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Thread: Astro Spectra P25 receive audio

  1. #1
    deputy13 No Longer Registered

    Default Astro Spectra P25 receive audio

    I wonder if there is anything that can be done to the ASTRO Spectra to improve the receive audio. The P25 system I monitor is sometimes difficult to understand what they are saying. Is this just the codex in the ASTRO Spectra and I shouldn't expect anything better? I didn't see anything in the software unless I am missing a setting.

    ASTRO Spectra CPS R05.03

    Host firmware is R10.72.00
    DSP firmware is N08.03.05
    Flash is: 548008-0004C0-0


  2. #2
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    Check your overall radio alignment. if the referance osc is off freq it can cause the exact symptoms you are describing.

  3. #3
    deputy13 No Longer Registered

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    Thanks for the reply. Not sure what reference to adjust in the tuner software. Is there any document besides Motorola's on how to do the adjustments? Only documention I have is for the Spectra not the ASTRO.

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    First you need a service monitor, do you have one? If not take it to your local shop and have them do it.

  5. #5
    deputy13 No Longer Registered

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    I have two service monitors and two spectrum analyzers.

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    Good then you will want to adjust the reference oscillator.

  7. #7
    deputy13 No Longer Registered

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    I adjusted the reference oscillator using the tuner software. It was about +250 hz. Made the adjustment and audio seems a little better. Thanks.

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    Try running through the TX mod balance and limit, that affects what it expects on RX as well.

  9. #9
    deputy13 No Longer Registered

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    Ok didn't realize that function. I followed what was described on this form to set the levels for TX Audio in the CPS software. I'll look at the tuner software and see what I can optomize.

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    Make sure you read the help screens it will tell you what to set the deviation for, 2.83Khz if I recall correctly.

  11. #11
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    The basic service manual contains the full tuning instructions. I haven't looked but my guess is its available on the site. If not contact me I have it in PDF

    Jason