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Re: [softrock40] Re: Daughter board on SR 15/17m

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  • Jose Bonanca
    Hi Paul, no I don t get around 84450KHz the most i got was 79230 UNSTABLE so I guess there must be an error somewhere. I got this reading with 7 turns when i
    Message 1 of 12 , Dec 1, 2007
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      Hi Paul,
       
      no I don't get around 84450KHz the most i got was 79230 UNSTABLE so I guess there must be an error somewhere.
      I got this reading with 7 turns when i reached 6 turns the oscillator stopped.
      The total amount is 9 turns... As I don't have an impedance meter I am done. can't see what else casn be wrong
       
      Can your give me some more suggestions.
      Thanks for the help.
      73 de Jose

      On Dec 1, 2007 12:05 PM, Paul Kiciak <paul@...> wrote:

      Hi Jose,



      > Paul I do not have the crystal for 17m however
      > i do have two crystal for 15m 28060 and 28224.
      > What would be the recommended tuning frequency
      > please.

      For 15m operation only, I'd recommend tuning
      the tank with the 1000 pF capacitor across the
      selected crystal to about 3*28150 = 84450 kHz
      within about 500 kHz.

      I suppose you could also probe one of the 74AC74
      outputs and then you would be looking for about
      21100 kHz within about 125 kHz.


      > I'm afraid some transistor is again not working
      > because I get 48000 to 50000 not stable and
      > 62000 with the 1k capacitor.

      62 MHz with the capacitor is too low. I'd guess
      you will have to take a turn or two off the inductor
      before you can tune it to 84.45 MHz by moving the
      turns about on the core.

      Hopefully after that, the frequency will be stable
      with the crystals that you have.

      73
      Paul N2PK




      --
      Jose Bonanca  (CT1aos)
    • mikecol2
      ... I guess ... am done. ... Hi Jose, I was playing around with the 15m/17m oscillator board (N2PK) today and have some data for you. With the suggested 9
      Message 2 of 12 , Dec 1, 2007
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        > no I don't get around 84450KHz the most i got was 79230 UNSTABLE so
        I guess
        > there must be an error somewhere.
        > I got this reading with 7 turns when i reached 6 turns the oscillator
        > stopped.
        > The total amount is 9 turns... As I don't have an impedance meter I
        am done.
        > Can your give me some more suggestions.

        Hi Jose,

        I was playing around with the 15m/17m oscillator board (N2PK) today
        and have some data for you.
        With the suggested 9 turns I measured .26uH on my AADE L/C meter.
        With that coil (L100) in place my oscillator measured:
        w 1800 pf cap: 71Mhz
        w 1500 pf cap: 71.4Mhz
        w 470 pf cap: 72.7Mhz
        w 100 pf cap: 76.4Mhz
        w 28.06 XTAL: 84.25Mhz
        w 28.224 XTAL: 84.73Mhz

        The cylinder 28Mhz XTAL Tony gave us to try didn't oscillate with the
        stock 9T coil.

        Just to compare my 20m/30m: it resonated at about 46Mhz. Using the
        tank circuit of .43uH (spec'ed) with the 12pf the calculated
        additional Cexternal is about 15pf.
        If you add this Cexternal of 15pf to the 6.8pf and .22uH for the
        15m/17m circuit it calculates out to a resonant freq of 73Mhz. This
        matches quite well to what I measured using the caps instead of the XTAL.

        Hope that help some. Summary: mine works fine with the stock 9T
        specified.

        73, Mike Collins KF4BQ
      • Jose Bonanca
        Thank you very much Mike. this is what i needed but now I think my Q101 is troubled because i am measuring 10V30 on the emitter. Nice data you get. will try
        Message 3 of 12 , Dec 1, 2007
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          Thank you very much Mike. this is what i needed but now I  think my Q101 is troubled because i am  measuring 10V30 on the emitter.
          Nice data you get. will try to replace Q101.
           
          Thanks
          73 de Jose.


           
          On Dec 1, 2007 7:54 PM, mikecol2 <mikecol@...> wrote:


          > no I don't get around 84450KHz the most i got was 79230 UNSTABLE so
          I guess
          > there must be an error somewhere.
          > I got this reading with 7 turns when i reached 6 turns the oscillator
          > stopped.
          > The total amount is 9 turns... As I don't have an impedance meter I
          am done.
          > Can your give me some more suggestions.

          Hi Jose,

          I was playing around with the 15m/17m oscillator board (N2PK) today
          and have some data for you.
          With the suggested 9 turns I measured .26uH on my AADE L/C meter.
          With that coil (L100) in place my oscillator measured:
          w 1800 pf cap: 71Mhz
          w 1500 pf cap: 71.4Mhz
          w 470 pf cap: 72.7Mhz
          w 100 pf cap: 76.4Mhz
          w 28.06 XTAL: 84.25Mhz
          w 28.224 XTAL: 84.73Mhz

          The cylinder 28Mhz XTAL Tony gave us to try didn't oscillate with the
          stock 9T coil.

          Just to compare my 20m/30m: it resonated at about 46Mhz. Using the
          tank circuit of .43uH (spec'ed) with the 12pf the calculated
          additional Cexternal is about 15pf.
          If you add this Cexternal of 15pf to the 6.8pf and .22uH for the
          15m/17m circuit it calculates out to a resonant freq of 73Mhz. This
          matches quite well to what I measured using the caps instead of the XTAL.

          Hope that help some. Summary: mine works fine with the stock 9T
          specified.

          73, Mike Collins KF4BQ




          --
          Jose Bonanca  (CT1aos)
        • mikecol2
          ... Q101 is ... No problem. Hope you get the circuit up and running!! You probably know already but the emitters of Q100 and Q101 are biased about 5.3V or so
          Message 4 of 12 , Dec 1, 2007
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            > Thank you very much Mike. this is what i needed but now I think my
            Q101 is
            > troubled because i am measuring 10V30 on the emitter.
            > Nice data you get. will try to replace Q101.

            No problem. Hope you get the circuit up and running!!

            You probably know already but the emitters of Q100 and Q101 are biased
            about 5.3V or so ( i.e. 12V supply divided by 2 (from base resistor
            divider) and down another .7 (Vbe of transistor) ).


            73, Mike Collins KF4BQ
          • Jose Bonanca
            yes Mike...I got the unit working now. It reads 84255.1KHz. Very good. Many thanks. Regards jose ... -- Jose Bonanca (CT1aos)
            Message 5 of 12 , Dec 1, 2007
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              yes Mike...I got the unit working now.
              It reads 84255.1KHz.
              Very good.
              Many thanks.
              Regards
              jose

              On Dec 1, 2007 8:19 PM, mikecol2 <mikecol@...> wrote:

              > Thank you very much Mike. this is what i needed but now I think my
              Q101 is
              > troubled because i am measuring 10V30 on the emitter.
              > Nice data you get. will try to replace Q101.

              No problem. Hope you get the circuit up and running!!

              You probably know already but the emitters of Q100 and Q101 are biased
              about 5.3V or so ( i.e. 12V supply divided by 2 (from base resistor
              divider) and down another .7 (Vbe of transistor) ).

              73, Mike Collins KF4BQ




              --
              Jose Bonanca  (CT1aos)
            • Paul Kiciak
              Hi Jose, ... Not much. You could check voltages, I suppose, to see if they make sense. I don t know why the oscillator would quit with six turns. It seems that
              Message 6 of 12 , Dec 1, 2007
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                Hi Jose,

                >Can your give me some more suggestions.

                Not much. You could check voltages, I suppose,
                to see if they make sense. I don't know why
                the oscillator would quit with six turns.

                It seems that something is wrong since you
                report the frequency isn't stable but that
                depends on the range that you see too.

                As I say, I have had no experience with the
                17/15m kit so can't contribute much more.

                I did do a little work at 10m with
                a 112 MHz oscillation frequency. That had
                fewer turns yet and think I switched to an
                air core inductor. In any case, the oscillator
                shouldn't stop with six turns as you report,
                so it appears there is something wrong in the
                build.

                73,
                Paul N2PK
              • mikecol2
                ... Excellent!! Mine ended up at 84251.38Khz after everything was solder up correctly :) Short crystal (marked 28.2C76) ended up at 84731.94Khz. 73, Mike
                Message 7 of 12 , Dec 1, 2007
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                  >
                  > yes Mike...I got the unit working now.
                  > It reads 84255.1KHz.
                  > Very good.

                  Excellent!! Mine ended up at 84251.38Khz after everything was solder
                  up correctly :) Short crystal (marked 28.2C76) ended up at 84731.94Khz.

                  73, Mike Collins KF4BQ
                • Jose Bonanca
                  Fine Paul... I have the full unit working from a few minutes ago... I am already enjoying the band...Although its almost dead. Many thanks for your help. Won t
                  Message 8 of 12 , Dec 1, 2007
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                    Fine Paul...
                    I have the full unit working from a few minutes ago...
                    I am already enjoying the band...Although its almost dead.
                    Many thanks for your help.
                    Won't forget that.
                     
                    Regards
                    de Jose

                    On Dec 1, 2007 8:41 PM, Paul Kiciak <paul@...> wrote:

                    Hi Jose,



                    >Can your give me some more suggestions.

                    Not much. You could check voltages, I suppose,
                    to see if they make sense. I don't know why
                    the oscillator would quit with six turns.

                    It seems that something is wrong since you
                    report the frequency isn't stable but that
                    depends on the range that you see too.

                    As I say, I have had no experience with the
                    17/15m kit so can't contribute much more.

                    I did do a little work at 10m with
                    a 112 MHz oscillation frequency. That had
                    fewer turns yet and think I switched to an
                    air core inductor. In any case, the oscillator
                    shouldn't stop with six turns as you report,
                    so it appears there is something wrong in the
                    build.

                    73,
                    Paul N2PK




                    --
                    Jose Bonanca  (CT1aos)
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