Some time ago I posted my problems with using USB for my data processing device (Ortmaster), and I found that some, and perhaps many, USB cables had poor connections between the plug shrouds and the cable shields. The problem was that the crimp was made over the folded-back shield braid and the plastic jacket, so that as the material softened, or as moisture entered, the connection became unreliable. Good cables measured less than a couple of ohms; bad cables measured 10, 20, or more ohms, and sometimes open circuit, varying as I bent the cable near the strain relief.
I found some cables with gold-flashed connectors that measured less than 1 ohm for 10 feet, and they have been working well. I found that some supposedly high-end cables, like Belkin, costing nearly $20 (compared to about $3 for mine), were inconsistent and often much worse, especially after a few flexes.
Recently I bought three USBA-to-miniB cables from Banggood.com, for $1.22 each:
They look very good and they seem to work well, and I liked the in-line filter (but it is non-magnetic, so probably just a plastic glob). When I checked the resistance between connectors, I got no continuity or resistance at all, and when I poked the multimeter lead through the cable, it still showed no connection, and apparently, no shield.
I did a bit of searching, and found one company that shows its USB cables as being unshielded:
The USB specification seems to require shielding for full-speed and high-speed USB, but not low-speed.
However, I think USB 2.0 is at least full-speed, and the cables are clearly marked USB 2.0. I did a quick check of other USB cables, and some seem to have no shield, while others (mostly thicker ones or with visible braid in clear jacket) do have a functional shield with continuity between connectors.
I don't know how important shielding might be for most USB purposes. I have heard that the purpose of the shield is more to reduce radiated RF emissions, than for noise immunity, but it seemed to make a big difference in my Ortmaster USB connection. However, it could be that the intermittent connection caused current spikes in the shield and noise coupled into the data lines.
Any similar experiences? Opinions? I will write an honest review on these cables but it's not worth trying to send them back for a refund. However, they may give me a credit on future purchases. I buy from them often and mostly have been pleased with their products, especially considering the price.
Thanks,
Paul