Hi Tony, I guess you wanted to send this to Patrick Lindecker the creator of Multipsk..
cheers Patrick VK2PN PS... just a humble ham... can't program. Tony wrote: > > Patrick, > > Thanks for the suggestions. I did try manipulating PSK31 to run at > roughly half speed. I changed the baud rate to 16.5. The sensitivity > increased by 2 to 3db (according to the path simulator). > > While on this subject Patrick, I wanted to ask if you thought it was > possible to create software that could measure ionospheric > disturbances such as frequency Doppler / spread? > > The PSK31 tuning indicator found on most software seems to show this > by indicating a rapid shift in frequency. Another kind of "dial" or > graphic might be useful or maybe just the data; frequency spread in > Hz, Hz/sec etc. > > A steady signal source like WWV might be useful for this kind of > measurement as well. > > Tony, K2MO > > > > ----- Original Message ----- > From: "Patrick Lindecker" <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> > To: <digitalradio@yahoogroups.com <mailto:digitalradio@yahoogroups.com>> > Sent: Saturday, July 12, 2008 5:39 AM > Subject: Re: [digitalradio] Re: KV9U - Mode Sensitivity / Robustness > > Hello all, > > Another Patrick here. > > For an honest comparaison, logically the result might be normalized to > a standardized text throughput (based, for example, on BPSK31). For > example, the Olivia 32-1000 has a throughput of 24.4 wpm. MFSK16 about > the same as PSK31 (a little less than 50). This because, it is > mechanical to improve a minimum S/N: if you decrease the speed > transmission by 2 you have a gain of 3 dB on the minimum S/N (however > in the reality it is only about 3 dB because the new parameters are > not at the exactly same quality of "optimality"). > Note: a word is a group of 6 characters. > > In fact, it is not totally honest, because characters can be 6, 7 or 8 > bits large and of course the more bits you have and better it is (with > 8 bits you can transmitted accented latin characters or non-latin > characters, when you can't in 7 bits and in 6 bits you cannot > distinguish small or capital letters). > > Now to normalize it is easy. For example, if the text throughput is > half the normalized text throughput, the determined minimum S/N is > increased by 3 dB and so on (10* log(ratio)). > > 73 > Patrick (F6CTE) > > ----- Original Message ----- > From: Patrick Novak > To: digitalradio@yahoogroups.com <mailto:digitalradio@yahoogroups.com> > Sent: Saturday, July 12, 2008 9:06 AM > Subject: Re: [digitalradio] Re: KV9U - Mode Sensitivity / Robustness > > > Yes... that would be the ONLY proper test... the statistics would > tell us... > > cheers > P > > Tony wrote: > Patrick, > > I for one would like to try different modes and compare them > under real conditions. There can be too many variables. > > I agree, I think the simulator can tell a lot about mode performance, > but it > has it's limitations. > > It might be a good idea to test modes according to type. Seems > fruitless to > compare a mode that's known to be extremely sensitive and robust > against the > "average" chat mode. > > Good point about switching frequency when testing; need to mind the wide > modes in the narrow band segments etc. > > There was a lot more activity along these lines when sound-card modes > were > first introduced. Wonder if anyone recalls digital beaconing? > > Station S59DOR had one on 10 meters that would transmit the different > Hellschreiber modes. > > Macros allowed the software (IZ8BLY's Hellschreiber) to switch modes > automatically. Have a screenshot of the beacon if anyone is interested. > > Glad to see the enthusiasm Patrick! It's the stuff that keeps the hobby > alive. > > Tony, K2MO > Kings Park, NY > > > > > > ----- Original Message ----- > From: "Patrick Novak" <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> > To: <digitalradio@yahoogroups.com > <mailto:digitalradio@yahoogroups.com>>; <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>> > Sent: Friday, July 11, 2008 11:09 PM > Subject: Re: [digitalradio] Re: KV9U - Mode Sensitivity / Robustness > > > Hi Tony and it is good to see your posting to the group. > > I for one would like to try different modes and compare them under real > conditions. There can be too many variables. I understand it is > impossible > to do it exactly but how about this scenario: > > We will start a contact and send a short file in one mode, then switch to > a different mode (close/same frequency/band) and send the same file > again. > Try several modes and then compare the number of errors in each mode. > If we have a large sample set we will be able to make an educated > guess at > the mode which performs best. > There could be a group or individual who will keep the results table, or > each or OF us (experimenters) will keep own statistics. > What do you think? What everybody thinks? > > regards es 73 > Patrick > VK2PN > > > > Tony wrote: > > 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. > > > > > > -- > ~~~~~~~~~~~~~~~~~~~~~ > Patrick VK2PN > QF56pe > Sydney Australia > > > > > ------------------------------------ > > Announce your digital presence via our Interactive Sked Page at > http://www.obriensweb.com/sked <http://www.obriensweb.com/sked> > > Check our other Yahoo Groups.... > http://groups.yahoo.com/group/dxlist/ > <http://groups.yahoo.com/group/dxlist/> > http://groups.yahoo.com/group/contesting > <http://groups.yahoo.com/group/contesting> > http://groups.yahoo.com/group/themixwgroup > <http://groups.yahoo.com/group/themixwgroup> > Yahoo! Groups Links > > > > > > > -- > ~~~~~~~~~~~~~~~~~~~~~ > Patrick VK2PN > QF56pe > Sydney Australia > -- ~~~~~~~~~~~~~~~~~~~~~~~ Patrick VK2PN QF56pe on the Australian coast ------------------------------------ Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups.... http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
