X-108 Info RF-Ingress to USB - any ideas?

Discussion in 'X-108' started by DD5LP, Feb 18, 2019.

  1. DD5LP

    DD5LP Crack-Boarder X-108 Member

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    As the Xiegu's OLED is a disgrace that it cannot be read even in normal light outside, I am now using PocketRxTx on my Lenovo smart phone connected to the USB port on the X108G. This is a good solution as the frequency can be read and changed, along with various other functions (power, band, preamp, etc. etc.).

    However I have a couple of major problems - that in one direction (especially on 20m, not so bad on 40m) noise from the smart phone raises the noise level about 4-5 S-points when connected! The second problem is that when I hit Tx at 20w SSB the USB connection often stops working and worse still the rig gets locked in Tx so releasing the PTT has no effect. the only siolution is to power off and on the X108.

    I have tried several different cables. I have also tried the usual ferrite clamp-ons (HF ferrite version) on the USB cable without any change to the situation. I have tried wrapping the USB lead around a ferrite core - again, no improvement.

    What I am now considering is adding somthing like 0.01 mFd ceramic caps inside the X108G on the differential data lines in the USB socket, to earth.

    Has anyone here ever done this and is it even worth trying. I would have thought some kind of RF-decoupling would already be on the CAT circuit?

    73 Ed DD5LP.
    Last edited: Feb 18, 2019

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