At 12:19 PM 10/28/2006, A.R.S. - W5AMI wrote: >One thought on this to anyone thinking about scanning "ranges" of >frequencies, in particular, the higher bands such as 20 meters +: > >Spurs will stop the scan every time one is encountered. This will >tend to get worse the higher in freq. you go. If you only want to >scan certain preset frequencies, it will perform much better.
>At this point, I would much rather see Flex fix the spur issues than >put ANY thought to scanning! So with that, I wonder how close Eric >and Bob are getting toward resolving the spur issues? Sure would like >to get an update on that. I don't know that there is a solution for reducing the spurs. All DDSes have spurs (although they're pretty far down.. -70dBc to -80 dBc would be typical). They are predictable in position and magnitude. There is also a clever technique that's been proposed (and implemented in at least one DDS) that runs a second NCO in parallel which generates only the spurs and subtracts them. But that would be a different radio, not some software fix or hardware mod to the SDR1000. Here's a link to good analysis by Martin Pechanec: http://www.geocities.com/CapeCanaveral/5611/dds.html _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
