On Thu, Mar 15, 2012 at 7:19 AM, Bob Kay <[email protected]> wrote: > I've been trying to follow the discussions on the increased sampling rates > that VAC can now use ( 96 & 192 khz). By increasing the sampling rate I'm > still not 100% clear on what improvements I will hear (or see).
You won't see/hear any because your digital mode program is still downsampling to a lower sample rate, either 8,000 or 11,025 Hz. The performance is determined by the filters you select, not the sample rate. The only time the greater sample rate is useful in VAC is if you are passing the full bandwidth I/Q signal through to a program that can use it, like cwskimmer. Integer downsampling of an already bandwidth limited signal, i.e. one that has passed through the IF filter, causes no loss of information. So downconverting from 192kHz or 96kHz to 48kHz as has been done in the past is no-cost. So, for people who are not using cwskimmer or another program that does its own filtering/processing and can accept the full bandwidth I/Q signal, there is no advantage to the new, higher sample rate in VAC. Now we need to wait for the digital mode programs to catch up to PowerSDR. -- Brian Lloyd, WB6RQN/J79BPL 3191 Western Dr. Cameron Park, CA 95682 [email protected] +1.767.617.1365 (Dominica) +1.916.877.5067 (USA) _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software.
