderabad, high-voltage AC overhead cables at about 40 yards from the Hell set. There were also frequent mains power fluctuations and interruptions. Solutions were to rewire the entire installation, add electrical noise suppression to ceiling fans, identify noisy cars and install electrical noise suppression on their ignition system, prevent non-essential ( = foreign) cars from entering the premises during Hell transmission times, forbid switching on/off of electrical equipment during transmission times, turn on receiver 2 hrs ahead of transmission time (to warm up and reduce drift), and consider installing constant-output-voltage transformer/converters and the possibility of a remote antenna.
• MKH (Magyar Központi Híradó Rt "Hungarian Central News"); ref. 95E. This agency was also part of the "Hell Commune" (ref. 95G).
• MTI (Magyar Távirati Iroda; "Hungarian Telegraphic Office", Hungary): transmission of newscast in French by Hell (p. 103 in ref. 84), to Reuters/London, AFP/Paris and others; receives Hellcasts from Reuters/London, with Hellschreibers of "recent manufacture" (1948; p. 32 in ref. 88). Hellcasts continued at least through January of 1958 (ref. 96). At least in 1939, MTI subscribed to Hell-casts from DNB, Havas, Stefani, Polish Telegraph Office, and German Telegraph Office (ref. 277).
• NCNA (New China News Agency, Hsin Hua Tung-hsün, Xinhua; government news agency of the People's Republic of China, founded 1931; named Red China News Agency until 1937): broadcast Hellschreiber messages to its offices in Prague, Hong Kong, Tokyo, and Karachi at least until 1957 (ref. 97), and to East-Asia (in English) at least until well into 1959 (ref. 98). It also monitored Hell broadcast from other agencies (ref. 99, 100). Broadcast national and international news as Hellschreiber messages from Beijing to newspapers and voice broadcasting stations throughout China. The Chinese national meteorological service is also known to have used Hellschreiber. NCNA still had news Hellcasts 16 hours a day in 1980, to domestic/provincial subscribers (ref. 180). Occasional transmissions on a dozen different short wave freqencies were observed in 1887/88 (ref. ), and may even have continued to the early 1990s. The NCNA also appears to have used the Hell Blatschreiber system, as in 1956, the Foreign Broadcast Information Service (FBIS) of the CIA placed Blattschreiber equipment in operation at the their Okinawa Bureau, "to cover NCNA numeral code from Peking, with good results". Ref. 186.
• NTB (Norsk Telegrambyrå; Norway); using the Hell "strimmelskriver" (tape printer) system since 1934, for news broadcasts from Berlin, Rome, Paris, London and Moscow (ref. 101). Hellcasts with Norwegian news in English twice daily. Norway also used the Feld-Hell system during the German occupation during WW2, and NTB later switched over to the Hell Blattschreiber).
• OST (Oy Suomen Tietotoimisto; Finland); ref. 95L. This agency was also part of the "Hell Commune" (ref. 95E, 95K).
• PAP (Polska Agencja Prasowa; Poland): twice daily auxiliary transmissions in Russian and English by Hell, 4500 words/day. This agency was part of the "Hell Commune".
• Pars Agency (Iran): subscribed to Hellschreiber transmissions from Reuters.
• P.I.-ANETA (Persbiro Indonesia Aneta): subscribed to Hellschreiber transmissions from Reuters (6000 words daily) and ANP (Netherlands, 2500 words daily). It was the first news agency in the Dutch East Indies (now Indonesia). By 1941 Aneta had become the semi-official news agency of the East Indies government. The agency's operations were restricted under Japanese occupation, and it eventually closed by 1946. Aneta changed its name to Persbiro Indonesia (Indonesian Press Bureau) in 1954 and merged into the rival Antara news agency in 1963. P.I.-ANETA did not itself send out Hellcasts.
• PTI (Press Trust of India): subscribed to Globe Reuters' Hellschreiber transmissions, with reception at the Bombay office, by the Indian government on behalf of PTI. The Indian government had no intention to introduce the Hell system for inland or external telegraph services (ref. 185, 1956).
• Reuters (Globereuter, Reuters international news agency, ref. 161A): Hell transmissions from England, 20-30k words/day. Transmissions to North America, Far East, Middle East and Europe, South and Central Africa; 15-25k words/day per zone. Hellcasts and up to 22 hours a day (ref. 163A). Reuters' Hell-service changed from the 12-line to 7-line Hell-font in August of 1939 (ref. 75). Reuters continued Hell-casts at least until 1958 (ref. 102). Reuters offered its subscribers to lease or rent Hell-printers (to be maintained by the subscriber) and radio receivers, ref. 159D. Also see ref. 172A-172F.
• RB (Ritzaus Bureau I/S, Denmark): used Hellschreiber since 1934, probably including sending, until it started to transition to teleprinters in 1949 (ref. 103). This agency was also part of the "Hell Commune".
• SAPA (South African Press Association): subscribed to Reuters' Hellschreiber transmissions, and had one Hell-printer from Reuters in 1950.
• Singapore: had no national news agency; Reuters receives its own Hellcasts and distributes. AP also receives Hell service from London. (1948; p. 130, 131 in ref. 56).
• STT (Suomen Tietotoimisto; Finska Notisbyrån Ab (FNB; Finnish Telegram Bureau): this agency was part of the "Hell Commune" and could receive Hellcasts.
• TANJUG (Telegrafska Agencija Nova Jugoslavija; Yugoslavia); had its own domestic Hellcasts to offices/subscribers outside the five main cities. Subscribed to Hellcasts from foreign agencies. (p. 129 in ref. 84, 117).
• TASS (Telegrafnoie Agentstvo Sovetskogo Soiuza, Телеграфное агентство Советского Союза, Telegraph Agency of the Soviet Union): After the WW2, TASS had large scale press message broadcasts in Hellschreiber format, using equipment recuperated in its occupational zone. It had regular broadcasts in Russian, English, French, and German. TASS continued Hellschreiber broadcasts through the 1950s and probably until the mid-1960s (ref. 98, 104-109). Hell transmissions to Europe in English and Russian (24h/day), French and German (12h/day), mix of Soviet and foreign news. In 1952, used a number of shortwave frequencies (6880-15780 kHz).
• TT (Tidningarnas Telegrambyrå; Sweden): subscribed to Hellcasts from other agencies that were not available via teleprinter (p. 122 in ref. 84); TASS, Reuters (exclusive rights for Sweden, ref. 161B), Havas, DNB, starting in 1934 (ref. 110). No Hellcasts. This agency was also part of the "Hell Commune".
• UP (United Press (formally United Press Associations, UPA), USA): Hellschreiber printers at the UP office in Berlin, and UP listening stations in Valhalla, NY/USA, Barnet (near London/UK), Santiago/Chile, and Buenos Aires/Argentina (who also received Hellcasts from DNB, Tass, and Stefani). Ref. 148 (1942).
• Venezuela: Reuters receives its own Hellcasts and distributes. (1948; p. 187 in ref. 97)
• Xinhua : see NCNA (New China News Agency) above
• Zpravodajská Agentima Slovenska (Z.A.S., Slovenia; dissolved in 1951): 3 Hellprinters for Hellcasts from Reuters and TASS.

The above list is not exhaustive. There other news agencies that used Hell, but I have no documentary evidence of that (yet). Many newspapers, such as The New York Times, also printed Hellcasts directly (ref. 144). Radio Free Europe (RFE, a US government- and CIA-funded broadcast organization founded in 1949, merged with Radio Liberty in 1953) monitored Hellcasts from AGERPRES, ATA, BTA, Tanjug, MTI, PAP, CTK, and TASS (ref. 156). Other types of news organizations also subscribed to hellcasts. E.g., the news room of Radio Monte-Carlo had several Hellschreiber printers in operation around 1951 (ref. 193). The International Telecommunication Union (ITU) covered Hellschreiber transmissions at least through 1973. Ref. 173A/B/C/D.

Figure 13: Presse Hell print outs with German news, at the London office of AP - 1945

(source: ref. 149)

The Chinese news and meteorological services (like the Japanese news services) also used the Hellschreiber system for transmission of pictographic characters. Note that there are about 50 thousand different characters in use, of which 10 thousand in common use and 4 thousand suffice for news casts (ref. 178). So character entry was not done done with a keyboard, but with a system that optically scanned hand-written text, similar to the ZETFAX of the Hell company, the RCA Tapefax, and the RC-58B system of the US Army (WWII). The Toho Denki Kabushikigaisha company (Eastern Electric Ltd.) in Japan made such Hellschreiber systems for the Japanese and Chinese markets (ref. 93). Toho Denki K.K. was a fax equipment manufacturer, and became part of Matsushita Graphic Communication Systems Inc. in 1962.

Figure 14A: Hellcast in Chinese: "... was appointed as government official of the Republic of China [ = Taiwan]"

(source: ref. 93)

Fig. 14B: Hellcast in Chinese: "...formal diplomatic relations between two countries. The Government of the Republic of China..."

(source: ref. 176)

Figure 14C: Hellcast in Chinese: "The destination is important. The maintenance manual shall be visible"

(source: ref. 108)

Figure 14D: Hellcast in Chinese - recorded from a Beijing station on 14040 kHz (late 1970s/early 1980s)

(source: Fig. 11.1.f in ref. 140, courtesy RSGB; used with permission)

In November of 1939, after the German invasion of Poland, the Dutch news agency ANP and the Belgian news agency BELGA took the initiative to found an association of neutral national news agencies, together with the Scandinavian agencies NTB (Norway), TT (Sweden), STT (Finland), RB (Denmark), and the Swiss agency SDA. This was a response to the fact that the largest agencies (Wolff/DNB, Havas, Reuters, and Associated Press) were no longer independent and objective. This association was called the "Hell Commune", as these newscasts were in Hell-format. Ref. 112, 188, 191. The member-agencies sent their news messages to the Commune's headquarters in Amsterdam (via teleprinters or other means), where they were merged into a common newscast. These Hellcasts were broadcast by Radio Kootwijk, the powerful long-wave and shortwave transmitter station of the Dutch PTT, located about 75 km east of Amsterdam (ref. 113). Official Hellcast services started in February of 1940, only to come to an end 3 months later, upon the German invasion of The Netherlands. Ref. 95A-95D. In total, the Commune counted over 20 members. Ref. 95K. The "Commune" agencies re-united again in the fall of 1945 as "Group '39", named after the year in which the "Hell Commune" was founded. There were test transmissions during the spring of 1949 (ref. 95D, 95E), but it does not appear that regular "Commune" Hellcasts ever resumed.

In April of 1947, the Dutch state-owned radio system was split into domestic and international broadcasts. The latter was handled by "Radio Nederland Wereldomroep" (RNW, Radio Netherlands World Service). During the 1950s, overage was extended to the Dutch East and West Indies, Australia, New Zealand, South Africa, Canada, and Brasil. RNW broadcast news copyrighted by ANP, without paying ANP for the service. This resulted in ANP losing money on its Hellcast to, e.g., the Dutch West Indies. At the same time, ANP's newspaper customers were pressuring ANP to lower the subscription fees for the Hell-service, as they were facing steep increases in the cost of newsprint paper. Ref. 95G. This situation prompted ANP to try and start the Dutch Wereld-Helldienst ("World Hell-Service"), in cooperation with the Dutch government. ANP tried, in vain, to get RNW to provide to free-of-charge time on RNW transmitters as compensation. The Dutch P.T.T., monopoly owner of all transmission rights in the country, charged hefty fees to ANP for transmission time. Ref. 95H, 95J. ANP even solicited the services and influence of His Royal Highness Prince Bernhard of The Netherlands, and accused the P.T.T. of foul play. Ref. 95F, 95L. ANP's World Hell-Service never materialized...

EARLY HELL-PRINTER MODELS

Rudolf Hell's first Hellschreiber prototypes used electro-chemical printing, without the characteristic spinning helix. The paper tape was impregnated with yellowish potassium ferrocyanide (prussiate of potash, "gelbes Blutlaugensaltz", unlike the red ferricyanide). Often, ammonium nitrate was added as a deliquescent (to keep the paper damp). The tape has to be moist, so as to conduct electrical current. Passing current through the yellowish salt solution causes electro-oxidation to decompose the salt solution into a compound called Prussian Blue ("preußisch Blau", "Berlin Blau"). The impregnated paper tape only turns dark blue at the electrode with the highest potential. The tape is bleached at the electrode with the lower/negative potential. Typically, a potential of about 1 volt suffices. Heating the compound causes toxic cyanide to be released.

Instead of a spindle, the printer had 14 styluses, placed into a column across the paper tape, touching the tape (ref. 1). Electrical current was applied sequentially ( = scanning) to each individual stylus, the current circuit being closed via the moist paper tape and a metal roller underneath the tape. This form of printing proved impractical: the paper tape had to be kept moist, it had an unpleasant smell, the chemicals would cause the paper tape to fall apart, dried paper tape would shrink, and printed text faded (ref. 121). Note that electro-chemical tape printers where not at all new, see the "How it works" page.

Figure 15: Hell's 1929 prototype with electrical printing on chemically impregnated paper tape

(source: Fig. 2 in ref. 1; the label on the base printer reads "Dr.-Ing. Rudolf Hell")

As stated above, this printing method did not use a printing helix, and was impractical. It was abandoned in 1931, in favor of the first generation Hell-printer that did have a printing helix. The new printer had a roll of plain paper tape, and a roll of thin single-use carbon-paper ribbon ("Kohlepapier"), the same width as the paper tape. The ribbon is placed between the printer-paper tape and the printer spindle. The paper tape and carbon-ribbon are continuously pressed against the spindle. The spindle is dentilled (i.e., the thread is "toothed"). Reception of a tone pulse caused an electro-magnet to vibrate and rub the paper tape back and forth against the carbon-paper and spindle, in the direction across the width of the paper tape. This caused carbon particles to be transferred from the carbon-tape onto the paper tape, at the point where the spindle thread touched the paper. This printer was industrialized and manufactured by Siemens-Halske, who also provided the required fast printer-solenoid technology. Clearly, the fact that this printing methods requires using carbon tape (or inked ribbon) is neither practical nor elegant. Another disadvantage is that significant rubbing or tapping force is required to transfer the carbon "ink" from the tape onto the paper. This causes friction and inertia, which makes maintaining constant speed of the paper tape and spindle difficult - as noted by Rudolf Hell in his 1950 Morse-printer patent (US patent 2731322; column 1, lines 40-45).

Figure 16: Carbon-paper and dentilled spindle mechanism

(source left image: Fig. 3 in ref. 1 and Fig. 5 in ref. 122; right image: Fig. 1 in Hell's patent 698550)

Patent number	Patent office	Year	Inventor(s)	Patent owner(s)	Title (original)	Title (translated)
698550	RPA	1935	Dr.-Ing. Rudolf Hell	Dr.-Ing. Rudolf Hell	Anordnung zur Aufzeichnung von Schriftzeichen, die durch Bildelementen entsprechende Impulsreihen durch ein Magnetsystem und eine umlaufende Schreibspindel übertragen und deren Linien aus gleichlangen, parallel zur Auzeichnungsrichtung verlaufenden Strichen zusammengesetzt werden	Device for recording characters, decomposed into pixel impulses, with a magnet-system and turning printer spindle, as lines made up of same-length strokes parallel to the printing direction

Figure 17: Early combination of a Hellschreiber keyboard-sender and printer with carbon tape - 1931

(source: Fig. 4 in ref. 1)

The next four illustrations show the model "S5" Hellschreiber printer and keyboard-sender system. Ref. 195. It was the standard free-running Hell system, i.e., not a start-stop Hell system. The printer did require sufficiently strong audio tone pulses, either from a radio receiver or from an audio amplifier. The tone pulses (500-1000 Hz tone frequency) drove the 4-pole printer solenoid directly. I.e., the tone pulses were not rectified. The printer was capable of printing up to 400 characters per minute! By stacking three paper tapes and three carbon tapes, three copies of the received text could be printed simultaneously.

Figure 18A: The 1932 Hellschreiber printer model "S5 E" with carbon tape

(source: ref. 195; the printed text reads "up to 400 characters per minute"; the "E" in "S5 E" stands for "Empfänger" = receiver = printer)

Figure 18B: Dimensions of the 1932 Hellschreiber printer model "S5 E"

(source: ref. 195)

At 180 characters/min =  3 characters/sec, the associated keyboard-sender generated characters with a 240 baud telegraphy speed, corresponding to a pixel pulse duration of 4.167 msec. Ref. 195 states that each pixel duration corresponded to about 1/80 of the complete character transmission duration. I.e., a dot-matrix font of close to 80 row/column elements, e.g., 9x9. This does not correspond to one of the known Hellschreiber fonts...

Figure 19A: The 1932 model Hellschreiber keyboard-sender model "S5 G"- with external motor

(source: ref. 195; the "G" in "S5 G" stands for "Geber" = sender)

This keyboard-sender was quite compact:

Figure 19B: The dimensions of the 1932 Hellschreiber keyboard-sender model "S5 G"

(source: ref. 195)

Note that the keyboard layout in the drawing has a space-bar, whereas the actual sender does not. Also, the orientation of the toggle switches on the motor module is different.

The next two illustrations show a slighly different printer model (probably from 1933): the roll of paper tape is now on the right-hand side of the unit:

Figure 20: Right-to-left: "Siemens-Hell" printer, printer keying-amplifier, Telefunken radio receiver E 376 with loop antenna

(source: Fig. 5 in ref. 122; also: Fig. 13 in ref. 123)

Figure 21: An early Siemens-Hell-Schreiber, with carbon tape - 1933

(source: Fig. 9 in ref. 124, Fig. 6 in ref. 125)

"PRESSE HELL" PRINTER MODEL "T EMPF 12"

The T.empf.12 (Telegrafieempfänger 12) is the original Siemens-Halske commercial Hellschreiber "Empfangsfernschreiber" printer model. This "Presse Hell" printer was used extensively throughout the 1930s by news papers and news agencies, as well as the German postal system.

Two versions of the T.empf.12 were made: T.empf.12a and T.empf.12b. Both are simple "printer only" devices: they comprise a power supply, a motor with centrifugal speed regulation, and a printer spindle with an electro-magnet. These Hellschreibers do not contain the electronic circuitry that is required to energize the electromagnet. This means that a suitable detector-amplifier ("Zwischengerät", "Tastgerät", "Tastverstärker") must be placed between the loudspeaker output of the radio receiver and the printer magnet. An other option is to use a special "Hellempfänger" (Hell-receiver) with a solenoid-driver.

The basic characteristics of the T.empf.12a Hellschreibers are as follows (ref. 126):

• Year of manufacture: 1933.
• Printer spindle: one two-turn dentilled thread (prints two identical lines of text).
• Ink source for the spindle: single-use carbon paper ("Kohlepapier").
• Telegraphy speed: selectable, 5 or 2.5 chars/sec, i.e., 300 or 150 chars/min. This is equivalent to 245 or 122.5 Bd. Speed selection was done by changing two gear wheels.
• Printer solenoid current: 10 mA (grey printer module T.syst.23a/b) or 20 mA (black printer module T.syst.23c/d/e). Ref. 142
• Tone frequency: 900 Hz.
• Motor: universal (AC/DC) motor, with centrifugal speed regulator.
• Power: selectable, 110/125/150/220 volt AC, 50 Hz (ref. 1).
• Remote control (for unattended operation): optional. This required additional circuitry for detecting the control signal, a relay for the motor, and a toggle switch. A tone pulse of at least 0.5 sec would turn the motor on, whereas a tone of about 8 sec would turn the motor off.
• Accessory: a winder for the printed tape, powered by a clock spring; model Fm.div.359c.
• Housing: sheet metal.

The associated printer-amplifier had three vacuum tubes (valves). The types depended on whether the amplifier was AC-powered or DC-powered (i.e., with batteries for the tubes' anode and heater-filament). AC-powered: RGN 1054 4-volt dual-diode, REN 904 triode and RE 604 power-triode. DC-powered: REN 1821 triode and two REN 1822 power-triodes. Ref. 126.

Figure 23: The front of "Presse Hell" printer model T.empf.12a

(source: Fig. 1 in ref. 126)

Figure 24: Joining and separating of the carbon tape and the paper tape in the T.empf.12a

Figure 25: The rear of "Presse Hell" model T.empf.12a - cover removed

(source: Fig. 2 in ref. 126)

Fig. 26: T.empf.12a printer at the Hungarian news agency MTI - printed tape is transcribed with a typewriter (1934)

(source: Filmhíradók Online; E376 receiver to the right of the printer)

Figure 27: Several T.empf.12a "Presse-Hell" printers at Reuters in Manila/Philippines - 1950s (!)

(source: Fig. 40 in ref. 127)

Siemens-Hell printer model T.empf.12b looks similar to model 12a. However, the photos below clearly show that there is no roll of carbon paper installed above the roll of paper tape! Model 12b - and all subsequent Hell-printer models - use an inked felt ring to keep the printer spindle covered with ink. This also means that model 12b does not have a vibrator below the paper tape, and the spindle has a solid thread instead of a dentilled thread.

The initial electro-magnet comprised two cores and windings, configured as part of two separate circuits, one of which was resonant at 900 Hz. Ref. 1. I.e., the printer-solenoid was not energized with DC-pulses, but directly with the received (and amplified) 900 Hz tone pulses.

The basic characteristics of the T.empf.12b Hellschreiber are as follows:

• Years of manufacture: 1934-1939.
• Ink source for the spindle (for this and all subsequent Hell-printer models): inked felt ring.
• Size: 36x22x22 cm (WxDxH; ≈14x8½x8½ inch)
• Weight: 11 kg (≈ 24 lbs)
• Power consumption: 45 watt
• Price: see the "Hell equipment prices" page.

Figure 28A: A 1934 "Presse Hell" model T.empf.12b (serial number 5747)

(source: "Hell strimmelskriver Siemens & Halske" in the collection of the Norsk Teknisk Museum (Oslo/Norway))

Figure 28B: Another "Presse Hell" model T.empf.12b

(source: armyradio.wiki, ©2020 M. Boesch, used with permission)

Figure 29A: Rear of the T.empf.12b - without cover

(source: Fig. 10 in ref. 128)

Figure 29B: T.empf.12b - without cover

(source original image: armyradio.wiki, ©2020 M. Boesch, used with permission)

Figure 30: T.empf.12b printers, each with an E38 radio receiver - ANP news agency (The Netherlands) - 1939

(source/photographer: Wiel van der Randen)

Fig. 31: T.empf.12b printers in the info center of the "Reichssendeleitung" of the "Großdeutsche Rundfunk" - January 1940

(photographer: Curt Ullmann, published by "Hier Berlin und alle deutschen Sender", 1940, nr. 24)

Fig. 32: Radio room of the Swedish news agency Tidningarnas Telegrambyrå (TT) with model T.emp.12b Hell-printers, and E 376 receivers

(source: ref. 110)

Figure 33: T.empf.12b printer with keying-amplifier - connected to an HF-radio telephone system

(source: Fig. 57 in ref. 129)

Fig. 34: A complete Presse-Hell receiver station with a Telefunken E376 radio, keying amplifier, T.empf.12b and tape winder

(source: Fig. 9 in ref. 11)

Fig. 35: A complete Presse-Hell receiver station ca. 1940, with a Telefunken E415 radio, keying amplifier, T.empf.12b and tape winder

(source: Fig. 1 in ref. 141)

The Swiss army also used T.empf.12b printers, in combination with with model T.verst.16a keying-amplifiers, model T.send.17 Hell-senders, model T.sum.3 tone oscillators, and Lorenz EO 509/I general-coverage receivers. All are visible in the photo below.

Figure 36: Swiss Army Hellschreiber field-system "36" (with T.empf .12b and Lorenz EO509 radio)

(source: ref. 130; location: Swiss Army Kdo. III AK in Lucerne, 1941)

Siemens-Hell printer model T.empf.12c is nearly identical to model 12b, both inside and outside, based on photos. I have not been able to determine the exact difference.

Figure 37: Equipment label on the rear of a Tempf12c printer

"PRESSE HELL" PRINTER MODEL "T EMPF 14"

In 1940, model T.empf.12 was replaced with model T.empf.14. Again, this is a "Presse Hell" device, used extensively by newspapers and news agencies. Its printer solenoid is DC-powered. The printer does not have a built-in tone-detector/printer-amplifier. So an external detector/amplifier is required between the printer and the phone line or radio receiver. Alternatively, a special radio receiver with built-in detector/amplifier can be used. E.g., the Minerva and Telefunken Hell-receivers.

Figure 37: Front-view of a Siemens-Hell-Schreiber T.empf.14

Figure 38: Close-up of the printer module of a Siemens-Hell-Schreiber T.empf.14

Figure 39: Right- & left-hand side of a Siemens-Hell-Schreiber T.empf.14

Main characteristics of the T.empf.14 are:

• Years of manufacture: 1940-45, 1947 - ?
• Printer spindle: 2-start (i.e., two single-turn threads that are 180° shifted).
• Telegraphy speed: 5 characters/sec (300 chars/min).
• Housing: molded Bakelite ("Preßstoff").
• Size: 31x23x21 cm (≈12x8x9½ inch).
• Weight: 6½ kg (≈14 lbs).
• Motor: 4000 rpm "universal motor", i.e., an AC series-motor (a.k.a. AC commutator motor). Such motors can operate on both DC and single-phase-AC current of about the same voltage. Here: 220 Volt AC/DC, or 110 VDC / 125 VAC (ref. 131, 132A, 132B, 133). The motor has a centrifugal speed regulator.
• In some machines, a combination of jumpers (wire bridges) is used to select between the various voltages.
• In some machines, changing between 110/125 and 220 volt operation requires changing out the motor, in addition to setting the jumpers (ref. 134B).
• In some machines, a 110/125 volt motor with series-resistors is used (mounted on the motor), and operation of 220 volt requires changing jumper settings and changing the series-resistors (ref. 134B).
• Some machines are only for a single voltage. Units with serial number 12000 and above are 220 V only, as they do not have the possibility to install wire bridges for 110/125 volt operation.
• Careful: these days, "220 volt" power outlets actually carry 240 volt! This will burn out a 220 V printer! I use a rheostat to actually run my T.empf.14 on about 117 volt.
• EMI suppression for the carbon brushes is provided from 37.5 kHz – 30 MHz.
• As in the T.empf.12, about half of the T.empf.14 circuitry is for remote on/off control: it involves a regular relay, a time-delay relay, a thermal timer relay, six relay contacts, and a contact that is actuated by the armature of the printer magnet. The relative complex switching sequence is illustrated in ref. 135, ref. 136. A constant tone of at least 0.5 sec is used to turn the machine on, a tone pulse of 7-10 sec to turn it off (ref. 131, 133; at least 8 sec per ref. 132), 4 sec with the toggle switch in the "o" position.
• Some versions of this model have an audio transformer followed by a full-wave selenium rectifier bridge at the input. This allows direct hook-up to a "Fernmeldeleitung" (standard 48 or 60 volt DC telephone line).

The Siemens-Hell-printers normally have manufacturing/inspection stamps and maintenance notes on the inside (all with a date):

Figure 40: Left: 5-June-1940 (acceptance?) stamp inside the printer; right: 22-Nov-1967 general overhaul

Figure 41: Left: Jan-1982 - last recorded maintenance; right: Feb-1979 and March-1984 maintenance dates in DENA printer

Figure 42: Rear of a T.empf.14 - cover removed

(original unedited photo: H. Fykse (L6NCA) used with permission)

Figure 43: The quality-control acceptance stamps in the machine shown above are from 16 and 30 September 1940

("T69" and "T104" identify the inspector of Siemens-Halske's telegraphy equipment manufacturing department)

Figure 44: Rear of the same T.empf.14 machine - cover removed, circuit card lowered

(the two stacks of small disks in the lower left-hand corner are "Gleichrichtersäule" - dry-disk rectifier-diode stacks)

Figure 45: T.empf.14 manufacturing at Siemens

(source: Bundesarchiv, "Fabrikationssaal bei Siemens" [Factory floor at Siemens] in "Welt im Bild" of 14-Nov-1947)

Figure 46: The label on the housing and on the motor of my first T.empf.14

(the motor is a 110 volt AC / 125 volt DC "universal" motor)

On all T.empf.14 equipment labels that I have seen so far, the "Alphab." field is left blank. I presume that this field was intended to indicate whether the machine was intended for the (old) 12-line or for the 7-line Hell font. However, unlike the T.empf.12a, the T.empf.14 was only used with the 7-line Hell font, so there was no need to mark up the label.

Figure 47: The label on another T.empf.14

(source: © Mauro Fattori (IK2WRS); used with permission)

Figure 48A: Mounting of printer module onto an interface plate and onto the chassis and drive unit

(source: adapted from ref. 132B; also see ref. 285)

Figure 48B: Cut-away view of the motor and gearing

(source: adapted from ref. 132B; also see ref. 285)

Figure 48C: Printer material and tool box for the T.empf.14

(source: adapted from ref. 285)

Figure 49: Printer module of my T.empf.14 - cover removed

Figure 50: Printer module of my T.empf.14 - side & front, cover removed

Figure 51: Printer module of my T.empf.14 - front & bottom, cover removed

The large black Bakelite detent-wheel at the bottom of the module is for adjusting the height of the printer-hammer. This external wheel can be turned up to 180° in either direction. A leaf spring on the printer housing prevents the wheel from spinning freely. The Bakelite wheel has the MPAD marking 34 31. Here, "34" identifies the "Preßwerk" - the factory where the material was molded: Siemens-Schuckertwerke, Abteilung Isolierstoffe, in Berlin-Siemenststadt. The material code "31" refers to "rapidly curing Bakelite". See the "molding marks" section of the RV12P4000 vacuum tube page.

The two photos above show two orange-colored solenoids. They are marked as follows:

• 750.5600  = DC-resistance (750 ohms), 5600 wire turns
• 0,07 CuL  = 0.07 mm enameled copper wire (a.k.a. magnet wire, magwire)
• T.Bv.3/474  = telegraphy manufacturing specification 3/474
• Ausgabe II = Issue 2
• Siemens-Halske Logo

As stated above, model T.empf.14 was introduced in 1940. Around that same time, a nearly identical printer module appeared on the military Feld-Hell machine, replacing the original single-solenoid module.

There are several pressed markings on the inside of the Bakelite rear-cover of my machine: the type designator T.empf.14.T105 (T105 may be the part number of the cover itself), the entwined S-H Siemens-Halske logo, and the MPAD code 34 Z2. Again, the factory code "34" implies Siemens-Schuckertwerke. The material code "Z2" refers to "Phenolharz (Bakelit) mit Zellstoff als Füllstoff". I.e., Bakelite with cellulose filler (e.g., shredded paper).

Figure 52: Markings on the inside of the bakelite rear-cover of my T.empf.14

Figure 53: Tape printed by the above machine

(fragment of the telegram (ref. 137) sent as part of "Operation Walküre/Valkyrie" by Graf von Stauffenberg et al; it was actually never broadcast to Hell-printers)

Figure 54: T.empf.14 printer - receiving wireless Hellcast from DNB in Berlin, 1941

(source: ref. 138A, note the paper tape winder to the left of the typewriter)

Figure 55: T.empf.14 printer - same image, but taken at different angle and different Hell print-out at bottom

(source: ref. 138B, 138C; note the E38 receiver to the right of the printer)

Fig. 56: Photo of DENA stand at a 1946 West-Berlin trade show - T.empf.14 printer, Minerva 499 SH radio receiver, tape winder

(source: adapted from image in ref. 139)

Fig. 57: T.empf.14 printer and a Minerva 499 SH radio at the "Tagesspiegel" ["Daily Mirror"] newspaper in Berlin (1946)

(source: ref. 196)

Figure 58: T.empf.14 with a T.verst.18a amplifier and a Telefunken long-wave radio

Here is a 10 sec video clip that I made of a T.empf.14 printer in action:

In 1950 (!), Rudolf Hell patented a Hell-printer that looks very much like the T.empf.14 Presse-Hell machine. It comprises a simple, cheap, small record-player (turntable) motor with centrifugal speed-regulator, printer-amplifier, fixed-frequency radio receiver and loudspeaker (hidden behind the roll of paper tape), and associated controls. The paper-transport is direct-drive, the spindle drive is geared. The motorized printer module is inserted from the front, the receiver-amplifier module from the rear.

Figure 59: Proposed Hell-printer with integrated radio and printer-amplifier

(source: Fig. 1 in Hell patent 872515)

Patent number	Patent office	Year	Inventor(s)	Patent owner(s)	Title (original)	Title (translated)
872515	DPA	1950	Dr.-Ing. Rudolf Hell, Dipl.-Ing. Heinz Taudt	Siemens & Halske A.G.	Faksimile-Schreiber für Schriftzeichenübertragung mit baulicher Vereinigung des Schreibsystems, des Antriebsmotors und des für den Betrieb des Schreibsystems erforderlichen Verstärkers	Fax-printer for character transmission, with integration of the printer-head, motor, and printer-amplifier

My 3D/stereoscopic photos of the T.empf.14 are here.

REFERENCES

• Ref. 1: "Die Entwicklung des Hell-Schreibers" by the inventor himself: Rudolf Hell; pp. 2-11 in "Gerätentwicklungen aus den Jahren 1929-1939", in "Hell - Technische Mitteilungen der Firma Dr.-Ing. Rudolf Hell", Nr. 1, Mai 1940
• Ref. 2: pp. 212-214, 310-312 in "Nachrichtenagenturen im Nationalsozialismus: Propagandainstrumente und Mittel der Presselenkung", André Uzulis, P. Lang Verl., 1955, 356 pp., ISBN 9783631480618
• Ref. 3: pp. 112-113 in "DNB: Darf nichts bringen – Eine Nachrichtenagentur im Dritten Reich", André Uzulis, pp. 107-114 in ""Diener des Staates" oder "Widerstand zwischen den Zeilen"?: Die Rolle der Presse im "Dritten Reich"", Christoph Studt (ed.), Vol. 8 of "Schriftenreihe der Forschungsgemeinschaft 20. Juli 1944 e.V.", XVIII. Königswinterer Tagung Februar 2005, von Lit Verlag, 2007, 208 pp.
• Ref. 4: "Neue Stufe der Nachrichtenübermittlung. Der Hellschreiber wird den Sprechfunk ersetzen", p. 261, 262 in "Der Zeitungs-Verlag: Fachblatt für das gesamte Pressewesen", Vol. 40, Nr. 17, 29 April 1939
• Ref. 4A: (referenced in ref. 4): "Mensch und Maschine in Einklang", in "Zeitungs-Verlag", Vol. 40, Nr. 14, 8 April 1939, pp. 211-212
• Ref. 5: "Die Einführung des Hell-Schreibers vom DNB aus gesehen. Rückschau auf den ersten Betriebsmonat", p. 36-38 in "Der Zeitungs-Verlag: Fachblatt für das gesamte Pressewesen", Vol. 42, Nr. 4, 25 January 1941
• Ref. 6: pp. 92, 93, 107, 126-128, 148-151, 157, 158 in "Die Geschichte der Nachricht und ihrer Verbreiter", Vol. 2 of "Report über Nachrichtenagenturen", Hansjoachim Höhne, Nomos-Verl.-Ges., 1977, 181 pp.
• Ref. 7: p. 123 in "Die Telegraphen-Union", Martin Nietemeier, pp. 87-134 in "Telegraphenbüros und Nachrichtenagenturen in Deutschland - Untersuchungen zu ihrer Geschichte bis 1949", Jürgen Wilke (ed.), De Gruyter Sauer, 2010 (1st ed.1991)
• Ref. 8: "Deutsches Nachrichtenbüro 1923-1945 (1946-1948) - Einleitung", Kristin Hartisch, Bundesarchiv R34, 2005
• Ref. 9: "News in Morse", in "Wireless World"
• Ref. 9A: p. 180 in Vol. 56, Nr. 5, May 1950
• Ref. 9B: p. 169 in Vol. 59, Nr. 4, April 1953
• Ref. 9C: p. 56 in Vol. 62, Nr. 2, February 1956
• Ref. 10: "DNB-Presse-Empfänger für Telefonie und Telegrafie Type E 38", DNB product brochure, 4 pp.
• Ref. 11: p.7 in "Siemens-Hell-Schreiber", Fernmeldetechnik, Siemens & Halske A. G., Wernerwerk, Berlin-Siemensstadt, 2. 37. 5. T., SH6592, 1937, 7 pp.
• Ref. 12: "Der SH-Feldschreiber", Siemens-Halske AG, Berlin-Siemensstadt, SH 7535. 1.2.39. TT1., 11 pp. (courtesy Siemens Corporate Archives, München)
• Ref. 13: "Hellschreiber", p. 266 in "Von der Pressfreiheit zur Pressefreiheit - Südwestdeutsche Zeitungsgeschichte von den Anfängen bis zur Gegenwart", Klaus Dreher, Konrad Theiss Verl., 1983, 364 pp.
• Ref. 14: "Telefunken-Zeitung - Nauen-Nummer" (special Nauen issue), Jg. 3, Nr. 17, August 1919, 119 pp.
• Ref. 15: "Siemens-Hellschreiber-Übermittlung des DNB und der Transocean GmbH", p. 22 in "Zeitungswissenschaft - Monatsschrift für internationale Zeitungsforschung mit Archiv für Presserecht", Essener Verlagsanstalt, Vol. 15, Nr. 1, January 1940
• Ref. 16: "The German Embassy case", Chapter 7 in "The History of the Radio Intelligence Division Before and During World War II, 1940 - 1945I", A.A. Evangelista, E.M. Glunt, D. Flanagan, October 2012, 286 pp.
• Ref. 17: "Telegraphenbüros und Nachrichtenagenturen in Deutschland: Untersuchungen zu ihrer Geschichte bis 1949", Vol. 24 of "Kommunikation und Politik", Jürgen Wilke (ed.), De Gruyter Saur, 1991, 360 pp., ISBN: 978-3-598-20554-5, 978-3-11-135559-7
• Ref. 17A: pp. 213-266 "Das Deutsche Nachrichtenbüro", Jürgen Reitz
• Ref. 17B: ca. p. 191: "Die Transocean GmbH", Cornelius Klee
• Ref. 17C: pp. 236-247, 260-265, 270-281, 286-287, 290-293, 296-297, 300-301, 308-309
• Ref. 18: p. 96 in "Die erfolgverführte Nation: Deutschlands öffentliche Stimmungen 1866 bis 1945", Rudolf Stöber, Franz Steiner Verlag, 1998, 394 pp.  [pdf]
• Ref. 19: Letter of 15 April 1941 from the DNB to the German foreign office, about problems with at reception of DNB Hellschreiber broadcasts in Hsinking/China. Source: Bundesarchiv, Berlin.
• Ref. 20: "Nachrichten wirklich am laufenden Band - Vom Brief zur Funk-Nachricht / Schnellste Übermittlung durch Hell- und Fernschreiber", Helmut Lemcke, p. 5 in "Litzmannstädter Zeitung" newspaper, Jg. 26, Nr. 332, 28 November 1943; also. "Der Schlußdienst - der Kampf um die letzte Sekunde", Benno Wittke, p. 4 in "Litzmannstädter Zeitung", Jg. 26, Nr. 332, 28 November 1943
• Ref. 21: "Die Modernisierung des Fernmeldenetzes der Ungarischen Staatseisenbahnen", István Tari, Gyõzõ Balogh, in "Signal + Draht: Zeitschrift für das Signal- und Fernmeldewesen der Eisenbahnen", Vol. 90, nr. 7/8, July 1998, pp. 16-19
• Ref. 22: p. 73 of "The dawn of amateur radio in the U.K. and Greece: a personal view", Norman F. Joly, Ability Printing, 1990, 151 pp., ISBN-10: 0951562800
• Ref. 23: p. 55 in "History of international broadcasting, Volume 1", James Wood, IEE History of Technology series, Institution of Engineering and Technology (publ.), 1994, 264 pp.
• Ref. 24: p. 227 in "War II: Soldiers of the Press", Richard Pyle, pp. 216-254 in "Breaking News - How Associated Press has covered war, piece, and everything else", reporters of the Associated Press, N. Eklund Later (ed.), 1^st ed., Princeton Architectural Press, 2007, 432 pp., ISBN 1563986890
• Ref. 25: pp. 227, 228 in "Breaking news: how the Associated Press has covered war, peace, and everything else", Nancy Ecklung-Later (ed.), 1^st ed., Princeton Architectural Press, 2007, 432 pp., ISBN-10: 156898689
• Ref. 26: 2 pages from "Hell Printer - Operating and Maintenance Instructions", Issue 2, July 1944, Document M 9501 (Tg), Office of the Engineer-in-Chief, Post Office Engineering Dept. (Radio Branch) GPO, London
• Ref. 27: "DX Listening Digest", 00-23, February 5, 2000
• Ref. 28: "Siemens "Hellschreiber" direct writing telegraph machine", Metropolitan Police: Metropolitan Police: Office of the Commissioner: Correspondence and Papers, 1935, record 36/GEN/227 MEPO 2/3864 in the collection of The National Archives; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Ref. 29: p. 366 in "Telephony and Telegraphy", W.G. Radley, pp. 359-367 in "Journal of the Institution of Electrical Engineers", Vol. 84, Issue 507, March 1939
• Ref. 30: p. 575 in "Telephony and Telegraphy", W.G. Radley, pp. 569-576 in "Journal of the Institution of Electrical Engineers - Part I: General", Vol. 93, Issue 72, December 1946
• Ref. 31: ITU conference 1938; "Propositions transmises au bureau de l'union, pour être soumises à la conference" [proposals to be submitted to the ITU conference], Vol. 1 of "Documents de la Conférence internationale des radiocommunications di Caire (1938)", International Telecommunications Union (ITU), Bern; no English version available; source: ITU
• Ref. 31A: pp. 218, 219: proposal nr 392 R by C.I.N.A - "Considérations générales sur la largeur de bande des émetteurs de t.s.f. modulés par signaux Siemens-Hell" [general considerations about the bandwidth of radio transmitters that are modulated with Siemens-Hell signals]; at 5 chars/sec (punch tape operation), the 12-line Hell-font with a shortest pulse of 2 msec and shortest pause of 3.12 msec has a shortest cycle of 5.12 msec, hence a max cycle rate of 195 Hz, and 97.5 Hz with manual/keyboard operation at 2.5 chars/sec. Tests by Siemens-Halske, Cable & Wireless (UK), and the German Central Postal Authority (R.P.Z) have concluded that a applying a low-pass filter with a corner frequency of 230 Hz at the transmitter is sufficient, and results in 390 Hz occupied bandwidth.
• Ref. 31B: p. 558, proposal nr. 615 R; due to the ever increasing use of the Hell teletype system, the German delegation proposes to expand the "occupied bandwidth table" with a line item for Hell teletype at a speed of 50 WPM, with a bandwidth of 390 Hz (1.6x the fundamental frequency) for CW transmission, and 390 Hz + 2x the tone frequency for tone-modulated transmissions; bandwidth to be limited at the transmitter; for the 7-line Hell-font, the resulting bandwidth will be 2x195 Hz.
• Ref. 31C: p. 581, 582, proposal nr. 634 R; the delegation of the USA proposes to update the "occupied bandwidth" table, incl. expansion with Hell.
• Ref. 32: "Die drahtlose Welle fängt Verbrecher" [wireless captures criminals], in "Funkschau", Vol. 9, Nr. 2, 12 January 1936, p. 11
• Ref. 33: copy of items in file CO 323/1652/2 "Palestine: use of Hellschreiber machine by German consul-general (1939)". Summary of the contents of ref. 33A-33B. Items are in the collection of The National Archive; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Ref. 33A: Draft letter from General Post Office, Telecommunications Dept., London, to E.B. Boyer, dated 7^th January 1939, 2 pages.
• Ref. 33B: Draft letter regarding installation of Hellschreiber apparatus at the German Consulate-General at Jerusalem and unsatisfactory reception of D.N.B. news service on long wave, dated February 1939, 2 pages.
• Ref. 34: copy of items in file CO 323/1652/24 "Palestine: issue of license for Hellschreiber machine to German & Italian consuls-general" (1939)". Summary of the contents of ref. 34A-34B. Items are in the collection of The National Archive; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Ref. 34A: Letter from High Commissioner for Palestine to Mr. M. MacDonald (Principal Secretary of State for the Colonies), dated 21^st July 1939, 5 pages.
• Ref. 34B: Letter to the Colonial Office, dated 25^th August 1939, 4 pages.
• Ref. 35: p. 10 in "Allied Propaganda in World War II: The Complete Record of the Political Warfare Executive (FO 898) - From the National Archives (PRO)", Cumulative Guide Reels 1-168, Philip Taylor (gen. ed.), Thomson Gale, 2005, 43 pp.
• Ref. 36: "Britain's Monitoring Service - Interception on the Grand Scale" in "Wireless World", Vol. 51, Nr. 7, July 1945, pp. 211, 212
• Ref. 37: "Listening To The World", Christopher Cross, in "Radio News", January 1946, pp. 64, 66, 141.
• Ref. 38: "Monitoring Service - Man and Machine - Wartime Secrets Revealed", in "The Geraldton Guardian and Express", September 26, 1945, p. 3
• Ref. 39: "The war-time activities of the engineering division of the B.B.C.", H. Bishop, in "J. of the IEE - Part IIIA: Radiocommunication", Vol. 94, Issue 11, March 1947, pp. 169-185
• Ref. 40: pp. 69, 144 in "Assigned to listen - The Evesham experience, 1939-43", Olive Renier, Vladimir Rubinstein (eds.), BBC External Services, 1986, 154 pp., ISBN-10 0563205083.
• Ref. 42: "Wolff's Telegraphisches Bureau 1849-1933", Dieter Basse, K.G. Sauer Verl., 1991, 346 pp., ISBN 3598205511
• Ref. 43: "B.B.C. sound broadcasting 1939-60. A review of progress", Pawley, E.L.E., in "Proc. of the IEE - Part B: Electronic and Communication Engineering", Volume108, Issue 39, May 1961, pp. 279 - 302
• Ref. 44: "The Engineering Facilities of the BBC Monitoring Service", C.J.W. Hill, H.S. Bishop, "BBC Engineering Division Monograph", Nr. 22, January 1959, BBC, 28 pp.
• Ref. 45: "Caversham Park", T. Holloway, in "Meccano Magazine", Vol. XXXVI, No. 7, July 1951, pp. 292, 293
• Ref. 46: pp. 165 in "Die U-Boot-Funkschaltungen/Verkehrskreise", Chapter 8.2 of "Funkpeilung als alliierte Waffe gegen deutsche U-Boote 1939 - 1945" ["Huff Duff versus U-Boat wireless communication 1939-1945"], Arthur O. Bauer, Ralph Erskine, Klaus Herold, 1^st ed., 1997, 323 pp., ISBN-13; 978-3000021428; source: cdvandt.org
• Ref. 47: "Picking News Out of the Air; Services Put Radio to Work", in "Newsweek" (US ed.), Vol. 19, 2 February 1942, pp. 62-63
• Ref. 48: p. 11 in "Patrolling the Ether: US–UK Open Source Intelligence Cooperation and the BBC's Emergence as an Intelligence Agency, 1939–1948", Laura M. Calkins, in " Intelligence and National Security", Vol. 26, 2011, Nr. 1, pp. 1-22
• Ref. 49: p. 216 in "Kreuzer Prinz Eugen: Unter 3 Flaggen", Paul Schmalenbach, Koehler Verlag, 1998, 226 pp.
• Ref. 50: "Ausstattung der Funkaufklärungsstelle Neumünster nach einer Liste des Oberkommandos der Kriegsmarine - SKL III in Flensburg-Mürwik im Mai 1945" [Equipage of the Signal Intelligence Station Neumünster, per a list of the Navy Supreme Command, Seekriegsleitung III (SKL, Supreme Naval Command) in Flensburg-Mürwik, May 1945], from p. 326 in "Blitz & Anker, Band 2: Informationstechnik, Geschichte & Hintergründe", Joachim Beck, September 2005, ISBN 3833429976, 636 pp.
• Ref. 51: pp. 36, 40, 46 in "The Signal Intelligence Agency and the Supreme Command, Armed Forces", Volume 3 of "European Axis Signal Intelligence in World War II as Revealed by "TICOM" Investigations and by Other Prisoner of War Interrogations and Captured Material, Principally German", Army Security Agency, Washington DC, 136 pp., 1-May-1946, WDGAS-14, declassified 01-June-2009
• Ref. 52: p. 49 in "Signal Intelligence Service of the Army High Command", Vol. 4 of "European Axis Signal Intelligence in World War II as Revealed by "TICOM" Investigations and by Other Prisoner of War Interrogations and Captured Material, Principally German", Army Security Agency, Washington DC, 240 pp., 1-May-1946, WDGAS-14, declassified 23-Oct-1998
• Ref. 53: p. 161 in "Trial of the major war criminals before the international military tribunal, Nuremberg, 14 November 1945 - 1 October 1946", Vol. 33 of "International Military Tribunal Nuremberg", Nuremberg, 1949, 603 pp.
• Ref. 54: pp. 49, 50 in "The German Police", Supreme Headquarters Allied Expeditionary Force Evaluation and Dissemination Section, G-2 (Counter Intelligence Sub-Division), prepared jointly by M.I.R.S. (London Branch) and E.D.S. in consultation with the War Office (M.J. 14(d)), April 1945, 453 pp.
• Ref. 55: p. 114 in "Bericht des Bundesrates an die Bundesversammlung über die antidemokratische Tätigkeit von Schweizern und Ausländern im Zusammenhang mit dem Kriegsgeschehen 1939 - 1945 (Motion Boerlin). Erster Teil. (Vom 28. Dezember 1945", Bundesblatt der Schweizerischen Eidgenossenschaft, Vol. 98, Band 1, No. 1, 4 January 1946
• Ref. 56: "Press, radio, film, 1948: Burma, India, Federation of Malaya, Pakistan, Singapore", Commission on Immediate Technical Needs in Press, Radio and Film of War-devastated Countries" (Comm.Tech.Needs) 2/4A-E, United Nations Educational Scientific and Cultural Organization (UNESCO), 3 July 1948, 144 pp.
• Ref. 57: "German Radio Station Quits after Repeating "The End"", in "Ogdenburg Advance-News" (newspaper), 4 February 1945, p. 41
• Ref. 58: pp. 72, 74 in "The Psychological Warfare Division Supreme Headquarters Allied Expeditionary Force - An Account of Its Operations in the Western European Campaign, 1944-1945", 1951, 138 pp.
• Ref. 59: "DANA", H. Warner Waid (editor), pp. 9, 10, 32 in "Weekly Information Bulletin", No. 59, 16 Sept. 1946, 32 pp., Office of the Assistant Chief of Staff, G-5 Division USFET, Information Branch
• Ref. 60: "A German News Service is Born" [DANA, incl. Hellschreiber service, see p. 11], pp. 10-12, 20 in "Military Government - Weekly Information Bulletin", No. 34, March 1946, Office of the Director, Office of Military Government (U.S.), United States Forces European Theatre, Reports and Information Branch
• Ref. 61: "Germany's New Press - Review of Development in U.S. Zone", pp. 19-22, 27 in "Information Bulletin No. 154", Office of Military Government for Germany (U.S. Control Office, APO 742, US Army, 8 February 1949, 33 pp.
• Ref. 62: p. 51 in "History of the Information Control Division OMGUS [Office of Military Government, United States] 1944 to June 30, 1946", E.J. Warkentin (ed.), 2013, 169 pp. [pdf]
• Ref. 63: p. 22 in "ICD History III July 1, 1947-June 30, 1948" in "The History of American Information Control in Germany (1944-1948)", 82 pp. Erwin J. Warkentin (ed.)
• Ref. 64: p. 5 in "The German Press in the US-Occupied Area 1945-1948", Office of Military Government for Germany (U.S.), Information Services Division, Special Report of the Military Governor, November 1948, 45 pp.
• Ref. 65: pp. 7-19, 49, 68-70, 126 in "40 Jahre dpa, DEUTSCHE PRESSE-AGENTUR GmbH", Hans Benirschke (ed.), dpa publ., Hamburg 1989, 127 pp.
• Ref. 66: Chapter 17 in "Black Boomerang", Sefton Delmer, Secker & Warburg, 1962
• Ref. 67: cover page of "Der Siemens-Hell-Schreiber und der neue Telefunken-Langwellen-Hell-Empfänger", in "Hochfrequenztechnik und Funk-Praxis - Zeitschrift für Funktechnik", Vol. 1, Nr. 14, December 1948
• Ref. 68: "Norddeich Radio während des 2. Weltkrieges 1939 – 1945", ["Norddeich Radio During the WW2 1939-1945"], Hans-Jörg Pust, source: pust-norden.de. [pdf German,  pdf English]
• Ref. 69: p. 4 in "The history of the German Press Agency dpa", 9 pp.
• Ref. 70: "In eigener Sache - Rendezvous in Düsseldorf", p. 12 in "Der Spiegel", Nr. 45, 8 November 1947, SPIEGEL-Verlag Rudolf Augstein GmbH & Co. KG
• Ref. 71: p. 145 in "Der Telegraf: Entstehung einer SPD-nahen Lizenzzeitung in Berlin 1946 bis 1950", Susanne Grebner, LIT Verlag, 2002, 472 pp.
• Ref. 72: p. 164 in "Das Wiener Verlagswesen der Nachkriegszeit: Eine Untersuchung der Rolle der öffentlichen Verwalter bei der Entnazifizierung und bei der Rückstellung arisierter Verlage und Buchhandlungen", Ursula Schwarz, Bachelor ("Magister") thesis, University of Vienna, 2003, 201 pp. [pdf]
• Ref. 73: "Wer setzt schon auf Caprice? In den Wettbüros deutscher Buchmacher herrscht Katerstimmung", Esther Knorr-Anders, in "DIE ZEIT", Nr. 2, 8 January 1982, p. 52 [pdf]
• Ref. 74: "Tien jaar geleden kreeg Hitler zijn oorlog", p. 1 of "Utrechts Nieuwsblad" [Dutch newspaper], 1 September 1949
• Ref. 75: articles in "The Post Offfice Electrical Engineers' Journal" (POEEJ)
• Ref. 75A: "Reuters' Wireless Services", W. West, in "The Post Office Electrical Engineers' Journal", Vol. 39, July 1946, pp. 48-52.
• Ref. 75B: "p.  213 in "Overseas Telecommunications", in "The Post Office Electrical Engineers' Journal", Vol. 49, October 1956, Part 3, pp. 205-215. Source: worldradiohistory.com, accessed February 2023.
• Ref. 76: p. 170 in "Castro and Stockmaster: A Life in Reuters", M. Nelson, Troubadour Publ. Ltd., 2011, 272 pp.
• Ref. 77: "Reuters and the news service", §7.2.2, p. 240 in "A History of Telegraphy: Its History and Technology", Ken Beauchamp, Institution of Electrical Engineers, Vol. 26 of "History of Technology Series", 2001, 408 pp., ISBN-10: 0852967926
• Ref. 78: p. 13 in "Telecommunications in War", S.A. Angwin, in "J. of the IEE, Part IIIA: Radiocommunication", Vol. 94, Issue 11, Nov. 1947, pp. 7-15
• Ref. 79: "The Japanese Code", p. 102 in "Codes of the World", deNeuf, Walters, Anderson, Folkman, Dickow, Mundt, Geisel, Cady, Cookson, Williams, Miller, pp. 102-110 in "Ports O' Call: a book of the wireless pioneers", Vol. 4, 1976, Society Of Wireless Pioneers (SOWP), 112 pp.
• Ref. 80: p. 190, 191 in "La propaganda alemana en la Segunda República Española", I. Schulze-Schneider, in "Historia y Comunicación Social", Nr. 4, 1999, pp. 183-197
• Ref. 81: "p. 6 in "The creation of European News - News agency cooperation in interwar Europe", Heidi Tworek, in "Journalism Studies" Vol. 14, Issue 5, 2013, pp. 730-742 [pdf]
• Ref. 82: "Listening Posts Speed News to Journal Readers", p. 5 of "The Wisconsin State Journal", 4 June 1942
• Ref. 83: "Reuters Century 1851-1951", Graham Storey, Max Parrish & Co, 1951, 276 pp. [pdf 17 MB]
• Ref. 84: "News agencies, Their Structure and Operation", Issue 42, UNESCO, 1953, 208 pp. [pdf English, pdf French (235 pp., 17 MB)]
• Ref. 85: "p. 130 in "Zwischen Sympathie und Eigennutz: NS-Propaganda und die türkische Presse im Zweiten Weltkrieg", Berna Pekesen, LIT Verlag, 2014, 242 pp.
• Ref. 86: 31-May-1949 - internal note (in Dutch) from the Chief telegraphist (Mr. H. Mater) of the ANP news agency in The Hague/The Netherlands, about the EMA printers in the ANP radio rooms in Amsterdam and Rotterdam. In total 21 EMA Hell-printers: 6x model HSG-2 (serial nr. 104, 111-115, all OK, 2 missing ink-roller), 6x model HS125 with additional amplifier stage (serial nr. 57-59, 63-65, all OK), 2x model HS125 without additional amplifier stage (serial nr. 60, 62; nr. 60 with bad transformer and broken fuse holder, nr. 62 OK). Of these 21, 2 (1x HS125 1x HSG2) will go to Batavia/Dutch East Indies, 4 to Dutch West Indies, 14 are in the radio rooms, 1 with printer module missing and to be returned to EMA . In total 4 Siemens Hell-printers: 3 old model printers for long wave European traffic (news agencies DPD, CTK, NTB), 1 new model for short wave traffic (TASS), 1 new model in Amsterdam and 1 in Rotterdam; no replacement ordered yet for the new printer shipped to Curacao. Still awaiting ink rollers ordered from Siemens (as is ANETA in New York). Still awaiting replacement transformer from EMA for HS125 nr. 60, various parts for HSG2 nr. 111 and HSG-2 schematic. Questions what to do with the present EMA printers, and if EMA will add an amplifier-stage to HS125 serial nr. 62.
• Ref. 87: p. 470 in vol. 2 of "Het laatste jaar", Vol. 10b of "Het Koninkrijk der Nederlanden in de Tweede Wereldoorlog", L. de Jong, Martinus Nijhoff Publ., 1982, 1543 pp.
• Ref. 88: "Press, radio, film, 1948: surveys of Austria, Hungary, Italy", Commission on Immediate Technical Needs in Press, Radio and Film of War-devastated Countries" (Comm.Tech.Needs) 2/2, United Nations Educational Scientific and Cultural Organization (UNESCO), 3 July 1948, 99 pp.
• Ref. 89: "Bulletin", in "Binghamton Press", Vol. 66, No. 251, 3 February 1945, p. 1
• Ref. 90: "Gründung der Austria Presse Agentur", Edith Dorfler, Wolfgang Pensold, pp. 24-37 in "Medien & Zeit - Kommunikation in Vergangenheit und Gegenwart, Vol. 15, Nr. 4, 2000
• Ref. 91: p. 39 in "The Domei News Agency", chapter IV in "Japan's Political Warfare", P. de Mendelssohn, Taylor & Francis US, 2010, 186 pp.
• Ref. 92: "El Radioteleinscriptor Siemens Hell", in "Revista de telecommunicación Electron", No. 42, 15 December 1935, pp. 4-6; No. 43, 15 December 1935, pp. 8-10
• Ref. 93: "Oriental approach to transpacific transmission", Donald K. deNeuf (WA1SPM; SK), pp. 16, 18 in "Proceedings of The Radio Club of America, Inc.", Vol. 51, Nr. 1, March 1977
• Ref. 94: p. 67 in "The Japanese press" (Nihon Shinbun Kyōkai), Japan Newspaper Publishers and Editors Association, 1969
• Ref. 95: Hell Commune, Group '39, Dutch Hell World Service (source: National Archives of The Netherlands in The Hague).
• Ref. 95A: 28-Dec-1946 - Letter (in Dutch) from the company "Admiral Radiorichtingzoekers Zenders Ontvangers" [radio direction-finders, transmitters, receivers] (Mr. van den Bosch) in The Hague/The Netherlands, to ANP news agency in The Hague/The Netherlands, reporting assessment of feasibility of a new long wave, long range transmitter for Hell broadcast: construction is too expensive, and takes at least 1 year. For transmissions to Moscow, Indonesia, the Americas, and the Pacific, a 50 kW shortwave transmitter with directional antennas in the 20-40 m bands would be adequate. Transmitters and antennas have a lead time of 3 months. A 50 W transmitter for the 80-200 m band could cover The Netherlands, Belgium and Britain, and would cost 10k DFL incl. antenna and installation.
• Ref. 95B: 6-May-1947 - letter (in English) from the ANP news agency in The Hague/The Netherlands (Gen Mgr, Mr van de Pol), to the members of the Group '39, about cost advantages of Hell broadcast by the Hell Commune to the members of the Group, for news reporting on sporting events (soccer, chess, cycling, swimming, Olympic winter & summer games, speed skating).
• Ref. 95C: 13-May-1947 - letter (in English) from the ANP news agency in The Hague/The Netherlands (Gen Mgr, Mr van de Pol) to the members of the Group '39, reporting on mixed results from test transmissions of the European Hell Commune, P.T.T. fee increase from 40 DFL (pre-WW2) to 60 DFL per hour (about 2040 words), purchase by ANP of 20 Hell-printers from EMA, monthly cost to Commune members for 200 words daily, feeding messages by telex to a Hell-hub in The Hague or Copenhagen; news agencies Belga, Anep, ATS, possibly APA/Austria, ANSA/Italy; this constitutes a plan to resurrect the Hell Commune.
• Ref. 95D: 26-April-1949 - note (in English) from the ANP news agency in The Hague/The Netherlands (Gen. Mgr. Mr van de Pol) [to the members of the Hell Commune, announcing 10-minute Hell test transmissions with the Hell-Commune transmitter on long wave (84.5 kHz), on 3/4/5 May, at 9:00, 15:00, and 21:00 GMT, and requesting reception reports and a piece of printed tape.
• Ref. 95E: 4-May-1949, table listing reception reports for Hell test transmissions on 2, 3, and 4-May-1949, each day at 09:00, 15:00, and 21:00 hours [from The Netherlands] from members of the Hell Commune: APA/Austria, PAP/Poland, AA/Greece, Tanjug/Yugoslavia, OST/Finnland, MKH/Hungary, ANSA/Italy, CTK/Czechoslovakia, AE/Spain, NT/Norway, RB/Denmark, BELGA/Belgium, TT/Sweden, Reuters/Britain, DPD/Germany, DENA/Germany, AA = Agence d'Athène, OST = Oy Suomen Tietotoimisto, MKH = Magyar Központi Híradó Rt "Hungarian Central News" (i.e., not MTI = Magyar Távirati Iroda, lit. "Hungarian Telegraphic Office"
• Ref. 95F: 19-November-1951 - letter (in Dutch) from the ANP news agency in The Hague/The Netherlands (Gen. Dir. van de Pol) to the Stichting Wereldomroep (Dutch national World Service), requesting support from the Wereldomroep; ANP is losing money on its Hell-service to the Dutch West Indies, were local correspondents edit, print & forward news to local government, governors, newspapers, and companies. E.g., one major newspaper in Willemstad/Curacao has cancelled the paid ANP service in favor of copying radio broadcasts from the Wereldomroep - without paying ANP for copyright. Newspapers are also pressuring ANP to reduce fees, as newsprint paper prices are being increased by 18%. ANP is forced to close its offices in the West Indies. ANP, in coordination with the Dutch government, wants to start an ANP "Wereld-Helldienst" [Hell World Service]. ANP request that the Wereldomroep allow ANP to use its transmitters free of charge, for 15-20 pages of text per day. ANP points out that the Wereldomroep is government-funded, and undermines ANP getting paid for copyright and other services, though ANP still has to pay full transmission fees.
• Ref. 95G: Nov-1951 - internal note (in Dutch) of the ANP news agency in The Hague/The Netherlands; fees charged before WW2 by the Dutch P.T.T. for simultaneous bi-directional transmission to the East & West Dutch Indies (16.90 DFL for the first 20 minutes, 0.55 DFL per minute thereafter, 25000 DFL annually for 100 minutes per day); assuming same fee (25000 DFL annually) for additional omni-directional broadcast; the price of Hell set-up for a receiving station for the planned ANP "Wereld-Helldienst" [Hell World Service] (EMA printer for 2300 CHF or 2200 DFL for Siemens printer - preferred; special receiver 5500 DFL, antenna 100 DFL, total ca. 7800 DFL = ca. 770 DFL annually over 10 years; paper & ink consumption 0.25 DFL daily); calculation of the fee to be charged per receiving station (annually 1770 DFL, assuming 50 stations and 50000 DFL P.T.T. transmission fees).
• Ref. 95H: 30-November-1951 - draft letter (in Dutch) of the ANP news agency in The Hague/The Netherlands [probably to the Dutch government] about ANP's justification for the "Wereld-Helldienst" [Hell World Service]; the Service is in the national interest, as well as the interest of large companies and of citizens abroad. Service: multiple daily Hell newscasts (international news, Dutch news, news from Dutch overseas possessions) to overseas offices of the Ministry of Foreign Affairs and other Ministries, large overseas offices Dutch companies such as Philips, Royal Petroleum, KLM, banks, The Netherlands Trading Society ("Nederlandse Handelsmaatschappij"), cultural organizations, Netherlands Harbor Construction Co. ("Nederlandse Mij. voor Havenwerken"), etc. Hell-casts primarily in Dutch, some in English. Fee-based service, based on number of participating receiving stations, independent of location. Organization with Advisory board. Service also useful in case of new war; to support this, ANP is investigating cooperation with the South African Broadcast Co. for use of their transmitters.
• Ref. 95J: 30-Nov-1951 - draft letter (in Dutch) of the ANP news agency in The Hague/The Netherlands [probably to the Dutch government] with the fees charged by the Dutch P.T.T. for transmissions (annually ca. 25000 DFL, for 100 minutes daily in 2 directions, 75000 DFL for 1x broadcast and 2x directional), and the calculation of the fee to be charged per receiving station (annually 1875 DFL, assuming 40 stations and 75000 DFL P.T.T. transmission fees).
• Ref. 95K: 1951? - list of names of contacts at 13 of the 20 news agencies (other than ANP) that are part of the Hell Commune.
• Ref. 95L: 26-February-1952 - 3-page letter (in Dutch) of the ANP news agency in The Hague/The Netherlands (Gen. Dir. van de Pol) to His Royal Highness Prince Bernhard of The Netherlands, about ANP's planned "Wereld-Helldienst" [Hell World Service]; submittal of status report and draft budget are overdue, as ANP has come to the conclusion that the cooperation with the Dutch World Service will not be possible (limited transmission time is possible, but the World Service has formal objections that probably cannot be overcome). Negotiations with the Dutch P.T.T. have also not been positive (no transmission time will be made available for broadcast to receiving stations within Europe, no transmitters available for transmission to stations outside Europe). ANP suspects foul play by the P.T.T., as an earlier request for test transmissions for a European sports newscast service was honored immediately. For Hell-casts to the Dutch East & West Indies, ANP already has transmission time. Estimate for cost of a Hell receiving station (ca. 6000 DFL = 1200 DFL annually over 5 years, Siemens and Telefunken equipment, general overhaul after 15-20 years), estimate of P.T.T. transmission fees (annually 30000 DFL, per beam direction), annual fees per receiving station based on number of stations of each beam; ANP considers it impossible that the P.T.T. would not have transmission time available for 1 hour per day, spread out over the day; the Board of the P.T.T. appears to be opposed to Hell transmissions, based on its large bandwidth, and the P.T.T. now is fully convinced by ARR-TOR (wireless telex with automatic repeat request in case of certain character distortions), even though it requires 2 channels and is too expensive for news casts. Until this resistance/opposition is overcome, the time is not right for convocation of interested parties. The ANP offers to install a Hell receiving station at the royal palace, so His Royal Highness can see for himself, how easy its operation is, as well as telex machine with connection to the ANP domestic service.
• Ref. 96: p. II 6 in "U.S. Journalists Interview Münnich", 1958, 4 pp.  [pdf]
• Ref. 97: pp. 296, 308 in "The New China News Agency and Foreign Policy in China", Roger L. Dial, pp. 293-318 in "International Journal", Vol. 31, No. 2, News and Nations (Spring, 1976)
• Ref. 98: pp. 127, 129 in "The Founding of the Sino-Albanian Entente", Daniel Tretiak, in "The China Quarterly", No. 10, April-June 1962, pp. 123-143
• Ref. 99: p. 55 in "The Ts'an-k'ao Hsiao-hsi: How Well Informed Are Chinese Officials about the Outside World", Henry G. Schwarz, The China Quarterly, No. 27, July-September 1966, pp. 54-83
• Ref. 100: pp. 296, 308 in "The New China News Agency and Foreign Policy in China", Roger L. Dial, in "International Journal", Vol. 31, No. 2, Spring 1976, "News and Nations", pp. 293-318
• Ref. 101: "Hell strimmelskriver Siemens & Halske"; source: Norsk Teknisk Museum (Norwegian Museum of Technology)
• Ref. 102: "Jimmy Hahn", blog entry on 27-Feb-2014 by E. Mendoza in "The Baron" (website for topical and historical information of interest to Reuters people past and present)
• Ref. 103: "Organisationer, Ritzau og andet samvirke", in "De Danske Aviser"
• Ref. 104: "New U.S: European Spy Centers Planned", transcript of a Hellschreiber press message from TASS (Soviet Press Service), August 22, 1948, 1 p.
• Ref. 105: p. 3 in "Analysis of Soviet Foreign Propaganda Broadcasts" [TASS Hellschreiber service in English, French, German], de-classified CIA document, Central Intelligence Group, ORE 2, 23 July 1946, 13 pp.
• Ref.106: p. 8 in "Evidence of USSR Military Intentions in Soviet Propaganda Broadcasts", de-classified CIA document, ORE 64-48, 27 August 1946, 14 pp.
• Ref. 107: transcript of a Hellschreiber press message from a TASS (Soviet Press Service) European broadcast, 30 August 1947, 1p., de-classified CIA document
• Ref. 108: "Hellschreiber - Nostalgie oder Realität?", Helmut Liebich DL1OY, in "Funkschau", 11/1990, pp. 58-61
• Ref. 109: p. 72 in "Radio hole-in-the-head/Radio liberty: an insider's story of Cold War broadcasting" ["TASS" Hellschreiber service], James Critchlow, American University Press, 1995, 192 pp.
• Ref. 110: "En ny radioskrivare. Hur utrikesnyheterna förmedlas" [with English machine-translation], Erik H. Lundgren, pp. 45-49 in "Nordisk Familjeboks Månadskrönika", Vol. 2, Nr. 1, January 1939
• Ref. 111: "Press, radio, film, 1948: Cuba, Dominican Republic, Ecuador, Haiti, Honduras, Mexico, Peru, Uruguay, Venezuela", Commission on Immediate Technical Needs in Press, Radio and Film of War-devastated Countries" (Comm.Tech.Needs) 2/3A-(i), United Nations Educational Scientific and Cultural Organization (UNESCO), 3 July 1948, 208 pp.
• Ref. 112: "Collaboration between News Agencies in Nordic Countries", UNESCO International Commission for the Study of Communication Problems, Series 16, 1978, 8 pp.
• Ref. 113: pp. 55, 56 in "Radio Kootwijk biografie van een zendstation en een dorp in het hart van de Veluwe", Cees van der Pluijm, Koninklijke BDU Uitgevers, 2014, 224 pp., ISBN 9789087882167
• Ref. 114: p. 132 in "Spymistress: the life of Vera Atkins, the greatest female secret agent of World War II", William Stevenson, Arcade Publishing, 2007, 354 pp.
• Ref. 115: p. 327 in "Hitler in der spanischen Arena: die deutsch-spanischen Beziehungen im Spannungsfeld der europäischen Interessenpolitik vom Ausbruch des Bürgerkrieges bis zum Ausbruch des Weltkrieges, 1936-1939", Hans-Henning Abendroth, F. Schöning Verl., 1973, 411 pp.
• Ref. 116: "The BBC Monitoring Service - A short engineering history", Peter C.J. Hill, Proc. 2^nd IEEE Region & Conference on the History of Telecommunications (HISTELCON), Madrid, 3-5 November 2010, pp. 1-4
• Ref. 117: "Tehnika Tanjuga (II)", Svetislav Jordovič, Ilija Crnobrnja, in "Radioamater", Časopis Saveza radioamatera Jugoslavije [Journal of the Amateur Radio Association of Yogoslavia], September 1959, pp. 250-251.
• Ref. 118: p. 321 in "Shanghai und die Politik des Dritten Reiches", Astrid Freyeisen, Konigshausen & Neumann, 2000, 544 pp., ISBN-10: 3826016904
• Ref. 119: "Siemens-Hell-Schreiber", pp. 109, 110 in "Siemens-Zeitschrift", Bd. 18, H. 3/4, March/April 1938
• Ref. 120: p. 198 in "Blitz & Anker: Informationstechnik - Geschichte und Hintergründe, Volume 1", Joachim Beck, BoD, 2005, 560 pp.
• Ref. 121: "Anwendung von Faksimile-Hellschreibern für den Boden-Bord-Verkehr" ["Application of the fax-Hellschreiber for ground-ground radio traffic"], Rudolf Hell, pp. 67-75 in "Flugsicherungs-Verfahren und -Technik: Grundsätzliches über die Technik für Flugsicherung und Betrachtung der wichtigsten technischen Hilfsmittel außer Radar", Teil IIIB in "Flugnavigation und Flugsicherung", Vol. 7 of "Bücherei der Funkortung", proceedings of the "Internationale Jahrestagung des Ausschuß für Funkortung", Berlin; Verkehrs- und Wirtschafts-Verlag, 1958, 107 pp.
• Ref. 122: "Voici "des machines à écrire" pour télégraphier soi-même de son domicile" [machines for teleprinting yourself at home], Paul Lucas, in "La Science et la Vie", No. 209, November 1934, pp. 406-410.
• Ref. 123: "Die Fortentwicklung des Fernschreibverkehrs über Draht und drahtlos", P. Storch, in "Elektrotechnische Zeitschrift (ETZ)" [Hellschreiber, Handsender, Lochstreifensender on pp. 141-143], Jg. 55, Heft 5, 1 February 1934, pp. 109-112, 141-143
• Ref. 124: "Stand der Siemens-Hell-Fernschreibtechnik", Rudolf Zimmerman, Siemens & Halske A.G. - Wernerwerk, Technische Mitteilungen des Fernmeldewerks, Abteilung für Telegrafengerät, SH 7997. 0,5. 1043. TT1. M/1401, May 1940, 10 pp. (courtesy Siemens Corporate Archives, München)
• Ref. 125: "Der Siemens-Hell-Schreiber", H. Stahl, Siemens & Halske A. G., Wernerwerk, Berlin-Siemenstadt, 1934, 15 pp. SH5358, 1.34.1,5 T.; reprint from "Telegraphen- und Fernsprechtechnik", Jg. 22, Heft 11, November 1933, pp. 291-295
• Ref. 126: "Bedienungsanweisung für den Siemens-Hell-Schreiber T.empf.12a", Siemens & Halske AG, Wernerwerk, Telegrafen-Abteilung, Berlin-Siemensstadt, March 1935, 17 pp., Te 11/3
• Ref. 127: p. 314 in "The power of news - The history of Reuters", Donald Read, Oxford Press, 2^nd ed., 1999, 518 pp. Source: archive.org.
• Ref. 128: "Der Siemens-Hell-Schreiber", Alexander B. Damjanovic, in "Zeitschrift für Fernmeldetechnik, Werk- und Gerätebau", Siemens & Halske A.G., Wernerwerk, Jg. 17, Nr. 12, 1936, 7 pp., SH 6554, 1. 37. 0,5 T.
• Ref. 129: pp. 65, 66 in "Hochfrequenz-Nachrichtentrechnik für Elektrizitätswerke" [Hellschreiber over 30-220 kV power lines], 2^nd ed., Gerhard Dreßler, Heinrich-Karl Podszeck, Springer Verlag, 1952, 183 pp.
• Ref. 130: referenced pages in "Die Funkertruppe: Beitrag zur Geschichte des Funkwesens bei den Übermittlungstruppen 1904 bis 1979", Rudolf J. Ritter, Vol. 1 of "Monographien zur Geschichte der Übermittlungstruppen", Bern, Bundesamt für Übermittlungstruppen, 1991, 112 pp. [File size: 13 MB]
• Ref. 131: "Der neue Siemens-Hell-Schreiber", Wilhelm Heller, Technische Mitteilungen des Fernmeldewerks, Abt. F. Telegrafengerät, May 1940, Siemens & Halske A. G., Wernerwerk, SH7996, 1.8.40 T T1., 4 pp. (courtesy Siemens Corporate Archives, München)
• Ref. 132: T.empf.14 description and operating instructions
• Ref. 132A: "Siemens-Hell-Schreiber (T empf 14) - Beschreibung und Betriebsvorschrift" [incl. longwave reception setup with Funk Empf 61 receiver, shortwave with additional converter], Siemens-Halske AG, Wernerwerk F, Te 11/46, WWT. 1000., S. 47. 1494 Reg.-Nr. 115, November 1946, 21 pp. (courtesy Heinz Blumberg, DC4GL).
• Ref. 132B: - updated version of ref. 132A, with more photos - Siemens-Hell-Schreiber (T empf 14) - Beschreibung und Betriebsvorschrift" [incl. longwave reception setup with "E 515X" receiver, shortwave with dedicated receiver], Siemens-Halske AG, Wernerwerk, Te 11/46, 1946, 29 pp. Source: hamfu.ch, retrieved 30 September 2020.
• Ref. 133: pp. 6-8 in "Der Siemens-Hell-Schreiber", Siemens & Halske A.G., Siemens Fernmelde Technik, SH 8354. 443. TT1., 1943, 7 pp. (courtesy Siemens Corporate Archives, München)
• Ref. 134: schematics
• Ref. 134A: "T.empf.14 Schaltplan-1"
• Ref. 134B: "T.empf.14 Schaltplan-2" (courtesy Heinz Blumberg, DC4GL)
• Ref. 135C: "Annotated circuit card of T.empf.14 with serial number 12039", Frank Dörenberg, 24 January 2014
• Ref. 135: "Remote control sequence of the Presse Hell printer", Frank Dörenberg, August 2014, 8 pp.
• Ref. 136: p. 65 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. 137: Teleprinter telegram pages and transcribed text with announcement by Graf von Stauffenberg et al as part of "Operation Walküre".
• Ref. 138:"Die schnelle Nachrichtenübermittlung…" [Fast news broadcast]
• Ref. 138A: p. 7 in "Deutscher Morgen / Aurora Allemã", German weekly newspaper published in Saõ Paulo/Brazil, Vol. 10, nr. 10, 7 March 1941.
• Ref. 138B: p. 1 in "Badener Zeitung" (newspaper), Vol. 62, 25 January 1941 [pdf].
• Ref. 138C: p. 3 in "Salzburger Volksblatt" (newspaper), Vol. 9, 23 January 1941.
• Ref. 139: "Leistungsschau des Berliner USA-Sektors", 2 pp. in "Funk-Technik", Vol. 2, Nr. 16, 1947
• Ref. 140: "The Hellschreiber System", pp. 11.1-11.3 in "Teleprinter Handbook", A. G. Hobbs (G8GOJ), E. W. Yeomanson (G3IIR), Arthur C. Gee (G2UK), Radio Society of Great Britain, 2^nd ed., 1983, 350 pp., ISBN 0900612592
• Ref. 141: "Die Bedeutung der Siemens-Hell-Geräte für die neuzeitliche Telegrafie" [Importance of Siemens-Hell equipment for modern telegraphy], K. Maßmann, E. Jansen in "Zeitschrift für Fernmeldetechnik, Werk- und Gerätebau (Zeitschrift des Verbandes deutscher Schwachstrom-Industrieller)", Vol. 21, 1940, Nr. 3, pp. 39-44.
• Ref. 142: 2 pages from maintenance manual T.Pr.58/10 for Schreibsystem T.syst.23a/b/c/d/e, Siemens & Halske A.G., Wernerwerk, 3 Sept. 1941; courtesy P. Trepte.
• Ref. 143: p. 60 of "RTTY - The exciting world of Radio Teletype Monitoring", Robert Margolis, in "Popular Communications", January 1989, pp. 59-61
• Ref. 144: "Getting the News - Fast!", Mike Bienstock, in "Popular Electronics", April 1959, pp. 61, 62, 109
• Ref. 145: "Vor 70 Jahren lief der APA-Hellschreiber heiß" ["70 years ago, the APA-Hellschreiber was running hot"], Kleine Zeitung Steiermark (newspaper), 1 Sept 2016
• Ref. 146: "Some Eventful Highlight's of AP's First Century", Decatur Herald and Review (newspaper), 2 May 1948, p. 14
• Ref. 147: "AP Maintains News Pickup Center of World", Valley Sunday Morning Star-Monitor-Herald (newspaper), 21 December 1941, p. 16
• Ref. 148: "Listening Post Gets News", The San Bernardino County Sun (newspaper), 2 June 1942, p. 6
• Ref. 149: "Lochner told: Go Back To Berlin!", The Akron Beacon Journal Sun (newspaper), 11 February 1945, p. 33
• Ref. 150: "Balkan King Used Nazi Invention to Get Allied News", St. Louis Post-Dispatch (newspaper), 17 November 1944, p.1
• Ref. 151: "Nazi Newscast Interrupted by 'End! The End!'". St. Louis Post-Dispatch (newspaper), 4 February 1945, pp.1, 2
• Ref. 152: "News Monopoly of Germany Seen in Merger", The Los Angeles Times (newspaper), 11 September 1949, pp. 1, 10
• Ref. 153: "US Plans New Units In Germany", The Baltimore Sun (newspaper), 29 September 1945, p. 6
• Ref. 154: "Der drahtlose Hellschreiber" [The wireless Hellschreiber], paragraph in "Von der Trommelsprache zum drahtlosen Fernschreiber", Josef Kreuz, p. 11 in "Salzburger Volksblatt" (newspaper), Vol. 70, Nr. 283, 30 November 1940 [pdf]
• Ref. 155: p. 394 in "Agerpres, the Rumanian National News Agency", T.E. Kruglak, in "Journalism Quarterly", Vol. 35, Nr. 3, Summer 1958, pp. 343-347, 394
• Ref. 156: "RFE Monitoring", p. 11-13 in the minutes of NATO-SHAPE Officers' Briefing, visit to RFE in Stuttgart-Böblingen on 15 Sept 1955
• Ref. 157: copy of items in file CO 875/40/1 "London Press Service: Hellschreiber machines; CO PR Dept., CFC (1948)". Items are in the collection of The National Archives; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Summary of the contents of ref. 157A-157F.
• Ref. 157A: London Press Service document "Notes for Information Officers on the installation, working and general maintenance of [Hellschreiber] printers for reception of the London Press Service", 1948, 11 pp.
• Ref. 157B: Letter from O.J. Whitley (Colonial Office, Information Dept., London) to Mr. Campbell, dated 19^th November 1948, 2 pp. Summary: list of 19 British colonies that will take London Press Service by Hellschreiber.
• Ref. 157C: Letter from Mr. M. McLoughlin (Central Office of Information, London) to Mr. O.J. Whitley (Colonial Office, Information Dept., London), dated 22^nd October 1948, 1 p. Summary: Hellschreiber printer (value ₤120 each) ready to ship to Post on Mauritius and in Gold Coast, Marconi CR 100 radio receiver ready for Gold Coast (value ₤ 60).
• Ref. 157D: Letter from Mr. A.K. Gore to Mr. Whitley (COI, London), dated 12^th October 1948, 3 pp. Summary: changes to Hellschreiber working of London Press Service; service to India & Pakistan started 28^th June 1948, to Canada 16^th August 1948, to Northern Europe 4^th October 1948, to the Americas 11^th October 1948; table with Hellschreiber transmission schedule and frequencies for the Americas; split into several traffic categories: “general”, “political & reconstruction”, “diplomatic”, “industrial & economic”, “weekday summary”, “features”, “press summary”, “regional”.
• Ref. 157E: Letter from M. McLoughlin (Central Office of Information, London) to O.J. Whitley (Colonial Office, Information Dept., London), dated 18^th August 1948, 3 pp. Summary: table with analysis of reception reports for Hellschreiber tests to the Americas, conducted 12^th–17^th July 1948.
• Ref. 157F: Table with analysis of Hell test transmissions to South & Central America and Ottawa/Canada – conducted 5^th-7^th June 1948, 1 p.; incl. several samples of printed paper strips.
• Ref. 158: pp. 44-45 in "Organising the Propaganda instrument: The British Experience", by John B. Black, Martinus Nijhoff Publ., 1975, 116 pp.
• Ref. 157: copy of items in file CO 875/40/2 "London Press Service: Hellschreiber machines; CO PR Dept. (1949)". Items are in the collection of The National Archives; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Summary of the contents of ref. 159A - ref. 159D.
• Ref. 159A: "L.P.S. [London Press Service] North and South America Hell and Morse transmissions as at 1^st May, 1949", 1 page.
• Ref. 159B: "Colonies taking the London Press Service with or without Hellschreiber equipment", dated 31^st July 1949, 1 page.
• Ref. 159C: Circular letter from M. McLoughlin (Central Office of Information, London) to Information Officers at 13 diplomatic and 2 colonial Posts in Europe, dated 1949, 1 page.
• Ref. 159D: "Reuters Hellschreiber Service" by A.F.E. Evans, Engineer Officer, 1949, 2 pages.
• Ref. 160: copy of items in file INF 12/139 "Hellschreiber working committee, March-December 1947". Items are in the collection of The National Archives; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Summary of the contents of ref. 160A - ref. 160C.
• Ref. 160A: "Notes of a meeting held in Mr. Lovell’s room, Central Office of Information, on 27^th March, 1947 to consider the relative merits of Hellschreiber and Teletype working as far as the London Press Service is concerned", by Mr. M. McLoughlin, 3 pp.
• Ref. 160B: "Foreign Office Posts requiring Hellschreiber machines – Final List", date unknown [mid 1947].
• Ref. 160C: "Provisional London Press Service schedule to accommodate change to Hell working to North and South America on 1^st October 1947", date unknown [mid-1947], 1 page.
• Ref. 160D: "Notes of a meeting held in Mr. Lovell’s room, Central Office of Information, on 26^th June, 1947 to consider the supply of Hellschreiber instruments, fix a new target dated to commence working, and examine the possibility of extending the service to the Americas at an earlier date", dated 30^th June 1947, 4 pp.
• Ref. 161: copy of items in file FO 371/43535 "Gentleman’s Agreement on use of a Hellschreiber machine by British Legation in Sweden (1944)". Items are in the collection of The National Archives; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Summary of the contents of ref. 161A - ref. 161C.
• Ref. 161A: Telegram from Ministry of Information, London, to [British Legation in] Stockholm, Sweden, dated 7^th October 1944, 1 page.
• Ref. 161B: Telegram from Press Attaché of British Legation in Stockholm to Ministry of Information in London, dated 11^th October 1944, 1 page.
• Ref. 161C: Letter from G. Kirk (Director of Communications Broadcasting Division of Ministry of Information, London) to Anthony Haigh (Foreign Office, London) , dated 19^th October 1944, 1 page.
• Ref. 162: copy of items in file FO 953/1039 "Reasons for difficulty in operating Hellschreiber machine in Belgrade, Yugoslavia". Items are in the collection of The National Archives; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Summary of the contents of ref. 162A - ref. 162F.
• Ref. 162A: File binder cover, 2 pages. "Gives reasons for the difficulty to operate the Hellschreiber machine at Belgrade".
• Ref. 162B: "London Press Service in Belgrade", letter from J.A. Robinson, dated 21^st July 1950, 1 page.
• Ref. 162C: Letter from the Information Officer (British Embassy, Belgrade, Yugoslavia) to Foreign Office, Information Policy Department, dated 24^th August 1950, 1 page.
• Ref. 162D: Letter from P.L. Carter (Foreign Office, Information Policy Department) to L.G. Durrell (British Embassy, Belgrade, Yugoslavia), dated 18^th September 1950, 1 page.
• Ref. 162E: Letter from L.G. Durrell (British Embassy, Belgrade, Yugoslavia) to Mr. P.L. Carter (Foreign Office, Information Policy Department), dated 27^th November (1950), 1 page.
• Ref. 162F: Draft letter from Mr. P.L. Carter (Foreign Office, Information Policy Department) to Mr. L.G. Durrell (British Embassy, Belgrade, Yugoslavia), dated 27^th November (1950), 2 pages.
• Ref. 163: copy of item in file INF 12/419 "Hellschreiber Working Committee, technical reception arrangements (1948/49)". Item is in the collection of The National Archives; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Ref. 163A: Letter entitled "Experiences of Reuters with Hell Printers and Relays provided through Post Office Channels", from E. Davis (Reuters) to Mr. Perkins (Post Office, Chief of Communications), dated 27^th February 1948, 3 pages.
• Ref. 163B: "London Press Service: Transfer to Hellschreiber working – Statement by the central Office of Information", dated 23^rd March 1949, 4 pp.
• Ref. 164: copy of item in file ref. IOR/L/I/1/1213 File 464/26B(vi) "Hellschreiber tests (1948)". Item is in the collection of the British Library; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Ref. 164A: List of London Press Service long & shortwave frequencies, 3 pages.
• Ref. 164B: Letter from Kenneth Jowers (Director, British Information Services (BIS), Karachi/Pakistan) to Mr. M. McLoughlin (Central Office of Information (C.O.I.), London), dated 17^th April 1948, 3 pages.
• Ref. 164C: Letter from Mr. Jowers (BIS, Karachi/Pakistan, India) to Messrs. M. McLoughlin (COI, London) and Crawley (CRO, London), dated 21^st July 1948, 2 pages.
• Ref. 164D: Letter from Mr. D.D. Condon (Editor in Chief, BIS, New Delhi, India) to Mr. G.F. Crawley (CRO, London), dated 23^rd July 1948, 5 pages.
• Ref. 164E: Letter from Mr. Kenneth Jowers (Director at BIS, Karachi/Pakistan) to Mr. Howe, dated 31^st July 1948, 1 page.
• Ref. 164F: Letter from Mr. Kenneth Jowers (Director at BIS, Karachi/Pakistan) to Mr. G.F. Crawley (CRO Information Dept., London), dated 8^th September 1948, 2 pages.
• Ref. 165: pp. 512-516, 524 in "Activities at Knockholt", J.A. Reeds, Appendix B in "Breaking Teleprinter Ciphers at Bletchley Park - General Report on Tunny with Emphasis on Statistical Methods (1945)", 1^st ed., I.J. Good, D. Michie, G. Timms (J.A. Reeds, W. Diffie, J.V. Fields, eds.), John Wiley & Sons, IEEE Press, 2015, 735 pp. Source: onlinelibrary.wiley.com, accessed August 2022. [pdf, See note 1]
• Ref. 166: "Bandbreitenfragen bei Anwendung der Siemens-Hell-Fernschreibtechnik" [signal bandwidth issues with A2 and A3 modulation], Rudolf Zimmermann, 7 pp., Technische Mitteilungen des Fernmeldewerks, Siemens & Halske A.G., Wernerwerk, Abteilung für Telegrafengerät, Berlin-Siemensstadt, May 1940, SH 7998, 1. 8. 40. T T1.
• Ref. 167: p. 16 in "The projection of Britain abroad", P.M. Taylor, Chapter 1 in "British Foreign Policy, 1945-56", M. Dockrill, J.W. Young (eds.), Springer Verlag, 1989, 256 pp.
• Ref. 168: copy of item in file ref. IOR/L/I/1/1214 File 464/26B(vii) "Hellschreiber Working Committee minutes (1948)". Item is in the collection of the British Library; material with UK Crown Copyright, used in accordance with the Open Government License [pdf].
• Ref. 168A: Part of the Minutes of 5^th meeting of the C.O.I. Hellschreiber Working Committee, 30^th June 1948, 4 pages.
• Ref. 169: "Siemens – Hellschreiber / Marconi", internal memo of Telefunken Ges.f.drahtl.Telegraphie m.b.H., 21 May 1935, 1 page; source: corporate archives of DTM Berlin, part of file nr. I.2.060C-02427.
• Summary (in English) of the contents of ref. 169.
• Ref. 170: "Hell Fabrik-Berlin", Section 2.0, AL. No. 16 (sheet 23), SubCommittee for the Investigation of German Electronic and Scientific Organisation (SIGESO, subordinate to the British Supply department), 27 September 1945. Source: www.cdvandt.org.
• Ref. 171: miscellaneous documents about Hel activities of the Dutch news agency ANP (source: National Archives of The Netherlands in The Hague).
• Ref. 171A: 8-March-1939 - 1-page "Eerste proeven van de Hell-verbinding tusschen Amsterdam en Batavia" [First trials with Hell-link between A.N.P. news agency in Amsterdam and Batavia (Jakarta/Indonesia)]; includes print-out of Hell tape of Hell transmission (presumably shortwave) from ANP/Batavia, as received at ANP, in response to a Hell-transmission of a message from ANP management in Amsterdam; transmission/reception in both direction was excellent.
• Ref. 171B: early 1947 - 1-page tentative calendar of major worldwide sports events to be covered in 1947 and 1948 by Hellcasts of the ANP.
• Ref. 171C: 19-June-1948 - 2-page internal ANP memo to Mr. van der Pol regarding local radio interference making reception of Reuters Hell casts at the Radio Room in downtown The Hague difficult, despite corrective actions by the RCD (Radio Controle Dienst, the radio monitoring service of the Dutch PTT).
• Ref. 171D: 15-December-1948 - 2-page internal ANP memo of Mr. Mater to Mr. van der Pol, reporting on a visit on 14-Dec-1948 of De Arbeiderspers (AP, publishing company in Amsterdam, publisher of the newspaper "Het Vrije Volk", 1947 through the late 1960s). Upon referral to the AP by the Volkskrant (Amsterdam-based newspaper), the representative in The Netherlands of the German D.P.D. news agency loaned a Hell-printer and printer amplifier to the AP, for evaluating the longwave DPD Hell-casts. AP conclusions: paper tape requires staff for transcribing or gluing tape onto paper sheets (even though actual reception is automatic), expenses are not negligible (PTT license, paper, ink, staff), problems with radio interference at the down-town Amsterdam receiving location, DPD's Hell-cast copy of Reuters copy arrived an hour and a half later than the teletype directly from Reuters. The Siemens printer and amplifier looked better than the ANP's EMA equipment. AP obtained paper tape rolls from A.E. Ruys en Co. Papier Groothandel in Amsterdam, at considerably lower cost and shorter lead times than from ANP's supplier (Neparofa in Roterdam): DFL 19.48 vs DFL 37.00 per 100 rolls.
• Ref. 171E: "ANP Programma Hell-uizendingen ingaande op 9 Mei 1949", transmission schedule for daily ANP Hellcasts in Dutch and English language (with frequencies, direction, transmitter callsigns), effective 9^th May 1949.
• Ref. 172: the following documents were obtained via The BT Digital archives search engine (search term "Hell") and are used in accordance with the terms of the non-commercial Creative Commons Licence CC BY-NC-SA, © Coventry University:
• Ref. 172A: "Reuterian European Service by the Hell System. A Report on Short Wave Reception Tests Carried Out in Budapest, Prague, Belgrade and Bucharest June 15th to July 1st 1938", A. Cook, J.D. Parker, General Post Office Engineering Department Radio Report No. 493, 28^th August 1939, 13 pp.; BT Digital Archives, document ref. TCB 226/493.
• Ref. 172B: "Investigation into Difficulties in the Reception in Norway Sweden and Denmark on the "Hell-Schreiber" Emissions from Leafield (GIX)", G.T. Evans, in association with T.A. Davies WTS Telecom. Dept., General Post Office Engineering Department Radio Report No. 577, Copy No. 15, July-August 1936 , 14 pp.; BT Digital Archives, document ref. TCB 226/577.
• Ref. 172C: "Design of an aerial with wide aperture for Reuter's Hellschreiber short wave transmissions to Europe", L.L. Hall, D.E. Watt-Carter, General Post Office Engineering Department Radio Report No. 1096, Copy No. 1, February 1944, 13 pp.; BT Digital Archives, document ref. TCB 226/1096.
• Ref. 172D: "A Multi-Channel VF Telegraph System for Hell-Schreiber Signals", A. Cook, L.T. Arman, P.R. Hutton-Penman, S.W. Bliss, General Post Office Engineering Department Radio Report No. 1200, Copy No. 31, 6^th August 1944, 11 pp.; BT Digital Archives, document ref. TCB 226/1200.
• Ref. 172E: "The Effect of Random Noise and Selective Fading on Hell Printer Telegraph Signals Transmitted by MCW" [tests carried out at GPO Radio Laboratories, Dollis Hill, incl. photos of printed paper tape strips], W.J. Bray, H.G. Lillicrap, F.C. Owen, General Post Office Engineering Department Radio Report No. 1556, Copy No. 12, August 1944, 22 pp.; BT Digital Archives, document ref. TCB 226/1556.
• Ref. 172F: "The Effect of Random Noise and Selective Fading on Hell Printer Telegraph Signals Transmitted by a Frequency-Shift System", W.J. Bray, H.G. Lillicrap, F.C. Owen, General Post Office Engineering Department Radio Report No. 1588, Copy No. 12, September 1944, 9 pp.; BT Digital Archives, document ref. TCB 226/1588.
• Ref. 173: Documents of plenary sessions of the International Radio Consultative Committee (C.C.I.R.) of the ITU:
• Ref. 173A: pp. 133, 305, 312 in "Documents of the VIIth Plenary Assembly, Vol I - Recommendations made by the Committee, reports, Resolutions Adopted by the Committee, Questions to be Studied, Study Programmes", London, 1953, 442 pp. [pdf]
• Ref. 173B: pp. 29, 32, 157 in "Documents of the XIth Plenary Assembly, Vol III - Fixed and Mobile Services, Standard-Frequencies and Time-Signals, Monitoring of Emissions", Oslo, 1966, 444 pp. [pdf]
• Ref. 173C: p. 33 in "Documents of the XIIth Plenary Assembly, Vol III - Fixed Service at Frequencies Below About 30 MHz (Study Group 3), Standard Frequencies and Time Signals (Study Group 7), Vocabulary (ClV)", New Delhi, 1970, 312 pp. [pdf]
• Ref. 173D: p. 7 in "Extract of the Preface to the International Frequency List", International Telecommunication Union (ITU), 7^th edition, 1 February 1973, 60 pp.
• Ref. 174: "What can an understanding of the operation of the BBC Monitoring Service during WWII tell us about the value of the transcripts?", Laura Johnson, presented at workshop "Listening to the world: BBC monitoring and the second world war", AHRC BBC Monitoring Collection Research Network, January 2016, 5 pp. [pdf]
• Ref. 175: "Comité radioélectrique de la Commission internationale de la police criminelle" p. 319 in "Journal des Télécommunications", ITU, Vol. 2, Nr. 12, December 1935.
• Ref. 176: "Tall Tales of Tape", pp. 12, 32 in "Monitoring Times", Vol. 3, Nr. 6, June 1984.
• Ref. 177: "The Monitoring Service", pp. 75-77 in "BBC Sound Broadcasting - Its Engineering Development", BBC, August 1962, 97 pp. [pdf].
• Ref. 178: "Chinese language becomes a bit faster", Chris Moss, in "New Scientist", Vol. 77, February 1978, pp. 418-420.
• Ref. 179: p. 115 in "Die Funkführung der U-Boote in der Praxis" [U-boat wireless communication organisation ], Chapter 8 (pp. 154-168) in "Funkpeilung als alliierte Waffe gegen deutsche U-Boote 1939-1945" ["Huff Duff versus German U-boat wireless communications 1939-1945"], Arthur Bauer, Ralph Erskine, Klaus Herold, 1st ed., A. Bauer (publ.), ISBN 3000021426, 323 pp. Source: cdvandt.org. Accessed 10 March 2019.
• Ref. 180: p. 13 in "FBIS-BBC Field Coverage Schedule - 16 December 1980", Foreign Broadcast Information Service (Central Intelligence Agency (CIA) Directorate of Science, 16 December 1980, 98 pp. Document nr.CIA-RDP89-00642R000100120001-6 (sanitized/declassified/released 2-Oct-2007). [pdf]. Accessed 10 March 2019.
• Ref. 181: pp. 148-149 in "Der Allgemeine Deutsche Nachrichtendienst (ADN): gute Nachrichten für die SED", Michael Minholz, Uwe Stirnberg, K.G. Sauer Verlag (publ.), 1955, 502 pp.
• Ref. 182: "Letter to (SANITIZED)" [pdf], Foreign Broadcast Information Service (FBIS), American Embassy London, 7 September 1954, 1 p. Document nr. CIA-RDP80-00765A000100020015-6 (sanitized / declassified / released 23-Sept-2009). Accessed 10 March 2019.
• Ref. 183: performance and distortion
• Ref. 183A: "Eine Untersuchung zur Bekämpfung von Doppelzeichen im Kurzwellen-Hell-Telegrafie-betrieb", H. Haberland, pp. 32-40 in "Hell - Technische Mitteilungen der Firma Dr.-Ing. Rudolf Hell - Gerätentwicklungen aus den Jahren 1929-1939", Nr. 1, May 1940.
• Ref. 183B: "Military Teletypewriter Systems of World War II", F.J. Singer, Transactions of the AIEE, Vol. 67, Issue 2, 1948, pp. 1398-1408
• p. 1403: pre-war: transmission of TTY pulses over long-haul HF radio was not done merely by connecting TTY machine to radio facilities, since no features to overcome fading, QRM, QRN disturbances. Hence, FSK introduced.
• Ref. 184: "Ferrell's Confidential Frequency List" [pdf], Geoff Halligey, 7^th ed., 1988, Gilfer Associates, Inc., ISBN 0914542206, 380 pp. Accessed 16 March 2019.
• Ref. 185: "Introduction of Hellschreiber Transmission System" [pdf], Official Debates of Rajya Sabha (Parliament of Indian), 1956 session nr. 14, 1 August 1956, p. 248. Accessed 16 March 2019.
• Ref. 186: "Letter of Instruction", memorandum from Chief of Foreign Broadcast Information Service (FBIS), 12 January 1956, 8 pp. Document nr. CIA-RDP83-00586R000300130017-9 (sanitized / declassified / released 7 August 2013). Accessed 25 March 2019.
• Ref. 187: p. 32 in "War Department Pamphlet No. 31-148: Civil Affairs Guide - The German Merchant Marine", United States Department of the Army, 5 October 1944, 418 pp.
• Ref. 188: "Fünf Jahre „Algemeen nederlandsch Persbureauˮ", in "Deutsche Zeitung in den Niederlanden", Nr. 27, 1 July 1940.
• Ref. 189: "„Domeiˮ - die Stimme Japans", in "Deutsche Zeitung in den Niederlanden", Nr. 240, 3 February 1942.
• Ref. 190: "1 Jahr DANA", DANA, 31 August 1946, 16 pp.
• Ref. 191: "The Caversham Story", Alan Hunter, pp. 5-7 in "BBC Radio Times", 27 January 1950.
• "Listening to War" [story of the BBC's Monitoring Service during the Second World War], recording of the broadcast on BBC Radio 4 UK, on 14 January 1981; duration: 1 hour. Accessed August 2022.
• Ref. 192: "Het persagentschap Belga, ontstaan en ontwikkeling", Frans Kieckens, PhD thesis at Rijksuniversiteit Gent, Belgium, 1973, 166 pp. Retrieved: 6 September 2019. [pdf, 54 MB]
• Ref. 193: "Ici Radio Monte-Carlo", p. 30 in "Pionier - Zeitung für die Übermittlungstruppen" (Offiz. Organ des Eidg. Verbandes der Übermittlungstruppen (EVU) und der Vereinigung der Schweiz. Feld-Telegraphen-Offiziere und -Unteroffiziere), Vol. 24, Nr. 2, April 1951. Retrieved 27 September 2019. [pdf]
• Ref. 194: Radio Kootwijk, The Netherlands
• Ref. 194A: "Belangrijke data uit de geschiedenis van HOLLAND RADIO" ["Important dates in the history of Holland Radio", a.k.a. "Radio Kootwijk", covers period May 1923 - December 1940], Rijkstelegraafkantoor Amsterdam, 10 pp. Source: nvhrbiblio.nl. Retrieved 9 June 2020.
• Ref. 194B: "Het Rijks-Radiostation te Kootwijk" ["The state radio station at Kootwijk"], in "De Leidsche Courant" (newspaper), vol. 21, no. 6708, 30 September 1930, pp. 1-2.
• Ref. 194C: "Het Rijksradiostation te Kootwijk" ["The state radio station at Kootwijk"] in "Provinciale Geldersche en Nijmeegsche Courant" (newspaper), 30 September 1930, p. 9.
• Ref. 194D: "Technische ontwikkeling van den Rijksradiodienst" ["Technical development of the state radio service], N. Koomans, in "Nieuwe Leidsche Courant" (newspaper), special issue "P.T.T. nummer", 26 July 1933, pp. 11-13.
• Ref. 194E: "PDK Kootwijk Holland" in "Short-Wave Station List" in "All-Wave Radio - The Journal of World Radio", Vol. 3, Nr. 8, August 1937, p. 431.
• Ref. 194F: "Tussen zand en zenders - Geschiedenis van Radio Kootwijk", Coby de Haan-van der Meulen (ed.), Leona Udo-van der Sloot (ed.), Betsy van der Pol-Woonink, 1988, 147 pp. Source: nvhrbiblio.nl. Retrieved 9 June 2020.
• Ref. 195: "Der Fernschreiber Type S5 - Tastensender und elektromechanischer Streifenschreiber" ["Teleprinter model S5 - keyboard sender and electromechanical tape printer", drawings dated 14 May 1932], Dr. Ing. Rudolf Hell Co. in Berlin-Neubabelsberg, June 1932, 6 pp. Source: BArch file nr. (Signatur) RL 3/4164, used in accordance with "Erstinformation für Ihren Besuch im Bundesarchiv in Freiburg, Stand Juni 2016".
• Ref. 196: "Der Tagesspiegel" [US-licensed Berlin newspaper], pp. 14, 15, 17 in "Weekly information bulletin", No. 60, 23 September 1946, Office of the Military Government for Germany, U. S. Control Office, APO 742, U. S. Army. Source: archive.org, retrieved 10 April 2020.
• Ref. 258: Hell printers used in German submarines / U-Boote (U-boats) and FuG29 receiver
• Ref. 258A: p. 202 in "Die Seehunde Klein-U-Boote : Letzte deutsche initiative im Seekrieg 1939-1945" ["The "Seehund" (= seal) small U-boats - the final German initiative in the naval war of 1939-1945"], Klaus Mattes, Verlag E.S. Mittler & Sohn GmbH (publ.), 1995, 224 pp.
• Ref. 258B: pp. 203-204 in "Die deutschen Funkführungsverfahren bis 1945", Fritz Trenkle, Hüthig Verlag (publ.), 1987, 236 pp.
• Ref. 258C: p. 32 in "Wochenbericht K.T.B. 8.1./14.1. 1945" [weekly report for 8-14 January 1945] in "Kriegstagebuch Chef-T.L.R. v. 13.12.44 bis Kriegsende" [war diary of the Head of the Technische Luftrüstung, from 13 December 1944 until the end of the war]. Source: www.cdvandt.org. Accessed: 6 December 2019.
• Ref. 271: "L'information mondiale - De la Tchécoslovaquie à la Yougoslavie", on p. 3 in "Le Clairon" weekly newspaper of Saint-Hyacinthe, Canada, Vol. XLII, No. 33, 14 August 1953. Source: banq.qc.ca, retrieved 16 September 2021.
• Ref. 272: "Psychologische Kriegführung im Zweiten Weltkrieg" [US Army, Presse Hell transmissions 1944/45], Toby E. Rodes, in "ASMZ : Sicherheit Schweiz : Allgemeine schweizerische Militärzeitschrift", Vol. 163, Nr. 4, December 1997, pp. 20, 21. Source: e-periodica.ch, retrieved 4 May 2021.
• Ref. 274: "The Monitor Machine and Man", in "OVER THE AIR - BBC London Letter - A weekly miscellany" column on p. 3 in "The Ellesmere Guardian" newspaper, Vol. 66, No. 66, 24 August 1945.
• Ref. 275: p. 72 in "The war of words", Vol. III of "The history of broadcasting in the United Kingdom", Asa Briggs, Oxford University Press (publ.), 1970, 766 pp. Source: nvhrbiblio.nl, accessed 8 October 2021.
• Ref. 277: "Magyar Távirati Iroda (MTI) Ki nem adott közlemények ["Unpublished announcements"], 1 July 1939, 1 p. Source: library.hungaricana.hu, retrieved 12 November 2021.
• Ref. 278: "Research Branch Secret War Diary", W. Gordon Radley, Dollis Hill General Post Office (GPO). Source: British Telecom (BT) Archives - The Dollis Hill war diary;  two volumes: Volume 1 of 2, 216 pp. [file size 43 MB; a much smaller transcript file is here],  Volume 2 of 2, 144 pp. [file size 25 MB; a transcript file is here].
• Ref. 278A: "Design and Construction of simple Telegraph Printer", diary entry for 9 July 1940, p. 41 in Volume 1 of 2.
• Ref. 278B: "Design of a Simple Telegraph Printer", diary entry for 21 September 1940, p. 55 in Volume 1 of 2.
• Ref. 278C: "Design of a Simple Telegraph Printer", diary entry for 27 November 1940, pp. 65/66 in Volume 1 of 2.
• Ref. 278D: "Simple Telegraph Printer for Army Use", diary entry for 11 December 1940, p. 69 in Volume 1 of 2.
• Ref. 278E: "Electrolytic paper strip for Army Lightweight Telewriter", diary entry for 16 March 1944, p. 232 in Volume 2 of 2.
• Ref. 285: "Ersatzteil - Stückliste zu Hellschreiber-Anlage 1942" ["Replacement parts list for the 1942 Hellschreiber system"; T Loch 1 m, T send 17, T sum 5 a, T verst 18, T empf 14, Werzeugkasten (tool box), Schreibmaterial (printer supplies); diagrams, schematics, equipment photos; note: schematics and most parts list pages are partial/cutt off], January 1942, 62 pp. Courtesy G. Hütter. [file size 22 MB].
• Ref. 286: pp. 100-102 in "Establishing broadcast monitoring as Open Source Intelligence: the BBC Monitoring Service during the Second World War", Laura Johnson, PhD dissertation, Dept. of War Sudies, King's College London (publ.), 2013, 618 pp. Licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International licence. Retrieved 31 August 2022. [pdf]

External links last checked: February 2016 unless noted otherwise.