Intro to Hellschreiber What was Old is made New again…

What is Hellschreiber? A method of fax-like teleprinting. A “fuzzy” mode which uses the brain as part of the decoding process. A “live” person-to-person QSO mode On/Off keyed, PSK or Multitone, it’s excellent for QRP and Stealth operating.

What’s all this “Fuzzy” Business??? • For “fuzzy” modes, the human brain is an integral part of the decoding. • Morse is a fuzzy mode, as is FAX and SSTV. • A Hellschreiber transmission is literally read off of paper tape or a video screen. • The brain does pattern recognition and QRM/N rejection when receiving Hell.

Dr. Hell’s “Clear Writer” Invented in 1929. Used by news services worldwide 1930s-1960s, SE Asia through 1980s. Various military uses 1930s-50s. Dutch amateurs began restoring surplus machines in the 1970s.

Feld-Hell Traditionally, on/off keyed CW or MCW 8.162 ms per element, 400 ms/character Great in active, post-storm solar condx

Global DX with Feld-Hell Gary, WB3DSJ < > Felix, DP1POL U.S.A. - Antarctica

PSK-Hell Phase Shift Keyed, cosine shaping 105 Hz / 245 Hz bandwidth, very sensitive Ionospheric Doppler effect resistant World’s first PSK-Hell DX QSO, 21 Aug 1999 (10 W) Courtesy Murray, ZL1BPU

FM-Hell Frequency shift keyed; 50 Hz / 123 Hz wide Extremely clear text reception, sensitive Overcomes pulse, crash noise quite well

MultiTone-Hell First demonstrated in 1937 Works in the frequency domain with 5 to 16 tones Concurrent MT allows high resolution fonts Sequential MT superb in noisy band conditions

Hard and Soft Any 80286-or-better PC, DOS or Windows 95, 98, XP G3+ Macintosh, OS 8.1+ Same interface as PSK-31, or HamComm Tape rig’s mic to a PC speaker!

Operating Tune-up for Feld-Hell is the same as Morse Treat other Hell modes just as you would PSK-31; that is, don’t overdrive the rig (use min. TX drive), no TX audio compression Most N.A. activity is on 20 meters, just above the PSK-31 area, and below RTTY “Narrow” filters can help (as with anything) Call CQ, see who’s out there, and have fun!

Acknowledgements Murray Greenman, ZL1BPU, and the “Fuzzy Modes” website, provided invaluable assistance in preparing this presentation. Thanks, Murray! And thanks to all of you who attended the presentation today. We’ll see you in HELL! 73! Dave – K7CCC