Fwd: [psk31] Hunting Really Weak Signals]

Frank Gentges gentges@itd.nrl.navy.mil
Thu, 18 Mar 1999 04:49:54 +0000 (GMT)

Thanks for reminding us of Hamview.  We have had problems running desktop 
PCs next to our sensitive LF receivers and antennas.  The problem is most 
likely the horizontal sweep circuits of the monitor.  Instead we are able 
to use notebook computers with LCD displays.  

In my case I use a Toshiba Satellite Pro 425 with a 100 mHz Pentium and an
active matrix display capable of 800x600 pixels.  The built-in sound card is
non-replaceable and is based on the "ESS 688" chip set.  It is built by ESS
at <<http://www.esstech.com>>.  While it is claimed to support Sound Blaster
it is in fact different and does not support Hamview.  I would really like to
have your program (which I have run on my desktop) run on this or similar
notebooks since they are quieter in their LF noise.  If you want, I would be
glad to test any changes you want to try to find a solution and maintain an
email dialogue. 

In addition, it looks like the signal to noise on the amateur LF signals 
are going to be very low so bandwidths well below 1 Hz may be needed to 
detect transatlantic signals.  I just measured European LF broadcast 
signals at best at 19 dB in a 200 Hz bandwidth.  On another day with 
better propagation I hope we could see higher.  But given their ERP, 
and this data it means we need a lot of processing gain to detect the 
much lower amateur ERP.

I am CC:ing the AMRAD tacos group so they can see what we are looking 
at.  We should go to direct email to work the problem while lowering 
the tacos clutter.

Frank Gentges K0BRA

On Wed, 17 Mar 1999, Alberto di Bene wrote:

> >
> >  Here's a tip for anyone interested in hunting really weak psk31 signals.
> >
> Another software useful for the task could be :
> <shameless-plug>
>  Hamview,   freely downloadable from  http://www.freeyellow.com/members/padan
> </shameless-plug>
> Alberto di Bene,   I2PHD