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Re: [wsjtgroup] Linux Mint 15 , cant open /dev/ttyS0

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  • Richard Bown
    On Sat, 27 Jul 2013 20:16:11 +0100 ... Found the problem, a bit embarrassing as it was cause my my bad design. On the M-Audio D66/D44 breakout box I had added
    Message 1 of 3 , Jul 28, 2013
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      On Sat, 27 Jul 2013 20:16:11 +0100
      Richard Bown <richard@...> wrote:

      > Hi,
      > Trying linux mint 15, 64 bit, as Fed 19 has dropped a few files from
      > the repos, and no way of getting wsjtx to build.
      > Getting something strange, even though I'm in the dialout group, when
      > wsjt goes to TX it can't open /dev/ttyS0., currently running r3228,
      > which has been OK.
      > it also wont when wsjt is run from root. ,
      > Any ideas ?
      >
      >
      Found the problem, a bit embarrassing as it was cause my my bad design.

      On the M-Audio D66/D44 breakout box I had added a 5pin Din skt and
      connected that to the COM port on the computer.

      I had taken DTR and RTS via a 1mH choke and series resistor to the
      first two audio outputs so that there was DC superimposed on the Tx
      audio line.
      One going to one rig and the other to another rig, both homebrew.
      Simple on each rig to use a NPN transistor or N-channel mosfet to pull
      down the PTT line.
      I had decoupled the RTS and DTR lines on the computer side of the 1mH
      choke with 10 nF and on the other side ( rig side ) with a 2uF Tant.
      I have forgotten to put a steering diode in series with the RF choke to
      stop the Tantalum cap seeing negative voltage, and one of them went
      short as it was reversed biased.
      It was just Sod's Law that allowed this to happen at the same time as
      changing from Fedora to Linux mint on the computer in the shack.

      I use a short batch file to start wsjt in either RTS or DRT control so
      it automatically selects the correct transceiver, depending whether I'm
      playing on VHF or microwave.

      Sorry if its off topic and only understandable to those which know
      which end of the soldering iron gets hot.
      Two diodes now fitted :)


      --
      --
      Best wishes / 73
      Richard Bown
      Email : richard@...
      Email : richard@...
      HTTP : http://www.g8jvm.com
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