Thank you for everyone's interest. I wrapped the external disk and its cable with aluminum foil. This process provided a distance of about 10 cm. I do not have a USB hub with external power.
Unfortunately, I cannot find a quality USBA, male, female cable anytime soon. As far as I know, 500mA current can be drawn from the USB2 port, and 900mA from the USB3 port. I think there should be no power problem in this case. I will still try it with a hub that works with external power. And there is no USB problem in dmesg output. Can the USB3 port be used with the USB2 protocol in terms of software?
