FW: RE: Big surprise! (Leif Asbrink Sept 14 2002)

[Leif Asbrink <leif.asbrink@xxxxxxxxxxxxxxxxxxxx]

-----Original Message-----
From: owner-linrad@xxxxxxxxxxxxxxx
[mailto:owner-linrad@xxxxxxxxxxxxxxx]On Behalf Of Leif Asbrink
Sent: Saturday, September 14, 2002 12:00 AM
To: Linrad
Subject: RE: [linrad] Big surprise!


Hi Kohjin and all,
 
> What a wonderful world of DSP, I just can't believe Linrad is such great!
> I still have many things to solve but was surprised to run a 
> recording file
> of FRH1135. http://ham.te.hik.se/homepage/sm5bsz/arrl2001/
> I was just shocked and spent more than 8 hours hopping around the band
> by clicking the mouth. 20Hz band width of the filter forced me 
> wake up till
> morning because of smooth and elegant sound of CW tone.
> I would strongly recommend to install the software and try to 
> listen, there
> will be another world of EME or perhaps another mode too.
Hmmm, remember SM5FRH has a VERY BIG antenna..........

However, as you surely have noticed extremely few stations are so weak
that you can not copy easily at much lower levels. Use the peak S-meter
to find the maximum during a 1 minute sequence. This number stays nearly
constant for each station (unless there is an antenna positioning or tx
error). You will find that practically all stations can be copied at
8dB lower S/N (get N from the S-meter on the noise floor)

8dB below SM5FRH is a normal 4-yagi station:-)

> I wrote in my previous post;
> >I am running with both SB16 (Vibra 16 X) for output and Santa Cruz
> >for input for the moment.
> 
> It's strange above was not operative.
> The output device (Vibra16X) didn't show to select when Santa Cruz
> selected for input device and no sound could be heard at all.
> (by selecting the same Santa Cruz for output, it was forced so)
> I had tried many options for many things but no joy.
> Then I switched the devices vice versa, bingo!
> I am now using Vibra16X for input and Santa Cruz for output.
> It seems it works just fine but don't know what's going on here.
> I am using OSS/Linux not yet licenced.
Well, all those soundcards make life hard;-) I do not know
what works and what does not work but I hope with more Linrad
users it will become known on this list:-)

> My 500MHz Pentium III with 384MB ram shows rather high CPU load.
> I observed around 90% by 'ps aux' command in remote login shell.
> I wonder if this is the case in your system too?
Have you tried the different FFT versions ? With Pentium III you can
use MMX and SIMD instructions that run a good deal faster than ordinary 
floating point. You need them to process 2 x 96 kHz bandwidth.

> OK, now it's the time to buy a Delta44 and think about the RF hardware :-)
Hmmm, or trying to find out what other good soundcards that just
became available (if any ???????)
I will stay with the Delta 44 for a while, my time is already used 
more than 100% :-)


73

Leif  /  SM5BSZ





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