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Re: [softrock40] FT990 and Softrock

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  • Tony Parks
    Good morning Alan, Thanks for the feedback on IF use of the Lite II. Adam Jacobs and I have a project started where an attempt will be made to span many
    Message 1 of 43 , Apr 24, 2013
      Good morning Alan,

      Thanks for the feedback on IF use of the Lite II.

      Adam Jacobs and I have a project started where an attempt will be made to span many popular IF frequencies with an RX Ensemble II board.

      Tentatively I am thinking the four BP filters will be configured as follows:

      400 kHz to 800 kHz
      4 MHz to 8 MHz
      8 MHz to 16 MHz
      35 MHz to 50 MHz

      I think the above ranges should cover most of the popular IF frequencies. 

      Division on the Si570  clock will be by 8 where the lower three ranges will be fundamental sampling and the 35 MHz to 50 MHz range will be 1/3 sub-harmonic sampling.


      I have started the build of a "IF" configured RX Ensemble II and it should be interesting to see if performance in the 35 MHz to 50 MHz range is good enough for IF use.  My plan is to ship the built RX to Adam tomorrow and hopefully he will have some initial results by this coming weekend.


      Alan, I continue to very, very much appreciate all that you do to help people be successful with the Softrock kits!  If there are kits you would like to have I would be happy to send them to you at no charge to you.

      Thanks much!

      73,

      --
      Tony Parks
      kb9yig@...
      http://fivedash.com
      


      On Wed, 2013-04-24 at 07:26 +0000, Alan wrote:
       

      ----- Original Message -----
      Subject: Re: [softrock40] FT990 and Softrock

      > It would be possible to do a special version of the RX Ensemble II
      > receiver kit that would span all of the popular IF frequency
      > applications. I think it is possible to set the default starting
      > frequency so that a desired center frequency for the RX Ensemble II
      > would come up with application of power to the board.
      >

      Tony

      A Lite + Si570 that could be preset to an exact frequency could have more uses other than as an IF.
      I use several Lites to which I have added Si570s for single frequency monitoring of HF.
      That single frequency can be preset exactly and always startup on that frequency. But there is the ability to change it at any time
      by plugging in the USB.
      With the USB connected one could use it as a receiver covering ranges of frequencies similar to those covered by the RXTX options.

      For use with IF it would be more versatile than a crystal controlled Lite.
      There would be no problem finding a crystal.
      Any exact frequency could be preset and changed if required.

      I'm not sure how far above 160MHz a CMOS Si570 will go but I think the FST3215 will work maybe up to 70MHz with "subharmonic
      mixing"?
      At the higher frequencies a preamp would be needed but this is often used with IF conversions to provide isolation.

      73 Alan G4ZFQ




    • ve3tmt
      Hey Adam, The X-FI Fatal1ty PCI card arrived today. Hoping to get it installed tonight. Curious to see what it will improve on the display. Max
      Message 43 of 43 , May 3 10:55 AM
        Hey Adam,

        The X-FI Fatal1ty PCI card arrived today. Hoping to get it installed tonight. Curious to see what it will improve on the display.

        Max

        --- In softrock40@yahoogroups.com, Adam Jacobs <jacobs.adam@...> wrote:
        >
        > Hi Max,
        > Mirroring of the image in HDSDR is caused by a problem with the
        > quadrature phase input. Either something is shorted, there's a problem
        > in the transformer, or more likely there is a problem in windows or the
        > soundcard end of things. I've had this problem come up lots of times,
        > for me it was always a windows problem. :S
        > You should be able to debug where the issue is occurring by following
        > the signal back from the PC. L/R stereo lines should be 90' out of
        > phase. There are debug steps on the build site as well.
        >
        > -73 Adam W7QI
        >
        > On 4/26/2013 3:45 AM, ve3tmt wrote:
        > >
        > > Hi Alan,
        > >
        > > Check out the 2nd screen capture in my photo album. I am getting an
        > > exact mirror image of the signal down the band. I don't know if this
        > > was there before or not. Any idea what causes this?
        > >
        > > I don't think any lines are shorted, but I can double check tomorrow.
        > > The R + L audio coming off the Softrock run through separate isolation
        > > transformers but I think they are fine.
        > >
        > > Max
        > >
        > > --- In softrock40@yahoogroups.com
        > > <mailto:softrock40%40yahoogroups.com>, "Alan" <alan4alan@> wrote:
        > > >
        > > >
        > > > ----- Original Message -----
        > > > Subject: [softrock40] Re: FT990 and Softrock
        > > >
        > > >
        > > > >
        > > > > Lets assume I am looking at a signal on 20m USB. The signal is
        > > nice and centered in the display. When I switch to 40m LSB the
        > > > > received signal is way off to the far side of the display.
        > > > >
        > > > > Is there any setting to adjust so both sidebands are centered in
        > > the display?
        > > > >
        > > >
        > > > Max,
        > > >
        > > > I think this explains
        > > <https://sites.google.com/site/g4zfqradio/hdsdr-if-pano>
        > > >
        > > > Adam,
        > > >
        > > > >Alan might also
        > > > >> have an attenuator in series with his IF tap, unless he is
        > > tapping at a
        > > > >> different location than me. The signals I see are MUCH stronger and
        > > > >> redder on the waterfall.
        > > >
        > > > No, all I've done is roughly calibrate the "S" meter.
        > > >
        > > > I have made a few steps towards tapping the 47.15 IF but it is not
        > > so simple.
        > > > Some form of interface will be required, maybe a JFET buffer or
        > > amplifier.
        > > >
        > > > 73 Alan G4ZFQ
        > > >
        > >
        > >
        >
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