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Unshielded USB cables?
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P E Schoen
Oct 10, 2016, 6:23:00 AM10/10/16
to
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:
http://www.banggood.com/Wholesale-4_3-FT-USB-2_0-A-to-Mini-B-Male-to-Male-5-PIN-Cable-p-25168.html?rmmds=myorder
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:
http://www.questtechnologyintl.com/product.cfm?product=54#.V_tfI8nLweA
The USB specification seems to require shielding for full-speed and
high-speed USB, but not low-speed.
http://www.usb.org/developers/docs/usb20_docs/usb_20_091216.zip
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
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:
http://www.banggood.com/Wholesale-4_3-FT-USB-2_0-A-to-Mini-B-Male-to-Male-5-PIN-Cable-p-25168.html?rmmds=myorder
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:
http://www.questtechnologyintl.com/product.cfm?product=54#.V_tfI8nLweA
The USB specification seems to require shielding for full-speed and
high-speed USB, but not low-speed.
http://www.usb.org/developers/docs/usb20_docs/usb_20_091216.zip
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
P E Schoen
Oct 12, 2016, 1:23:18 AM10/12/16
to
I posted a review of the USB cable on the Banggood site, and they emailed me
asking for a video. So:
============================================
I made a video which was attached, but at 313 MB it was too large to send.
But you may download from:
http://enginuitysystems.com/pix/electronics/USB_Cable_3131.AVI
I hope it shows what I found, and as I said, the cable looks good and works
OK, but being unshielded, it is not as advertised. It is a good deal for the
money, and I have found other USB cables without shields, or with shields
that are not securely connected to the grounding shells of the connectors.
I hope this helps.
Paul
From: forums...@banggood.com
Sent: Tuesday, October 11, 2016 9:19 PM
To: pa...@pstech-inc.com
Subject: review 18734207 SKU013840
Dear customer,
We are sorry to hear this news,for :
> I bought three of these cables and I was very pleased with the appearance
> and apparent quality. But I measured no continuity between the two
> connector shells. I even poked a multimeter lead through the jacket and
> there appears to be no shield at all. Also, the plastic item on the cable
> is supposed to be a ferrite bead to reduce common mode noise, but it is
> non-magnetic and probably fake. The cable seems to work OK, but it is not
> as advertised since it is not shielded.
Would you please provide us the video to show the situation ?
Hope for your kindly understanding.
Looking forward to hearing from you soon.
Best regards,
Doris
asking for a video. So:
============================================
I made a video which was attached, but at 313 MB it was too large to send.
But you may download from:
http://enginuitysystems.com/pix/electronics/USB_Cable_3131.AVI
I hope it shows what I found, and as I said, the cable looks good and works
OK, but being unshielded, it is not as advertised. It is a good deal for the
money, and I have found other USB cables without shields, or with shields
that are not securely connected to the grounding shells of the connectors.
I hope this helps.
Paul
From: forums...@banggood.com
Sent: Tuesday, October 11, 2016 9:19 PM
To: pa...@pstech-inc.com
Subject: review 18734207 SKU013840
Dear customer,
We are sorry to hear this news,for :
> I bought three of these cables and I was very pleased with the appearance
> and apparent quality. But I measured no continuity between the two
> connector shells. I even poked a multimeter lead through the jacket and
> there appears to be no shield at all. Also, the plastic item on the cable
> is supposed to be a ferrite bead to reduce common mode noise, but it is
> non-magnetic and probably fake. The cable seems to work OK, but it is not
> as advertised since it is not shielded.
Would you please provide us the video to show the situation ?
Hope for your kindly understanding.
Looking forward to hearing from you soon.
Best regards,
Doris
Adam
Oct 12, 2016, 3:48:04 AM10/12/16
to
On 2016-10-10, P E Schoen <pa...@pstech-inc.com> wrote:
> 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.
Yes. It's gotten worse now - it seems like all the USB A-B cables
> 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.
currently on the market, even the big brand names, have crimped shield
termination. The shell to shell resistance may meet USB 2.0 6.6.3 at the
time of factory test, but never at the time the cable reaches the end
customer. Consumers don't know the difference because the cables seem to
be functionally operational. USB-IF has not taken any enforcement or
outreach action.
> I did a bit of searching, and found one company that shows its USB cables as
> being unshielded:
>
> http://www.questtechnologyintl.com/product.cfm?product=54#.V_tfI8nLweA
specification. I've seen very few of them. One major interconnect
manufacturer is selling one, or was for a while, but they describe it as
"USB 2.0 suitable" rather than USB 2.0 compliant or certified.
Regarding the link you found, I believe it's a mistake in their catalog.
If you look at the actual drawing for their product (link below) it
seems to specify 80 strand braided aluminum shield.
http://www.questtechnologyintl.com/files/specsheets/NUB-3103.pdf
> The USB specification seems to require shielding for full-speed and
> high-speed USB, but not low-speed.
devices, for example the cable built into a mouse. Unshielded detachable
cables are prohibited. I don't know chapter and verse off hand, but it's
in the spec.
> However, I think USB 2.0 is at least full-speed, and the cables are clearly
> marked USB 2.0.
2.0 cables must meet the same requirements, regardless of device speed.
> 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.
is to try to design USB devices to work reliably with open or resistive
shield connections.
-- Adam
P E Schoen
Oct 14, 2016, 4:57:33 AM10/14/16
to
Well, Banggood decided to refund the full purchase price of $3.66 for the
three cables, rather than post my honest review. They said they would change
the description to remove the "shielded" part, but they have not yet done
so.
http://www.banggood.com/Wholesale-4_3-FT-USB-2_0-A-to-Mini-B-Male-to-Male-5-PIN-Cable-p-25168.html?rmmds=myorder
Oh, well, I guess that was to be expected. They don't like to "look bad",
even if they are.
Paul
three cables, rather than post my honest review. They said they would change
the description to remove the "shielded" part, but they have not yet done
so.
http://www.banggood.com/Wholesale-4_3-FT-USB-2_0-A-to-Mini-B-Male-to-Male-5-PIN-Cable-p-25168.html?rmmds=myorder
Oh, well, I guess that was to be expected. They don't like to "look bad",
even if they are.
Paul
Tim Williams
Oct 14, 2016, 5:01:27 AM10/14/16
to
As if you had to guess, about a site that sounds like it sells excellent
quality dildos but happens to sell poor quality cables instead. I mean,
what a bummer!
Wait, what a non-bummer, if you get my...nevermind...
Tim
--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com
"P E Schoen" <pa...@pstech-inc.com> wrote in message
news:ntq6l8$ap7$1...@dont-email.me...
quality dildos but happens to sell poor quality cables instead. I mean,
what a bummer!
Wait, what a non-bummer, if you get my...nevermind...
Tim
--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com
"P E Schoen" <pa...@pstech-inc.com> wrote in message
news:ntq6l8$ap7$1...@dont-email.me...
P E Schoen
Oct 14, 2016, 5:59:21 AM10/14/16
to
"Tim Williams" wrote in message news:ntq6si$bik$1...@dont-email.me...
> As if you had to guess, about a site that sounds like it sells excellent
> quality dildos but happens to sell poor quality cables instead. I mean,
> what a bummer!
> Wait, what a non-bummer, if you get my...nevermind...
It is a funny name. They say "Best Bang for the Buck", and there are various
humorous takes on that as well ;)
I have bought quite a few fairly good things from them at very good prices.
These cables are pretty good (and I can't complain much after a full
refund). I was very happy with the Nikon Coolpix replacement cable, which
has continuity between connector shells and and actual magnetic noise filter
(although it might be just some old rusty nuts covered with plastic).
http://www.banggood.com/Wholesale-Nikon-UC-E6-USB-Cable-for-3200-3700-4100-Coolpix-Camera-p-18056.html?rmmds=myorder
Paul
> As if you had to guess, about a site that sounds like it sells excellent
> quality dildos but happens to sell poor quality cables instead. I mean,
> what a bummer!
> Wait, what a non-bummer, if you get my...nevermind...
humorous takes on that as well ;)
I have bought quite a few fairly good things from them at very good prices.
These cables are pretty good (and I can't complain much after a full
refund). I was very happy with the Nikon Coolpix replacement cable, which
has continuity between connector shells and and actual magnetic noise filter
(although it might be just some old rusty nuts covered with plastic).
http://www.banggood.com/Wholesale-Nikon-UC-E6-USB-Cable-for-3200-3700-4100-Coolpix-Camera-p-18056.html?rmmds=myorder
Paul
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