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SoftRock 6 QRP Exiter - First CW Contacts?

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  • verduynj
    Bill, Tony, All, I made my first CW contact this morning with the SR6 Exciter Alpha prototype using the latest Version of PowerSDR Software which Bill released
    Message 1 of 4 , Oct 1, 2006
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      Bill, Tony, All,

      I made my first CW contact this morning with the SR6 Exciter Alpha
      prototype using the latest Version of PowerSDR Software which Bill
      released last Friday. Very pleased with this!!

      http://www.tracey.org/wjt/sdr1k/SoftRock40/PowerSDR-KD5TFD-srxmit-
      20060928.zip - thanks Bill!!

      I worked ON5CBK, Patrick at 11:15 UTC on 7015 Khz and received 599
      report .. Not bad for 0.6 Watt RF output!!
      Second contact was a solid 15 minute QSO with Joe, DM0K and received
      a 559 report.

      Is this the first CW contact with the Softrock Exciter or has somebody
      else beaten me to it?

      Some additional info from us who prototyped to Exciter:

      - Using (Dell on board Sigmatel STAC 92xx)s unwanted sideband and
      carrier suppression is at more -30dB down from full rated output as
      shown on a spectrum analyser. -30dB is the FCC requirement I
      understand.

      - With this particular soundcard it is advisable to stay away from
      the maximum sampling rate; otherwise output power and sideband
      suppression start to suffer. For example sampling freq 48K, I find I
      need to limit TX within 22 Khz range 7034 KHz - 7088 KHz. With 96K
      sampling rate I can cover 7014 KHz - 7096 KHz

      - Before putting the exciter you should do a sanity check by
      monitoring your transmission on a separate receiver.
      Connect the SR6 Exciter to a Dummyload.
      a) Tune the RX to the Transmit Frequency and position the RX Antenna
      lead near the Dummy load until you obtain an S9+10dB Smeter reading.
      b) Insert a 30dB attenuator in the antenna lead and note the new S-
      Meter reading.
      c) Now tune to Carrier Frequency (7056 KHz) and check whether the S-
      Meter reading is same or less as in step b)
      d) Tune to the unwanted sideband freq (7056 KHz +/- TX freq and check
      whether S-Meter reading is same or less as in step b.

      - Recent correspondence "Big signal at 0 Hz" on the reflector: I
      confirm that Exciter Carrier Suppression depends significantly on the
      amount of 1/f noise which a particular soundcard produces. I plan to
      tailor the I and Q response of the Exciter so it starts to drop below
      200Hz and see what difference this makes. Results will be updated via
      Tony.


      best 73s

      Jan

      G0BBL - M0PUB - G8BTR (QRP2K Design team)
    • Bill Tracey
      Hoo hah - a transceiver is born! Congratulations Jan -- very glad to hear the software seems to be working. As far as I know you re the 1st to get an on air
      Message 2 of 4 , Oct 1, 2006
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        Hoo hah - a transceiver is born! Congratulations Jan -- very glad to hear
        the software seems to be working. As far as I know you're the 1st to get
        an on air QSO w/ the setup.

        I just finished doing a little breakout board to hookup the little exciter
        to the computer serial port to try and get a look at it on a spectrum
        analyzer. Once I get some results from that will post what it looks like.

        As to staying away from the edges - at 48khz you should not be able to go
        more than +/- 24 khz; at 96 +/- 48 khz. I'll have to check the software to
        see if it is enforcing those limits for transmit. I know I want to look
        at some of the sound cards I have here and see how much the output falls
        off above 24 khz when running at 96 khz sampling -- there's some suspicion
        we may start running into the sound card's output filter stop band above
        24khz.

        Cheers,

        Bill (kd5tfd)

        At 09:25 AM 10/1/2006, you wrote:
        >Bill, Tony, All,
        >
        >I made my first CW contact this morning with the SR6 Exciter Alpha
        >prototype using the latest Version of PowerSDR Software which Bill
        >released last Friday. Very pleased with this!!
        ><....>
        > - With this particular soundcard it is advisable to stay away from
        >the maximum sampling rate; otherwise output power and sideband
        >suppression start to suffer. For example sampling freq 48K, I find I
        >need to limit TX within 22 Khz range 7034 KHz - 7088 KHz. With 96K
        >sampling rate I can cover 7014 KHz - 7096 KHz
        ><...>
        >best 73s
        >
        >Jan
        >
        >G0BBL - M0PUB - G8BTR (QRP2K Design team)
      • Terry
        ... received ... somebody ... from ... I ... Antenna ... reading. ... check ... the ... to ... below ... via ... Congrats Jan!! My exciter just came to life,
        Message 3 of 4 , Oct 1, 2006
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          --- In softrock40@yahoogroups.com, "verduynj" <Jan.Verduyn@...> wrote:
          >
          > Bill, Tony, All,
          >
          > I made my first CW contact this morning with the SR6 Exciter Alpha
          > prototype using the latest Version of PowerSDR Software which Bill
          > released last Friday. Very pleased with this!!
          >
          > http://www.tracey.org/wjt/sdr1k/SoftRock40/PowerSDR-KD5TFD-srxmit-
          > 20060928.zip - thanks Bill!!
          >
          > I worked ON5CBK, Patrick at 11:15 UTC on 7015 Khz and received 599
          > report .. Not bad for 0.6 Watt RF output!!
          > Second contact was a solid 15 minute QSO with Joe, DM0K and
          received
          > a 559 report.
          >
          > Is this the first CW contact with the Softrock Exciter or has
          somebody
          > else beaten me to it?
          >
          > Some additional info from us who prototyped to Exciter:
          >
          > - Using (Dell on board Sigmatel STAC 92xx)s unwanted sideband and
          > carrier suppression is at more -30dB down from full rated output as
          > shown on a spectrum analyser. -30dB is the FCC requirement I
          > understand.
          >
          > - With this particular soundcard it is advisable to stay away
          from
          > the maximum sampling rate; otherwise output power and sideband
          > suppression start to suffer. For example sampling freq 48K, I find
          I
          > need to limit TX within 22 Khz range 7034 KHz - 7088 KHz. With 96K
          > sampling rate I can cover 7014 KHz - 7096 KHz
          >
          > - Before putting the exciter you should do a sanity check by
          > monitoring your transmission on a separate receiver.
          > Connect the SR6 Exciter to a Dummyload.
          > a) Tune the RX to the Transmit Frequency and position the RX
          Antenna
          > lead near the Dummy load until you obtain an S9+10dB Smeter
          reading.
          > b) Insert a 30dB attenuator in the antenna lead and note the new S-
          > Meter reading.
          > c) Now tune to Carrier Frequency (7056 KHz) and check whether the S-
          > Meter reading is same or less as in step b)
          > d) Tune to the unwanted sideband freq (7056 KHz +/- TX freq and
          check
          > whether S-Meter reading is same or less as in step b.
          >
          > - Recent correspondence "Big signal at 0 Hz" on the reflector: I
          > confirm that Exciter Carrier Suppression depends significantly on
          the
          > amount of 1/f noise which a particular soundcard produces. I plan
          to
          > tailor the I and Q response of the Exciter so it starts to drop
          below
          > 200Hz and see what difference this makes. Results will be updated
          via
          > Tony.
          >
          >
          > best 73s
          >
          > Jan
          >
          > G0BBL - M0PUB - G8BTR (QRP2K Design team)
          >
          Congrats Jan!! My exciter just came to life, I can get the PowerSDR
          to do an ID, then send constant dots and dashes. I am not familiar
          with PowerSDR, having used Rocky for SDR experiments up to now.

          I am hoping to be one of the first to have a SoftRock-to-SoftRock QSO
          (assuming I can figure out PowerSDR). Anybody else interested?

          My unit draws about 250ma in transmit, and puts out around 1/2 Watt.
          Still playing with it, I should be on the air later today (Sunday).

          Terry
          WB4JFI
        • Terry
          ... Alpha ... Bill ... 599 ... and ... as ... find ... 96K ... S- ... S- ... I ... PowerSDR ... QSO ... Watt. ... Sorry for the add-on reply, but has anyone
          Message 4 of 4 , Oct 1, 2006
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            --- In softrock40@yahoogroups.com, "Terry" <wb4jfi@...> wrote:
            >
            > --- In softrock40@yahoogroups.com, "verduynj" <Jan.Verduyn@> wrote:
            > >
            > > Bill, Tony, All,
            > >
            > > I made my first CW contact this morning with the SR6 Exciter
            Alpha
            > > prototype using the latest Version of PowerSDR Software which
            Bill
            > > released last Friday. Very pleased with this!!
            > >
            > > http://www.tracey.org/wjt/sdr1k/SoftRock40/PowerSDR-KD5TFD-srxmit-
            > > 20060928.zip - thanks Bill!!
            > >
            > > I worked ON5CBK, Patrick at 11:15 UTC on 7015 Khz and received
            599
            > > report .. Not bad for 0.6 Watt RF output!!
            > > Second contact was a solid 15 minute QSO with Joe, DM0K and
            > received
            > > a 559 report.
            > >
            > > Is this the first CW contact with the Softrock Exciter or has
            > somebody
            > > else beaten me to it?
            > >
            > > Some additional info from us who prototyped to Exciter:
            > >
            > > - Using (Dell on board Sigmatel STAC 92xx)s unwanted sideband
            and
            > > carrier suppression is at more -30dB down from full rated output
            as
            > > shown on a spectrum analyser. -30dB is the FCC requirement I
            > > understand.
            > >
            > > - With this particular soundcard it is advisable to stay away
            > from
            > > the maximum sampling rate; otherwise output power and sideband
            > > suppression start to suffer. For example sampling freq 48K, I
            find
            > I
            > > need to limit TX within 22 Khz range 7034 KHz - 7088 KHz. With
            96K
            > > sampling rate I can cover 7014 KHz - 7096 KHz
            > >
            > > - Before putting the exciter you should do a sanity check by
            > > monitoring your transmission on a separate receiver.
            > > Connect the SR6 Exciter to a Dummyload.
            > > a) Tune the RX to the Transmit Frequency and position the RX
            > Antenna
            > > lead near the Dummy load until you obtain an S9+10dB Smeter
            > reading.
            > > b) Insert a 30dB attenuator in the antenna lead and note the new
            S-
            > > Meter reading.
            > > c) Now tune to Carrier Frequency (7056 KHz) and check whether the
            S-
            > > Meter reading is same or less as in step b)
            > > d) Tune to the unwanted sideband freq (7056 KHz +/- TX freq and
            > check
            > > whether S-Meter reading is same or less as in step b.
            > >
            > > - Recent correspondence "Big signal at 0 Hz" on the reflector:
            I
            > > confirm that Exciter Carrier Suppression depends significantly on
            > the
            > > amount of 1/f noise which a particular soundcard produces. I plan
            > to
            > > tailor the I and Q response of the Exciter so it starts to drop
            > below
            > > 200Hz and see what difference this makes. Results will be updated
            > via
            > > Tony.
            > >
            > >
            > > best 73s
            > >
            > > Jan
            > >
            > > G0BBL - M0PUB - G8BTR (QRP2K Design team)
            > >
            > Congrats Jan!! My exciter just came to life, I can get the
            PowerSDR
            > to do an ID, then send constant dots and dashes. I am not familiar
            > with PowerSDR, having used Rocky for SDR experiments up to now.
            >
            > I am hoping to be one of the first to have a SoftRock-to-SoftRock
            QSO
            > (assuming I can figure out PowerSDR). Anybody else interested?
            >
            > My unit draws about 250ma in transmit, and puts out around 1/2
            Watt.
            > Still playing with it, I should be on the air later today (Sunday).
            >
            > Terry
            > WB4JFI
            >
            Sorry for the add-on reply, but has anyone looked at the exciter/amp
            on a spectrum analyzer? I used my homemade analyzer (Wes Hayward
            W7ZOI unit), and found the 2nd harmonic on 20 meters was only about
            12db down. I am looking at construction for errors. I assume its
            not the audio phasing (I/Q), as that would create an image within the
            40 meter band. I will feed a 20 meter signal into the board, and see
            if the receiver hears it strong, an indication the input filter is
            messed up. Then, I guess I will sweep the filter on the amplifier
            board.

            Is my assumption about the audio phasing correct?
            Terry
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