[K3] Aliases in Softrock panadapter display
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Not sure where best to post this but will try here first...
I've set up my Softrock panadapter again using NaP3 this time. Works very well with my M-Audio PCI card (96Khz) and the WBIR is effective too. One thing I wonder about is connected with the offset between the IF and the SR local oscillator frequency. The SR local osc runs at 8192 Khz which puts it outside any K3 filter passband. When I configure NaP3 with this frequency (and zero global offset etc) the K3 and panadapter display are exactly in sync and I can point and click etc. But the tuning point is naturally offset from the LO by ~23 Khz which means there's only about 25Khz 'usable' to one side of the tuning point in the display before it goes into alias territory (96/2 minus 23Khz...). Rocky seems to simply cut off the display at the sampling edges but NaP3 (and PSDR/IF?) doesn't and this can be a bit confusing when aliases are displayed. This is easily worked around by for eg winding up the zoom to make the illegal band disappear, but it would be nice to be able to have LO and filter centre coincident. I notice that the background colour indicates +/- 48Khz but it's centred around the IF centre and not the LO frequency which would be better. Hope I've explained myself OK..! 73, Stewart, GW0ETF PS It's all linked together with LP-Bridge in case that's relevant... ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: [K3] Aliases in Softrock panadapter display
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Stewart,
I also use the Softrock. My settings with CW Skimmer: Radio: SoftRock IF Sampling rate: 96 kHz CW pitch: 550 Hz Audio IF: minus 23379Hz My settings with Power SDR-IF (love this one because it nicely integrates with the K3): Setup, General, Radio Model: SDR-1000 Setup, Audio, Sampling Rate: 96000 Setup IF, IF Frequencies, Global offset minus 23379, LO center 8215000 Hopes this will point you in the right direction. 73 Arie PA3A Op 20-1-2012 11:52, Stewart Rolfe schreef: > Not sure where best to post this but will try here first... > > I've set up my Softrock panadapter again using NaP3 this time. Works very well with my M-Audio PCI card (96Khz) and the WBIR is effective too. One thing I wonder about is connected with the offset between the IF and the SR local oscillator frequency. > > The SR local osc runs at 8192 Khz which puts it outside any K3 filter passband. When I configure NaP3 with this frequency (and zero global offset etc) the K3 and panadapter display are exactly in sync and I can point and click etc. But the tuning point is naturally offset from the LO by ~23 Khz which means there's only about 25Khz 'usable' to one side of the tuning point in the display before it goes into alias territory (96/2 minus 23Khz...). Rocky seems to simply cut off the display at the sampling edges but NaP3 (and PSDR/IF?) doesn't and this can be a bit confusing when aliases are displayed. > > This is easily worked around by for eg winding up the zoom to make the illegal band disappear, but it would be nice to be able to have LO and filter centre coincident. I notice that the background colour indicates +/- 48Khz but it's centred around the IF centre and not the LO frequency which would be better. > > Hope I've explained myself OK..! > > 73, > > Stewart, GW0ETF > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: [K3] Aliases in Softrock panadapter display
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In reply to this post by GW0ETF
Stewart, my NaP3 setup calls for
Sampling rate 96000 then on the IF freq page: Global offset -6000 LO Center 8215000 swap I/Q yes This gives 48khz on each side. BTW, Arie, try NaP3. It gives the same display as PSDR-IF but apparently has no bugs; at least I've encountered none in 3 months of continuous use. 73, Tony KT0NY On Fri, Jan 20, 2012 at 4:52 AM, Stewart Rolfe <[hidden email]> wrote: > > I've set up my Softrock panadapter again using NaP3.... -- http://www.isb.edu/faculty/facultydir.aspx?ddlFaculty=352 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I use LP-Bridge v1.02 and NaP3 with my K3 and softrock my Global settings differ
Global offset has to be set at -23070 the rest are the same as Tony's. I have tried to use LPB2 v1.01 and neither the -6000 or 23070 settings work for me for starters receive is on the wrong side no matter which LSB or USB and checking or un-checking I/Q shift doesn't fix it after playing a while PERHAPS if I set the global for -6000 and then played with each mode's setting individually, I could get it to work much to much effort I finally just settled for running LP-Bridge v1.02 and NaP3 works great. -- ymmv Sam Morgan K5OAI
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In reply to this post by Arie Kleingeld PA3A-2
Thanks for the replies so far. However none tell me anything new...
There seems two ways to sync K3 and software (NaP3 in this case):- 1/ Set Global Offset to zero and and the SDR LO frequency to what it actually is, ~8192 Khz 2/ What you all seem to do is set SDR LO frequency to the K3 IF centre, ~8215 Khz and then fiddle about with the Global Offset to get the radio and software to sync. Yes, I can do either but in both cases the SDR LO=0Hz centre point will be offset from the tuned signal by approx 23 Khz. This means that if the tuned signal is centred, the extreme ~23 Khz of the side opposite the SDR Local Oscillator will be in the alias region. Try injecting a signal and tuning it across the display toward this region. As it crosses this point it dies away to be replaced I assume by an alias coming in from the opposite side (which is not visible). If the display was chopped off here as in Rocky, or indicated by a change in background colour that would be better. As I said earlier I think this is no more than a niggle in an excellent program but I feel my earlier post didn't get the message across... 73, Stewart, GW0ETF
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