Maybe on the ground to the radio? Do you use an external tuner? If so then you can ground there.
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Fortunately USB-C cables are made for high-speed connectivity so they have better braid-shielding over the center conductors; Many of the older USB-A cables had miserable shielding and I had to do through a process to find good ones for my SDR Play Duo to minimize RFI. You can also get a couple of clip-on ferrites and wrap as many turns of the USB cable through the ferrite... The more turns through the ferrite the greater the attenuation will be.
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Not grounding at the tuner could result in some 'weird' effects where the SWR looks good leaving the radio to the tuner, but the radio and laptop are also acting like part of the antenna system.
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Tisha, AA4HA
Tisha Hayes, AA4HA