Hello Rockers
Built a SoftRock40 and tried the more common SW packs available for Win.
Running winxp home on a 1.4 Centrino laptop with a SB audigy 2 NX (usb)
With PowerSdr had to use 2048 blocks and 45 ms latency to get it to
work without hiccups. (all other features are very nice).
With Alberto I2PHD SDRadio again had to use 2048 blocks and 48khz
(liked better the way BandWidth is controlled) at 96 khz sampling it
begins to sound rough and hiccupy.
Then came Phil Covington's SharpDsp MiniConsole (which still lacks a
panadapter display and some other niceties) and here I can set a 4096
blocks value (some more latency, true) and Lo and Behold! works really
nicely with 96 khz sampling rate.
Now I get more than 90 khz of the band (which in region 1 is almost all
the band!!). Amazingly the sensitivity is uniform all the way (heard a
rumor that even at 96 khz there is a AntiAliasing analog filter on the
Audigy input...proven wrong!)
Tried the new Rocky by Alex VE3NEA and regrettably it does not work
with my Audigy (gives a 'unable to start input from SoundBlaster Audigy
2 NX) so cannot test operation at 96 khz. Well I'll wait and see if
more people have the same problem...
Will try to operate on external supply and see if the noise at the LO
is power supplied by the USB or a ground loop (or both).
Hav'nt seen the I/Q automatic balancing work yet but in the other SW
packs it is really something to be addressed because the image once
nulled on a certain frequency is definitly growing and changing on
other freq. So a mapping (table and interpolation) or the automatic
way shoult be implemented IMHO.
Have a nice (Rocky??) weekend de Joe
