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I am learning how to build USB cables as a hobby.

For my early attempts, I did not attempt to shield the cable, I just skipped the bare shield wiring I've seen in other USB cables. However, recently I have found that some of my USB cables don't work properly (the usb device is not recognized on Windows) or some of them only work in a short period of time before the device is disconnected. So, I am now trying to include shielding in my USB cables.

I have tried crimping a bare shield wire to the USB housing at both the devices and host ends of the cable. Is this correct? The wire I use is 24/28awg and I also apply a silicone glue to prevent a short circuit.

What is the correct method of adding shielding into my USB cable builds? Is grounding the shield at both ends of the cable correct? Or should I just crimp the shield on only one side? Or not shield at all?

How I recently do my cables. It works however the connection isn't very good and a few minute later it disconnects.

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  • \$\begingroup\$ Show a photo. "I did not attempt to shield the cable." Does this mean that you used unshielded cable or that you used shielded cable but didn't connect it? What are you trying to connect? USB V1, 2 or 3? Use the edit link below your question to edit in the missing information. \$\endgroup\$ – Transistor Apr 5 at 14:09
  • \$\begingroup\$ It's only USB 2.0. I use the same cable for both but at first I didn't connect them to the metal housing - I just add more photos thank you. \$\endgroup\$ – underpk Apr 5 at 15:30
  • \$\begingroup\$ What is the model/type/inner construction of the cable you are using for this job? Please be exact. \$\endgroup\$ – Ale..chenski Apr 6 at 18:42
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    \$\begingroup\$ "I am learning how to build USB cables as a hobby." pick a better hobby. There is no reason to build ordinary USB cables as they will be inferrior to overmolded ones. Only special cases are worth bothering with. \$\endgroup\$ – Chris Stratton Apr 11 at 1:35
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No, the problem is your not using twisted pairs. USB uses differential signalling with an impedance of 90Ω (transmission line impedance). You also need a shield to protect against noise.

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According to baseline USB 2.0 specifications, the USB cable must have signal (green-white) wires as a twisted pair with 90 Ω differential impedance.

And no, the shield should connect only metal shells, and shouldn't be connected to GND wire at all, see section 6.5.2 of USB 2.0 specifications.

Some of your cables do not work reliably likely because you have too wide cut-offs near soldering area, which creates impedance discontinuity, which causes reflections and intersymbol interference. USB cables must be tested on TDR (Time-Domain-Reflectometer) to ensure impedance uniformity across soldering joints.

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