I thought I would re-post this from 4/1/06, it was fun. I even got asked to do a presenation on it.
Andy--- In digitalradio@yahoogroups.com, "Andrew J. O'Brien" <aobri...@...> wrote: Just received this and thought I would pass it along, looks like a new one to play around with! Software is available from my site (see below). Announcing a new digital mode that uses the sound card of your PC. This one is DUSK-A1. developed by Walter DU1SK. DUSK has some fundamental differences from the other digital modes (PSK, MFSK Olivia, etc) in that this mode has been developed primarily for the low bands (80 and 160) with an emphasis on grey-line propagated signals. DUSK-AI takes advantage of AMI- Alternate Mark Inversion . Many digital hams will already be aware that AMI has a 12.5% density minimum. The reduced density minimum of DUSK-A1 creates a more tolerable AOA, or Angle of Arrival A position identification technology that detects the direction of a signal received from a transmitter at only one point. In this system, the transmitter's location is determined from the receivers' antenna position and the AOA of the signals that are from the antennas. In practical terms, grey-line like conditions are created regardless of the actual position of the sun. DUSK-A1 grey line performance, and sun position irrelevance , is also enhanced by the inclusion of CTA. Continuous Time Oversampling A technique that simplifies the job of synchronizing data generated from disparate sampling rates. The technique resamples and synchronizes audio data as needed, and it eliminates the substrate noise and feedthrough problems. The beta version of DUSK-A1 also includes Enhanced Data Rates for Global Evolution an enhanced radio modulation technique for GSM and TDMA (ANSI-136) networks that expands radio timeslots . The expanded time slots also factor in enhanced daylight propagation , especially on 160 meters. When combined with GPRS, it gives a maximum performance with narrow bandwidth. The software does not have full macro features or logging components as yet. Those wishing to test this new mode may download the free software at DUSK-A1 from http://www.obriensweb.com/dusk.htm --- End forwarded message ---
