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SDR Tools to be developped

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  • Jean-Paul Louis
    Hello All, I have been lurking into this group for several years now, and I am building my station from scratch. To get experience with the kits, I am
    Message 1 of 7 , Dec 10, 2013
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      Hello All,
      I have been lurking into this group for several years now, and I am building
      my station from scratch.
      To get experience with the kits, I am designing a small RF generator that will become a kit if there is interest. 
      It is based around the SI570, will cover from below 300 kHz to 160 MHz(CMOS chip), or 1400 MHz (LVDS chip).
      Level would be adjustable from S9+50dB down to S0, and an optional filter bank would allow the output to be a sine wave for testing receivers without harmonics of the RF signal.
      the kit will have a push button and a rotary encoder to set Frequency and level with a display 16x2 characters, or no rotary encoder but scroll buttons.
      Will be powered by a battery, and USB or RS232 interface will allow external control.

      Please send feedback to my email address : Jean-Paul at SDR4U dot com,
      as I do not want to clutter this group.

      Jean-Paul
      AC9GH
      EN61vr99



    • Sid Boyce
      Great idea Jean-Paul. I have the K5BCQ si570 Controller with the SR v6.3 and a set of +12V relay switched BPF s that I am thinking of putting together to use
      Message 2 of 7 , Dec 11, 2013
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        Great idea Jean-Paul.

        I have the K5BCQ si570 Controller with the SR v6.3 and a set of +12V relay switched BPF's that I am thinking of putting together to use with a switched attenuator box.

        My Marconi synthesized signal generator ceased putting out RF and I haven't got around to fault finding on it.

        Such a unit even as a standby would be quite useful and much cheaper than the Elecraft XG3.
        There are also many guys without a signal generator of any kind.
        73 ... Sid.

        On 11/12/13 04:15, Jean-Paul Louis wrote:
         

        Hello All,

        I have been lurking into this group for several years now, and I am building
        my station from scratch.
        To get experience with the kits, I am designing a small RF generator that will become a kit if there is interest. 
        It is based around the SI570, will cover from below 300 kHz to 160 MHz(CMOS chip), or 1400 MHz (LVDS chip).
        Level would be adjustable from S9+50dB down to S0, and an optional filter bank would allow the output to be a sine wave for testing receivers without harmonics of the RF signal.
        the kit will have a push button and a rotary encoder to set Frequency and level with a display 16x2 characters, or no rotary encoder but scroll buttons.
        Will be powered by a battery, and USB or RS232 interface will allow external control.

        Please send feedback to my email address : Jean-Paul at SDR4U dot com,
        as I do not want to clutter this group.

        Jean-Paul
        AC9GH
        EN61vr99





        -- 
        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
        
      • Clif Holland
        While the chips mentioned can do what is proposed and the filters built to convert to a sine wave I still have questions. How are you going to get the
        Message 3 of 7 , Dec 11, 2013
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          While the chips mentioned can do what is proposed and the filters built to
          convert to a sine wave I still have questions. How are you going to get the
          isolation in the level setting stages? To take a ~-23dBm signal down to
          below -130dBm requires some serious shielding and isolation between steps. A
          simple wafer switch and a handfull of resistors won't work. Look at the
          insides of the Marconi for how they did it. I've never seen the insides of a
          Marconi but I've seen several HP's and I'm sure it's about the same.

          Clif Holland KA5IPF
          www.avvid.com




          ----- Original Message -----
          From: "Sid Boyce" <sboyce@...>
          To: <softrock40@yahoogroups.com>
          Sent: Wednesday, December 11, 2013 5:38 AM
          Subject: Re: [softrock40] SDR Tools to be developped


          > Great idea Jean-Paul.
          >
          > I have the K5BCQ si570 Controller with the SR v6.3 and a set of +12V
          > relay switched BPF's that I am thinking of putting together to use with
          > a switched attenuator box.
          >
          > My Marconi synthesized signal generator ceased putting out RF and I
          > haven't got around to fault finding on it.
          >
          > Such a unit even as a standby would be quite useful and much cheaper
          > than the Elecraft XG3.
          > There are also many guys without a signal generator of any kind.
          > 73 ... Sid.
          >
          > On 11/12/13 04:15, Jean-Paul Louis wrote:
          >>
          >> Hello All,
          >>
          >> I have been lurking into this group for several years now, and I am
          >> building
          >> my station from scratch.
          >> To get experience with the kits, I am designing a small RF generator
          >> that will become a kit if there is interest.
          >> It is based around the SI570, will cover from below 300 kHz to 160
          >> MHz(CMOS chip), or 1400 MHz (LVDS chip).
          >> Level would be adjustable from S9+50dB down to S0, and an optional
          >> filter bank would allow the output to be a sine wave for testing
          >> receivers without harmonics of the RF signal.
          >> the kit will have a push button and a rotary encoder to set Frequency
          >> and level with a display 16x2 characters, or no rotary encoder but
          >> scroll buttons.
          >> Will be powered by a battery, and USB or RS232 interface will allow
          >> external control.
          >>
          >> Please send feedback to my email address : Jean-Paul at SDR4U dot com,
          >> as I do not want to clutter this group.
          >>
          >> *Jean-Paul*
          >> AC9GH
          >> EN61vr99
          >>
          >>
          >>
          >>
          >
          >
          > --
          > 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
          >
          >
        • vbifyz
          Another problem is harmonics. It is difficult to filter out odd harmonics of the square wave so it looks like a sine wave. To do this for a wide range of
          Message 4 of 7 , Dec 11, 2013
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            Another problem is harmonics. It is difficult to filter out odd harmonics of the square wave so it looks like a sine wave. To do this for a wide range of frequencies is a real challenge.

            Much easier starting point is a low cost DDS board from e-Bay, based on AD9850, like this one:

            http://www.ebay.com/itm/1pcs-DDS-Signal-Generator-Module-AD9850-0-40Mhz-Sine-Square-Wave-/370702915726?pt=LH_DefaultDomain_0&hash=item564f9d988e


            73, Mike

          • Sid Boyce
            Band pass filters should help. As a matter of fact I have a AD9851 DDS Function Signal Generator 0 - 50MHz DDS signal source DDS Module which I could use.
            Message 5 of 7 , Dec 11, 2013
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              Band pass filters should help.
              As a matter of fact I have a AD9851 DDS Function Signal Generator 0 - 50MHz DDS signal source DDS Module which I could use.

              Terminating it in 50 ohms gave a very low output on the scope but S9 only requires 50 uV.
              73 ... Sid.

              On 11/12/13 22:35, 3ym3ym@... wrote:
               

              Another problem is harmonics. It is difficult to filter out odd harmonics of the square wave so it looks like a sine wave. To do this for a wide range of frequencies is a real challenge.

              Much easier starting point is a low cost DDS board from e-Bay, based on AD9850, like this one:

              http://www.ebay.com/itm/1pcs-DDS-Signal-Generator-Module-AD9850-0-40Mhz-Sine-Square-Wave-/370702915726?pt=LH_DefaultDomain_0&hash=item564f9d988e


              73, Mike



              -- 
              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
              
            • Sid Boyce
              I also thought of amplification for standalone testing of power amplifiers. 73 ... Sid. ... -- Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
              Message 6 of 7 , Dec 11, 2013
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                I also thought of amplification for standalone testing of power amplifiers.
                73 ... Sid.

                On 11/12/13 23:40, Sid Boyce wrote:
                 

                Band pass filters should help.
                As a matter of fact I have a AD9851 DDS Function Signal Generator 0 - 50MHz DDS signal source DDS Module which I could use.

                Terminating it in 50 ohms gave a very low output on the scope but S9 only requires 50 uV.
                73 ... Sid.

                On 11/12/13 22:35, 3ym3ym@... wrote:
                 

                Another problem is harmonics. It is difficult to filter out odd harmonics of the square wave so it looks like a sine wave. To do this for a wide range of frequencies is a real challenge.

                Much easier starting point is a low cost DDS board from e-Bay, based on AD9850, like this one:

                http://www.ebay.com/itm/1pcs-DDS-Signal-Generator-Module-AD9850-0-40Mhz-Sine-Square-Wave-/370702915726?pt=LH_DefaultDomain_0&hash=item564f9d988e


                73, Mike



                -- 
                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
                


                -- 
                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
                
              • Jean-Paul Louis
                Mike, A DDS will be a lot worse than a square wave because of the huge amount of spurious near the carrier. Those will be almost impossible to remove. A
                Message 7 of 7 , Dec 11, 2013
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                  Mike,
                  A DDS will be a lot worse than a square wave because of the huge amount of spurious near the carrier. Those will be almost impossible to remove.

                  A careful design of switchable low-pass filters covering octave of frequency.
                  LP 1MHz, 2MHz, 4MHz, 8MHz, 16MHz, 32MHz, 64MHz, 128MHz, etc..
                  is a lot more feasible than trying to find and remove the spurious signals of the DDS.
                  The LP filters will be of Cauer type to improve the suppression of 3rd harmonic and others by more than 45dB.
                  But please, do not clutter this group as this is off-topic for SDR.

                  73,
                  Jean-Paul
                  AC9GH
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