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RE: [Q15X25] Status of Q15X25?

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  • Rick Williams
    ... least not for me), and has been more or less shoved off. I see an E-mail like yours about once every couple of months, which reminds me I m subscribed to
    Message 1 of 33 , Nov 14, 2004
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      Scott, K4SET wrote:

      >>>>> Q15X25 was a great idea, but it didn't really work (at
      least not for me), and has been more or less shoved off. I see an E-mail
      like yours about once every couple of months, which reminds me I'm
      subscribed to this list still. You asked about the speed. It has/had the
      potential support up to 2500bps. Never saw it do that, or anything close,
      but it does have that potential.

      =====

      Do you or anyone else have some idea as to what the problem is? The concept
      seems sound so something must be glitching it?

      >>>>> I still think it has potential, but it would take lots of work, and I
      don't
      think it's being worked on any longer. Most that try to operate this mode
      get frustrated and drop it. You would need to work out a sked with someone
      as there is no activity that I'm aware of. If you still want to pursue it,
      here are a couple of links:
      http://www.qsl.net/zl1bpu/Q15X25/Q15X25.html
      (it's open source, and the Linux development seemed to be the most exciting)

      ======

      I have gone to this site a number of times in the past and then tried the
      link on Windows versions but do not find any program at the site it points
      to. Nothing that is obvious for that mode anyway.

      Can we get a definitive answer as to whether or not the mode is being worked
      on any longer?

      The fact that it used the Motorola EVM was not a plus other than perhaps an
      early platform to develop new modes. With today's computers so low cost and
      powerful, these outboard processors I feel act as an impediment to wide
      scale adoption.

      Linux is coming along, albeit slowly, and a lot more slowly than I
      envisioned five years ago:( It has some big hurdles to overcome yet in order
      to be used much for amateur radio. The equipment requirements for Linux have
      matched MS Windows as of late, so you can not use your really old discarded
      PC. And dual boot has it dangers, speaking from personal experience:(

      >>>>> I wimped out and just set it up to use with MixW (here are
      instructions on
      that):
      http://home.att.net/~ronchap/q15x25modes/q15x25.htm
      http://home.att.net/~ronchap/q15x25modes/q15x25ud.htm


      =====

      I use a TenTec Pegasus for my primary rig so find MixW to be incompatible.
      It is the only program that I have used that crashes my rig control program.

      >>>>> Rick Muething (KN6KB) is the one developing SCAMP. Rick and I had
      thought
      Q15X25 might do want we wanted, which is a soundcard mode that would work
      with the Winlink B2F protocol for binary message transfers. Rick got it all
      working in theory, but the performance was terrible, with every single
      connection eventually ending in a dropped connection, and we were never able
      to successfully send any traffic. The best we saw in optimal conditions, and
      after much fussing to get a perfectly clean signal and optimal setting
      tweaks was it struggle most of the way through a 2K text file, and then drop
      the connection before it was done.. It's very fussy about the signal quality
      and path quality, but I think there is much more wrong than just that.

      ======

      One wonders if there was some single problem that was causing the link
      failures, but maybe it was mutiple causes?

      >>>>> Rick went on to develop SCAMP, which is now very
      close. Rick is on a trip right now, but if your interested I don't think
      he'd mind if I sent you the paper that was presented at the ARRL/TAPR 2004
      DCC. When he gets back we will be starting to do some very early Alpha
      testing over RF. So far the results of his testing through a path simulator
      are very promising.

      =====
      Yes, I am sure many of us who did not attend the DCC would like to read the
      paper. I know that I sure would have liked to have seen the presentation.
      There are probably some of us, myself for sure, who would have an interest
      in testing the mode.

      When I first heard about it in the last month or so, when Rick mentioned it
      on the WinLink lists, it sounded almost too good to be true. So even if it
      ran just a bit better than Pactor I, it would be a winner. If it really can
      come close, as Rick has suggested, as being between Pactor II and III, well
      that would be fabulous!

      Many of us refuse to buy the SCS modem due to the proprietary nature and
      non-competitive market of such a product, and have literally stood by for a
      decade thinking that someone would be coming up with an ARQ mode for HF.
      Maybe this will finally be it.

      Sincerely,

      Rick, KV9U
    • Stewart
      GE, Rick - I guess all I can say is that the proof is in the the pudding and my comments are based on experience, which after should be the ultimate test.
      Message 33 of 33 , Nov 17, 2004
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        GE, Rick -

        I guess all I can say is that the proof is in the the pudding and my
        comments are based on experience, which after should be the ultimate
        test. Incidentally, I would add that we do re-review programs that
        had been looked at previously.

        What has to be remembered is that MARS stations are not concerned
        with going around the world point-to-point. Our nets generally
        involve distances of 200 to 300 miles, give or take, although there
        are nets that do cover a much larger area and can require the use of
        relays to get some stations checked in. Additionally, we are
        essentially using clear channels and formal net procedures, hence we
        are generally not bogged down with QRM, deliberate or otherwise.
        Additionally, we have a number of channels available such that for
        part of the year we will use one frequency for a given net, and move
        2 or 3 or 4 MHz for the rest of the year, recognizing the seasonal
        changes in propagation.

        I have no particular quarrel with your comments about PACTOR.
        However, because it is an ARQ mode, when conditions go south, the
        ACKing and NAKing can really stretch out the time to send a message.
        Taking 20 minutes or more to send one message, even though it will be
        complete, seems to me not to make much sense and certainly ties up a
        frequency unnecessarily.

        I can sympathize, and agree, with your plaint about so many modes and
        finding someone to talk with. Fortunately, for me. if a new mode
        comes along we will take the opportunity to look at it on one of our
        digital nets, and then whatever happens will happen as far as what we
        do with it. If some of us want to look at it further, we will simply
        set up a sked and do so at a time of our convenience.

        With respect to FNpsk, I only know was is found on the referenced web
        site. I personally am not aware of any dedicated reflectors at this
        point in time, although that is not to say one doesn't exist.

        Finally, with respect to "lab" testing, it is essential for the
        development of software. However, as long as one does not disregard
        new advances, the old axiom about "not fixing something that works"
        is still valid.

        73,

        Stewart NNN0STE W1UVE


        --- In Q15X25@yahoogroups.com, "Rick Williams" <mrfarm@m...> wrote:
        >
        > Stewart wrote:
        >
        > >>>>> To encapsulate our thoughts on MT63, based on consistant use
        over two
        > years, there is nothing that has touched it when conditions have
        > deteriorated to the point that other modes have dropped out of
        sight.
        > It is not unusual to be receiving solid copy on the screen and not
        > see anything on the waterfall or hear anything from the speaker. P-
        > III, let alone any other mode, as good as it is, does not appear to
        > match MT63 down in the trenches.
        >
        > =====
        >
        > I wonder why your experiences are so different from the actual
        tests done
        > with measuring how deep into the noise MFSK16 and other modes are
        able to do
        > compared with MT63?
        >
        > Of all the modes MT63 is about the worst in terms of weak signals!
        >
        > Pactor is really very good and my understanding is that it works
        well below
        > what some have claimed at only -5 db S/N.
        >
        > But I think the largest factor for MARS is that MT63 is able to TX
        much
        > faster data rates due to the huge BW. Many times larger than most
        of the
        > other digital modes. This works OK on a voice channel but not so
        good for
        > spectrum conservation.
        >
        > One thing that MT63 does extremely well is handle multipath and if
        you are
        > often using NVIS, you will encounter this phenomenon to a greater
        degree
        > than longer distance TX. Is it possible that this may be another
        reason for
        > the apparent success of MT63?
        >
        > >>>> Incidentally, if you are interested, there is an excellent
        > implementation of an ARQ application of QPSK63 to be found at:
        > http://www.w1fn.org FNpsk, a freeware program, effectively
        > automates the conduct of a digital net to a very high degree.
        >
        > ======
        >
        > This is completely new to me and have not seen this before. Any
        others here
        > finding this to work well?
        >
        > Is there a list or group that discusses this mode?
        >
        >
        > What is happening though is that there are so many modes, and so
        few digital
        > operators of these modes, that you rarely find anyone else to
        connect with.
        > For example, I have tried MT63 on 30 and 40 meters with no luck
        finding
        > anyone else. With a more commonly used mode, such as PSK31, it is
        much
        > easier to find someone.
        >
        > 73,
        >
        > Rick, KV9U
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