1. Intro to Hellschreiber
What was Old is made New again…

2. 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.

3. 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.

4. 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.

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

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

7. 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

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

9. 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

10. 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!

11. 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!

12. 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