What is Hellschreiber?
Hellschreiber, or Hell, is a method of sending and receiving text using facsimile technology. It is unique in that the characters are not decoded, but "painted" or printed on a screen. There are several modes of Hellschreiber, the most popular being a single-tone version call Feld-Hell, an on-off keyed system with 122.5 dots/second, or about a 35 WPM text rate. FH has a narrow bandwidth of about 75 Hz. Feld-Hell also has the advantage of having a low duty cycle meaning your transmitter will run much cooler with this mode.
For a terrific explanation of Hellschreiber, we highly recommend the ZL1BPU web site, which explains everything you need to know about this mode, including the most pressing question, "why does Hell transmit two lines of text?
There is also a great introductory video on You Tube by Randy, K7AGE which you can see here or below.
Frank, N4SPP, is a long-time Hell practitioner who collects items related to Hellschreiber such as original technical articles and equipment (for example, Frank recently came into possession of an original, working 1938 Siemens Hell-Feldfernschreiber.) Frank has put together a fantastic web site about his station and our niche of Ham Radio, which we're previewing below.
To get the full impact of Frank's website, please visit it here.
A Hellschreiber field unit in action
Where did the name "Hell" come from?
We can thank the inventor, a German engineer named Rudolf Hell, who patented this early method of facsimile in 1929. Hellschreiber was the first successful direct printing text transmission system, and was very popular at a time when teleprinters were complex and expensive, because the Hell receiving mechanism had only two moving parts. At first the Hellschreiber was mostly used for land-line press services, which continued well into the 1980s. A military version was used by the German Condor Legion during the Spanish Civil War (1933). During WWII, Hellschreiber was widely used for field portable military communications, for which it proved to be very suitable because the equipment was simple and robust.
How can I operate Hellschreiber?
As with any digital mode, you need a PC and an interface to your radio. You'll also need software. Today there are a number of freeware programs that can have you up and running in Hell in a matter of minutes. Not freeware but a popular program is MixW. We are building a complete list of Hell applications on our software page. For questions you may have about software, or how to interface your PC with your rig, watch the video below, visit our Yahoo Groups to post a question.
Where can I find Hell signals?
In general, here is where you'll find most Hell activity. As with any ham radio mode, these are suggested frequencies but not etched in stone, so please listen first before transmitting, as you're also likely to hear MFSK, Olivia, BPSK, JT65, and other digital modes on or near these frequencies. Also, check https://hamspots.net/ for current activity.
160 METERS 1.843 to 1.844 (FT8 took over our existing frequency at 1.840)
80 METERS 3.578 to 3.584 (FT8 took over our existing frequency at 3.573)
40 METERS 7.080 to 7.086
30 METERS 10.137 10.144 (Region I)
20 METERS 14.063 (PREFERRED), 14.073 (Note 1)
17 METERS 18.105
15 METERS 21.063
12 METERS 24.924
10 METERS 28.063
6 METERS 50.286
Note 1: For 20 meter ops, the FHC calling frequency is 14.063 and UP to 14.069. PSK31 ops are on 14.070 and the QRP club uses 14.060 as their calling frequency. We do not wish to cause interference to each other. A reminder, QRP is a power reference, not a mode. If using 14.073, be sure to avoid interference with the JT65 or FT8 area. Even though some may encroach on our segment, we need to be be the good guys!
Hellschreiber is a Fuzzy Mode, classified as J2B. As such Hellschreiber may be transmitted on CW or phone amateur radio frequencies. The list above is a starting point for your activities. The club expects that operators will operate with the high ideals of Ham Radio in mind, and be vigilant against QRMing our fellow hams.
Are there any hams in Hell?
We assume you mean one of the two towns in the world named Hell. This one is in Michigan and courtesy of KC2RXS some contacts were made during a "Hell-expedition". LA1K won the DX category of the October 2008 Sprint operating from Hell, Norway.
Is Hellschreiber Permissible in the U.S. Under Part 97?
From Chris Imlay, W3KD, ARRL General Counsel:
FCC regulations are normally straightforward in terms of classifying amateur transmission modes. One need only determine the emission designator and then review Section 97.3(c) to determine which emission type applies: CW, data, image, MCW, phone, pulse, RTTY, SS or Test. Discussions with FCC staff concerning the legality of Hellschreiber resulted in the following classification, based on the determination of the proper emission designator. The legality of other amateur modes should be determined by the same method.
Is Hellschreiber a facsimile or a direct-printing telegraph system?
From Paul Rinaldo, W4RI, ARRL Technical Relations Manager:
The 1929 Hellschreiber (now known as “Feld-Hell” or “Field-Hell”) is a facsimile device for transmitting text, originally to be printed on tape. It can be transmitted using the emission designators A1C (Double sideband, a single channel containing quantized or digital information without the use of a modulating subcarrier, facsimile), F1C (Frequency modulation, etc, as above), or J2C (Single sideband, suppressed carrier, a single channel containing quantized or digital information with the use of a modulating subcarrier, facsimile). While permissible within Part 97 Rules as facsimile operating on frequencies where “image” emission is authorized (where phone, SSTV or fax is permitted), this may not be welcomed by other amateurs using the rather narrow frequencies normally used for image communications.
An alternative is to consider Hellschreiber as a direct-printing telegraph system and operate it in the RTTY/data segments of the HF bands (where it is already in use). Perhaps little known is the ITU definition of facsimile, namely: “A form of telegraphy for the transmission of fixed images, with or without half-tones, with a view to their reproduction in a permanent form.” So, it can be operated under these emission designations: A1B (Double sideband, a single channel containing quantized or digital information without the use of a modulating subcarrier, telegraphy for automatic reception), F1B (Frequency modulation, etc., as above), or J2B (Single sideband, suppressed carrier, a single channel containing quantized or digital information with the use of a modulating subcarrier, telegraphy for automatic reception.)
The multi-frequency versions of Hellschreiber can be operated under the above emission symbols F1C, J2C, F1B and J2B. Because only one frequency is transmitted at a time and there is only one stream of information, the second character 7 (for two or more channels containing quantized or digital information) does not apply. A1C or A1B would not be usable because these designate simply on/off keying. F1C or F1B would be possible if the different tones caused different frequency shifts. Bottom line: US amateurs may transmit Hellschreiber in the RTTY/data segments using single-sideband transmitters. J2B is the appropriate emission symbol.