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FW: ensemble 2 attenuator

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  • Glen
    Hello, I have wondered about the low signal coming out of the ensemble 2, and have an intermittent in the board somewhere. It got me poking around with a
    Message 1 of 5 , Jun 21, 2013
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      Hello,

      I have wondered about the low signal coming out of the ensemble 2, and have
      an intermittent in the
      board somewhere.

      It got me poking around with a generator and a scope. The signal goes
      through the first multiplexer
      and out up to the input of the attenuator. Apparently, two attenuators are
      used, one for 1-4Mhz
      and one for 4-8Mhz. However, the signal is almost unreadable on the scope
      on the output side of
      the attenuator.

      A little calculation shows the attenuator is 14db. I am wondering why,
      since there is no attenuator
      on the other two filters???

      73's

      Glen K4KV
    • Tony Parks
      Hi Glen, The attenuators in the lower frequency bands are there because of early experience with the SoftRock receiver design. It was found that the receiver
      Message 2 of 5 , Jun 21, 2013
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        Hi Glen,

        The attenuators in the lower frequency bands are there because of early experience with the SoftRock receiver design.  It was found that the receiver overloads on the lower frequency bands when used in Europe where where distances are "short" and some signals are big.   The attenuators could be taken out by removing the resistors and replacing the 120 ohm resistors with jumpers.

        I would be happy to send you another FST3253 in a letter later today.  Just send me your mailing address.

        What IF frequency  are you dealing with?

        73,
        --
        Tony Parks
        kb9yig@...
        http://fivedash.com
        


        On Fri, 2013-06-21 at 10:54 -0400, Glen wrote:
         
        Hello,

        I have wondered about the low signal coming out of the ensemble 2, and have
        an intermittent in the
        board somewhere.

        It got me poking around with a generator and a scope. The signal goes
        through the first multiplexer
        and out up to the input of the attenuator. Apparently, two attenuators are
        used, one for 1-4Mhz
        and one for 4-8Mhz. However, the signal is almost unreadable on the scope
        on the output side of
        the attenuator.

        A little calculation shows the attenuator is 14db. I am wondering why,
        since there is no attenuator
        on the other two filters???

        73's

        Glen K4KV




      • Tony Parks
        Hi Glen, I see where you have order a Lite II with an IF crystal. I will include an extra FST3253 in the envelope with your Lite II kit that is to be mailed
        Message 3 of 5 , Jun 21, 2013
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          Hi Glen,

          I see where you have order a Lite II with an IF crystal.  I will include an extra FST3253 in the envelope with your Lite II kit that is to be mailed later today.

          Thanks and 73,
          --
          Tony Parks
          kb9yig@...
          http://fivedash.com
          


          On Fri, 2013-06-21 at 10:54 -0400, Glen wrote:
           
          Hello,

          I have wondered about the low signal coming out of the ensemble 2, and have
          an intermittent in the
          board somewhere.

          It got me poking around with a generator and a scope. The signal goes
          through the first multiplexer
          and out up to the input of the attenuator. Apparently, two attenuators are
          used, one for 1-4Mhz
          and one for 4-8Mhz. However, the signal is almost unreadable on the scope
          on the output side of
          the attenuator.

          A little calculation shows the attenuator is 14db. I am wondering why,
          since there is no attenuator
          on the other two filters???

          73's

          Glen K4KV




        • Glen
          Tony, Taking the chip off of U8, and jumpering over U8 and replacing U10 did not fix the problem. Something else is wrong...hold off for the moment. And it
          Message 4 of 5 , Jun 21, 2013
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            Tony,
             
            Taking the chip off of U8, and jumpering over U8 and replacing U10 did not fix the problem.  Something else is wrong...hold off for
            the moment.  And it was working so well :-(
             
            I need to learn about the circuit to trouble shoot it.  I figure that the quadrature clocks rapidly switch the 8.215Mhz signals on and off
            at an extremely high rate, run through a filter to the op amp.  Somehow this acts similar to a mixer and produces a broadband
            audio response.  Have not wrapped my head around that yet...
             
            Given that  the inputs on pins 11 and 12 of the QSD chip were 50mv, I would have thought I would see a corresponding amplitude on
            the output.  I know that is extreme overload, but that overload is not making it to the sound card.
             
            73's
             
            Glen K4KV
             
            -----Original Message-----
            From: softrock40@yahoogroups.com [mailto:softrock40@yahoogroups.com]On Behalf Of Tony Parks
            Sent: Friday, June 21, 2013 11:33 AM
            To: softrock40@yahoogroups.com
            Subject: Re: [softrock40] FW: ensemble 2 attenuator

             

            Hi Glen,

            The attenuators in the lower frequency bands are there because of early experience with the SoftRock receiver design.  It was found that the receiver overloads on the lower frequency bands when used in Europe where where distances are "short" and some signals are big.   The attenuators could be taken out by removing the resistors and replacing the 120 ohm resistors with jumpers.

            I would be happy to send you another FST3253 in a letter later today.  Just send me your mailing address.

            What IF frequency  are you dealing with?

            73,

            --
            Tony Parks
            kb9yig@...
            http://fivedash.com
            


            On Fri, 2013-06-21 at 10:54 -0400, Glen wrote:
            Hello,

            I have wondered about the low signal coming out of the ensemble 2, and have
            an intermittent in the
            board somewhere.

            It got me poking around with a generator and a scope. The signal goes
            through the first multiplexer
            and out up to the input of the attenuator. Apparently, two attenuators are
            used, one for 1-4Mhz
            and one for 4-8Mhz. However, the signal is almost unreadable on the scope
            on the output side of
            the attenuator.

            A little calculation shows the attenuator is 14db. I am wondering why,
            since there is no attenuator
            on the other two filters???

            73's

            Glen K4KV




          • Glen
            Thanks Tony, I really never needed the Ensemble 2 for a panadapter. I will try the Lite II and see how she works. I am going to try and find some HDSDR
            Message 5 of 5 , Jun 21, 2013
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              Thanks Tony, I really never needed the Ensemble 2 for a panadapter.  I will try the Lite II and see how she works.
               
              I am going to try and find some HDSDR information on how to set up the Lite II...
               
              73's
               
              Glen K4KV
               
              -----Original Message-----
              From: softrock40@yahoogroups.com [mailto:softrock40@yahoogroups.com]On Behalf Of Tony Parks
              Sent: Friday, June 21, 2013 12:08 PM
              To: softrock40@yahoogroups.com
              Subject: Re: [softrock40] FW: ensemble 2 attenuator

               

              Hi Glen,

              I see where you have order a Lite II with an IF crystal.  I will include an extra FST3253 in the envelope with your Lite II kit that is to be mailed later today.

              Thanks and 73,

              --
              Tony Parks
              kb9yig@...
              http://fivedash.com
              


              On Fri, 2013-06-21 at 10:54 -0400, Glen wrote:
              Hello,

              I have wondered about the low signal coming out of the ensemble 2, and have
              an intermittent in the
              board somewhere.

              It got me poking around with a generator and a scope. The signal goes
              through the first multiplexer
              and out up to the input of the attenuator. Apparently, two attenuators are
              used, one for 1-4Mhz
              and one for 4-8Mhz. However, the signal is almost unreadable on the scope
              on the output side of
              the attenuator.

              A little calculation shows the attenuator is 14db. I am wondering why,
              since there is no attenuator
              on the other two filters???

              73's

              Glen K4KV




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