Rick, >Has anyone compared Domino EX with the top modes that get >through the worst conditions and, if so, what have you found?
I've compared a variety of sound card modes for sensitivity and robustness using an HF path simulator (see below). I first tested each mode for sensitivity by finding the lowest signal-to-noise ratio that would still produce 100% decode. These were direct-path simulations with no ionospheric disturbance. For what it's worth, DominoEX 11 baud, had about the same sensitivity as MT63 and Olivia 500/4. DominoEX 4 baud had about the same sensitivity as MFSK16. Olivia 500/16/8 were more sensitive than DominioEX 11 as well; Olivia mode sensitivity would increases with an increase in the number of tones. Things got interesting while testing for robustness with the ionospheric simulator. The Domino EX modes fell short to the point where they would not decode at all with certain disturbances regardless of SNR. The DominoEX modes seemed sensitive to frequency spread found on the more disturbed ionospheric paths, especially polar and low-latitude paths. I think it's important to remember that these are simulations and on-air testing may show different results. There are no static crash simulators with Pathsim so it's hard to simulate things like mode recovery time etc. If anyone is interested in path simulation, it's important to normalize the audio before it's feed into the simulator. Normalizing keeps the audio at the same level so one mode is not any louder or weaker than another. Tony, K2MO Kings Park, NY ______________________________________________________ Sensitivity Test ( lowest SNR that will produce 100% decode) (DIRECT PATH - NO IONOSPHERIC DISTURBANCE) RTTY 45................... -5db Feld Hell.....................-6db* DominoEX-11........ -8db MT63 1K................. -8db Olivia 500/4.............. -8db Olivia 500/8..............-10db PSK31................... -10db Olivia 500/16 .......... -12db MFSK16....................-14db DominoEX-4 baud...-15db * Simulated quiet band condx. Good contrast between text and white background. ______________________________________________ Sensitivity Test SNR -12db (DIRECT PATH - NO IONOSPHERIC DISTURBANCE) MFSK16.....................Perfect Copy Olivia 500/16..............Perfect Copy DominoEX 4 baud....Perfect Copy Oivia 500/8..................90% Olivia 500/4.................90% DominoEX 11 baud...90% PSK31.........................90% Feld Hell......................Faint Text * MT63 1K.....................No Copy RTTY 45 baud............No Copy * Feld Hell somewhat readable at this SNR under extremely quiet condx. _______________________________________________________ Sensitivity Test SNR -15db (faint signal in waterfall) (DIRECT PATH - NO IONOSPHERIC DISTURBANCE) DominoEX 4bd..........100% Copy MFSK16.......................95% Copy Olivia 1K/32.................90% Copy Olivia 500/16...............90% Copy Olivia 500/8................. <50% THE QUICK BROWN FOX :UMPS OB$[T,3AZY DOG T.`8 dIC `"N FSX JUd VCR g&?GZY 1PaOlj/== BROWZ+_ /|mu_S R pHB\7JY 9OG Olivia 500/4...................No Copy DominoEX 11bd...............50% tTHE QUICK BDOWN FOXGUMPSLiVER IE LA ' Y BCI THQUICK) ROWN FOX JU S OVCu THE LAZY DOG TH QUo OWN FN0 ZUMLx OGR THE tZY DOa? L PSK31...........................<50% E QUIhK BRO FOs J.MPS OVEC THE s -t( a OGTr �ITBRO N Ft uJU0PbtaVEXE LAZY t OpHE uPIOK BROWN FtoMPS OT0R li0 LA rY Ctep MT63..........................No Copy Feld Hell.....................No Copy RTTY 45....................No Copy _______________________________________________________________ High-Latitude Path Simulation (Moderate High-Latitude Disturbance, 3ms path delay, 10hz frequency spread, SNR -8db) (3ms path delay, 10hz frequency spread, SNR -8db) MFSK16......................Perfect Copy Olivia 500/16...............Perfect Copy Olivia 500/8..................Perfect Copy Olivia 500/4..................90% Feld Hell........................90%* DominoEX 4bd..........No Copy DominoEX 11bd........No Copy PSK31.........................No Copy RTTY45........................No Copy MT63............................No Copy * Text to background contrast marginal but readable. _______________________________________________________ Mid-Latitude Path Simulation (Storm condition Mid-Latitude Disturbance, 2ms path delay, 1hz frequency spread, SNR -8db) MFSK16......................Perfect Copy Olivia 500/16...............Perfect Copy Olivia 500/8..................90% Olivia 500/4..................90% DominoEX 4bd............90% MT63 1K.......................90% Feld Hell........................<90%* *Good text contrast, missing characters DominoEX 11bd THE QUIRK BROWN FOX JUMPTYOFttT3G LAZY DOG THE QROWN FOiRJUMPtJeoER TLAZY DOG THE QUICK NNOWOXlrUMPS OVER ti8AZY DOG PSK31 THe EaoICK BROWN F Jto c OTeR THE LAZY DOG THE Q4Icš BROWN MOX p HMPS OVIRHE LAZY DOG Tr4 QUICK BROWNa o e o JUMPS r -ER THE LY RTTY45 XMXSPYUIVK BRGWN FOKGDUMHR KZ4 ZILAZYHDOG OVZHE QUFKH?492,6FF JINQ QOCSKQ0/6&)'6 BMXDQ NQ QUICK YBRTZNLFMY JUVHS OVER PHE )-+6 DOG ______________________________________________________________ Low-Latitude Path Simulation (Storm condition Low-Latitude Disturbance, 6ms path delay, 10hz frequency spread, SNR -8db) MFSK16...................Pefect Copy Olivia 500/16............Perfect Copy Olivia 500/8..............90% Olivia 500/4..............90% Feld Hell....................Poor Copy* DominoEX 4bd .......No Copy DominoEX 11bd......No Copy MT63 1k....................No Copy PSK31......................No Copy RTTY45.....................No Copy * Feld Hell letters were diffuse (spread) making it difficult to read.
