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LO frequency offset adjustable?

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  • FRED
    I enjoy using PSDR-IQ v1.12.20 for SSB use. For various reasons I find this version to be more functional than the more recent releases. Question: The Local
    Message 1 of 5 , Oct 9, 2011
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      I enjoy using PSDR-IQ v1.12.20 for SSB use. For various reasons I find this version to be more functional than the more recent releases.

      Question: The Local Oscillator offset is fixed at 9 khz, ie: the RXTX frequency is 9 kHz higher than the Local Oscillator. Is there a way to easily increase this offset?
      I use a Softrock RXTX 6.3 and on the higher frequencies (28 MHz)I have a lot of ground loop "trash" around the Local Oscillator frequency and I would like to get farther away from that if possible, like maybe 15 or 20 kHz...

      Thanks
      Fred
      WA8PGE
    • g8voip
      Hi Fred, You can change the IF offset in v1.12.20. Setup General Hardware Config check the expert box in the Si570 section and you have access to the
      Message 2 of 5 , Oct 9, 2011
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        Hi Fred,

        You can change the IF offset in v1.12.20.

        Setup > General > Hardware Config > check the 'expert' box in the Si570 section and you have access to the IF offset in there.

        73, Bob G8VOI


        --- In powersdr-iq@yahoogroups.com, "FRED" <flsaas@...> wrote:
        >
        > I enjoy using PSDR-IQ v1.12.20 for SSB use. For various reasons I find this version to be more functional than the more recent releases.
        >
        > Question: The Local Oscillator offset is fixed at 9 khz, ie: the RXTX frequency is 9 kHz higher than the Local Oscillator. Is there a way to easily increase this offset?
        > I use a Softrock RXTX 6.3 and on the higher frequencies (28 MHz)I have a lot of ground loop "trash" around the Local Oscillator frequency and I would like to get farther away from that if possible, like maybe 15 or 20 kHz...
        >
        > Thanks
        > Fred
        > WA8PGE
        >
      • Alan
        ... From: FRED Subject: [powersdr-iq] LO frequency offset adjustable? ... Fred, If it s that bad it would be better to clean it up. Ground loops and pickup
        Message 3 of 5 , Oct 9, 2011
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          ----- Original Message -----
          From: "FRED"
          Subject: [powersdr-iq] LO frequency offset adjustable?


          >I enjoy using PSDR-IQ v1.12.20 for SSB use. For various reasons I find
          >this version to be more functional than the more recent releases.
          >
          > Question: The Local Oscillator offset is fixed at 9 khz, ie: the RXTX
          > frequency is 9 kHz higher than the Local Oscillator. Is there a way to
          > easily increase this offset?
          > I use a Softrock RXTX 6.3 and on the higher frequencies (28 MHz)I have a
          > lot of ground loop "trash" around the Local Oscillator frequency and I
          > would like to get farther away from that if possible, like maybe 15 or 20
          > kHz...
          >


          Fred,

          If it's that bad it would be better to clean it up. Ground loops and pickup
          are not that difficult to get to reasonable proportions.
          In the Si570 Expert configuration if you really must...

          73 Alan G4ZFQ
        • FRED
          Thanks Bob, that s exactly where it was! I saw the word expert and thought that was certainly not me! No wonder I couldn t find it 8-)BTW - glad to see you
          Message 4 of 5 , Oct 13, 2011
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            Thanks Bob, that's exactly where it was!  I saw the word "expert" and thought that was certainly not me! No wonder I couldn't find it    8-)
            BTW - glad to see you again!

            73
            Fred
            WA8PGE


            --- In powersdr-iq@yahoogroups.com, "g8voip" <g8voi.reeves59@...> wrote:
            >
            > Hi Fred,
            >
            > You can change the IF offset in v1.12.20.
            >
            > Setup > General > Hardware Config > check the 'expert' box in the Si570 section and you have access to the IF offset in there.
            >
            > 73, Bob G8VOI
            >
            >
            > --- In powersdr-iq@yahoogroups.com, "FRED" flsaas@ wrote:
            > >
            > > I enjoy using PSDR-IQ v1.12.20 for SSB use. For various reasons I find this version to be more functional than the more recent releases.
            > >
            > > Question: The Local Oscillator offset is fixed at 9 khz, ie: the RXTX frequency is 9 kHz higher than the Local Oscillator. Is there a way to easily increase this offset?
            > > I use a Softrock RXTX 6.3 and on the higher frequencies (28 MHz)I have a lot of ground loop "trash" around the Local Oscillator frequency and I would like to get farther away from that if possible, like maybe 15 or 20 kHz...
            > >
            > > Thanks
            > > Fred
            > > WA8PGE
            > >
            >
          • FRED
            Thanks for the reply Alan.Yes, I should clean it up, I realize this is just a band-aid fix but for the time being I m happy with the results of just moving
            Message 5 of 5 , Oct 13, 2011
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              Thanks for the reply Alan.
              Yes, I should clean it up, I realize this is just a band-aid  fix but for the time being I'm happy with the results of just moving further away from the trash around the LO.
              I'm really not sure if it is ground loop noise or not, it kind of looks like the display when you have the wrong band pass filters plugged into the 6.3 for the band you are on, if you know what I mean.  Like an impedance mismatched antenna.....
              It only does it with the 10/12/15 bandpass filter in, 40/80 and 30/20/17 band pass filters are ok and don't exhibit the junk around the LO.  And it is still there with NO antenna hooked up, and with the TX audio unplugged.

              Since I use CW/Rocky anyway 90% of the time, the junk around the LO is not a problem. (it is still there with Rocky too but only affects 5% of the display, and again only on 10m.)

              I'm about to get to my MOBO kit and maybe the junk wont be there as I expect my present 10/12/15 bandpass is the culprit.

              Thanks again for the reply.
              Fred
              WA8PGE

              --- In powersdr-iq@yahoogroups.com, "Alan" <alan4alan@...> wrote:
              >
              >
              > ----- Original Message -----
              > From: "FRED"
              > Subject: [powersdr-iq] LO frequency offset adjustable?
              >
              >
              > >I enjoy using PSDR-IQ v1.12.20 for SSB use. For various reasons I find
              > >this version to be more functional than the more recent releases.
              > >
              > > Question: The Local Oscillator offset is fixed at 9 khz, ie: the RXTX
              > > frequency is 9 kHz higher than the Local Oscillator. Is there a way to
              > > easily increase this offset?
              > > I use a Softrock RXTX 6.3 and on the higher frequencies (28 MHz)I have a
              > > lot of ground loop "trash" around the Local Oscillator frequency and I
              > > would like to get farther away from that if possible, like maybe 15 or 20
              > > kHz...
              > >
              >
              >
              > Fred,
              >
              > If it's that bad it would be better to clean it up. Ground loops and pickup
              > are not that difficult to get to reasonable proportions.
              > In the Si570 Expert configuration if you really must...
              >
              > 73 Alan G4ZFQ
              >
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