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Re: [powersdr-iq] Re: Power SDR and External usb sound cards I need Sound Blaster X-FI support

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  • Alan
    ... Subject: [powersdr-iq] Re: Power SDR and External usb sound cards I need Sound Blaster X-FI support ... Eric, My way of saying it is that the LO is by
    Message 1 of 14 , Mar 1, 2012
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      ----- Original Message -----
      Subject: [powersdr-iq] Re: Power SDR and External usb sound cards I need
      Sound Blaster X-FI support


      > PSDR has a built in audio IF shift. This is usually set at 9KHz
      > but can be changed.

      Eric,

      My way of saying it is that the LO is by default 9KHz below the RX
      frequency.
      But on TX it is moved up 9KHz so it sits in the "carrier" frequency
      position.
      The received IQ signals are 9KHz higher than the demodulated audio. But the
      TX IQ is at the audio frequency.
      This is the only way PDSR-IQ works. Other versions of PSDR have the option
      of a fixed LO but this can result in spurious signals breaching some
      country's regulations. A technical point, it does not alter the spurii, only
      the way they are classified.

      Regardless of the radio the LO has to be controlled by PSDR-IQ. All the
      radio's LO controller does is facilitate PSDR's request for a frequency
      change. Yes, it may do other things required by the radio to operate on the
      requested frequency.

      73 Alan G4ZFQ
    • kh2br
      Thank you so very much !!! I did not know how the software worked. Now it all makes sense to me. Robert KH2BR
      Message 2 of 14 , Mar 1, 2012
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        Thank you so very much !!! I did not know how the software worked.
        Now it all makes sense to me.
        Robert KH2BR

        --- In powersdr-iq@yahoogroups.com, "ericwd9" <ericwd9@...> wrote:
        >
        > PSDR has a built in audio IF shift. This is usually set at 9KHz
        > but can be changed. Some firmware controlled local oscillator
        > interfaces with PSDR have provision to equalize this by shifting the
        > local osc between RX and TX. Using MCW one can select a "tone"
        > frequency that will shift the TX signal to equal the RX signal.
        > On digital modes this can often be programmed into the software.
        > I use a SR6.3RXTX having a Sis570 LO controlled by a MoBo 4.3 that
        > has an on-board CPU that will calibrate and equalize the TX/RX
        > frequencies and select bands and filters 160-10m from PSDR IQ.
        > Having 2 "sound cards" and their drivers installed in Windoz
        > is problematic. To have full use of PSDR IQ one needs a supported
        > card or at least a 4in 4out card preferably with a sample rate of
        > at least 96KHz. One can pick up MAudio Delta 44 supported cards
        > on ebay for $150.00. Though the best all round "card" is Christos's
        > USBtoSDR for support,adaptability and ease of use.
        >
        > Regards 73 Eric VK5ZAG
        >
        > --- In powersdr-iq@yahoogroups.com, "Alan" <alan4alan@> wrote:
        > >
        > >
        > > ----- Original Message -----
        > >
        > > Subject: [powersdr-iq] Re: Power SDR and External usb sound cards I need
        > > Sound Blaster X-FI support
        > >
        > >
        > > >
        > > > I did notice something very unusual while I was transmitting on cw and
        > > > that was while monitoring on another receiver that SI570 was shifting from
        > > > the received frequency to the transmit frequency.
        > > > Is this the way PSDR is supposed to behave in cw?
        > >
        > > This is the way PDSR-IQ works. The RX is offset. TX is not.
        > >
        > > 73 Alan G4ZFQ
        > >
        >
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