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[Linrad] Re: Error: MAP65-IQ 4KHZ not MHZ



Joe,

There is a box in the lower left (until you move it) that lets you
enter the center frequency of your hardware. Since I use the SDR-IQ on
the 28 MHz IF of a DEMI transverter, I set the value to 28.125 to
cover the digital EME passband. With that set, I use an fadd of 116000
and I get pretty close to the right frequency on MAP65-IQ. I need to
tweak the SDR-IQ setting through LINRAD around 200 Hz to be right on,
but I don't know how to do that. The value in the box only allows 1
KHz resolution. So, I just keep track of the offset and watch the
value of DF in MAP65-IQ to decide which 1 KHz window to select for the
focused decode.

Ned

On Mar 10, 5:54 pm, Joe Taylor <j...@xxxxxxxxxxxxx> wrote:
> Hi Ned,
>
> You wrote something on the Linrad reflector that prompts me
> to ask a question.  Where does one set a frequency
> correction for the SDR-IQ in Linrad?  I haven't found this,
> I guess.
>
>         -- Joe, K1JT
>
> > You need to get it right in both apps. I used a signal generator and
> > got the offset frequency in LINRAD right first by watching its
> > display. And then I modified the fadd in MAP65-IQ to get its display
> > right. There is a 3rd offset which I cannot figure out how to control
> > My SDR-IQ is off around 200 Hz. There is not enough resolution in the
> > frequency correction in LINRAD to correct for that...maybe I can get
> > it right by adjusting fadd in MAP65-IQ. What happens with that SDR-IQ
> > frequency error  is that the station may be actually in the next 1 KHz
> > increment than what my displays suggest. So, when I dial my TX
> > frequency, I may be off by 1 KHz. To correct for that right now, I
> > look at the DF and when it is a big number I known it is in the next 1
> > KHz bin (which bin is determined by the sign of the DF).
>
> > Ned
>
> > AA7A
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