AM beating

ON5MZON5MZ
in Configuration and Operation

There's an issue with my old kiwiSDR1.

For some time now, the reception of every AM stations (in AM demodulation mode) has been accompanied by a beating sound, similar to what you'd hear in SAM mode.

I compared the settings with another KiwiSDR2 working well in AM but couldn't find any difference.

Can you help me?

TU Serge ON5MZ

Comments

  • G8JNJG8JNJ

    Hi Serge,

    I suspect that for some reason, the KiWi I/Q Balance needs to be reset.

    I think you can only do this via the I/Q extension on a KiWi that is on the same local network as your browser, as you need to disconnect the antenna whilst you perform the actions.

    Regards,

    Martin

  • ON5MZON5MZ

    Naturally, IQ balance... I should have thought of that.

    Thanks.

    on5mz

  • jksjks

    First, what software version is the Kiwi-1 running? This is shown on the admin page, status tab. We had a problem a number of years ago with carrier tones leaking through in AM mode.

    You should never have to re-balance the IQ. The default values are always correct. But if you did re-balance, and you didn't use the correct setup, then you could now have an out-of-balance condition causing carrier leaks as Martin mentions. This can occur by accidentally clicking the yellow IQ bal button of the IQ display extension when there is any sort of signal input.

    One way of telling if this has happened is to check the stored values for the IQ balance. Go to the admin page console tab. Click connect. Then enter this command: jk | gr dc_off The values for DC_offset_I and DC_offset_Q should both be -0.02, or values close to that if IQ bal has even been pressed (under correct conditions).

  • ON5MZON5MZ

    Hi!,

    It append on a 'KiwiSDR 1, v1.808', I suppose I have changed one parameter accidentally.

    So I will check your proposal this week.

    Thanks for your help.

    Serge ON5MZ

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