[hpsdr] OZY & new code release

[Alberto I2PHD]

Riho B., ES7AAZ wrote:
> 80m SSB audio sample, first 10 sec distorted(v1.4), next 15 sec normal(v1.3),
> last 7 sec distorted(v1.4) again:
> http://tentra.planet.ee/audio_sample.mp3
>   
EXACTLY what I hear on my setup ! The more I listen to it, the more I am 
convinced that
the problem is an insufficient anti-aliasing before a downsampling. I 
remember having
cut the number of taps in an anti-aliasing FIR filter I coded for Winrad 
a couple of years
ago (I did that trying to spare a few CPU cycles), but the audio then 
sounded exactly
as it sounds with the latest FPGA code, so I was forced to make again 
the length of
the FIR as it was before, and the problem disappeared.

It would be interesting, when Kirk will have solved the problem, to know 
if in this case
the reason for that distortion was a similar one.  TNX.

73  Alberto  I2PHD

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/attachments/20090615/0537a7fb/attachment-0004.htm>