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CW ?

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  • w4mmp
    Hi, I just recently finished a build of the RXTX. As I stated in previous post, I have a lot to learn about SDR. The latest issue I racked my brain over
    Message 1 of 10 , Dec 10, 2013
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      Hi,

          I just recently finished a build of the RXTX.  As I stated in previous post, I have a lot to learn about SDR.    The latest issue I racked my brain over was CW mode of transmission.  For quite some time I could not determine why the RXTX was not producing output when using Rocky in CW mode.   I thought for sure the PA section had a problem.  Long story short,  I finally decided to hook up the "line out".  This corrected the issue and the RXTX is outputting the full one watt.  So it appears to me the only way to use CW mode with the RXTX is to run MCW in J2A.  Is this true?  If so, while technically legal,  it is not the preferred method of CW transmissions.  Also again if true, was the RXTX designed not to be able to produce only carrier wave for CW mode?


      I can be "thick as a brick" at times :).   Please help clear up my confusion.


      73

      Ron / W4MMP

    • Alan
      ... Subject: [softrock40] CW ? ... Ron, MCW? Modulated Carrier Wave? As in AM or FM modulated by a tone? That s not produced by Rocky. It is a pure interrupted
      Message 2 of 10 , Dec 10, 2013
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        ----- Original Message -----
        Subject: [softrock40] CW ?


        >
        > For quite some time I could not determine why the RXTX was not producing output when using Rocky in CW mode. I thought for
        > sure the PA section had a problem. Long story short, I finally decided to hook up the "line out". This corrected the issue and
        > the RXTX is outputting the full one watt. So it appears to me the only way to use CW mode with the RXTX is to run MCW in J2A. Is
        > this true? If so, while technically legal, it is not the preferred method of CW transmissions. Also again if true, was the RXTX
        > designed not to be able to produce only carrier wave for CW mode?
        >
        >

        Ron,

        MCW? Modulated Carrier Wave? As in AM or FM modulated by a tone?

        That's not produced by Rocky. It is a pure interrupted carrier.

        73 Alan G4ZFQ
      • w4mmp
        Hi, Then why must line out be connected? I have just verified again, that no output will occur if line out is not connected. Everything works fine (cw,
        Message 3 of 10 , Dec 10, 2013
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          Hi,

             Then why must "line out" be connected?  I have just verified again, that no output will occur if line out is not connected.   Everything works fine (cw, paddle, iambic keying) when line out is connected.


          I'm still confused.


          73

          Ron  /  W4MMP

        • Dave Miller
          Ron, Without the line out the Ensemble does not work. The I/Q audio is an integral part of carrier generation. Without it you get no carrier. The PC or other
          Message 4 of 10 , Dec 10, 2013
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            Ron,
            Without the line out the Ensemble does not work. The I/Q audio is an integral part of carrier generation. Without it you get no carrier.
            The PC or other I/Q generation device ( STM32-SDR.com) is required.

            Dave
            VE7PKE


            On Tue, Dec 10, 2013 at 1:22 PM, <w4mmp@...> wrote:
             

            Hi,

               Then why must "line out" be connected?  I have just verified again, that no output will occur if line out is not connected.   Everything works fine (cw, paddle, iambic keying) when line out is connected.


            I'm still confused.


            73

            Ron  /  W4MMP


          • cbayona
            You need to read some articles on how SDR works but the simple explanation is as follows; 1. The Mixer ( 2 mixers and 2 clocks at 90 degree apart) to generate
            Message 5 of 10 , Dec 10, 2013
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              You need to read some articles on how SDR works but the simple
              explanation is as follows;

              1. The Mixer ( 2 mixers and 2 clocks at 90 degree apart) to generate
              the RF output is set to have the carrier fed into it, it's not at the
              right frequency to begin with anyway so the circuity is wired to
              cancel the clock source.

              2. This carrier is modulated by an two mixers one with I audio
              signal, the second mixer is modulated with the Q tones set 90 degrees
              apart from each other, the carriers used with the mixers are also at
              90 degrees from each other.

              3. The tone sets how far the sidebands are from the clock frequency
              RF clock at 1 MHz generates sidebands at 999KHz and 1001 KHz so if
              you wanted to move one KHz further away from the RF clock you would
              use a 2 KHz clock which generates 998 KHz and 1002 KHz with one of
              them being cancelled in the mixer output.

              4. Because of the circuitry when those mixer outputs are combined one
              of the RF outputs cancels so for argument lets say that only 1001
              KHz is not cancelled.

              5. Every time an 1KHz signal shows up then a 1001KHz signal appears
              on the output, this signal is a translation of the audio dignals on I
              and Q audio and the 1 MHz carrier clock.

              6. The audio is shaped as it's created so it rises in amplitude then
              after a while decays this ends generating a RF envelope 1t 1001Kz
              that has a proper rise and fall so there are no key clicks.

              7. If the I and Q signals are reversed then the 1001 signal is
              canceled and the 999KHz signal makes it out of the mixer, we just
              switched from USB to LSB signal.

              8. if the audio instead of being an amplitude shaped tone instead is
              the output of a microphone the we have sideband audio, but remember
              that the I and Q signals must be at 90 degrees apart no matter what
              the frequency is so the PC uses a special filter called a Hilbert
              Function to generate audio I and Q from a microphone.

              Either that or it's magic, there are several method used to generate
              the CW RF but this one is the one used in the Softrocks.

              At 03:22 PM 12/10/2013, you wrote:


              >Hi,
              >
              > Then why must "line out" be connected? I have just verified
              > again, that no output will occur if line out is not
              > connected. Everything works fine (cw, paddle, iambic keying) when
              > line out is connected.
              >
              >
              >I'm still confused.
              >
              >
              >73
              >
              >Ron / W4MMP
              >
              >
              >

              --
              Cecil - k5nwa
              < http://thepartsplace.k5nwa.com/ > < http://www.softrockradio.org/ >

              Never take life seriously. Nobody gets out alive anyway.
            • Sid Boyce
              I think the difficult bit, looking at the block diagram on http://www.wb5rvz.org/ensemble_rxtx/ is that it gives the false impression that with the key
              Message 6 of 10 , Dec 10, 2013
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                I think the difficult bit, looking at the block diagram on http://www.wb5rvz.org/ensemble_rxtx/ is that it gives the false impression that with the key connected that's all you need for CW TX and that the PC, software and sound card are not involved.
                73 ... Sid.

                On 10/12/13 22:37, cbayona wrote:
                 

                You need to read some articles on how SDR works but the simple
                explanation is as follows;

                1. The Mixer ( 2 mixers and 2 clocks at 90 degree apart) to generate
                the RF output is set to have the carrier fed into it, it's not at the
                right frequency to begin with anyway so the circuity is wired to
                cancel the clock source.

                2. This carrier is modulated by an two mixers one with I audio
                signal, the second mixer is modulated with the Q tones set 90 degrees
                apart from each other, the carriers used with the mixers are also at
                90 degrees from each other.

                3. The tone sets how far the sidebands are from the clock frequency
                RF clock at 1 MHz generates sidebands at 999KHz and 1001 KHz so if
                you wanted to move one KHz further away from the RF clock you would
                use a 2 KHz clock which generates 998 KHz and 1002 KHz with one of
                them being cancelled in the mixer output.

                4. Because of the circuitry when those mixer outputs are combined one
                of the RF outputs cancels so for argument lets say that only 1001
                KHz is not cancelled.

                5. Every time an 1KHz signal shows up then a 1001KHz signal appears
                on the output, this signal is a translation of the audio dignals on I
                and Q audio and the 1 MHz carrier clock.

                6. The audio is shaped as it's created so it rises in amplitude then
                after a while decays this ends generating a RF envelope 1t 1001Kz
                that has a proper rise and fall so there are no key clicks.

                7. If the I and Q signals are reversed then the 1001 signal is
                canceled and the 999KHz signal makes it out of the mixer, we just
                switched from USB to LSB signal.

                8. if the audio instead of being an amplitude shaped tone instead is
                the output of a microphone the we have sideband audio, but remember
                that the I and Q signals must be at 90 degrees apart no matter what
                the frequency is so the PC uses a special filter called a Hilbert
                Function to generate audio I and Q from a microphone.

                Either that or it's magic, there are several method used to generate
                the CW RF but this one is the one used in the Softrocks.

                At 03:22 PM 12/10/2013, you wrote:

                >Hi,
                >
                > Then why must "line out" be connected? I have just verified
                > again, that no output will occur if line out is not
                > connected. Everything works fine (cw, paddle, iambic keying) when
                > line out is connected.
                >
                >
                >I'm still confused.
                >
                >
                >73
                >
                >Ron / W4MMP
                >
                >
                >

                --
                Cecil - k5nwa
                < http://thepartsplace.k5nwa.com/ > < http://www.softrockradio.org/ >

                Never take life seriously. Nobody gets out alive anyway.



                -- 
                Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
                Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
                Senior Staff Specialist, Cricket Coach
                Microsoft Windows Free Zone - Linux used for all Computing Tasks
                
              • cbayona
                It clearly shows that the laptop audio is connected to the transmit audio on the SoftRock . It does not show what goes on inside the PC or the blocks but the
                Message 7 of 10 , Dec 10, 2013
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                  It clearly shows that the laptop audio is connected to the transmit
                  audio on the SoftRock . It does not show what goes on inside the PC
                  or the blocks but the audio out of the PC is connected to the audio
                  buffer of the transmit side, then on to the transmit mixer.

                  In any case some reading is required to truly understand what is going on.

                  <
                  <http://www.arrl.org/software-defined-radio>http://www.arrl.org/software-defined-radio
                  >

                  The above link is good reading on the basics on how an SDR radio
                  works, well at least one kind.

                  At 05:28 PM 12/10/2013, you wrote:


                  >I think the difficult bit, looking at the block diagram on
                  ><http://www.wb5rvz.org/ensemble_rxtx/>http://www.wb5rvz.org/ensemble_rxtx/
                  >is that it gives the false impression that with the key connected
                  >that's all you need for CW TX and that the PC, software and sound
                  >card are not involved.
                  >73 ... Sid.
                  >
                  >On 10/12/13 22:37, cbayona wrote:
                  >>
                  >>
                  >>You need to read some articles on how SDR works but the simple
                  >>explanation is as follows;
                  >>
                  >>1. The Mixer ( 2 mixers and 2 clocks at 90 degree apart) to generate
                  >>the RF output is set to have the carrier fed into it, it's not at the
                  >>right frequency to begin with anyway so the circuity is wired to
                  >>cancel the clock source.
                  >>
                  >>2. This carrier is modulated by an two mixers one with I audio
                  >>signal, the second mixer is modulated with the Q tones set 90 degrees
                  >>apart from each other, the carriers used with the mixers are also at
                  >>90 degrees from each other.
                  >>
                  >>3. The tone sets how far the sidebands are from the clock frequency
                  >>RF clock at 1 MHz generates sidebands at 999KHz and 1001 KHz so if
                  >>you wanted to move one KHz further away from the RF clock you would
                  >>use a 2 KHz clock which generates 998 KHz and 1002 KHz with one of
                  >>them being cancelled in the mixer output.
                  >>
                  >>4. Because of the circuitry when those mixer outputs are combined one
                  >>of the RF outputs cancels so for argument lets say that only 1001
                  >>KHz is not cancelled.
                  >>
                  >>5. Every time an 1KHz signal shows up then a 1001KHz signal appears
                  >>on the output, this signal is a translation of the audio dignals on I
                  >>and Q audio and the 1 MHz carrier clock.
                  >>
                  >>6. The audio is shaped as it's created so it rises in amplitude then
                  >>after a while decays this ends generating a RF envelope 1t 1001Kz
                  >>that has a proper rise and fall so there are no key clicks.
                  >>
                  >>7. If the I and Q signals are reversed then the 1001 signal is
                  >>canceled and the 999KHz signal makes it out of the mixer, we just
                  >>switched from USB to LSB signal.
                  >>
                  >>8. if the audio instead of being an amplitude shaped tone instead is
                  >>the output of a microphone the we have sideband audio, but remember
                  >>that the I and Q signals must be at 90 degrees apart no matter what
                  >>the frequency is so the PC uses a special filter called a Hilbert
                  >>Function to generate audio I and Q from a microphone.
                  >>
                  >>Either that or it's magic, there are several method used to generate
                  >>the CW RF but this one is the one used in the Softrocks.
                  >>
                  >>At 03:22 PM 12/10/2013, you wrote:
                  >>
                  >> >Hi,
                  >> >
                  >> > Then why must "line out" be connected? I have just verified
                  >> > again, that no output will occur if line out is not
                  >> > connected. Everything works fine (cw, paddle, iambic keying) when
                  >> > line out is connected.
                  >> >
                  >> >
                  >> >I'm still confused.
                  >> >
                  >> >
                  >> >73
                  >> >
                  >> >Ron / W4MMP
                  >> >
                  >> >
                  >> >
                  >>
                  >>--
                  >>Cecil - k5nwa
                  >>< http://thepartsplace.k5nwa.com/ > < http://www.softrockradio.org/ >
                  >>
                  >>Never take life seriously. Nobody gets out alive anyway.

                  --
                  Cecil - k5nwa
                  < http://thepartsplace.k5nwa.com/ > < http://www.softrockradio.org/ >

                  Never take life seriously. Nobody gets out alive anyway.
                • w4mmp
                  Hi, Yes, I can see I m seriously behind the curve on this. Thanks for the info. 73 Ron / W4MMP
                  Message 8 of 10 , Dec 10, 2013
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                    Hi,

                      Yes, I can see I'm seriously behind the curve on this.


                    Thanks for the info.


                    73

                    Ron / W4MMP

                  • Sid Boyce
                    We all had to start somewhere and trip over our own feet from time to time - situation normal. SDR demands a bit of a learning curve but that shouldn t stop
                    Message 9 of 10 , Dec 10, 2013
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                      We all had to start somewhere and trip over our own feet from time to time - situation normal.

                      SDR demands a bit of a learning curve but that shouldn't stop anyone from diving in and asking questions at any stage.

                      Help is always at hand so don't be afraid or feel too stupid to ask any relevant questions you have.
                      73 ... Sid.

                      On 11/12/13 01:55, w4mmp@... wrote:
                       

                      Hi,

                        Yes, I can see I'm seriously behind the curve on this.


                      Thanks for the info.


                      73

                      Ron / W4MMP



                      -- 
                      Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
                      Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
                      Senior Staff Specialist, Cricket Coach
                      Microsoft Windows Free Zone - Linux used for all Computing Tasks
                      
                    • w4mmp
                      Hi, OK, I did a mental reboot and studied SDR as it relates to the RXTX. I made seriously bad assumptions on how the transmit side works. I believe I now
                      Message 10 of 10 , Dec 13, 2013
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                        Hi,

                        OK,  I did a mental reboot and studied SDR as it relates to the RXTX.   I made seriously bad assumptions on how the transmit side works.   I believe I now have a handle on how this rig works.


                        So, other than Rocky and PowerSDR-I/Q are there any other SDR applications that support the RXTX "paddle" connection? I have searched the internet and found none, but that does not mean they don't exist.  


                        73

                        Ron / W4MMP

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