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Re: [linuxham] Re: Second Step?

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  • John Williams
    I have the following observations based on using a SDR-Widget (a very high quality ham designed sound card, that has a very low noise floor) and a Softrock
    Message 1 of 37 , Jan 2, 2012
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      I have the following observations based on using a SDR-Widget (a very high quality ham designed sound card, that has a very low noise floor) and a Softrock Ensemble RXTX SDR that is running on 40/30/20M bands.

      I have been successful (2 way QSO) with PSK31 and PSK125. I need a fairly strong signal to show on the waterfall and it appears that the signal strength indicator on the side and the waterfall are not in good syncronization. I have the waterfall upper signal level set to -40 and signal range set to 90db. Waterfall is clear and shows multiple types of signals.

      I enabled RSID this morning and it is decoding properly.

      PSKReporter and PSK browser is working normally.

      This may be all luck, but pretty impressive anyway. I plan to resurrect my sdr-shell config and run it that way. I am guessing that there is no telling what kind of transmit artifacts are present on the signal if the channels cannot be balanced for minimum image rejection as is necessary with PSDR and other FLDIGI front ends.

      John - ke5ssh

      On 1/2/2012 9:25 AM, John Greusel wrote:  
      Dave,

      Like John KE5SSH, I have found that Fldigi can encode and decode IQ signals to from softrocks.
      I'm thinking now (based on what you have said) that this is accidental and unintentional.
      Could it be that the digital nature of these modes is coming through the IQ signal into Fldigi as readable even though it hasn't been processed through a A/D signal process? I know these seems sort of far out but I have no other explanation at this point.
      It does encode and decode PSK31 pretty effectively.

      John
      KC9OJV
       



      From: w1hkj <w1hkj@...>
      To: linuxham@yahoogroups.com
      Sent: Monday, January 2, 2012 8:33 AM
      Subject: Re: [linuxham] Re: Second Step?

       
      John,

      I suggest you read the source code published for fldigi. It is
      available for download (you already have it if you are compiling from
      source). Specifically the code associated with sound i/o:

      src/soundcard/sound.cxx

      The current implementation of left and right channel is not an I/Q
      implementation. The audio input is treated as a mono baseband signal on
      the left channel. This is consistent with internal and external codecs
      that are used with all but sdr type receivers. The output is a mono
      base band signal on either the left, right or both channels. When both
      is deselected then the opposite channel can contain a mono baseband
      signal that can be used for PTT, CW keying, or FSK keying. The latter
      being user selectable.

      Dave

      On 01/02/2012 06:39 AM, John Williams wrote:
      > Hi Dave,
      >
      > I joined this group to ask more about this topic. Would appreciate a
      > more technical discussion...
      >
      > I am running 3.21.34 now on Ubuntu Linux 11.04 and using I/Q being fed
      > from an SDR-Widget/Softrock Ensemble RXTX thru pulse. It seems to be
      > working. I have been able to complete a few 20M QSOs with it and they
      > stated that the signal looked good on the waterfall. So it must be the
      > case that it is partially implemented but not yet fully functional?
      > Can you explain a bit more about this? I read some traffic on the ML
      > in 2009 about using some code from another project for the I/Q to
      > baseband conversion but found very little since then in the ML traffic.
      >
      > Having a standalone capability for softrock would be an outstanding
      > feature for FlDigi to complement some of the work going on with
      > QtRadio for SSB mode on Linux.
      >
      > John - ke5ssh
      >
      > On 1/2/2012 6:26 AM, w1hkj wrote:
      >>
      >> I/Q input and output is not currently supported by fldigi.
      >>
      >> Dave
      >>
      >> On 01/01/2012 06:36 PM, Ed wrote:
      >> > On Sun, 01 Jan 2012 20:08:09 -0000
      >> > "John"<n0ure@... <mailto:n0ure%40yahoo.com>> wrote:
      >> >
      >> >> Ed,
      >> >> SoftRock SRD (Software Defined Radios) use quadrature sampling
      >> >> detector. This produces the (signal I, 0-180) and the 90-270 degree
      >> >> shifted signal (quadrature Q) thus "IQ". With the two signals I& Q
      >> >> all of the demodulation can be done via DSP using the PC. So IQ SRDs
      >> >> have a stereo in and out for RX/TX. http://www.wb5rvz.com/ is a good
      >> >> link to start from.
      >> >>
      >> >> 73 John TI4/N0URE
      >> > Thanks, I'll take a look.
      >> >
      >> > Ed W3NR
      >> >
      >> >
      >> > ------------------------------------
      >> >
      >> > Yahoo! Groups Links
      >> >
      >> >
      >> >
      >> >
      >>
      >>
      >




      -- 
      
      John Williams
      
      KE5SSH - ham since 2007
      WQKA523 - GMRS for family use on the farm
      
    • John Williams
      I think that the si570 hamlib support will not need the device filled in. You probably need to add the softrock.rules as Sid described in one of his notes on
      Message 37 of 37 , Jan 2, 2012
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        I think that the si570 hamlib support will not need the device filled in. You probably need to add the softrock.rules as Sid described in one of his notes on the softrock list.

        On 1/2/2012 5:03 PM, Ed wrote:
         

        On Mon, 02 Jan 2012 22:45:07 -0000
        "John" <n0ure@...> wrote:

        > Ed,
        > I am making progress, slowly.
        > I found the source of must of my Update & Upgrade problems. The local
        > ISP DNS server is slow. I set to 8.8.8.8 and upgraded to 11.04. I did
        > have some problems at the start, just a gray screen with no action. I
        > had to go get an unsupported driver for Unity/Nvidia.
        >
        > I got the pavucontrol installed and jumped over to Fldigi config.
        > Hamlib devices now show TTYS0-31 but no USB. The lsusb command
        > follows.
        >
        > John
        >
        > john@clarkHam01:~$ lsusb
        > Bus 007 Device 003: ID 16c0:05dc VOTI shared ID for use with libusb
        > Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
        > Bus 006 Device 002: ID 051d:0002 American Power Conversion
        > Uninterruptible Power Supply Bus 006 Device 001: ID 1d6b:0001 Linux
        > Foundation 1.1 root hub Bus 005 Device 002: ID 046d:c51b Logitech,
        > Inc. V220 Cordless Optical Mouse for Notebooks Bus 005 Device 001: ID
        > 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 002: ID
        > 058f:9360 Alcor Micro Corp. 8-in-1 Media Card Reader Bus 004 Device
        > 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 001:
        > ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 001: ID
        > 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 001: ID
        > 1d6b:0002 Linux Foundation 2.0 root hub john@clarkHam01:~$
        >

        Well you are doing good so far.

        Well Linux found the USB hub, But why didn't fldigi find it.
        The /dev/ttyUSB0) should be the last thing after the serial ports. Only
        thing that I can think of is one of the device's you have plugged in is
        keeping fldigi from seeing the ports.

        If you run fldigi from a terminal are you seeing any errors ?

        Open Synaptic and remove brltty.

        Ed


        -- 
        
        John Williams
        
        KE5SSH - ham since 2007
        WQKA523 - GMRS for family use on the farm
        
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