[Elecraft] SDR-IF and I/Q questions

[Don Wilhelm]

Dick,

The cause of mirror images is normally associated with the two audio 
signals not being of equal amplitude and/or not 90 degrees out of phase 
when they enter the "number crunching" part of the software.  Yes, 
"ground loops" can cause that, but check your cables for integrity and 
be certain the volume controls for the "left" and "right" channels are 
producing the same amplitude input.  Some experimentation with the level 
controls may be necessary.

73,
Don W3FPR

On 11/11/2011 3:45 AM, Richard Fjeld wrote:
> Greetings to Don Wilhelm and others,
>
> I'm a couple Digests behind and I am responding to Vol 91, Issue 13. I have had responses similar to the following:
> .............................................
> I believe you are mixing two things (given the last paragraph of your post).
> The SDR software application has no connection with the serial or USB
> connection to the transceiver - the I/Q outputs are fed to the soundcard
> and those alone can provide a panadapter type display with no serial
> connection at all.
> .....................................................
>
> I knew I should have explained why I asked that.  If ground loops are involved in the mirrored image problem, as some have suggested, the RS232 arrangement could be a factor (depending upon how they are wired of course).
>
> In the meantime, I have installed NaP3 and it seems to have very good control between radio and software.  It is trimmed down from about 30 Mb (PSDR-IF) to less than 4 Mb (NaP3). I read it is taken from a newer version of PowerSDR which is good.  I still have numerous mirrored images with it which I will have to get to the bottom of.  That is why I asked the questions, to see if I can determine a focal point.
>
> By the way, when I installed both PSDR-IF and NaP3, I got a pop-up error message 2908 that I can't get away from unless I do a Ctl-Alt-Del.  If you get this, I found a work-around solution.
>
> So far, it looks like NaP3 is what I have been waiting for.  I haven't responded to all the replies I have received, but I am considering all of them and I thank you.
>
> I would still like to have some input (it can be off line if you like) of whether or not you have been successful at running a 'computerized pan-adapter' so that I can weed out the common denominator of this mirrored image problem.  I'd like to know YES, or NO,  and cpu type and speed, OS, soundcard, if USB to serial adapter or straight serial cable, and the SDR program .
>
> Thanks,
>
> Dick, n0ce
>
>
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