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Re: [TenTec] TenTec] SDR-1000 MDS

To: tentec@contesting.com
Subject: Re: [TenTec] TenTec] SDR-1000 MDS
From: Lee A Crocker <lee_crocker@yahoo.com>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sat, 15 Jul 2006 23:25:57 -0700 (PDT)
List-post: <mailto:tentec@contesting.com>
Jerry

I don't know anything about the FT 857.  I have had
many rigs that used crystal/mechanical filters that
distorted the signal and were virtually useless at
extremely narrow bamdwidths.  

I have had other rigs that used DSP that were marginal
at best.  The Pegasus comes to mind.  I don't even
find the DSP in the Orion to be very effective except
for the filtering function and the tunability of the
AGC.  Those 2 aspects of the DSP are invaluable.  I
don't find the 100 hz filter in the Orion rings.

With the SDR during CQWW I tuned in on 2 DX stations
that were 50 hz apart when I centered them at 350hz in
the passband.  In other words when I first had one
station at 350 and then tuned the other to 350 I had
moved frequency by 50hz.  One station was in the south
Carribean and the other was in eastern Europe.  There
were American stations and European stations calling
both.  So at any given time there was 3 to 6 stations
on freq calling.  I was on 80 M and I have good omni
directional DX antennas.  The stations were about s4
and the calling stations were as high as 20 over.  I
was able to take either station down to single signal
levels with the SDR, and I was able to work both
stations in succession with no trouble.  

I brought up the Orion on the same freq and was not
able to seperate the signals or the calling stations
no matter how I adjusted the controls, using the same
antenna switched over to the Orion.  There is no
ringing in the SDR at any filter or DSP setting.  At
25 and 10 hz both noise and offending signals outside
the passband dissappear.  At 10 hz bandwidth, centered
on a -73 dBm carrier, I found the filter has a
bandwidth of 33 hz at -130dBm, beyond 33 hz I was no
longer able to discern the s9 signal. No radio I have
ever used has this kind of performance.

73 W9OY

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