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RX/TX PPM correction Q

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  • "Glenn (KØBO)"
    Happy New years great Folks of FLDIGI! As I perform the WWV rate correction procedure as outlined on the on-line documentation, I see a setting for TX ppm .
    Message 1 of 2 , Jan 2, 2011
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      Happy New years great Folks of FLDIGI!

      As I perform the WWV rate correction procedure as outlined on the on-line
      documentation, I see a setting for "TX ppm". Should I enter the number I come
      up with for "RX ppm" in this window as well?

      Thank you all in advance for your answer and also for such fine work on what I
      say is the best "amateur radio" program available.
    • w1hkj
      ... That s good for starters Glenn. If you have two computers with fldigi running you can use each to calibrate the other for Tx ppm. Calibrate each for Rx
      Message 2 of 2 , Jan 2, 2011
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        Glenn (KØBO) wrote:
        > Happy New years great Folks of FLDIGI!
        >
        > As I perform the WWV rate correction procedure as outlined on the on-line
        > documentation, I see a setting for "TX ppm". Should I enter the number I come
        > up with for "RX ppm" in this window as well?
        >
        > Thank you all in advance for your answer and also for such fine work on what I
        > say is the best "amateur radio" program available.

        That's good for starters Glenn. If you have two computers with fldigi
        running you can use each to calibrate the other for Tx ppm.

        Calibrate each for Rx separately using the WWV clock signal.

        Hook the two computers up cross connected on the audio lines.

        Run fldigi on both in the MFSK mode.

        Send a small picture from A to B using the MFSKpic mode (right click on
        the Tx panel). The B computer will automatically start to decode and
        print the picture. Adjust A Tx ppm until there is no slant on the B
        picture. This will take a few attempts. Then repeat for B to A.
        You're done. Write down the Rx/Tx ppm values for both computers. They
        will be valid so long as you use the same audio codecs.

        If you don't have two computers you can do the same thing on the air
        with a buddy. Just be sure that you both have calibrated the Rx to the
        external standard.

        73, Dave, W1HKJ
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