Steve Ellington wrote: > photo it appears that the display is not averaging the signals as Flex > SDR. The QRN appears as little signals. With the Flex SDR- LP Pan, QRN > moves the entire base line up and down slowly but doesn't seem to appear > as a mess of little peaks, masking the actual CW signal. That's the > amazing thing about the I/Q system. I wonder if the P3 has the same
Averaging across multiple FFTs isn't related to whether or not I and Q feeds are used. Using I/Q feeds is just a way of running the A/D convertors at half the speed for the same overall bandwidth (although at the cost of having two A/D convertors, two mixers and more complex local oscillator circuitry). I think it also reduces the DSP power required by about a factor of two, as one solves for both positive and negative frequencies, whereas the negative frequencies from a single mixer are the same as the positive ones and are just thrown away at the end of the processing. -- David Woolley "we do not overly restrict the subject matter on the list, and we encourage postings on a wide range of amateur radio related topics" List Guidelines <http://www.elecraft.com/elecraft_list_guidelines.htm> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
