Hi Jerry,
> Hello Alex
>
> Can you distribute the simulated audio files?
I temporarily uploaded all audio files to my web site, the url's are
http://www.dxatlas.com/rtty/Flutter.zip
http://www.dxatlas.com/rtty/Awgn.zip
http://www.dxatlas.com/rtty/Echo.zip
http://www.dxatlas.com/rtty/Flat.zip
http://www.dxatlas.com/rtty/Selective.zip
These files are huge, and I cannot keep them permanently on the site.
> I couldn't get Virtual Audio Cable 2.04 installed under XP Pro, so
> downloaded the current V3.something, which appears to work, but I have no
> confidence in it because I can hear a buzzing in the RTTY audio files when
> I route them through it. No buzzing otherwise.
AVC 3 intentionally adds some noise to the audio, this is a shareware
limitation. V.2 does not do this. Besides, V.3 did not work on my Win2000
system, and I had no choice but switching to v.2.
> Since I have two sound cards in the computer my next step will be to try
to
> avoid using VAC (and the buzzing) by just patching externally from one
card
> to the other with a hardware cable.
I tried a loopback cable between the line output and line input of my
on-board sound card, and this worked, though I noticed that the noise level
slightly increased.
> In the process of learning how to use the various pieces, it occurred to
me
> that if you just packaged and distributed the final path-simulated audio
> files, it would cut out much of the work and uncertainty for the test
> preparation process.
I would like someone to repeat the whole procedure from scratch rather than
use the audio files that I used. If I made a mistake somewhere, such
independent test would reveal it. Besides, I discovered that 3-minute
simulations are too short and do not produce reliable results at low error
rates. E.g., if the program makes 3 mistakes in 904 chars, the actual error
rate is not necessarily 0.3%, it is somewhere between 0.1% and 0.5%.
73 Alex VE3NEA