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  • Ham Radio Digital Modes

    From Ed Vance@1:2320/105 to Daryl Stout on Monday, November 06, 2017 19:55:00
    Howdy! Daryl,

    I watch Television using a Digital TV Convertor box.

    While I was watching a show I noticed the image froze for a moment and I
    wasn't able to hear any sound until the freeze ended and thought about
    You using D-STAR, VOIP and maybe other Digital Modes for Amateur Radio.

    This happens often enought that I feel like it is a "Feature" of the
    change over from Analog to Digital Television, and I remember all the
    publicity about how good Digital TV would be.

    I remember that back when Analog Television was being broadcast if
    the Picture messed up the sound portion could still be heard on those
    TV Sets

    One of the local Amateurs who owned a TV and Radio Repair Shop talked
    about taking courses and buying Test Equipment so He would be able to
    service Digital Television Sets when they needed any fixing.

    Have You noticed if there any lapses or delays to the transmission that
    You are listening to when You're using any of those Digital Modes wheather during a QSO or You're SWL'ing the Band?

    I'm just curious and thought I'd ask someone who uses Digital Modes with
    their Ham Radio Station.

    Thanks, 73 de Ed W9ODR . .


    ... Have you checked your smoke detector batteries & Fire Ext, LATELY?!
    --- MultiMail/MS-DOS v0.49
    * Origin: CCO BBS - capcity2.synchro.net - 1-502-875-8938 (1:2320/105)
  • From Richard Menedetter@2:310/31 to Ed Vance on Tuesday, November 07, 2017 11:05:14
    Hi Ed!

    06 Nov 2017 19:55, from Ed Vance -> Daryl Stout:

    I watch Television using a Digital TV Convertor box.
    While I was watching a show I noticed the image froze for a moment and
    I wasn't able to hear any sound until the freeze ended and thought
    about You using D-STAR, VOIP and maybe other Digital Modes for Amateur Radio.

    Correct.
    That is indeed a characteristic of digital encoding.
    You have a perfect signal until the error correction is not able to cope with the bit error rate.
    At that point you will have audio/video artefacts or even small outages (depending on the conditions).

    On an analog signal you will hear/see degradation much earlier, but you will have some form of very staticy signal that you may be able to decode when you have very bad conditions.
    On digital on those conditions you will have no service.

    CU, Ricsi

    --- GoldED+/LNX
    * Origin: ?troffeeriuqertahtsenilgatetahuoytnod (2:310/31)
  • From Ed Vance@1:2320/105 to Richard Menedetter on Thursday, November 16, 2017 17:10:00
    11-07-17 11:05 Richard Menedetter wrote to Ed Vance about Ham Radio Digital Modes
    Howdy! Richard,

    @MSGID: <5A01D8F7.1697.amtradio@capitolcityonline.net>
    Hi Ed!

    06 Nov 2017 19:55, from Ed Vance -> Daryl Stout:

    I watch Television using a Digital TV Convertor box.
    While I was watching a show I noticed the image froze for a moment and
    I wasn't able to hear any sound until the freeze ended and thought
    about You using D-STAR, VOIP and maybe other Digital Modes for Amateur Radio.

    Correct.
    That is indeed a characteristic of digital encoding.
    You have a perfect signal until the error correction is not able to
    cope with the bit error rate.
    At that point you will have audio/video artefacts or even small outages (depending on the conditions).

    On an analog signal you will hear/see degradation much earlier, but you will have some form of very staticy signal that you may be able to
    decode when you have very bad conditions.
    On digital on those conditions you will have no service.

    Would You know if Amateur Radio Digital Modes are affected by QRN or QSB?

    That's what I'm wondering about. Thanks!

    73 de Ed, W9ODR . .


    ... To excel at what you do, you must love doing it.
    --- MultiMail/MS-DOS v0.49
    * Origin: CCO BBS - capcity2.synchro.net - 1-502-875-8938 (1:2320/105)
  • From Richard Menedetter@2:310/31 to Ed Vance on Sunday, November 19, 2017 12:00:18
    Hi Ed!

    16 Nov 2017 17:10, from Ed Vance -> Richard Menedetter:

    Would You know if Amateur Radio Digital Modes are affected by QRN or
    QSB?

    Not really ... I assume that atmospherics and fading will lead to elevated bit error rates.

    CU, Ricsi

    --- GoldED+/LNX
    * Origin: Why are you looking down here? The joke is above! (2:310/31)