HELL 80

This mode is not used a whole lot but it offers some really fast speeds compared to the regular Feld Hellschrieber. This mode due to its bandwidth might have lower signal to noise ratio , but handles multipath pretty well. 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 (not described here and not emulated by Multipsk). Note 2 : it is added a "DX" and a "Super DX" sub-mods (provided also for FELD HELL and PSKHELL).

Category:

Science & Technology

Tags:

• Feld Hellschrieber
• HELL 80
• Digital Mode
• Fuzzy Logic
• Data Modes
• Ham Radio
• Amateur Radio