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6m vs 2m

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  • Hal
    Would I do better on MS with 11el and 160 watts on 2m or 3el and 80 watts on 6m??
    Message 1 of 13 , Nov 30, 2010
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      Would I do better on MS with 11el and 160 watts on 2m or 3el and 80 watts on 6m??
    • Bob KD7YZ
      ... I do a lot of 6m MS with WSJT9 and can t say I ve ever worked _any_ 3-El Yagi people. And the number of 6m-MS stations under 100w I ve worked, that I can
      Message 2 of 13 , Nov 30, 2010
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        On 11/30/2010 7:32 AM, Hal wrote:
        >
        >
        > Would I do better on MS with 11el and 160 watts on 2m or 3el and 80
        > watts on 6m??

        I do a lot of 6m MS with WSJT9 and can't say I've ever worked _any_ 3-El
        Yagi people.

        And the number of 6m-MS stations under 100w I've worked, that I can
        think of, is small to "Not many" .

        I'm sure it's possible. But if you want to have the fun many of us have,
        3El & 80w wouldn't get you there most nights.

        --
        Bob Kd7YZ
      • Ira Franklin
        Hi Hal, this has been my experience with WSJT on 6 and 2. On 6 I have over 300 initial, 177 grids, 39 states and 7 DXCC all except maybe a dozen were made with
        Message 3 of 13 , Nov 30, 2010
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          Hi Hal, this has been my experience with WSJT on 6 and 2. On 6 I have over 300 initial, 177 grids, 39 states and 7 DXCC all except maybe a dozen were made with 100 watts to a 5 el Cushcraft or now M2 6M7JHV both at about 53 feet. Best distance 2183km.  On 2 meters have 106 initials, 86 grids, 30 states, 2 DXCC all with 100 watts or less. I now have M2 2M5WL temp back on ground but most of my contacts on 2 were made with a 4 el quad mounted on top of 10ft piece of emt conduit and rotated by hand.   As to antennas I have done much better with the 7 el on wsjt than I did with the 5 el. However my personal opion I think the 11 el on 2 will do very well. At times I honestly believe the 4 el quad did better on wsjt scatter that the 5WL. I attribute this to the tight pattern on the 5wl. I have thought very seriousy about getting rid of the 5WL and get a 9 el or something in that range.
              One other point, particular on 6 I have worked stations using as little as 10 watts and antennas from 160 dipoles, verticals, ground planes, loops etc. quite a few 3 el beams. The smaller antennas and lower power just usually take longer to complete.  As an example the 4 el quad on 2. Many were complete in about 10 min, but average time was likely closer to 45 min. So it takes patience.
           
              Hope this is of some help to you
          Ira k4ymq
          Alabama  EM63

          From: Bob KD7YZ <kd7yz@...>
          To: wsjtgroup@yahoogroups.com
          Sent: Tue, November 30, 2010 6:55:45 AM
          Subject: Re: [wsjtgroup] 6m vs 2m

           

          On 11/30/2010 7:32 AM, Hal wrote:
          >
          >
          > Would I do better on MS with 11el and 160 watts on 2m or 3el and 80
          > watts on 6m??

          I do a lot of 6m MS with WSJT9 and can't say I've ever worked _any_ 3-El
          Yagi people.

          And the number of 6m-MS stations under 100w I've worked, that I can
          think of, is small to "Not many" .

          I'm sure it's possible. But if you want to have the fun many of us have,
          3El & 80w wouldn't get you there most nights.

          --
          Bob Kd7YZ


        • Ben Nardi
          For what it s worth I have been on 6 meter MS using a 2 el Moxon at 20 feet with 100 W for about year and had a lot of fun with it with contacts out to 1000
          Message 4 of 13 , Nov 30, 2010
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            For what it's worth I have been on 6 meter MS using a 2 el Moxon at 20 feet with 100 W for about  year and had a lot of fun with it with contacts out to 1000 mi or so. I just recently built 600 W PA which certainly helps considerably and I am in process of raising my antenna height. With MS patience seems to be key.
             
            Regards
            Ben
            W3ZUP
             
            ----- Original Message -----
            From: Hal
            Sent: Tuesday, November 30, 2010 7:32 AM
            Subject: [wsjtgroup] 6m vs 2m

             

            Would I do better on MS with 11el and 160 watts on 2m or 3el and 80 watts on 6m??



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          • Curt Nixon
            GM Hal: I can give you a little perspective from a newbie s entry level station perspective. I began in MS on 2M with a WA5VJB cheap Yagi at 15 6el and 120W
            Message 5 of 13 , Nov 30, 2010
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              GM Hal:

              I can give you a little perspective from a newbie's entry level station
              perspective. I began in MS on 2M with a WA5VJB cheap Yagi at 15' 6el and
              120W from an old class C Motorola MASTR PA unit. Best to date was about
              `1200 miles during normal daily operation. It does work but hearing
              better would make it more productive during routine conditions.

              On 6M, I have a 100W brick feeding a 2el wire MOXON at about 25' ..While
              I have made many qso's with this setup on 6, I think it really
              represents about the minimum in the rx department. On 6, if the rox are
              plentiful, I can make contacts with a 40M dipole and 100W..its when they
              get "thin" that it is a proble. Most of the time, other (bigger)
              stations hear me ok but I get nothing. My next step up is a 5 element
              LFA for 6M.

              So, I would say, on your equipment list, and depending on what you want
              to achieve, your 2M setup will be much more productive if any conditions
              exist at all.

              WHile your 6M setup should work fine with good condx, it will often let
              you down in the rx department when other stations can hear you.

              Again, my opinions only, based upon last 2 years of ops with the
              equipment stated above. Hopefully it will give you some ideas.

              See you on PJ.

              Curt
              KU8L

              Hal wrote:
              >
              > Would I do better on MS with 11el and 160 watts on 2m or 3el and 80
              > watts on 6m??
              >
              >
            • David R. Hassall
              Dear Bob and group, The first two years on WSJT, I used a home brew 3 element 6M Yagi at 50 feet running 100 watts and RG-213/U coax. I worked My first 25
              Message 6 of 13 , Nov 30, 2010
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                Dear Bob and group,

                The first two years on WSJT, I used a home brew 3 element 6M Yagi at 50 feet
                running 100 watts and RG-213/U coax. I worked My first 25 initials
                on 6M using that setup. My longest contact was 1240 miles. Some
                of the contacts do take longer but it didn't seem to make any difference.

                I have upgraded to a M squared 6M5X at 50 feet. I have changed my coax to
                a LMR-400flex Clone and still run 100 Watts. With the larger antenna and
                better coax I hear more stations than before. I work Some stations easier
                now than before. I still have not contacted another station on WSJT FSK441
                farther than the 1240 Miles on 6M.

                With your higher power, You may be Heard better. But with the smaller
                antenna
                you lose the receive signal gain of the larger antenna. Most would say,
                Put up the biggest you can and hope for the best.

                73 Dave


                David R. Hassall WA5DJJ
                WEBSITE: http://www.zianet.com/dhassall/
              • Bill VanAlstyne W5WVO
                Hi Hal, I agree with Curt s assessment in general -- your prospective 2-meter setup sounds more productive than what you re proposing for 6 meters -- but I ll
                Message 7 of 13 , Nov 30, 2010
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                  Hi Hal,

                  I agree with Curt's assessment in general -- your prospective 2-meter setup
                  sounds more productive than what you're proposing for 6 meters -- but I'll
                  add a little here about antenna height, which hasn't already been covered by
                  others. The height of an antenna above ground as a function of wavelength is
                  a critically important factor for all antennas and all bands -- but it helps
                  to know why it is important for different modes of propagation.

                  For meteor scatter, you're working with true ionospheric propagation, not
                  tropospheric stuff. Meteor ablation and its resulting ionization happen at
                  the bottom of the E layer, the same height where sporadic-E propagation
                  happens -- about 90 km up, plus or minus a bit. A straightforward
                  trigonometric formula will tell you how the geometry of this works for
                  various path distances, and the WSJT software does this math for you. If you
                  ever wondered what the number following "El:" means in the WSJT main screen,
                  it's the optimum take-off angle for that path -- the number of degrees of
                  elevation above the horizon to produce an ideal reflective path off the
                  meteor trail to the station you're trying to work. The longer the path
                  distance, the lower the take-off angle required.

                  Let's say you're trying to work a station 1,100 miles away. That's a pretty
                  reasonable path for meteor scatter, but it's on the long side of what's
                  typical. The ideal take-off angle for a path that long is about 2 degrees.
                  Now, let's say you're trying to do this on 2 meters, and your yagi is 20
                  feet above ground. On 2 meters, 20 feet is about three wavelengths, and if
                  you model a yagi at three wavelengths above nominal "real earth" ground,
                  you'll find that you get the greatest concentration of your radiated energy
                  (called the primary lobe) at about 3 degrees above the horizon. Pretty
                  close! If you go up to 30 feet with the antenna, you're right at 2 degrees
                  take-off. 30 feet up is pretty easy to do, especially with a 2-meter
                  antenna.

                  Now let's look at the same path on 6 meters and put your 6-meter yagi at
                  that same 20-foot height above ground. On 6 meters, 20 feet is only one
                  wavelength, and if you model this, you find that your primary lobe is at
                  about 12 degrees, given average earth characteristics. Down at 2 degrees
                  where you want to be, your signal is about 10 dB down from the peak strength
                  of your primary lobe at 12 degrees. Ouch! Put your 6-meter yagi up at 30
                  feet, and things will improve a lot; your signal is now maybe 5 dB down from
                  the primary lobe. Not quite as bad, but not great. To get your 6-meter
                  primary lobe all the way down to 2 degrees, in fact, you would need to put
                  that yagi up at about 90 feet!! No, not too many guys are going to do
                  that -- so you put up with SOME signal loss on those long paths on 6 meters.
                  If you can't raise your antenna, you can best make up for this loss by using
                  a longer, higher-gain antenna (or a stacked array of antennas) with tighter
                  beamwidth for less noise pickup and more forward gain.

                  What's the point? Simply this: When you're thinking about antenna size,
                  antenna gain, and RF output power, you have to also figure path distance and
                  take-off angle into the equation. If you're running a 3-element yagi on 6
                  meters at 20 feet and you've never worked more than around 900 miles out on
                  meteor scatter, now you know why. It really isn't your lack of power or lack
                  of antenna gain; it's mostly about the take-off angle!

                  And this applies as much to receive as it does to transmit, if not more so.
                  Why more so? Two reasons: One, because the closer your antenna is to the
                  ground, the stronger will be its pick-up of man-made QRN, which is mostly
                  generated at ground level. Two, you can make up for a lack of signal at the
                  correct angle by using an amplifier on transmit, but NOT on receive.
                  Receiving is noise-limited. The very best thing you can do to improve your
                  signal-to-noise ratio is to live in a super-quiet QTH. The second-best thing
                  is to raise your antenna as far above the noise sources as possible. The
                  third-best thing is to use a longer, higher-gain, tighter beamwidth antenna,
                  which will pick up less noise -- unless, of course, your antenna is pointed
                  at the noise source!

                  One last word on 2 meters vs 6 meters. It's important to understand that
                  meteor scatter, like all modes of ionospheric propagation, depends on the
                  relationship between ionization intensity and wavelength. The shorter the
                  wavelength, the more intense the ionization must be in order to refract or
                  reflect radio waves. Meteors can produce extremely intense ionization, in
                  many cases intense enough to reflect 2-meter radio waves back to earth. The
                  problem is, this high ionization intensity degrades quickly to levels that
                  WILL NOT support propagation at 2 meters, but that WILL support propagation
                  at 6 meters. This is why 2-meter meteor pings are (on average) so much
                  shorter than 6-meter pings, and why (again, on average) you hear fewer pings
                  on 2 meters overall. Meteor scatter is easiest to work on 6 meters, harder
                  to work on 2 meters, and extremely difficult to work above 2 meters. The
                  shorter the wavelength, the weaker and shorter is the meteor-scatter
                  reflection, and the more antenna gain and power you need to make up for
                  that.

                  Now, if I could just raise MY antenna system another 20 or 30 feet, I might
                  be able to work Curt (1,340 miles). Many tries, no success as yet. :-)

                  Bill W5WVO
                  DM65qh


                  -----Original Message-----
                  From: Curt Nixon
                  Sent: Tuesday, November 30, 2010 15:40
                  To: Hal
                  Cc: wsjtgroup@yahoogroups.com
                  Subject: Re: [wsjtgroup] 6m vs 2m

                  GM Hal:

                  I can give you a little perspective from a newbie's entry level station
                  perspective. I began in MS on 2M with a WA5VJB cheap Yagi at 15' 6el and
                  120W from an old class C Motorola MASTR PA unit. Best to date was about
                  `1200 miles during normal daily operation. It does work but hearing
                  better would make it more productive during routine conditions.

                  On 6M, I have a 100W brick feeding a 2el wire MOXON at about 25' ..While
                  I have made many qso's with this setup on 6, I think it really
                  represents about the minimum in the rx department. On 6, if the rox are
                  plentiful, I can make contacts with a 40M dipole and 100W..its when they
                  get "thin" that it is a proble. Most of the time, other (bigger)
                  stations hear me ok but I get nothing. My next step up is a 5 element
                  LFA for 6M.

                  So, I would say, on your equipment list, and depending on what you want
                  to achieve, your 2M setup will be much more productive if any conditions
                  exist at all.

                  WHile your 6M setup should work fine with good condx, it will often let
                  you down in the rx department when other stations can hear you.

                  Again, my opinions only, based upon last 2 years of ops with the
                  equipment stated above. Hopefully it will give you some ideas.

                  See you on PJ.

                  Curt
                  KU8L

                  Hal wrote:
                  >
                  > Would I do better on MS with 11el and 160 watts on 2m or 3el and 80
                  > watts on 6m??
                  >
                  >


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                • Sebastian
                  Great information Bill! Something that I have wondered about meteor scatter is what you mentioned about 2 meters vs 6 meters. I do agree that it is easier
                  Message 8 of 13 , Nov 30, 2010
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                    Great information Bill!

                    Something that I have wondered about meteor scatter is what you mentioned about 2 meters vs 6 meters. I do agree that it is 'easier' to make meteor scatter contacts on 6 meters than on 2 meters.

                    However, why don't we also attempt meteor scatter on 10 meters? At this time, 10 meters is also pretty much dead, are there any technical reasons why 10 meters isn't used for meteor scatter?

                    Also, has there been any testing done with JTMS the 'experimental' mode in v9?

                    73 de Sebastian, W4AS

                    > One last word on 2 meters vs 6 meters. It's important to understand that
                    > meteor scatter, like all modes of ionospheric propagation, depends on the
                    > relationship between ionization intensity and wavelength. The shorter the
                    > wavelength, the more intense the ionization must be in order to refract or
                    > reflect radio waves. Meteors can produce extremely intense ionization, in
                    > many cases intense enough to reflect 2-meter radio waves back to earth. The
                    > problem is, this high ionization intensity degrades quickly to levels that
                    > WILL NOT support propagation at 2 meters, but that WILL support propagation
                    > at 6 meters. This is why 2-meter meteor pings are (on average) so much
                    > shorter than 6-meter pings, and why (again, on average) you hear fewer pings
                    > on 2 meters overall. Meteor scatter is easiest to work on 6 meters, harder
                    > to work on 2 meters, and extremely difficult to work above 2 meters. The
                    > shorter the wavelength, the weaker and shorter is the meteor-scatter
                    > reflection, and the more antenna gain and power you need to make up for
                    > that.
                    >
                    > Now, if I could just raise MY antenna system another 20 or 30 feet, I might
                    > be able to work Curt (1,340 miles). Many tries, no success as yet. :-)
                    >
                    > Bill W5WVO
                    > DM65qh
                  • Ben Nardi
                    Good point Sebastian During the 60 s and 70 s I worked with various HF research radars and echoes from meteor burns are huge in the 20-30 MHz region. I am sure
                    Message 9 of 13 , Nov 30, 2010
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                      Good point Sebastian
                       
                      During the 60's and 70's I worked with various HF research radars and echoes from meteor burns are huge in the 20-30 MHz region. I am sure that 10 meters would work out fine for this mode. It would seem that ISCAT would be good since burns tend to be long. Been quite a while ago but I seem to remember meteor trails lasting 30 sec to well over 1 min not that unusual. Would be interesting to try.
                       
                      73
                      Ben
                      W3ZUP
                      .
                       
                       
                      ----- Original Message -----
                      From: Sebastian
                      Sent: Tuesday, November 30, 2010 8:35 PM
                      Subject: Re: [wsjtgroup] 6m vs 2m

                       

                      Great information Bill!

                      Something that I have wondered about meteor scatter is what you mentioned about 2 meters vs 6 meters. I do agree that it is 'easier' to make meteor scatter contacts on 6 meters than on 2 meters.

                      However, why don't we also attempt meteor scatter on 10 meters? At this time, 10 meters is also pretty much dead, are there any technical reasons why 10 meters isn't used for meteor scatter?

                      Also, has there been any testing done with JTMS the 'experimental' mode in v9?

                      73 de Sebastian, W4AS

                      > One last word on 2 meters vs 6 meters. It's important to understand that
                      > meteor scatter, like all modes of ionospheric propagation, depends on the
                      > relationship between ionization intensity and wavelength. The shorter the
                      > wavelength, the more intense the ionization must be in order to refract or
                      > reflect radio waves. Meteors can produce extremely intense ionization, in
                      > many cases intense enough to reflect 2-meter radio waves back to earth. The
                      > problem is, this high ionization intensity degrades quickly to levels that
                      > WILL NOT support propagation at 2 meters, but that WILL support propagation
                      > at 6 meters. This is why 2-meter meteor pings are (on average) so much
                      > shorter than 6-meter pings, and why (again, on average) you hear fewer pings
                      > on 2 meters overall. Meteor scatter is easiest to work on 6 meters, harder
                      > to work on 2 meters, and extremely difficult to work above 2 meters. The
                      > shorter the wavelength, the weaker and shorter is the meteor-scatter
                      > reflection, and the more antenna gain and power you need to make up for
                      > that.
                      >
                      > Now, if I could just raise MY antenna system another 20 or 30 feet, I might
                      > be able to work Curt (1,340 miles). Many tries, no success as yet. :-)
                      >
                      > Bill W5WVO
                      > DM65qh



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                    • Barry Garratt
                      That s interesting Ben. Most folks that have worked in this field professionally will say that the lowest practical limit for MS is around 40 MHz. If you do
                      Message 10 of 13 , Nov 30, 2010
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                        That’s interesting Ben. Most folks that have worked in this field professionally will say that the lowest practical limit for MS is around 40 MHz. If you do the equations you end up with some very large transmitter power and large gain antennas. That’s not to say it can’t be done though. I remember a few years ago HARRP ran some test around 7 MHz bouncing a signal off the moon. They used their huge array and megawatts of power but they did get some great echoes. I personally have heard echoes off the moon on 10 meters. The antennas had slightly over 23 dB gain and as I recall the transmitter was over 5 kW. EME is hard enough on 6 meters so I’d imagine not too many folk will be trying it on 10 meters.

                         

                        Sorry got a little off track. Do you know of anyone with a big 10 meter array that would be willing to run some tests. Without doing the math I’d guess something in the range of 18 dB for the antenna and 1500 watts might work.

                         

                        What kind of antennas were you using and what power level were you running in the 20-30 MHz range Ben.

                         

                        Very 73,

                         

                        Barry KS7DX

                         

                         

                        From: wsjtgroup@yahoogroups.com [mailto:wsjtgroup@yahoogroups.com] On Behalf Of Ben Nardi
                        Sent: Tuesday, November 30, 2010 6:34 PM
                        To: wsjtgroup@yahoogroups.com
                        Subject: Re: [wsjtgroup] 6m vs 2m

                         

                         

                        Good point Sebastian

                         

                        During the 60's and 70's I worked with various HF research radars and echoes from meteor burns are huge in the 20-30 MHz region. I am sure that 10 meters would work out fine for this mode. It would seem that ISCAT would be good since burns tend to be long. Been quite a while ago but I seem to remember meteor trails lasting 30 sec to well over 1 min not that unusual. Would be interesting to try.

                         

                        73

                        Ben

                        W3ZUP

                        .

                         

                         

                        ----- Original Message -----

                        From: Sebastian

                        Sent: Tuesday, November 30, 2010 8:35 PM

                        Subject: Re: [wsjtgroup] 6m vs 2m

                         

                         

                        Great information Bill!

                        Something that I have wondered about meteor scatter is what you mentioned about 2 meters vs 6 meters. I do agree that it is 'easier' to make meteor scatter contacts on 6 meters than on 2 meters.

                        However, why don't we also attempt meteor scatter on 10 meters? At this time, 10 meters is also pretty much dead, are there any technical reasons why 10 meters isn't used for meteor scatter?

                        Also, has there been any testing done with JTMS the 'experimental' mode in v9?

                        73 de Sebastian, W4AS

                        > One last word on 2 meters vs 6 meters. It's important to understand that
                        > meteor scatter, like all modes of ionospheric propagation, depends on the
                        > relationship between ionization intensity and wavelength. The shorter the
                        > wavelength, the more intense the ionization must be in order to refract or
                        > reflect radio waves. Meteors can produce extremely intense ionization, in
                        > many cases intense enough to reflect 2-meter radio waves back to earth. The
                        > problem is, this high ionization intensity degrades quickly to levels that
                        > WILL NOT support propagation at 2 meters, but that WILL support propagation
                        > at 6 meters. This is why 2-meter meteor pings are (on average) so much
                        > shorter than 6-meter pings, and why (again, on average) you hear fewer pings
                        > on 2 meters overall. Meteor scatter is easiest to work on 6 meters, harder
                        > to work on 2 meters, and extremely difficult to work above 2 meters. The
                        > shorter the wavelength, the weaker and shorter is the meteor-scatter
                        > reflection, and the more antenna gain and power you need to make up for
                        > that.
                        >
                        > Now, if I could just raise MY antenna system another 20 or 30 feet, I might
                        > be able to work Curt (1,340 miles). Many tries, no success as yet. :-)
                        >
                        > Bill W5WVO
                        > DM65qh

                         


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                      • Bill VanAlstyne W5WVO
                        Ben’s response on m/s below 30 MHz is interesting. I would expect that path lengths would be comparatively shorter there than at 50 MHz and above. I think
                        Message 11 of 13 , Nov 30, 2010
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                          Ben’s response on m/s below 30 MHz is interesting. I would expect that path lengths would be comparatively shorter there than at 50 MHz and above. I think any experimentation on 10 meters would be quite interesting.
                           
                          Regarding JTMS – good question. Joe K1JT included JTMS in WSJT9 so experimentation could continue by those who wanted to do it. I know that nobody (including Joe) has been pushing this, and I think it is kind of languishing. In the formal testing we did prior to the WSJT9 beta release, JTMS did not show itself to be significantly better than the improved WSJT9 version of FSK441. Joe felt that in order to justify replacing a successful m/s mode (FSK441) with a new, incompatible mode (JTMS), JTMS would have to prove itself to provide a really significant improvement over FSK441. Since this didn’t happen (and we have statistically significant data that demonstrates that fact), the newly enhanced FSK441 (which is fully backward-compatible to the FSK441 version in WSJT7) was set up as the main m/s mode in the new release.
                           
                          Anybody that wants to continue testing with JTMS, however, is encouraged to do so. If you do any testing, it would be most useful to create a scientifically rigorous testing model whose output can be statistically analyzed against FSK441. One suggestion for a test model is as follows:
                           
                          (a) Two stations about 1,000 miles apart, each with two identical transceivers, would be linked to independently running parallel instances of WSJT9. The ideal distance between the stations should be determined such that a large number of pings, but no tropo or sporadic-E, could be expected on the band of choice. The entire test protocol could be run on both 6 meters and on 2 meters at different times, either by the same stations or by different stations appropriately configured as described here.
                           
                          (b) Transmissions would be made by one of the stations, reception (and recording through WSJT) would be made by the other station. Having just one station do the transmitting and one do the receiving cancels out any effect of differences in local noise level between two different stations. If the transmitting rig can take the duty cycle, WSJT can be optionally set up to transmit during both 1st and 2nd sequences for testing purposes. I know the Elecraft K3 can do this, for example, because I did it for an hour while monitoring the PA deck temperature, which stayed within acceptable limits. Otherwise, less robust transmitters can be set up to transmit either 1st or 2nd sequence, with the alternate time sequence being dead space whose only purpose would be to allow the transmitters to cool.
                           
                          (c) One transmitting transceiver would run JTMS, the other FSK441. Each setup would transmit the same beacon message “[callsign]/B [6-character grid]” on both modes at the same time. Each transceiver, whether receiving or transmitting,  would be connected to the same antenna with appropriate combiners where necessary. Using separate antennas for each transmitter and/or receiver would introduce unacceptable levels of variation.
                           
                          (d) If an Elecraft K3 transceiver with dual receivers is used on the receiving end, then only one transceiver would be required at that end, as the receivers in the K3 are completely identical and phase-locked, and they would be listening to the same time period and the same pings to a high degree of precision. The K3’s tight IF roofing filter allows use of frequencies 5 kHz apart without receive degradation even in the presence of extremely strong signals. (I’ve verified this using a very strong [but clean] local signal for test purposes. With the K3, I found I was actually able to decode weak pings on a frequency only 3 kHz from the strong signal. Using a Kenwood TS-2000, by comparison, I found I could not get within 20 kHz of the same strong signal and decode anything at all.) The K3 Line Out stereo output jack carries the mono audio output of each receiver. A splitter cable would be required to route the audio to two identical sound cards linked to two instances of WSJT9.
                           
                          As can be intuited, the point of this test architecture is to equalize all variables except the software being used for encoding and decoding. Everything else – transmitters, receivers, antennas, sound cards, and most important, the time sequences and their unique individual meteor pings – would be the same for both modes. We could then see how each mode performs on the same meteor ping, as well as having macro-level data for the whole test period (at least an hour, two hours if 50% duty cycle) that can be analyzed using standard statistical methods.
                           
                          Unfortunately, my K3 is not yet equipped with the KRX3 second receiver, and I only have one K3. I would recommend a K3/KRX3 for the receiving end of the test because of its phase-locked dual-receive capability and high dynamic range. I would want to keep the two test frequencies as close together as possible to minimize frequency-related differences in propagation. (Unfortunately, such differences cannot be entirely eliminated, since it is impossible in practical terms to use the same frequency at the same time for two different transmissions from the same station and antenna along the same path.)
                           
                          On the transmitting end, it’s not as important to have any particular radio used, as long as they are both the same and set up in exactly the same way.
                           
                          If anybody has equipment as described above and would like to take part in such an experiment, please let me know and I’ll try to coordinate it. Equipment pooling (borrowing) might be necessary.
                           
                          If there is insufficient interest in doing this kind of rigorous testing, then JTMS could end up being abandoned. “Could”, not “will”. That is ultimately up to Joe.
                           
                          Bill W5WVO
                           
                           
                           
                          From: Sebastian
                          Sent: Wednesday, December 01, 2010 01:35
                          Subject: Re: [wsjtgroup] 6m vs 2m
                           
                           

                          Great information Bill!

                          Something that I have wondered about meteor scatter is what you mentioned about 2 meters vs 6 meters. I do agree that it is 'easier' to make meteor scatter contacts on 6 meters than on 2 meters.

                          However, why don't we also attempt meteor scatter on 10 meters? At this time, 10 meters is also pretty much dead, are there any technical reasons why 10 meters isn't used for meteor scatter?

                          Also, has there been any testing done with JTMS the 'experimental' mode in v9?

                          73 de Sebastian, W4AS

                          > One last word on 2 meters vs 6 meters. It's
                          important to understand that
                          > meteor scatter, like all modes of
                          ionospheric propagation, depends on the
                          > relationship between ionization
                          intensity and wavelength. The shorter the
                          > wavelength, the more intense
                          the ionization must be in order to refract or
                          > reflect radio waves.
                          Meteors can produce extremely intense ionization, in
                          > many cases intense
                          enough to reflect 2-meter radio waves back to earth. The
                          > problem is,
                          this high ionization intensity degrades quickly to levels that
                          > WILL NOT
                          support propagation at 2 meters, but that WILL support propagation
                          > at 6
                          meters. This is why 2-meter meteor pings are (on average) so much
                          >
                          shorter than 6-meter pings, and why (again, on average) you hear fewer pings
                          > on 2 meters overall. Meteor scatter is easiest to work on 6 meters,
                          harder
                          > to work on 2 meters, and extremely difficult to work above 2
                          meters. The
                          > shorter the wavelength, the weaker and shorter is the
                          meteor-scatter
                          > reflection, and the more antenna gain and power you need
                          to make up for
                          > that.
                          >
                          > Now, if I could just raise MY
                          antenna system another 20 or 30 feet, I might
                          > be able to work Curt
                          (1,340 miles). Many tries, no success as yet. :-)
                          >
                          > Bill
                          W5WVO
                          > DM65qh

                        • Russ K2TXB
                          Bill, why would you expect path lengths to be shorter at 28 MHz? The ionization takes place at the same height, so the path length should be the same. In fact
                          Message 12 of 13 , Dec 1, 2010
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                            Bill, why would you expect path lengths to be shorter at 28 MHz?  The ionization takes place at the same height, so the path length should be the same. In fact path length is the same for two vs six meters - except that on six the path is often extended by coupling to other propagation methods such as ES.  Can happen on two as well, but seldom does.
                             
                            As for burn time, I would expect them to be much longer on 28 MHz, just as they are longer on six than two.
                             
                            73, Russ K2TXB
                             
                            PS: the real reason no one is talking much about using MS on 10 meters is that there are other propagation methods available on that band most of the time that can do the same or better.  Another reason is that this is a primarily VHF orentated group and most of us consider 10 meters to be a DC band.


                            From: wsjtgroup@yahoogroups.com [mailto:wsjtgroup@yahoogroups.com] On Behalf Of Bill VanAlstyne W5WVO
                            Sent: Tuesday, November 30, 2010 10:55 PM
                            To: wsjtgroup@yahoogroups.com; Sebastian
                            Subject: Re: [wsjtgroup] 6m vs. 2m

                             

                            Ben’s response on m/s below 30 MHz is interesting. I would expect that path lengths would be comparatively shorter there than at 50 MHz and above. I think any experimentation on 10 meters would be quite interesting.
                             
                            Regarding JTMS – good question. Joe K1JT included JTMS in WSJT9 so experimentation could continue by those who wanted to do it. I know that nobody (including Joe) has been pushing this, and I think it is kind of languishing. In the formal testing we did prior to the WSJT9 beta release, JTMS did not show itself to be significantly better than the improved WSJT9 version of FSK441. Joe felt that in order to justify replacing a successful m/s mode (FSK441) with a new, incompatible mode (JTMS), JTMS would have to prove itself to provide a really significant improvement over FSK441. Since this didn’t happen (and we have statistically significant data that demonstrates that fact), the newly enhanced FSK441 (which is fully backward-compatible to the FSK441 version in WSJT7) was set up as the main m/s mode in the new release.
                             
                            Anybody that wants to continue testing with JTMS, however, is encouraged to do so. If you do any testing, it would be most useful to create a scientifically rigorous testing model whose output can be statistically analyzed against FSK441. One suggestion for a test model is as follows:
                             
                            (a) Two stations about 1,000 miles apart, each with two identical transceivers, would be linked to independently running parallel instances of WSJT9. The ideal distance between the stations should be determined such that a large number of pings, but no tropo or sporadic-E, could be expected on the band of choice. The entire test protocol could be run on both 6 meters and on 2 meters at different times, either by the same stations or by different stations appropriately configured as described here.
                             
                            (b) Transmissions would be made by one of the stations, reception (and recording through WSJT) would be made by the other station. Having just one station do the transmitting and one do the receiving cancels out any effect of differences in local noise level between two different stations. If the transmitting rig can take the duty cycle, WSJT can be optionally set up to transmit during both 1st and 2nd sequences for testing purposes. I know the Elecraft K3 can do this, for example, because I did it for an hour while monitoring the PA deck temperature, which stayed within acceptable limits. Otherwise, less robust transmitters can be set up to transmit either 1st or 2nd sequence, with the alternate time sequence being dead space whose only purpose would be to allow the transmitters to cool.
                             
                            (c) One transmitting transceiver would run JTMS, the other FSK441. Each setup would transmit the same beacon message “[callsign]/B [6-character grid]” on both modes at the same time. Each transceiver, whether receiving or transmitting,  would be connected to the same antenna with appropriate combiners where necessary. Using separate antennas for each transmitter and/or receiver would introduce unacceptable levels of variation.
                             
                            (d) If an Elecraft K3 transceiver with dual receivers is used on the receiving end, then only one transceiver would be required at that end, as the receivers in the K3 are completely identical and phase-locked, and they would be listening to the same time period and the same pings to a high degree of precision. The K3’s tight IF roofing filter allows use of frequencies 5 kHz apart without receive degradation even in the presence of extremely strong signals. (I’ve verified this using a very strong [but clean] local signal for test purposes. With the K3, I found I was actually able to decode weak pings on a frequency only 3 kHz from the strong signal. Using a Kenwood TS-2000, by comparison, I found I could not get within 20 kHz of the same strong signal and decode anything at all.) The K3 Line Out stereo output jack carries the mono audio output of each receiver. A splitter cable would be required to route the audio to two identical sound cards linked to two instances of WSJT9.
                             
                            As can be intuited, the point of this test architecture is to equalize all variables except the software being used for encoding and decoding. Everything else – transmitters, receivers, antennas, sound cards, and most important, the time sequences and their unique individual meteor pings – would be the same for both modes. We could then see how each mode performs on the same meteor ping, as well as having macro-level data for the whole test period (at least an hour, two hours if 50% duty cycle) that can be analyzed using standard statistical methods.
                             
                            Unfortunately, my K3 is not yet equipped with the KRX3 second receiver, and I only have one K3. I would recommend a K3/KRX3 for the receiving end of the test because of its phase-locked dual-receive capability and high dynamic range. I would want to keep the two test frequencies as close together as possible to minimize frequency-related differences in propagation. (Unfortunately, such differences cannot be entirely eliminated, since it is impossible in practical terms to use the same frequency at the same time for two different transmissions from the same station and antenna along the same path.)
                             
                            On the transmitting end, it’s not as important to have any particular radio used, as long as they are both the same and set up in exactly the same way.
                             
                            If anybody has equipment as described above and would like to take part in such an experiment, please let me know and I’ll try to coordinate it. Equipment pooling (borrowing) might be necessary.
                             
                            If there is insufficient interest in doing this kind of rigorous testing, then JTMS could end up being abandoned. “Could”, not “will”. That is ultimately up to Joe.
                             
                            Bill W5WVO
                             
                             
                             
                            From: Sebastian
                            Sent: Wednesday, December 01, 2010 01:35
                            Subject: Re: [wsjtgroup] 6m vs 2m
                             
                             

                            Great information Bill!

                            Something that I have wondered about meteor scatter is what you mentioned about 2 meters vs 6 meters. I do agree that it is 'easier' to make meteor scatter contacts on 6 meters than on 2 meters.

                            However, why don't we also attempt meteor scatter on 10 meters? At this time, 10 meters is also pretty much dead, are there any technical reasons why 10 meters isn't used for meteor scatter?

                            Also, has there been any testing done with JTMS the 'experimental' mode in v9?

                            73 de Sebastian, W4AS

                            > One last word on 2 meters vs 6 meters. It's important to understand that
                            > meteor scatter, like all modes of ionospheric propagation, depends on the
                            > relationship between ionization intensity and wavelength. The shorter the
                            > wavelength, the more intense the ionization must be in order to refract or
                            > reflect radio waves. Meteors can produce extremely intense ionization, in
                            > many cases intense enough to reflect 2-meter radio waves back to earth. The
                            > problem is, this high ionization intensity degrades quickly to levels that
                            > WILL NOT support propagation at 2 meters, but that WILL support propagation
                            > at 6 meters. This is why 2-meter meteor pings are (on average) so much
                            > shorter than 6-meter pings, and why (again, on average) you hear fewer pings
                            > on 2 meters overall. Meteor scatter is easiest to work on 6 meters, harder
                            > to work on 2 meters, and extremely difficult to work above 2 meters. The
                            > shorter the wavelength, the weaker and shorter is the meteor-scatter
                            > reflection, and the more antenna gain and power you need to make up for
                            > that.
                            >
                            > Now, if I could just raise MY antenna system another 20 or 30 feet, I might
                            > be able to work Curt (1,340 miles). Many tries, no success as yet. :-)
                            >
                            > Bill W5WVO
                            > DM65qh

                          • oz1rh
                            I have been following this thread and would like to share my info on radiation angle/ground gain/antenna height available at www.oz1rh.com Radiation angle with
                            Message 13 of 13 , Dec 1, 2010
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                              I have been following this thread and would like to share my info on radiation angle/ground gain/antenna height available at www.oz1rh.com Radiation angle with ground gain can be calculated reasonable accurate with a pc. My text on ground gain applies to MS though it was written for EME.

                              I have a text on MS explaning the basic geometry and the European HSCW procedure. If you want info on troposcatter or 'traditional' ionoscatter there are texts on that too. Download the Word documents to get the best formatting.

                              I know the few lines on vertical polarization are thin, but should you have any improvements to the texts please let me know.

                              73, Palle, OZ1RH
                              www.oz1rh.com
                              www.oz9edr.dk
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