Hi guys, I was born and raised on Telegraph Rd (true,) I never bought a mic for my SDR, don't know psk from rtty and I have to agree with your comments but consider...
So okay until you get that first receive buffer filled you aren't going to hear anything on switch to receive: 512/48,000 = 0.01 seconds -- longest time to processing 1024/192,000 = 0.005 seconds -- shorter time to processing 512/192,000 = 0.0025 seconds -- shortest time to processing (mebbe even reasonable) Now consider the T/R switch has to close (mebbe 0.01sec) and processing has to occur after the receive buffer fills (give processing another 0.01 second, or more) and you have probably 0.0225 - 0.03 seconds minimum till you hear something in your phones... As computers get faster and multi threading gets better the processing will get shorter but.. the T/R and fill times will remain the same. It's interesting that faster turn around is reported with 512/48,0000. That may be because the processing of a shorter buffer is faster and swamps the sample time issues. It would be very interesting for some of you guys with good ears to try a 512/192,000 combo and see if that makes any difference. Of course the short buffer may be overwhelmed by the fast sample rate. Still I think mebbe those of you with really really hot boxes ought to give it a try... If the big determinant is processing time then multi-threading and more cores may help.. Say continuously processing the receive buffer even during transmit, then mebbe... Otherwise only solution I can see is to use pin diodes for T/R and keep filling the receive buffer while transmitting................... then throw the bad stuff in the receive buffer away and process the rest. That would be one heck of a trick without causing a pop! very best regards Rob AB7CF On Thu, 24 Apr 2008 16:58:24 +0000 Dave Blaschke <[EMAIL PROTECTED]> writes: > The best performance I can obtain for QSK is at the following > settings: > GENERAL-AUDIO-Buffer: Size 512, Sample Rate: 48000 > GENERAL-OPTIONS: Process Priority: High > DSP: TX Buffer Size: 512, RX Buffer Size: 512 > Delay (ms): 10 (minimum setting) > > At these settings I see around 10% CPU utilization on the PowerSDR > screen. > > With these settings, I am almost, but not quite there. Here is my > complaint. When returning from T to R there is an audible "pop" that > > tends to mask reception during Dits and Dahs. I am wondering if > Receive recovery is occurring quickly enough. Elimination of the > "pop" on transition from T to R would go a long way in smoothing out > > QSK, in my opinion. > > My method of comparing QSK capability between my SDR-5000 and my > FT1000D is to select the frequency on a constant carrier signal, and > > then key at 20 wpm to see how well I am able to hear the carrier > between Dits and Dahs. > > > Dave, W5UN > > > _______________________________________________ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > Knowledge Base: http://kb.flex-radio.com/ Homepage: > http://www.flex-radio.com/ > > > _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
