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Problem with using pseudofsk

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  • n2uz
    Hi all, I am trying to use pseudofsk with my Elecraft K3. The print on the receiving end is bad. I am running fldigi under Ubuntu. ASFK with rtty is ok.
    Message 1 of 8 , Jan 29, 2009
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      Hi all,
      I am trying to use pseudofsk with my Elecraft K3. The print on the
      receiving end is bad.

      I am running fldigi under Ubuntu.
      ASFK with rtty is ok.
      Switching the polarity of the pseudofsk signal in the K3 does not help.
      Switching the rev on the receiving end does not help.

      I made the circuit in the help files to generate the pseudofsk signal
      and it works ok when I use it to key the K3 for cw, so that is not
      the problem.

      Has anyone used the psuedofsk to run their rig? All indications on my
      end point to something wrong in that 1000 hz signal on the right
      channel not being correct.

      Jerry, N2UZ
    • w1hkj
      ... Do you have a dual channel oscilloscope available Jerry? If you do you can look at both the right and left channels. The left should be the AFSK and the
      Message 2 of 8 , Jan 29, 2009
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        n2uz wrote:
        > Hi all,
        > I am trying to use pseudofsk with my Elecraft K3. The print on the
        > receiving end is bad.
        >
        > I am running fldigi under Ubuntu.
        > ASFK with rtty is ok.
        > Switching the polarity of the pseudofsk signal in the K3 does not help.
        > Switching the rev on the receiving end does not help.
        >
        > I made the circuit in the help files to generate the pseudofsk signal
        > and it works ok when I use it to key the K3 for cw, so that is not
        > the problem.
        >
        > Has anyone used the psuedofsk to run their rig? All indications on my
        > end point to something wrong in that 1000 hz signal on the right
        > channel not being correct.
        >
        > Jerry, N2UZ
        >
        Do you have a dual channel oscilloscope available Jerry? If you do you
        can look at both the right and left channels. The left should be the
        AFSK and the right channel the on-off keyed 1000 Hz tone. Check to be
        sure that the on-off keying corresponds with the frequency shift on the
        AFSK (left side). Then do the same with your derived TTY control
        signal. Make sure that you do not have any glitches occurring on that
        final signal as they might provide false triggering to the K3. Finally,
        have you used the K3 in FSK mode with any other signal source?

        Dave
      • n2uz
        Dave, Yes, i have a dual scope. The left is the asfk and right is the on/off keyed 1000hz Since the asfk side is frequency shifted I can not see if it follows
        Message 3 of 8 , Jan 30, 2009
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          Dave,

          Yes, i have a dual scope. The left is the asfk and right is the
          on/off keyed 1000hz
          Since the asfk side is frequency shifted I can not see if it follows
          the right keyed side.

          I am sending a string of ryry....

          However the derived TTY control signal matches the on/off 100hz signal
          on the right side. Meaning the the doubler is working. Oh, another
          thing. CW keying works ok ( I have a switch on the output of the
          doubler transistor going to the cw key on the k3 and that works.

          No, on the K3 in fsk mode with another source.

          --- In linuxham@yahoogroups.com, w1hkj <w1hkj@...> wrote:
          >
          > n2uz wrote:
          > > Hi all,
          > > I am trying to use pseudofsk with my Elecraft K3. The print on the
          > > receiving end is bad.
          > >
          > > I am running fldigi under Ubuntu.
          > > ASFK with rtty is ok.
          > > Switching the polarity of the pseudofsk signal in the K3 does not
          help.
          > > Switching the rev on the receiving end does not help.
          > >
          > > I made the circuit in the help files to generate the pseudofsk signal
          > > and it works ok when I use it to key the K3 for cw, so that is not
          > > the problem.
          > >
          > > Has anyone used the psuedofsk to run their rig? All indications on my
          > > end point to something wrong in that 1000 hz signal on the right
          > > channel not being correct.
          > >
          > > Jerry, N2UZ
          > >
          > Do you have a dual channel oscilloscope available Jerry? If you do you
          > can look at both the right and left channels. The left should be the
          > AFSK and the right channel the on-off keyed 1000 Hz tone. Check to be
          > sure that the on-off keying corresponds with the frequency shift on the
          > AFSK (left side). Then do the same with your derived TTY control
          > signal. Make sure that you do not have any glitches occurring on that
          > final signal as they might provide false triggering to the K3.
          Finally,
          > have you used the K3 in FSK mode with any other signal source?
          >
          > Dave
          >
        • n2uz
          Dave, I just tried mmtty in FSK mode to the K3 and it worked great. The problem then is within fldigi. The doubler circuit generates about 4 volts and puts
          Message 4 of 8 , Jan 30, 2009
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            Dave,

            I just tried mmtty in FSK mode to the K3 and it worked great. The
            problem then is within fldigi. The doubler circuit generates about 4
            volts and puts the output transistor in saturation.

            The data must be bad. In fact, the diddle does not sound normal.

            Has anyone used the psuedofsk that you know of?

            Jerry, N2UZ

            --- In linuxham@yahoogroups.com, "n2uz" <jd.n2uz@...> wrote:
            >
            > Dave,
            >
            > Yes, i have a dual scope. The left is the asfk and right is the
            > on/off keyed 1000hz
            > Since the asfk side is frequency shifted I can not see if it follows
            > the right keyed side.
            >
            > I am sending a string of ryry....
            >
            > However the derived TTY control signal matches the on/off 100hz signal
            > on the right side. Meaning the the doubler is working. Oh, another
            > thing. CW keying works ok ( I have a switch on the output of the
            > doubler transistor going to the cw key on the k3 and that works.
            >
            > No, on the K3 in fsk mode with another source.
            >
            > --- In linuxham@yahoogroups.com, w1hkj <w1hkj@> wrote:
            > >
            > > n2uz wrote:
            > > > Hi all,
            > > > I am trying to use pseudofsk with my Elecraft K3. The print on the
            > > > receiving end is bad.
            > > >
            > > > I am running fldigi under Ubuntu.
            > > > ASFK with rtty is ok.
            > > > Switching the polarity of the pseudofsk signal in the K3 does not
            > help.
            > > > Switching the rev on the receiving end does not help.
            > > >
            > > > I made the circuit in the help files to generate the pseudofsk
            signal
            > > > and it works ok when I use it to key the K3 for cw, so that is not
            > > > the problem.
            > > >
            > > > Has anyone used the psuedofsk to run their rig? All indications
            on my
            > > > end point to something wrong in that 1000 hz signal on the right
            > > > channel not being correct.
            > > >
            > > > Jerry, N2UZ
            > > >
            > > Do you have a dual channel oscilloscope available Jerry? If you
            do you
            > > can look at both the right and left channels. The left should be the
            > > AFSK and the right channel the on-off keyed 1000 Hz tone. Check
            to be
            > > sure that the on-off keying corresponds with the frequency shift
            on the
            > > AFSK (left side). Then do the same with your derived TTY control
            > > signal. Make sure that you do not have any glitches occurring on
            that
            > > final signal as they might provide false triggering to the K3.
            > Finally,
            > > have you used the K3 in FSK mode with any other signal source?
            > >
            > > Dave
            > >
            >
          • w1hkj
            ... I did very early in the development cycle. But not recently. I will have to test this again with my FT-450. Stay tuned. Dave
            Message 5 of 8 , Jan 30, 2009
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              n2uz wrote:
              > Dave,
              >
              > I just tried mmtty in FSK mode to the K3 and it worked great. The
              > problem then is within fldigi. The doubler circuit generates about 4
              > volts and puts the output transistor in saturation.
              >
              > The data must be bad. In fact, the diddle does not sound normal.
              >
              > Has anyone used the psuedofsk that you know of?
              >
              > Jerry, N2UZ
              >
              I did very early in the development cycle. But not recently. I will
              have to test this again with my FT-450.

              Stay tuned.

              Dave
            • Martin
              I spent a lot time with this problem while assisted VE6YP in YPlog development (this project is now dead unfortunately). YPlog uses the same trick (rectifying
              Message 6 of 8 , Feb 1 1:56 AM
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                I spent a lot time with this problem while assisted VE6YP in YPlog
                development (this project is now dead unfortunately). YPlog uses the
                same trick (rectifying of the sound card output) to generate a precisely
                timed high speed CW and as far as I know, it has still the most precise
                CW above ~70 wpm.

                The main problem were the timing constants introduced by the interface.
                A too low value of filtering capacitor caused insufficient filtering,
                the radio tended to follow the sound card output frequency (if set too
                low). A too high value of this capacitor caused poor, smeared CW. Also,
                the response of different radios was different, therefore we used
                selectable envelope shape of the code element (exponential or
                trapezoidal). To save the bandwidth, the solution was to use HIGH AUDIO
                FREQUENCY output from the sound card (> 10 kHz) and quite low value of
                filtering capacitor, say ~ 0.022 uF. fldigi should use for the pseudo
                FSK a frequency in the 10-30 kHz range. Also, the interface schematic
                should me modified, I recommend full wave bridge rectifier with a 0.022
                uF capacitor. The transformer I used was 600 ohms (sound card side) to
                10 kohms (rectifier side).

                73,
                Martin, OK1RR

                w1hkj napsal(a):
                > n2uz wrote:
                >> Hi all,
                >> I am trying to use pseudofsk with my Elecraft K3. The print on the
                >> receiving end is bad.
                >>
                >> I am running fldigi under Ubuntu.
                >> ASFK with rtty is ok.
                >> Switching the polarity of the pseudofsk signal in the K3 does not help.
                >> Switching the rev on the receiving end does not help.
                >>
                >> I made the circuit in the help files to generate the pseudofsk signal
                >> and it works ok when I use it to key the K3 for cw, so that is not
                >> the problem.
                >>
                >> Has anyone used the psuedofsk to run their rig? All indications on my
                >> end point to something wrong in that 1000 hz signal on the right
                >> channel not being correct.
                >>
                >> Jerry, N2UZ
                >>
                > Do you have a dual channel oscilloscope available Jerry? If you do you
                > can look at both the right and left channels. The left should be the
                > AFSK and the right channel the on-off keyed 1000 Hz tone. Check to be
                > sure that the on-off keying corresponds with the frequency shift on the
                > AFSK (left side). Then do the same with your derived TTY control
                > signal. Make sure that you do not have any glitches occurring on that
                > final signal as they might provide false triggering to the K3. Finally,
                > have you used the K3 in FSK mode with any other signal source?
                >
                > Dave
                >
              • n2uz
                Dave, Did you have any success with your kenwood 450 under fsk and did you receive the pdf files of the output that I sent? snip............ ... indications on
                Message 7 of 8 , Feb 7 8:46 AM
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                  Dave,

                  Did you have any success with your kenwood 450 under fsk and
                  did you
                  receive the pdf files of the output that I sent?


                  snip............
                  >> Has anyone used the psuedofsk to run their rig? All
                  indications on
                  my
                  >> end point to something wrong in that 1000 hz signal on the
                  right
                  >> channel not being correct.
                  >>

                  Jerry N2UZ
                • w1hkj
                  ... Sorry, but I have not had a chance to test that yet. Yes I received the files. Dave
                  Message 8 of 8 , Feb 7 10:49 AM
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                    n2uz wrote:
                    > Dave,
                    >
                    > Did you have any success with your kenwood 450 under fsk and
                    > did you
                    > receive the pdf files of the output that I sent?
                    >
                    >
                    > snip............
                    > >> Has anyone used the psuedofsk to run their rig? All
                    > indications on
                    > my
                    > >> end point to something wrong in that 1000 hz signal on the
                    > right
                    > >> channel not being correct.
                    > >>
                    >
                    > Jerry N2UZ
                    >
                    Sorry, but I have not had a chance to test that yet. Yes I received the
                    files.

                    Dave
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