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RE: [wsjtgroup] To the party that just told me "less pwr" on 15M

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  • Ian GM4KLN
    Hi Ed I regularly get the strong station syndrome you refer to, as I am a perfect single-skip distance into southern EU, with huge sigs frequently upwards of
    Message 1 of 10 , Sep 22, 2013

      Hi Ed

      I regularly get the strong station syndrome you refer to, as I am a perfect single-skip distance into southern EU, with huge sigs frequently upwards of +15.

       

      All I need to do is turn AGC off: I can still copy weak sigs (- 20 to -25 typically) at the same time.  I can always turn pre-amps off, or even switch in the attenuator: I don’t ever recall not being able to resolve a weak sig with a little experimentation.

       

      Rig is an early IC-756.

       

      73, Ian GM4KLN

       

       

      From: wsjtgroup@yahoogroups.com [mailto:wsjtgroup@yahoogroups.com] On Behalf Of Ed
      Sent: 22 September 2013 23:10
      To: 'Bob'; wsjtgroup@yahoogroups.com
      Subject: RE: [wsjtgroup] To the party that just told me "less pwr" on 15M

       

       

       

      The problem I have,  and one that has no solution I believe,  is that these strong +12 signals blank my graphical display,  and I assume also block much weaker signals from being decoded.  Turning down the RF gain is not going to help copying the weak stations I am trying to decode.    I cannot operate if such a station is booming in.   Fortunately it seems to be a fairly rare occurrence so far.

       

      Ed   K7AAT

       

       

      From: wsjtgroup@yahoogroups.com [mailto:wsjtgroup@yahoogroups.com] On Behalf Of Bob
      Sent: Sunday, September 22, 2013 12:40 PM
      To: wsjtgroup@yahoogroups.com
      Subject: Re: [wsjtgroup] To the party that just told me "less pwr" on 15M

       

       

      Easiest thing to do is adjust one's own RF gain control.  If the "offending" signal looks normal, blame your good reception, NOT the other guy.  After all a +12 to someone one hop away might be a -20 to someone else a bit further down the pipe.

       

      I had fun with JT9 on 30 meters a couple of nights ago running 5 watts out and was hitting VK3AMA with a +3 report 10,000+ miles away.  I finished the QSO with the power at 0.5 watts.

       

      73, Bob, WB4SON

       

    • Bob
      Quoting: The problem I have, and one that has no solution I believe, is that these strong +12 signals blank my graphical display, and I assume also block
      Message 2 of 10 , Sep 22, 2013
        Quoting:  "The problem I have,  and one that has no solution I believe,  is that these strong +12 signals blank my graphical display,  and I assume also block much weaker signals from being decoded.  Turning down the RF gain is not going to help copying the weak stations I am trying to decode.    I cannot operate if such a station is booming in.   Fortunately it seems to be a fairly rare occurrence so far."


        First, to put this in perspective, let me give you a slightly different situation.  I'm operating during a contest and desperately want to work that rare DX station that is calling CQ in the 100 Hz gap between two KW stations with 7 element beams on 150 foot towers.  Now I might not be able to copy that rare DX station given the strong adjacent signals.  I might "wish" that the two strong stations would just go away, but I certainly have NO right to ask either of them to QSY or reduce power, or stop what they are doing for my sake.

        Second, what you see on the display is just that -- what is on the display.  It is a visual aid.  It has nothing to do with how the signals are decoded by WSJT -- fat signals on the display mean nothing other than the signal is so strong it still has energy across several bins.

        HOWEVER, and this is often the problem, if you do have one or two very strong signals, AND you have your AGC turned on, then you might have your RF gain automatically reduced to the point that you can't decode the desired signal.  There are two solutions:

        First: Turn your AGC off and reduce your RF gain to the point where your receiver no longer overloads from the strongest signals.  That has helped me many times.

        Second:  Use your filters.  Narrow the passband so that the strong signals are no longer in the passband.  Or use your notch filter to take them out.  Use of the filters almost always works.


        I'm sympathetic -- It would be a great world if all signals were -12, but they aren't.  Different paths make some weaker and some stronger.  Sometimes folks do run excessive power.  Others start sending RTTY in the JT65/JT9 area.  But it really is our job, as operators on "the other side" to do our best with the tools we have to work the ones we want.


        73
      • Carol & Fred Darrah
        There should never be a time when adjacent signals blank the graphical display while operating digital modes. If this is happening, I would think there are
        Message 3 of 10 , Sep 22, 2013
          There should never be a time when adjacent signals blank the graphical display while operating digital modes. If this is happening, I would think there are somethings wrong in your settings. I never run AGC. RF gain needs to be set to the lowest point you can set it, as it increases the noise levels. A check of your sound card settings is in order and if you use the Mic input be sure the Mic boost is off. The only time a signal should mess with the display is if it is very close to you in distance. Copying very weak stations is also more about the loss in your coax or switches, or even your tuner. I have used several radios and different computers and sound cards, in the past 20 years I have been on digital modes and never had the problem described.
          Fred  N9GUE



          From: Bob <wb4son@...>
          To: wsjtgroup@yahoogroups.com
          Sent: Sunday, September 22, 2013 9:14 PM
          Subject: Re: [wsjtgroup] To the party that just told me "less pwr" on 15M

           
          Quoting:  "The problem I have,  and one that has no solution I believe,  is that these strong +12 signals blank my graphical display,  and I assume also block much weaker signals from being decoded.  Turning down the RF gain is not going to help copying the weak stations I am trying to decode.    I cannot operate if such a station is booming in.   Fortunately it seems to be a fairly rare occurrence so far."


          First, to put this in perspective, let me give you a slightly different situation.  I'm operating during a contest and desperately want to work that rare DX station that is calling CQ in the 100 Hz gap between two KW stations with 7 element beams on 150 foot towers.  Now I might not be able to copy that rare DX station given the strong adjacent signals.  I might "wish" that the two strong stations would just go away, but I certainly have NO right to ask either of them to QSY or reduce power, or stop what they are doing for my sake.

          Second, what you see on the display is just that -- what is on the display.  It is a visual aid.  It has nothing to do with how the signals are decoded by WSJT -- fat signals on the display mean nothing other than the signal is so strong it still has energy across several bins.

          HOWEVER, and this is often the problem, if you do have one or two very strong signals, AND you have your AGC turned on, then you might have your RF gain automatically reduced to the point that you can't decode the desired signal.  There are two solutions:

          First: Turn your AGC off and reduce your RF gain to the point where your receiver no longer overloads from the strongest signals.  That has helped me many times.

          Second:  Use your filters.  Narrow the passband so that the strong signals are no longer in the passband.  Or use your notch filter to take them out.  Use of the filters almost always works.


          I'm sympathetic -- It would be a great world if all signals were -12, but they aren't.  Different paths make some weaker and some stronger.  Sometimes folks do run excessive power.  Others start sending RTTY in the JT65/JT9 area.  But it really is our job, as operators on "the other side" to do our best with the tools we have to work the ones we want.


          73


        • Ed
          For the record on this discussion, I too do NOT run with AGC turned on. I use a SignaLink USB interface and set it to show a signal level on WSJTX of
          Message 4 of 10 , Sep 22, 2013

             

            For the record on this discussion,  I too do NOT run with AGC turned on.  I  use a SignaLink USB interface and set it to show a signal level on WSJTX of between 20 and 30dB.   I believe that is the recommended range of Joe, the author.

             

            Additional,  I will grant that I have not played with my radios fine filter system to see if that helps.   Been busy this weekend.  Will experiment later.

             

            Ed   K7AAT

             

             

            From: wsjtgroup@yahoogroups.com [mailto:wsjtgroup@yahoogroups.com] On Behalf Of Carol & Fred Darrah
            Sent: Sunday, September 22, 2013 7:35 PM
            To: Bob; wsjtgroup@yahoogroups.com
            Subject: Re: [wsjtgroup] To the party that just told me "less pwr" on 15M

             

             

            There should never be a time when adjacent signals blank the graphical display while operating digital modes. If this is happening, I would think there are somethings wrong in your settings. I never run AGC. RF gain needs to be set to the lowest point you can set it, as it increases the noise levels. A check of your sound card settings is in order and if you use the Mic input be sure the Mic boost is off. The only time a signal should mess with the display is if it is very close to you in distance. Copying very weak stations is also more about the loss in your coax or switches, or even your tuner. I have used several radios and different computers and sound cards, in the past 20 years I have been on digital modes and never had the problem described.
            Fred  N9GUE

             

             


            From: Bob <wb4son@...>
            To: wsjtgroup@yahoogroups.com
            Sent: Sunday, September 22, 2013 9:14 PM
            Subject: Re: [wsjtgroup] To the party that just told me "less pwr" on 15M

             

             

            Quoting:  "The problem I have,  and one that has no solution I believe,  is that these strong +12 signals blank my graphical display,  and I assume also block much weaker signals from being decoded.  Turning down the RF gain is not going to help copying the weak stations I am trying to decode.    I cannot operate if such a station is booming in.   Fortunately it seems to be a fairly rare occurrence so far."

             

             

            First, to put this in perspective, let me give you a slightly different situation.  I'm operating during a contest and desperately want to work that rare DX station that is calling CQ in the 100 Hz gap between two KW stations with 7 element beams on 150 foot towers.  Now I might not be able to copy that rare DX station given the strong adjacent signals.  I might "wish" that the two strong stations would just go away, but I certainly have NO right to ask either of them to QSY or reduce power, or stop what they are doing for my sake.

             

            Second, what you see on the display is just that -- what is on the display.  It is a visual aid.  It has nothing to do with how the signals are decoded by WSJT -- fat signals on the display mean nothing other than the signal is so strong it still has energy across several bins.

             

            HOWEVER, and this is often the problem, if you do have one or two very strong signals, AND you have your AGC turned on, then you might have your RF gain automatically reduced to the point that you can't decode the desired signal.  There are two solutions:

             

            First: Turn your AGC off and reduce your RF gain to the point where your receiver no longer overloads from the strongest signals.  That has helped me many times.

             

            Second:  Use your filters.  Narrow the passband so that the strong signals are no longer in the passband.  Or use your notch filter to take them out.  Use of the filters almost always works.

             

             

            I'm sympathetic -- It would be a great world if all signals were -12, but they aren't.  Different paths make some weaker and some stronger.  Sometimes folks do run excessive power.  Others start sending RTTY in the JT65/JT9 area.  But it really is our job, as operators on "the other side" to do our best with the tools we have to work the ones we want.

             

            73

             

          • k4djg
            As I use FlexRadio (F1.5K and F3K), I haven t found a way to turn OFF AGC. If I have just missed something, will someone please set me straight, as I WANT to
            Message 5 of 10 , Sep 24, 2013

               As I use FlexRadio (F1.5K and F3K), I haven't found a way to turn OFF AGC.  If I have just missed something, will someone please set me straight, as I WANT to turn it off!


              Bob, K4DJG



              ---In wsjtgroup@yahoogroups.com, <k7aat.ed@...> wrote:

               

              For the record on this discussion,  I too do NOT run with AGC turned on.  I  use a SignaLink USB interface and set it to show a signal level on WSJTX of between 20 and 30dB.   I believe that is the recommended range of Joe, the author.

               

              Additional,  I will grant that I have not played with my radios fine filter system to see if that helps.   Been busy this weekend.  Will experiment later.

               

              Ed   K7AAT

               

               

              From: wsjtgroup@yahoogroups.com [mailto:wsjtgroup@yahoogroups.com] On Behalf Of Carol & Fred Darrah
              Sent: Sunday, September 22, 2013 7:35 PM
              To: Bob; wsjtgroup@yahoogroups.com
              Subject: Re: [wsjtgroup] To the party that just told me "less pwr" on 15M

               

               

              There should never be a time when adjacent signals blank the graphical display while operating digital modes. If this is happening, I would think there are somethings wrong in your settings. I never run AGC. RF gain needs to be set to the lowest point you can set it, as it increases the noise levels. A check of your sound card settings is in order and if you use the Mic input be sure the Mic boost is off. The only time a signal should mess with the display is if it is very close to you in distance. Copying very weak stations is also more about the loss in your coax or switches, or even your tuner. I have used several radios and different computers and sound cards, in the past 20 years I have been on digital modes and never had the problem described.
              Fred  N9GUE

               

               


              From: Bob <wb4son@...>
              To: wsjtgroup@yahoogroups.com
              Sent: Sunday, September 22, 2013 9:14 PM
              Subject: Re: [wsjtgroup] To the party that just told me "less pwr" on 15M

               

               

              Quoting:  "The problem I have,  and one that has no solution I believe,  is that these strong +12 signals blank my graphical display,  and I assume also block much weaker signals from being decoded.  Turning down the RF gain is not going to help copying the weak stations I am trying to decode.    I cannot operate if such a station is booming in.   Fortunately it seems to be a fairly rare occurrence so far."

               

               

              First, to put this in perspective, let me give you a slightly different situation.  I'm operating during a contest and desperately want to work that rare DX station that is calling CQ in the 100 Hz gap between two KW stations with 7 element beams on 150 foot towers.  Now I might not be able to copy that rare DX station given the strong adjacent signals.  I might "wish" that the two strong stations would just go away, but I certainly have NO right to ask either of them to QSY or reduce power, or stop what they are doing for my sake.

               

              Second, what you see on the display is just that -- what is on the display.  It is a visual aid.  It has nothing to do with how the signals are decoded by WSJT -- fat signals on the display mean nothing other than the signal is so strong it still has energy across several bins.

               

              HOWEVER, and this is often the problem, if you do have one or two very strong signals, AND you have your AGC turned on, then you might have your RF gain automatically reduced to the point that you can't decode the desired signal.  There are two solutions:

               

              First: Turn your AGC off and reduce your RF gain to the point where your receiver no longer overloads from the strongest signals.  That has helped me many times.

               

              Second:  Use your filters.  Narrow the passband so that the strong signals are no longer in the passband.  Or use your notch filter to take them out.  Use of the filters almost always works.

               

               

              I'm sympathetic -- It would be a great world if all signals were -12, but they aren't.  Different paths make some weaker and some stronger.  Sometimes folks do run excessive power.  Others start sending RTTY in the JT65/JT9 area.  But it really is our job, as operators on "the other side" to do our best with the tools we have to work the ones we want.

               

              73

               

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