garylinnrobinson wrote: > I didn't do my comparison's on MixW and Olivia Aid - I did them with > DM780 and just recently FLDigi on a separate computer but same sound > feed from transceiver since FLDigi is on Linux. Same results. > > You can say it's just Gary but I don't believe it. And it is doesn't > apply to PSK or RTTY they work abt the same on all the progs. > > If I have to own a special computer or special soundcard or do some > special soundcard alignment that I haven't already done - too many > hoops for the regular user let alone a guy who has worked in the > computer industry as a tech and programmer as I have.
There are several factors to consider in order to achieve a fair relative evaluation, and I am sure you know with your claimed background. First, with the data you have at hand could you achieve a quantitative evaluation? As Lord Kelvin stated a long time ago, in science and engineering you actually need numbers to avoid fuzziness. To dissipate doubts, it could be useful if you could also provide your data sets for independent evaluation. Second, are your two computers identical? Same sound card, processor, speed, memory, you certainly wouldn't need to be told all the factors to weigh. Third, as I understand, the "AC97 timing syndrome" only happens on Windows. On Linux and Unix derivatives, queues, semaphores, etc, have different priorities, and so far, Linux fares better with "run of the mill" soundcards and associated delays, even when that does not make differences insignificant, for many reasons, not related exclusively to timing. Signal levels, distortion, noise, A/D and D/A converters linearity, Hamming distances of different modulation formats, FEC, data interleaving are also important factors and certainly have an influence on received BER. Something that would be quite peculiar, if proven true, is that all modes show exactly the same problems. It seems important to sort out this particular allegged behavior with valid data to substantiate it. Linux certainly could give an edge to FLDigi, which is, in fact, also a good performer. It might be interesting to evaluate also GMFSK or other available programs, for sake of completeness. I feel that the last paragraph of your posting above is particularly unfair. In many aspects of life, there exist well known price/performance tradeoffs, be clothing, cars, CPU's, soundcards, just to mention a few well known and some relevant ones. When the multimode boxes were predominant, there were designs and brands that were undoubtedly superior to others. I believe that it is a formidable feat to achieve a similar perforance between dedicated boxes with single tasking processors and computers with multiple running tasks on a multitasking or task switching environment like Windows, at the cost it gets achieved. I have not made any well documented comparisons myself previously, and I am using an average card for receiving, an Audigy 2, which is not a Delta, an EMU, or a higher cost cousin, but neither an AC97. So far, I have not found substantial differences between MultiPSK and MixW, before I began using MultiPSK almost exclusively when versions 4.xx appeared. My soundcard does not require a noticeably different setting from its default. Nevertheless, hardware differences may be so many among users, and behaviors under different OS versions that an independent developer cannot evaluate all possible influences without the beta testers and users feedback. Other programs I also use corroborate such a situation. I believe that all users could certainly gain with a fair evaluation that unveils problems that a developer alone cannot certainly find. 73, Jose, CO2JA
