[Elecraft] [K3] Aliases in Softrock panadapter display

[Arie Kleingeld PA3A]

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
>