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Thread: New prob T2020-321-004

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    Default New prob T2020-321-004

    Hi from UK
    Now it seems that i have another prob with this radio (T2020-321-004)
    it keeps cutting out on Rx, seems only on speech peaks, which i think maybe
    something to do with the filters in the IF stage.

    I found some info somewhere that showed that this model has a IF filter of +\ 7.5Khz
    if this is true, then that would account for the cutting out on speech peaks on Rx.

    Would it just be a case of changing the IF filter, or are there other things to change ?

    Regards Howard
    73's de Howard G7LQY
    E-mail: howard_g7lqy@sky.com
    LARGE FILES TO: hjpayneg7@yahoo.com
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    Loc: IO83UO
    GQRP: 12549



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    Default

    G'day Howard,

    Yes, the 321 is a narrow bandwidth version, having an IF bandwidth of 7.5kHz

    It sounds like it's over-deviating or that the vco is going out of lock.

    Has the radio suddenly developed this problem or did you get the radio with the problem existing?

    If the latter, chances are someone has been fiddling.

    Either way, a full alignment of both TX & RX sections may be required.

    Are the received signals being transmitted in narrow band? If not, then the receiver could simply be over-deviating causing clipping.

    Is it a series1, 1.5 or series two model?

    Cheers

    Col

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    Default

    Hi Col
    Thanks for the reply on this matter

    The radio was bought at a radio rally here in the UK, it's a series1, it had only 2 channals loaded (Taxi firm). The radio had this problem from me getting it

    Regards
    Howard
    73's de Howard G7LQY
    E-mail: howard_g7lqy@sky.com
    LARGE FILES TO: hjpayneg7@yahoo.com
    Qthr: qrz.com
    Loc: IO83UO
    GQRP: 12549

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    Cool

    Col is mostly correct.

    The -321 indicates it should be a narrow band. RX signals deviated more than 2.5kHz will start to cause the mute to chop. Alignment wont fix, only a wide band IF module. If you can find one, it just needs to be plugged in. Fits under the inside metal cover over the RF section.

    The Fixer

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