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Rocky transmits where it wants.

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  • kb3cuf
    Hi All- Using and trying to QSO with... Rocky 3.6, USB synth, RxTx 6.3 on 9v DC supply. When I do the I/Q tx balance, I can get deep nulls OK. When I transmit
    Message 1 of 6 , Mar 14, 2010
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      Hi All-
      Using and trying to QSO with...
      Rocky 3.6, USB synth, RxTx 6.3 on 9v DC supply.

      When I do the I/Q tx balance, I can get deep nulls OK. When I transmit using tone, or PSK, I can be anywhere in the band! Example- I transmitted at 7.060 PSK, and the my inline counter had me at 7.010. It's not consistent, or even transmits in the same place, not a fixed offset, etc. Sometimes it's right, most of the time not.

      I've verified the counter by using the main rig, same results.

      RF knocking the frequency off could be a possibilty, but the receive seems to be stable. (e.g. WWV is right on freq.)

      Any ideas?

      73
      Larry
      KB3CUF
    • aa9wqham@aol.com
      You can t measure frequency using PSK31. Use a constant carrier like AM. You can do it with a constant tone. But you have to add or subtract the tone value
      Message 2 of 6 , Mar 14, 2010
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        You can't measure frequency using PSK31. Use a constant carrier like AM. You can do it with a constant tone. But you have to add or subtract the tone value from the reading depending on upper or lower SSB.
         
        Larry 
         
        In a message dated 3/14/2010 9:03:43 P.M. US Eastern Standard Time, acklin@... writes:
         

        Hi All-
        Using and trying to QSO with...
        Rocky 3.6, USB synth, RxTx 6.3 on 9v DC supply.

        When I do the I/Q tx balance, I can get deep nulls OK. When I transmit using tone, or PSK, I can be anywhere in the band! Example- I transmitted at 7.060 PSK, and the my inline counter had me at 7.010. It's not consistent, or even transmits in the same place, not a fixed offset, etc. Sometimes it's right, most of the time not.

        I've verified the counter by using the main rig, same results.

        RF knocking the frequency off could be a possibilty, but the receive seems to be stable. (e.g. WWV is right on freq.)

        Any ideas?

        73
        Larry
        KB3CUF

      • Larry Acklin
        OK, I get it. I think my antenna system is at fault. I have about 1.5V of AC between the coax shield and my building ground. If I hook up the antenna, I get
        Message 3 of 6 , Mar 14, 2010
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          OK, I get it.  I think my antenna system is at fault.  I have about 1.5V of AC between the coax shield and my building ground.  If I hook up the antenna, I get a big spike at 0.  Listening to the audio I can hear the hum.  Time to re-route coax and check grounds...
           
          Larry

          On Mon, Mar 15, 2010 at 2:32 AM, <aa9wqham@...> wrote:
           

          You can't measure frequency using PSK31. Use a constant carrier like AM. You can do it with a constant tone. But you have to add or subtract the tone value from the reading depending on upper or lower SSB.
           
          Larry 
           
          In a message dated 3/14/2010 9:03:43 P.M. US Eastern Standard Time, acklin@... writes:
           

          Hi All-
          Using and trying to QSO with...
          Rocky 3.6, USB synth, RxTx 6.3 on 9v DC supply.

          When I do the I/Q tx balance, I can get deep nulls OK. When I transmit using tone, or PSK, I can be anywhere in the band! Example- I transmitted at 7.060 PSK, and the my inline counter had me at 7.010. It's not consistent, or even transmits in the same place, not a fixed offset, etc. Sometimes it's right, most of the time not.

          I've verified the counter by using the main rig, same results.

          RF knocking the frequency off could be a possibilty, but the receive seems to be stable. (e.g. WWV is right on freq.)

          Any ideas?

          73
          Larry
          KB3CUF


        • Mr Doug -
          If you have the antenna isolated properly that voltage should make no difference. The antenna is isolated from ground in the Softrocks by virtue of being a
          Message 4 of 6 , Mar 14, 2010
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            If you have the antenna isolated properly that voltage should make no difference. The antenna is isolated from ground in the Softrocks by virtue of being a winding on the input toroid. As long as you do not connect it to the softrock ground it will be isolated. Using a metal chassis that is connected to the Sofrock ground with a coax connector (BNC, UHF, etc.)  mounted on it defeats this isolation. You should do something to make sure it is isolated. I use isolated BNC connectors. The shell is insulated from the mounting screw. You could also use insulated washers, screw terminals with an adapter to a coax fitting, etc.

            Keeping the antenna isolated is probably one of the most important things with the Softrocks because invariably it is grounded elsewhere. In fact for coax systems it should be grounded where it enters the house for lightning protection. Since this ground is at some other place on your property then the computer ground it will have potential difference.  1.5 volts is not uncommon. It could be more. Most people do not bond grounds together which should be done for safety reason. An example would be that you have an outside antenna and where it enters the house you have a ground rod which the shield of the coax is bonded to. In your hamshack you have everything grounded using the house electrical ground. You would think that since the house ground which uses a ground rod and the antenna ground which also uses a ground rod would be at the same potential but that is usually not the case. It depends on how close the ground rods are to each other, the ground resistance, and a whole host of other things. Bonding these two ground rods together (as well as any others) with at least #6 copper will mostly solve the problem and also reduce the chance of arcing and big potential differences in a lightning hit.

            Doug



            From: Larry Acklin <acklin@...>
            To: softrock40@yahoogroups.com
            Sent: Sun, March 14, 2010 11:08:04 PM
            Subject: Re: [softrock40] Rocky transmits where it wants.

             

            OK, I get it.  I think my antenna system is at fault.  I have about 1.5V of AC between the coax shield and my building ground.  If I hook up the antenna, I get a big spike at 0.  Listening to the audio I can hear the hum.  Time to re-route coax and check grounds...
             
            Larry

            On Mon, Mar 15, 2010 at 2:32 AM, <aa9wqham@aol. com> wrote:
             

            You can't measure frequency using PSK31. Use a constant carrier like AM. You can do it with a constant tone. But you have to add or subtract the tone value from the reading depending on upper or lower SSB.
             
            Larry 
             
            In a message dated 3/14/2010 9:03:43 P.M. US Eastern Standard Time, acklin@gmail. com writes:
             

            Hi All-
            Using and trying to QSO with...
            Rocky 3.6, USB synth, RxTx 6.3 on 9v DC supply.

            When I do the I/Q tx balance, I can get deep nulls OK. When I transmit using tone, or PSK, I can be anywhere in the band! Example- I transmitted at 7.060 PSK, and the my inline counter had me at 7.010. It's not consistent, or even transmits in the same place, not a fixed offset, etc. Sometimes it's right, most of the time not.

            I've verified the counter by using the main rig, same results.

            RF knocking the frequency off could be a possibilty, but the receive seems to be stable. (e.g. WWV is right on freq.)

            Any ideas?

            73
            Larry
            KB3CUF



          • Larry Acklin
            Speaking of grounding... I have the RxTx6.3 in a diecast alum box. It is totally floating with respect to the box (isolated BNC, power, etc.) What common
            Message 5 of 6 , Mar 15, 2010
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              Speaking of grounding...
               
              I have the RxTx6.3 in a diecast alum box.  It is totally floating with respect to the box (isolated BNC, power, etc.)  What common point should I bond to the box?  I'm thinking DC 0V, and no other?
               
              Larry
              KB3CUF

              On Mon, Mar 15, 2010 at 12:53 AM, Mr Doug - <dsc3507@...> wrote:
               

              If you have the antenna isolated properly that voltage should make no difference. The antenna is isolated from ground in the Softrocks by virtue of being a winding on the input toroid. As long as you do not connect it to the softrock ground it will be isolated. Using a metal chassis that is connected to the Sofrock ground with a coax connector (BNC, UHF, etc.)  mounted on it defeats this isolation. You should do something to make sure it is isolated. I use isolated BNC connectors. The shell is insulated from the mounting screw. You could also use insulated washers, screw terminals with an adapter to a coax fitting, etc.

              Keeping the antenna isolated is probably one of the most important things with the Softrocks because invariably it is grounded elsewhere. In fact for coax systems it should be grounded where it enters the house for lightning protection. Since this ground is at some other place on your property then the computer ground it will have potential difference.  1.5 volts is not uncommon. It could be more. Most people do not bond grounds together which should be done for safety reason. An example would be that you have an outside antenna and where it enters the house you have a ground rod which the shield of the coax is bonded to. In your hamshack you have everything grounded using the house electrical ground. You would think that since the house ground which uses a ground rod and the antenna ground which also uses a ground rod would be at the same potential but that is usually not the case. It depends on how close the ground rods are to each other, the ground resistance, and a whole host of other things. Bonding these two ground rods together (as well as any others) with at least #6 copper will mostly solve the problem and also reduce the chance of arcing and big potential differences in a lightning hit.

              Doug



              From: Larry Acklin <acklin@...>
              To: softrock40@yahoogroups.com
              Sent: Sun, March 14, 2010 11:08:04 PM
              Subject: Re: [softrock40] Rocky transmits where it wants.

               

              OK, I get it.  I think my antenna system is at fault.  I have about 1.5V of AC between the coax shield and my building ground.  If I hook up the antenna, I get a big spike at 0.  Listening to the audio I can hear the hum.  Time to re-route coax and check grounds...
               
              Larry

              On Mon, Mar 15, 2010 at 2:32 AM, <aa9wqham@aol. com> wrote:
               

              You can't measure frequency using PSK31. Use a constant carrier like AM. You can do it with a constant tone. But you have to add or subtract the tone value from the reading depending on upper or lower SSB.
               
              Larry 
               
              In a message dated 3/14/2010 9:03:43 P.M. US Eastern Standard Time, acklin@gmail. com writes:
               

              Hi All-
              Using and trying to QSO with...
              Rocky 3.6, USB synth, RxTx 6.3 on 9v DC supply.

              When I do the I/Q tx balance, I can get deep nulls OK. When I transmit using tone, or PSK, I can be anywhere in the band! Example- I transmitted at 7.060 PSK, and the my inline counter had me at 7.010. It's not consistent, or even transmits in the same place, not a fixed offset, etc. Sometimes it's right, most of the time not.

              I've verified the counter by using the main rig, same results.

              RF knocking the frequency off could be a possibilty, but the receive seems to be stable. (e.g. WWV is right on freq.)

              Any ideas?

              73
              Larry
              KB3CUF




            • Mr Doug -
              The power ground, audio ground, and USB ground are all connected together in the SofRock. Since the audio and USB are (hopefully) common grounded at the
              Message 6 of 6 , Mar 15, 2010
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                The power ground, audio ground, and USB ground are all connected together in the SofRock. Since the audio and USB are (hopefully) common grounded at  the computer, you should also isolated the power ground. If you are using a wall wart power source this is probably the case but if you are using a power supply that has its negative lead connected to ground at some other point then that would not be the case. This may or may not be a problem. I have always used a wall wart here. The case ground that the Sofrock card is mounted in is connected to the softrock ground, the antenna ground is isolated from the case. Wall warts have their own issues in that they often are not very well filtered. I usually put a 1000uf electrolytic across the power inside the box. I have seen ripple as bad as a volt or more on 12 volts on some of them. You would like it to be in the low millivolt range if possible. 



                From: Larry Acklin <acklin@...>
                To: softrock40@yahoogroups.com
                Sent: Mon, March 15, 2010 9:04:41 AM
                Subject: Re: [softrock40] Rocky transmits where it wants.

                 

                Speaking of grounding...
                 
                I have the RxTx6.3 in a diecast alum box.  It is totally floating with respect to the box (isolated BNC, power, etc.)  What common point should I bond to the box?  I'm thinking DC 0V, and no other?
                 
                Larry
                KB3CUF

                On Mon, Mar 15, 2010 at 12:53 AM, Mr Doug - <dsc3507@yahoo. com> wrote:
                 

                If you have the antenna isolated properly that voltage should make no difference. The antenna is isolated from ground in the Softrocks by virtue of being a winding on the input toroid. As long as you do not connect it to the softrock ground it will be isolated. Using a metal chassis that is connected to the Sofrock ground with a coax connector (BNC, UHF, etc.)  mounted on it defeats this isolation. You should do something to make sure it is isolated. I use isolated BNC connectors. The shell is insulated from the mounting screw. You could also use insulated washers, screw terminals with an adapter to a coax fitting, etc.

                Keeping the antenna isolated is probably one of the most important things with the Softrocks because invariably it is grounded elsewhere. In fact for coax systems it should be grounded where it enters the house for lightning protection. Since this ground is at some other place on your property then the computer ground it will have potential difference.  1.5 volts is not uncommon. It could be more. Most people do not bond grounds together which should be done for safety reason. An example would be that you have an outside antenna and where it enters the house you have a ground rod which the shield of the coax is bonded to. In your hamshack you have everything grounded using the house electrical ground. You would think that since the house ground which uses a ground rod and the antenna ground which also uses a ground rod would be at the same potential but that is usually not the case. It depends on how close the ground rods are to each other, the ground resistance, and a whole host of other things. Bonding these two ground rods together (as well as any others) with at least #6 copper will mostly solve the problem and also reduce the chance of arcing and big potential differences in a lightning hit.

                Doug



                From: Larry Acklin <acklin@gmail. com>
                To: softrock40@yahoogro ups.com
                Sent: Sun, March 14, 2010 11:08:04 PM
                Subject: Re: [softrock40] Rocky transmits where it wants.

                 

                OK, I get it.  I think my antenna system is at fault.  I have about 1.5V of AC between the coax shield and my building ground.  If I hook up the antenna, I get a big spike at 0.  Listening to the audio I can hear the hum.  Time to re-route coax and check grounds...
                 
                Larry

                On Mon, Mar 15, 2010 at 2:32 AM, <aa9wqham@aol. com> wrote:
                 

                You can't measure frequency using PSK31. Use a constant carrier like AM. You can do it with a constant tone. But you have to add or subtract the tone value from the reading depending on upper or lower SSB.
                 
                Larry 
                 
                In a message dated 3/14/2010 9:03:43 P.M. US Eastern Standard Time, acklin@gmail. com writes:
                 

                Hi All-
                Using and trying to QSO with...
                Rocky 3.6, USB synth, RxTx 6.3 on 9v DC supply.

                When I do the I/Q tx balance, I can get deep nulls OK. When I transmit using tone, or PSK, I can be anywhere in the band! Example- I transmitted at 7.060 PSK, and the my inline counter had me at 7.010. It's not consistent, or even transmits in the same place, not a fixed offset, etc. Sometimes it's right, most of the time not.

                I've verified the counter by using the main rig, same results.

                RF knocking the frequency off could be a possibilty, but the receive seems to be stable. (e.g. WWV is right on freq.)

                Any ideas?

                73
                Larry
                KB3CUF





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