New Hf Digital Modes Sadars 2009

Presentation to Shefford & District ARSGareth Howell – M5KVK

AgendaSome backgroundNew modes to be coveredA couple of odd-balls

Some BackgroundTwo basic families:PSK

(Digital Binary Phase-Shift Keying) PSK 31, 63, 125 etc No error correction Low bandwidth

MFSK (Multi Frequency-Shift Keying) RTTY, Piccolo, Coquelet MFSK 4, 8, 16 (42WPM) Sensitive Good rejection of Doppler

New Modes to be coveredDominoExOlivia

DominoExMurray ZL1BPU18 tone FSKDesigned to overcome limitations in MFSKOptimised for NVIS (80/40/30m)VaricodeIncremental Frequency Keying

Reduces tuning sensitivityAnd drift

CharacteristicsVariants named after Baud rateImproved tolerance to multi-pathImproved rejection of impulse noiseNo need for FEC in normal use

Higher speed than MFSKShorter sync time

i.e. faster turn around in QSO mode

DominoEx 8Used on poorer circuits (50WPM)

DominoEx 16Higher speed, used on better circuits

(100WPM)

OliviaInvented by Pavel SP9vRC64-FSK - sequentialMultiple variants

Tones and BandwidthMultiple Baud ratesVaricode and Forward Error Correction

CharacteristicsHorses for courses

Fewer tones mean higher speedMore tones add robustness

Works over very poor S/N circuitsOften not visible or audibleVoluntary channelisation

Olivia VariantsBandwidth/Tones500/16

19.5 wpmUsed for CQ and QSOs in average conditions

1000/3224.4 wpmUsed for CQ and QSOs in average conditions

500/829.3 WPMQSOs on higher bands

1000/16500/4250/8

Olivia Variants

Olivia 500/16

Olivia 1000/16

A couple of odd-ballsHF-ALEWSJT

HFLINK (ALE)Automatic Link Establishment (ALE)Focused on emergency communicationsPermanent Global network

24x7 on 8 HF bandsMIL-STD-188-141A

SSB/Text/SMS/InternetScanningSounding

WSJTJT65Very slow speedOptimised for very weak signals

Troposcatter/EME/65-MFSK, FECJT65-HF variant for HF

References-1Domino

DominoEX - an IFK Mode for HF http://snurl.com/n7vwv

OliviaWB8ROL Olivia Digital Mode Information

Page http://snurl.com/n7vqzThe International Olivia Digital Mode

Group http://snurl.com/n7vsoOlivia Frequencies http://snurl.com/n7vze

References-2HFLINK

http://snurl.com/n7wdhJT65A and WSJT

The Complete Bozo's Guide to HF JT65A http://snurl.com/n7w4z

Schedshttp://snurl.com/n7vv8

Questions ??