HELL 80
Creator : Siemens company in the 1960's
Description :
Baud rate : 315 (one pixel is 3.175 ms long)
Reading direction : column by column, from down to up and from left to right,
Matrix : height: 9 pixels et width: 7 pixels…so a total of 63 pixels per character. For each character, 2 lines and 2 columns are reserved for the frame.
Speed : 50 wpm (5 characters by second)
Modulation : FSK two tones with a shift between tones of 300 Hz. Normally, the white is at 1625 Hz and the black at 1925 Hz.
Receive mode : USB
Character set : all ASCII printable characters except small letters, carriage return (+ line feed) and error reset character. The used font derived from the one used for FELD HELL,
Shape of pulse : rectangular
Bandwidth : about 800 Hz (due to rectangular shape),
Synchronization : no need, each column is displayed vertically 2 times (but transmitted once)
Pmean/Ppeak : 1
Lowest S/N : - 4 dB
Note 1 : a start-stop mode also exists in the original system
Note 2 : it is added a "DX" and a "Super DX" sub-mods (provided also for FELD HELL and PSKHELL).
