[TenTec] Carl, Pmni, 756 etc

Tom Rauch W8JI@contesting.com
Thu, 14 Mar 2002 22:02:50 -0500


> First let me say no all DSP implementations are alike.  If DSP is done
> properly, DSP is no different than any other type of filtering.   It

Except we probably need at least 12 bits of digitized information 
and a very good low-noise fast A-D convertor to have dynamic 
range that equals that of a conventional crystal filter.

Right now that means it costs much more to have the same 
performance as conventional filters provide, but I expect that will 
change in a few years.

The best solution is to do a good front end with narrow conventional 
filters, and then a DSP system for final selectivity. Of course the 
first filter would be what sets the window for excellent dynamic 
range.  
 
> is just much more flexible.  The CW signals through my rx340 sound
> wonderful and very pure tone.  I hear none of the problems that Tim
> decsribed.  I never use my Omni V.9 anymore because the SSB and CW
> sound so clear and nice in the RX340.

> The design of the RX340 takes great care to never overload the
> DSP processor.  

What is the close-spaced two-tone IM dynamic range, and the 
blocking DR? (None of the useless 10kHz spaced stuff that makes 
the receiver look better than it is in the real world please!)
73, Tom W8JI
W8JI@contesting.com