Topband: SDR-IQ experience during CQ 160 contest

Tree tree at kkn.net
Sun Jan 31 10:00:38 PST 2010


A few days before the CQ 160 CW contest, I received my new SDR-IQ "receiver"
from HRO.  It is a small box - with a USB cable and a BNC connector for
the antenna.  The power for it comes from the computer via the USB cable.

During the contest, I was using it with the Skimmer software and it was 
connected to a small coax receiving loop.  I was recording the band from 
1800 to 1890 so I can play back anything I might want to listen to during
the log checking process.

It didn't take long for this setup to exceed my expectations.  First off,
I found it possible to transmit and have the SDR still receiving away when
using 100 watts.  Due to a local AM station issue - I had to move the null
of my loop away from my TX antennas - so this was not possible with a KW.

What was amazing is some of the callsigns the system started hearing.  This
box heard all continents and found a number of Europeans that I really was
not hearing much better with my beverages.  It seems the trick is that 
many signals do eventually peak up and the skimmer is very patient.  

At times, there were over 400 callsigns listed that skimmer had found.  
Some of these were busted calls - and about half of them were callsigns
from people answering CQs - but that is still a lot of good data.  

A good friend of mine started CQing and I noticed his call pop up on 
the skimmer display.  I was the first to answer him after only 5 CQs,
an elapsed time of about 30 seconds.  I went back and created a sound 
file of his CQs and my answer.  

It's easy to see why this is "assisted".  The power of this system is very 
impressive.  I would say it was very close to being as useful as packet.

It will be interesting using this during a good opening to Europe as an
aid to find guys perhaps before they get spotted.

73 Tree N6TR
tree at kkn.net


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