FW: Soundcards (Leif Åsbrink Sept 18 2002)

[Leif Åsbrink <leif.asbrink@xxxxxxxxxxxxxxxxxxxx]

-----Original Message-----
From: owner-linrad@xxxxxxxxxxxxxxx
[mailto:owner-linrad@xxxxxxxxxxxxxxx]On Behalf Of Leif Åsbrink
Sent: Wednesday, September 18, 2002 9:24 PM
To: Linrad
Subject: RE: [linrad] Soundcards


Hi All,
 
> Although it is currently expensive (about 1000 USD), the LynxTWO can
> sample at up to 192 KHz!  With I/Q detection this would seem to give an
> extraordinary bandwidth.  
> 
> I'd be interested to hear comments on what others think about using this
> card in I/Q mode with a Linrad waterfall bandwidth of over 100 KHz.  Or,
> not using quad detection, and getting 90 KHz or so bandwidth.  Or just
> using it with 192 KHz sampling and quad mixing, and 90 KHz bandwidth,
> and REALLY not having to worry about aliasing ;)  
> 
> Also interested in comments about the card in general...I agree with
> Kohjin that it seems like the card to beat.
> 
> http://www.pcavtech.com/soundcards/LynxTWO/index.htm test of the LynxTWO
> 
> http://www.pcavtech.com/soundcards/delta-66/index.htm test of the
> Delta66
> 
> 
> I wonder how Leif thinks it might work with the new WSE hardware?  And
> in what mode he would suggest running it with the WSE hardware?  E.g.
> 192 KHz sampling rate to really avoid aliasing? Or less?
The WSE RX2500 is designed for sampling at 96kHz. Sampling faster
will not improve much since anti-aliasing is already pretty good:-)

Changing components to run at higher bandwidths will of course be possible
and some day there may be an alternative unit for that. The LynxTWO seems
to be much better than the Delta44. The RX2500 should work much better
with it - but I do not think the improvement will be very useful (yet)
simply because all transmitters in use today have noise sidebands that
will make it impossible to use the extremely high dynamic range:-(

I hope the situation will change in the future. It will be possible to
make a transmitter that matches RX2500 (and it's companions RX10700 etc)
so two amateurs who both use these units will be able to operate at close
frequency separation without causing interference to each other at signal
levels unthinkable today.

73

Leif  /  SM5BSZ 





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