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Forum Newbie
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Last Login: Tuesday, September 21, 2010 4:13 PM
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| In PowerSDR 1.8x we had to select Direct I&Q Output to VAC for CWSkimmer to work properly, and CWSkimmer was configured to look at a SoftRock-IF with 9600 Hz IF. If I wanted to revert to DM780 for digital modes, I had to deselect the Direct I&Q Output to VAC. Now in PowerSDR 2 I accidentally found that something with a 9600 Hz IF is still being fed to the VAC, despite not selecting Direct I&Q Output to VAC. In fact, I'm watching W1AW transmitting on 14.046910 at UTC 00:32 in both CWSkimmer and DM780. And I find that even when I select Direct I&Q Output to VAC, there is no change in the CWSkimmer waterfall display, but, as expected the DM780 waterfall goes blank. So... is PowerSDR 2 leaving I&Q data in the VAC buffer above 3 kHz? Or is it demodulating everything, and leaving some demod images above 3 kHz - hence sending identical data to both I&Q channels for CWSkimmer? Either way, I like this (possibly) unintended behavior. 73 de N7AIG
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Last Login: Sunday, April 15, 2012 2:14 PM
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How do you have the VAC Driver, input and output configured in PowerSDR?
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Tim - W4TME
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Forum Newbie
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Last Login: Tuesday, September 21, 2010 4:13 PM
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| Ahh... very interesting new discovery... I normally have my CWSkimmer taking its input from the VAC Channel 1. For some reason Win/7 keeps re-ordering my audio channels in the dialogs after I plugin and disconnect headphones, microphones, etc. I just discovered that CWSkimmer had its input channel reassigned to the FlexRadio Microphone stream! That accounts for the dual behavior with DRM780. Not sure why a "microphone" stream would be echoing the current output stream. But it appears to be the usual I&Q that would have been sent to the VAC, had I selected DIQV. By accident, on one of the first days that I had my new FK3, I was modulating that same FlexRadio stream from my DRM780 and getting massive spill-over -- in effect I was creating DSB modulation, as verified by a second receiver. That channel obviously need I&Q data, not 2 channels of the same mono stream. Heh! At any rate, reading directly from the "FlexRadio Microphone" stream seems to work like a champ, and leaves my DRM780 fully functional, so I can switch rapidly between CW and Data modes. Now, if only the F3K had a PIN diode TR switch to support full QSK... 73 de N7AIG
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Now, if only the F3K had a PIN diode TR switch to support full QSK...
It wouldn't make any difference in the keying speed. The relays are fast enough for full QSK. The issues is not hardware, it is latency in the software messaging protocol and the lack of reproducibly accurate keying timing. Both are being seriously worked on. It will probably not make PowerSDR v2.0.0, but look for CW improvements in v2.2.0 (the subsequent release).
BTW, PIN diodes increase the TX IMD which is why relays where used instead.
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Tim - W4TME
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Last Login: Tuesday, September 21, 2010 4:13 PM
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| I see a checkbox labeled "Calibrate IQ" in the Direct IQ to VAC group... Presumably, by sending the direct FK3 IQ stream to CWSkimmer I'm bypassing this spur correction, right? I didn't notice any obvious differences, but I didn't examine the CWSkimmer waterfall very carefully either. And yes, I've had some comments from QSK ops asking why the long delays in turnaround. I can't sense it, but they can. And I understand the issues about latency. I'm not that terribly bothered by lack of full QSK yet - I'm not expert in CW ops, preferring some casual CW but mostly Digital Modes. Once all the computer-side glitches got ironed out, the FK3 is a truly unbeatable system. I keep going back and forth between the FK3 and the ICOM 756Pro3, but I'm finding it very hard to do without the PanFall display, and the FK3 RX is superb. When I absolutely need QSK, then I can always fall back to the 756. 73 de N7AIG
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