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Re: don't count on anyone putting out a call

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  • list2
    Hi Craig and All, This brings up an interesting phenomenon that I discovered while working with MT63 for MARS. From what I understand MT63 was designed to
    Message 1 of 14 , Jan 3, 2009
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      Hi Craig and All,
      This brings up an interesting phenomenon that I discovered while working
      with MT63 for MARS. From what I understand MT63 was designed to always
      start at 500 Hz audio. I believe most Digital programs including HRD DM780
      (my favorite) do not have any flexibility in this. TX Army MARS has decided
      to transmit 1000 Hz wide MT63 starting at 1000 Hz audio instead of 500 Hz.
      MixW allows this. However, if you don't have MixW, you may not be able to
      copy this kind of MT63 Transmission. I'm still trying to figure this one
      out. For TX Army MARS it forces one to always use MixW.

      Steve, W2MY, AAR6CX

      -----Original Message-----
      From: MT63@yahoogroups.com [mailto:MT63@yahoogroups.com]On Behalf Of Craig
      Wallen

      Subject: [MT63] Re: don't count on anyone putting out a call


      I have been fairly active on 80m mt63 here lately with pretty good results,
      if you like a sked let me now on the 80m band .. but, for some reason I am
      having a hard time decoding a few stations and I can not put my finger on
      why I can't but, 98% of the stations I decode fine . usually 500hz wide
      /short
    • Simon (HB9DRV)
      Just offset the radio by x Hz. I will look at this in the future, but these MARS guys are going against the MT63 proposal from the guy who invented it. Simon
      Message 2 of 14 , Jan 3, 2009
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        Just offset the radio by x Hz. I will look at this in the future, but these
        MARS guys are going against the MT63 proposal from the guy who invented it.

        Simon Brown, HB9DRV
        www.ham-radio-deluxe.com

        ----- Original Message -----
        From: "list2" <list2@...>


        > Hi Craig and All,
        > This brings up an interesting phenomenon that I discovered while working
        > with MT63 for MARS. From what I understand MT63 was designed to always
        > start at 500 Hz audio. I believe most Digital programs including HRD
        > DM780
        > (my favorite) do not have any flexibility in this. TX Army MARS has
        > decided
        > to transmit 1000 Hz wide MT63 starting at 1000 Hz audio instead of 500 Hz.
        > MixW allows this. However, if you don't have MixW, you may not be able to
        > copy this kind of MT63 Transmission. I'm still trying to figure this one
        > out. For TX Army MARS it forces one to always use MixW.
        >
      • David Kleber
        Craig, I think I watched your qso for about 45 minutes the other night from here in Pittsburgh, PA. 100% copy on both stations here. I ve never used .5k
        Message 3 of 14 , Jan 3, 2009
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          Craig,

          I think I watched your qso for about 45 minutes the other night from
          here in Pittsburgh, PA. 100% copy on both stations here.

          I've never used .5k before but I was quite impressed with the copy.
          Either you or the other station (I can't remember which) was pretty
          weak, but I had 100% throughout.

          -Dave, KB3FXI

          --- In MT63@yahoogroups.com, "Craig Wallen" <kf4hou@...> wrote:
          >
          > I have been fairly active on 80m mt63 here lately with pretty good
          results, if you like a sked let me now on the 80m band .. but, for
          some reason I am having a hard time decoding a few stations and I can
          not put my finger on why I can't but, 98% of the stations I decode
          fine . usually 500hz wide /short
          >
          > [Non-text portions of this message have been removed]
          >
        • David Kleber
          Steve, I was of the understanding that the standard was 500 Hz at the bottom of the signal, too. But can t you simply put your rig in fine VFO tune and move
          Message 4 of 14 , Jan 3, 2009
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            Steve,

            I was of the understanding that the standard was 500 Hz at the bottom
            of the signal, too.

            But can't you simply put your rig in fine VFO tune and move the
            received signal to 500 Hz bottom? I would think you should still get
            100% copy even if the sending station is transmitting 1k bottom. All
            that should change is your dial frequency.

            In our testing here in Western PA, we use a procedure where the first
            station sends a 1000 Hz marker tone that all other stations tune to
            with their VFO. Assuming all stations have done proper sound card
            calibrations, this puts us all on the same page. Also, the very
            narrow 1000 Hz tuning tone is much easier to see on the waterfall. We
            use MT63 1k long as our standard and as you probably know, the
            signature on the waterfall from a weak station can sometimes be very
            light. Our tuning procedure has really helped take some of the
            frustration out of the mode, especially for our less experienced members.

            It's good to see folks using video and RSID to help identify MT63 to
            those who may not know what mode they're seeing/hearing. Once you
            bring them on board, they won't soon forget!

            -Dave, KB3FXI


            --- In MT63@yahoogroups.com, "list2" <list2@...> wrote:
            >
            > Hi Craig and All,
            > This brings up an interesting phenomenon that I discovered while working
            > with MT63 for MARS. From what I understand MT63 was designed to always
            > start at 500 Hz audio. I believe most Digital programs including
            HRD DM780
            > (my favorite) do not have any flexibility in this. TX Army MARS has
            decided
            > to transmit 1000 Hz wide MT63 starting at 1000 Hz audio instead of
            500 Hz.
            > MixW allows this. However, if you don't have MixW, you may not be
            able to
            > copy this kind of MT63 Transmission. I'm still trying to figure
            this one
            > out. For TX Army MARS it forces one to always use MixW.
            >
            > Steve, W2MY, AAR6CX
            >
            > -----Original Message-----
            > From: MT63@yahoogroups.com [mailto:MT63@yahoogroups.com]On Behalf Of
            Craig
            > Wallen
            >
            > Subject: [MT63] Re: don't count on anyone putting out a call
            >
            >
            > I have been fairly active on 80m mt63 here lately with pretty good
            results,
            > if you like a sked let me now on the 80m band .. but, for some
            reason I am
            > having a hard time decoding a few stations and I can not put my
            finger on
            > why I can't but, 98% of the stations I decode fine . usually 500hz wide
            > /short
            >
          • list2
            Hi Dave, The problem is that during Hurricane Ike, Texas Army MARS demonstrated that mixed mode operation was more efficient than either an all MT63 net, or an
            Message 5 of 14 , Jan 3, 2009
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              Hi Dave,
              The problem is that during Hurricane Ike, Texas Army MARS demonstrated that
              mixed mode operation was more efficient than either an all MT63 net, or an
              all voice net. Checking in and regular business is done in USB but when a
              message is sent, it is sent in MT63 on the voice frequency starting at 1000
              Hz audio. The shift between voice and MT63 is immediate. If they send it
              on the voice frequency starting at 1000 Hz audio, I need to tune my
              receiver down 500 Hz to actually print it on the screen. Once the message
              is sent they immediately go back to voice mode. But I need to tune up 500
              Hz to listen to USB again. I end up missing the first part of the message
              and the first part of the voice transmission immediately after the MT63
              traffic. I thought of making two macros to do the shifting in DM780 but I
              haven't figured that out completely yet. I could also program VFO B 500 Hz
              lower. I do wish MARS kept to the MT63 standard. I don't think it would
              hurt their operations at all.

              Steve, W2MY, AAR6CX

              -----Original Message-----
              From: MT63@yahoogroups.com [mailto:MT63@yahoogroups.com]On Behalf Of David
              Kleber
              Sent: Saturday, January 03, 2009 7:32 PM
              To: MT63@yahoogroups.com
              Subject: [MT63] Tuning/Audio Frequency


              Steve,

              I was of the understanding that the standard was 500 Hz at the bottom
              of the signal, too.

              But can't you simply put your rig in fine VFO tune and move the
              received signal to 500 Hz bottom? I would think you should still get
              100% copy even if the sending station is transmitting 1k bottom. All
              that should change is your dial frequency.

              In our testing here in Western PA, we use a procedure where the first
              station sends a 1000 Hz marker tone that all other stations tune to
              with their VFO. Assuming all stations have done proper sound card
              calibrations, this puts us all on the same page. Also, the very
              narrow 1000 Hz tuning tone is much easier to see on the waterfall. We
              use MT63 1k long as our standard and as you probably know, the
              signature on the waterfall from a weak station can sometimes be very
              light. Our tuning procedure has really helped take some of the
              frustration out of the mode, especially for our less experienced members.

              It's good to see folks using video and RSID to help identify MT63 to
              those who may not know what mode they're seeing/hearing. Once you
              bring them on board, they won't soon forget!

              -Dave, KB3FXI
            • David Kleber
              Very interesting, Steve. Which brings up another subject, hence the change in the subject line. I really wish we (Amateur Service) would move to regs by
              Message 6 of 14 , Jan 3, 2009
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                Very interesting, Steve.

                Which brings up another subject, hence the change in the subject line.

                I really wish we (Amateur Service) would move to regs by bandwidth
                rather than mode. And there's nothing to say that there couldn't be
                gentelmens agreements on where you could do this, but wouldn't it be
                great if we could mix phone and MT63 on the same HF freqs?

                -Dave, KB3FXI

                --- In MT63@yahoogroups.com, "list2" <list2@...> wrote:
                >
                > Hi Dave,
                > The problem is that during Hurricane Ike, Texas Army MARS
                demonstrated that
                > mixed mode operation was more efficient than either an all MT63 net,
                or an
                > all voice net. Checking in and regular business is done in USB but
                when a
                > message is sent, it is sent in MT63 on the voice frequency starting
                at 1000
                > Hz audio. The shift between voice and MT63 is immediate. If they
                send it
                > on the voice frequency starting at 1000 Hz audio, I need to tune my
                > receiver down 500 Hz to actually print it on the screen. Once the
                message
                > is sent they immediately go back to voice mode. But I need to tune
                up 500
                > Hz to listen to USB again. I end up missing the first part of the
                message
                > and the first part of the voice transmission immediately after the MT63
                > traffic. I thought of making two macros to do the shifting in DM780
                but I
                > haven't figured that out completely yet. I could also program VFO B
                500 Hz
                > lower. I do wish MARS kept to the MT63 standard. I don't think it
                would
                > hurt their operations at all.
                >
                > Steve, W2MY, AAR6CX
                >
              • Jim Haynes
                However I guess if they were using 2KHz MT63 rather than 1KHz then you would again want the MT63 to start at 500 Hz and end at 2500 Hz, rather than starting at
                Message 7 of 14 , Jan 3, 2009
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                  However I guess if they were using 2KHz MT63 rather than 1KHz
                  then you would again want the MT63 to start at 500 Hz and end
                  at 2500 Hz, rather than starting at 1 KHz and ending at 3 KHz.
                  Even that might be too high, depending on the filters in the radio.

                  Jim W6JVE



                  jhhaynes at earthlink dot net
                • David Little
                  This is the reason for the 500 HZ start freq; especially on NTIA freqs which are channelized. It is hard to move from the concept of center of intelligence ,
                  Message 8 of 14 , Jan 3, 2009
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                    This is the reason for the 500 HZ start freq; especially on NTIA freqs
                    which are channelized.

                    It is hard to move from the concept of "center of intelligence", to a
                    start frequency that allows the full potential of the mode to be
                    utilized, but you have echoed the thought process as to the reason some
                    of these "standards" were created.

                    David
                    KD4NUE



                    -----Original Message-----
                    From: MT63@yahoogroups.com [mailto:MT63@yahoogroups.com] On Behalf Of
                    Jim Haynes
                    Sent: Saturday, January 03, 2009 10:14 PM
                    To: David Kleber
                    Cc: MT63@yahoogroups.com
                    Subject: Re: [MT63] Mixed Mode Transmissions



                    However I guess if they were using 2KHz MT63 rather than 1KHz
                    then you would again want the MT63 to start at 500 Hz and end
                    at 2500 Hz, rather than starting at 1 KHz and ending at 3 KHz.
                    Even that might be too high, depending on the filters in the radio.

                    Jim W6JVE

                    jhhaynes at earthlink dot net







                    [Non-text portions of this message have been removed]
                  • list2
                    Hi Dave and all, Thanks for the change in subject line. Yes, well I guess the ARRL assumed that it was such a good idea that they did not need to work on grass
                    Message 9 of 14 , Jan 4, 2009
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                      Hi Dave and all,
                      Thanks for the change in subject line.

                      Yes, well I guess the ARRL assumed that it was such a good idea that they
                      did not need to work on grass roots support of it by the membership. The
                      opposition to their regulation by bandwidth proposal was so intense that
                      they dropped it like a hot potato.

                      I do see operating digital and SSB on the same frequency to be a great
                      advantage for MARS. I guess hams sort of do this on 20 meters with SSTV.
                      In fact it seems to be one of the big differences in operating between
                      ARES/RACES and MARS at least here in Texas. The other difference is the
                      training on actual operations required down here for MARS. I did not feel
                      qualified to use HF in an emergency until I started doing NCS duties for
                      Army MARS. No training is really required for ARES/RACES although I know a
                      few people in both of these groups who are very good. But for the general
                      membership of these groups you just need a ham license.

                      I would think that with the general push toward using ham radio as an
                      alternate means of communication for many institutions, that either the FCC
                      would mandate the use of digital/voice operations on the same frequency (or
                      at least during emergencies), or the FCC would get a bunch of proposals by
                      hams to permit it to a limited extent.

                      I think that most hams don't realize how good combined digital/voice works.
                      I don't think MARS realized it down here until after we actually used it in
                      some emergencies and it worked out so well.

                      Just a note for comparison on efficiency. During all MT63 nets (or any
                      digital net is concerned), it is very difficult for me to check in without
                      QRMing everyone else. With a voice check-in, after giving the call of the
                      NCS, you drop the mic and listen to see if anyone else is checking in. This
                      prevents doubles most of the time. I have not figured out a way to do this
                      on MT63, especially with the delay in transmission associated with MT63.
                      That's why checking in with voice and the sending traffic in MT63 is the
                      best of both worlds.

                      Steve, W2MY



                      -----Original Message-----
                      From: MT63@yahoogroups.com [mailto:MT63@yahoogroups.com]On Behalf Of David
                      Kleber
                      Subject: [MT63] Mixed Mode Transmissions


                      Very interesting, Steve.

                      Which brings up another subject, hence the change in the subject line.

                      I really wish we (Amateur Service) would move to regs by bandwidth
                      rather than mode. And there's nothing to say that there couldn't be
                      gentelmens agreements on where you could do this, but wouldn't it be
                      great if we could mix phone and MT63 on the same HF freqs?

                      -Dave, KB3FXI
                    • Craig Wallen
                      Something I have learned is it is almost essential to have your TX frequencies locked , so you can have the ability to move around the RX in MT63. There are a
                      Message 10 of 14 , Jan 4, 2009
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                        Something I have learned is it is almost essential to have your TX frequencies locked , so you can have the ability to move around the RX in MT63. There are a lot of stations not lined up good or do not have a good calibration done on there sound card.

                        I can't remember what the leeway is on being off frequency , but it seems to be pretty tight at least in mixw .

                        I am usually around the 1200hz area of the pass band or so. If I am near the 500hz area on the low side , I am fairly close to my filter and also my EQ setting on my soundcard, I get slightly less audio drive there.

                        yea 500hz BW will have better signal to noise ratio , but makes it a bit less robust due to propagation effects, but it is not by a whole lot at all. It is a Good trade off on the lower bands.

                        I think it would be neat to have a sked with some one in western EU to try a contact on 80m with mt63, not sure if that has done yet or not. If any one in western EU would like to attempt this email me.

                        [Non-text portions of this message have been removed]
                      • Paul L Schmidt, K9PS
                        Indiana Navy-Marine Corps MARS uses 2 kHz 95+% of the time; only dropping down to 1 kHz if conditions are extremely bad (High QRN, etc.). Of course, when
                        Message 11 of 14 , Jan 5, 2009
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                          Indiana Navy-Marine Corps MARS uses 2 kHz 95+% of the time;
                          only dropping down to 1 kHz if conditions are extremely bad
                          (High QRN, etc.). Of course, when conditions are that bad,
                          SSB probably isn't working well either.

                          Even if the filters whack the tones on the edges (e.g. a 1.8
                          or 2.1 kHz filter), they're not far enough down on the skirts
                          to present a real problem, and MT63 has a LOT of redundancy
                          built in to compensate.

                          Uncalibrated or improperly calibrated sound cards cause a lot
                          more trouble than filters :(

                          It'd be awfully nice to be able to do mixed-mode on the ARES
                          and RACES HF nets... too bad they threw the baby out with the
                          bathwater on the regulation-by-bandwidth proposal a while
                          back.

                          73,

                          - ps


                          Jim Haynes wrote:
                          > However I guess if they were using 2KHz MT63 rather than 1KHz
                          > then you would again want the MT63 to start at 500 Hz and end
                          > at 2500 Hz, rather than starting at 1 KHz and ending at 3 KHz.
                          > Even that might be too high, depending on the filters in the radio.
                          >
                          > Jim W6JVE
                          >
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