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Re: [digsstv] Decoding Speed

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  • Dave Jones
    Hi Tom, Here is a list of digital SSTV frequencies: http://www.kiva.net/~djones/dignet.txt 73 Dave KB4YZ KC8UDX wrote
    Message 1 of 6 , Dec 30, 2003
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      Hi Tom,

      Here is a list of digital SSTV frequencies:
      http://www.kiva.net/~djones/dignet.txt

      73 Dave KB4YZ


      KC8UDX wrote
      Also, was checking out a few hams working 20mtr tonight but lost them. Is there a certain freq on 80mtr or 40 mtr?
       
      Thanks Again,
       
      73s
      Tom, KC8UDX
    • qrq_cw
      KC8UDX wrote: ... A kenwood 520 is going to have a fixed (probably 2.8kHz) SSB filter. Look at your waterfall display- do you notice
      Message 2 of 6 , Dec 31, 2003
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        "KC8UDX" <KC8UDX@n...> wrote:

        <snip>

        > Tried different adjustments on Kenwood with just
        > minor changes to sig/noise ratio.

        A kenwood 520 is going to have a fixed (probably 2.8kHz) SSB filter.
        Look at your waterfall display- do you notice that it's noticeably
        dimmer towards the right side? This might indicate you've got too
        much rolloff on the high end. If all the "bars" look reasonably
        equally bright then bandwidth probably isn't a problem. With a 520
        there aren't a lot of adjustments you can make, except playing with
        RF gain and AF volume. Just make sure you're not overdriving the
        input to the soundcard.


        > Any filter programs out there that might help
        > cleanup the signal?

        I would recommend as little filtering or processing of the signal as
        possible. This modulation scheme is sensitive to phase and amplitude
        distortion and filtering can only make it worse. I run my bandwidth
        filters wide open and have had the best success with that. Attempts
        to use filters to cut down on adjacent channel interference or using
        the automatic notch to wipe out the perpetual "tuner-uppers" only
        results in bad blocks or no decode anyway. Give the decode engine
        the whole signal and let the error correction deal with any
        interference.

        My $.02

        Mark K5LXP
        Albuqueruqe, NM
        k5lxp@...
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