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"Upper" and "lower" base frequencies

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  • martinezjohnnie
    Hello, The PSR-500 and BCD396XT both require upper and lower base frequency settings when creating custom tables or bandplans for Motorola UHF systems
    Message 1 of 6 , Apr 27, 2009
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      Hello,

      The PSR-500 and BCD396XT both require "upper" and "lower" base frequency settings when creating "custom tables" or "bandplans" for Motorola UHF systems (and rebanded 800 MHz systems).

      The Radioreference guide generally only identifies one base frequency (presumably the "lower" one) for these systems.

      How does one go about calculating the "upper" base frequency? Is there a formula for doing so?

      Thanks!

      -Johnnie
    • uniden.upman
      Oddly enough, the answer is the same on both lists :) : For Uniden models, you can use:
      Message 2 of 6 , Apr 27, 2009
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        Oddly enough, the answer is the same on both lists :) :

        For Uniden models, you can use:

        http://info.uniden.com/twiki/bin/view/UnidenMan4/CalculatingUpperBaseFrequencies

        (There is a handy Excel spreadsheet at the bottom of that page.)

        I don't know of a similar resource for the PSRs.

        UPMan

        --- In BCD396XT@yahoogroups.com, "martinezjohnnie" <kc5igh@...> wrote:
        >
        > Hello,
        >
        > The PSR-500 and BCD396XT both require "upper" and "lower" base frequency settings when creating "custom tables" or "bandplans" for Motorola UHF systems (and rebanded 800 MHz systems).
        >
        > The Radioreference guide generally only identifies one base frequency (presumably the "lower" one) for these systems.
        >
        > How does one go about calculating the "upper" base frequency? Is there a formula for doing so?
        >
        > Thanks!
        >
        > -Johnnie
        >
      • Richard A. Victor
        The values from RR are in MHz for the Base Frequency and kHz for the Step (or Spacing). Be sure to change the Step to MHz when using the Uniden supplied
        Message 3 of 6 , Apr 27, 2009
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          The values from RR are in MHz for the Base Frequency and kHz for the
          Step (or Spacing). Be sure to change the Step to MHz when using the
          Uniden supplied formula. The failure to do this will result in
          calculations such as

          UpperBase = 480.500 + ((759 - 380) * 12.5) =

          480.500 + (379 * 12.5) = 5218 rather than

          480.500 + (379 * .0125) = 485.2375

          The spreadsheet does it for you automatically.

          Dick (who still remembers his high school physics teacher who was a
          stickler for getting the units right when working with formulas).

          At 10:33 AM 4/27/2009, you wrote:
          >Oddly enough, the answer is the same on both lists :) :
          >
          >For Uniden models, you can use:
          >
          >http://info.uniden.com/twiki/bin/view/UnidenMan4/CalculatingUpperBaseFrequencies
          >
          >(There is a handy Excel spreadsheet at the bottom of that page.)
          >
          >I don't know of a similar resource for the PSRs.
          >
          >UPMan
          >
          >--- In BCD396XT@yahoogroups.com, "martinezjohnnie" <kc5igh@...> wrote:
          > >
          > > Hello,
          > >
          > > The PSR-500 and BCD396XT both require "upper" and "lower" base
          > frequency settings when creating "custom tables" or "bandplans" for
          > Motorola UHF systems (and rebanded 800 MHz systems).
          > >
          > > The Radioreference guide generally only identifies one base
          > frequency (presumably the "lower" one) for these systems.
          > >
          > > How does one go about calculating the "upper" base frequency? Is
          > there a formula for doing so?
          > >
          > > Thanks!
          > >
          > > -Johnnie
        • martinezjohnnie
          It looks like I should have navigated a little further into the on-line manual. Thanks for the information, Paul, and sincere thanks for all you ve
          Message 4 of 6 , Apr 27, 2009
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            It looks like I should have navigated a little further into the on-line manual.

            Thanks for the information, Paul, and sincere thanks for all you've individually done to drive scanner technology to the level we all enjoy today!

            -Johnnie
          • martinezjohnnie
            Thanks,Dick. I ve printed your comments and Paul s reference for deeper study tonight. I want to understand the design principles behind these band plans a
            Message 5 of 6 , Apr 27, 2009
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              Thanks,Dick.

              I've printed your comments and Paul's reference for deeper study tonight.

              I want to understand the design principles behind these band plans a little better than I do at present. Until then, I'll do the best I can to do the math correctly.

              I have this nagging feeling that I could drive this car a little better if I understood what was happening under the hood!

              Thanks again.

              -Johnnie
            • Richard A. Victor
              Maybe we re better off not knowing what s going on under the hood. It might be like the saying about two things that you shouldn t watch--making laws and
              Message 6 of 6 , Apr 27, 2009
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                Maybe we're better off not knowing what's going on under the
                hood. It might be like the saying about two things that you
                shouldn't watch--making laws and making sausage. :-) I doubt it though.

                Dick

                At 06:38 PM 4/27/2009, you wrote:
                >Thanks,Dick.
                >
                >I've printed your comments and Paul's reference for deeper study tonight.
                >
                >I want to understand the design principles behind these band plans a
                >little better than I do at present. Until then, I'll do the best I
                >can to do the math correctly.
                >
                >I have this nagging feeling that I could drive this car a little
                >better if I understood what was happening under the hood!
                >
                >Thanks again.
                >
                >-Johnnie
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