Looking for a lightweight and flexible USB 3.0 Cable

[Michael GilliganParticipant @michaelgilligan61133]

[Michael GilliganParticipant @michaelgilligan61133]

I have a rather nice little Motic C-mount camera, but the USB 3.0 cable that came with it is bulky, heavy, and too stiff !

Type A connector for the computer, and the’double-decker’ Type B for the camera … The big problem is the clip-on Ferrite, located on a loop of cable near the camera connector.

 

First : A question for our Electronics experts … Does the Ferrite need to be located at the camera-end or would it still do its job if located near the mid-point of the cable ?

Second : can anyone suggest a suitable replacement cable ? … Flat and/or Flexible, and preferably without an enormous Ferrite contraption on it.

Thanks

MichaelG.

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Worth a thousand words :

Edited By Michael Gilligan on 01/10/2023 14:06:09

[Ian ParkinParticipant @ianparkin39383]

Just unclip the ferrite and do without it ….i've never found that they make any difference

or relocate to where you want it

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, Ian

I was nervous about doing that, because of stories about USB 3.0 interfering with both Bluetooth and Wi-Fi

MichaelG.

[John Doe 2Participant @johndoe2]

Yes, the ferrite is required and it does need to be located as close to the device as possible. (In these very cost conscious times, manufacturers would not include something unless it was absolutely needed!).

It is there to suppress radio frequency interference, (RFI), from the device, radiating to other devices, and interfering with them. (The cable acts as an aerial).

Removing the ferrite might seem to have no discernible effect, but for example, your mobile phone reception at home might become slightly worse, or your Wi-Fi might become slower, or less reliable in some rooms. Devices using Wi-Fi might become unreliable, (which could have safety implications). Your computer might occasionally misbehave, or your TV signal might suffer interference on some channels.

Not suppressing RFI is a bit like dropping litter – you probably won’t be seen or caught, but you will contribute to turning the place into a dump, metaphorically.

 

(I am not judging at all, just saying).

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[JourneymanParticipant @journeyman]

This nylon braided type might be more flexible. This is USB 3B to USB C just a guess as you haven’t mentioned the other end of the cable!

John

[Michael GilliganParticipant @michaelgilligan61133]

A good guess, John …thanks

I have two Mac minis [an Intel and an M1]

Both have USB Type A connectors, but theThunderbolt connectors are different styles.

See Wikipedia:

https://en.wikipedia.org/wiki/Thunderbolt_(interface)

Cable flexibility is only an issue at the camera-end though.

MichaelG.

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Edit: __ as the Pantomime season is upon us:

”Oh yes, I did !“

[JourneymanParticipant @journeyman]

Sorry, missed that 🙁     Must read things more carefully!

In that case this one

John

[Michael GilliganParticipant @michaelgilligan61133]

For the curious amongst us:

https://support.apple.com/en-gb/guide/mac-help/mh35952/mac#:~:text=You%20can%20use%20either%20Thunderbolt,cables%20with%20Mini%20DisplayPort%20devices.

MichaelG.

[Michael Gilligan]

On Michael Gilligan Said:

Thanks, Ian

I was nervous about doing that, because of stories about USB 3.0 interfering with both Bluetooth and Wi-Fi

MichaelG.

Removing the ferrite choke allows the cable to act as an efficient antenna that sprays electronic effluent into the neighbourhood.  It can and does cause trouble, ranging from breaking up nearby phone conversations to blotting out Air Traffic Control or the Ambulance Service.

More likely to be a nuisance than serious, such as causing all the Wifi connections in a block of flats to misbehave whilst the device is transmitting data, usually by slowing down rather than failing outright.  Nonetheless electronic smog should be kept down. In the UK most of us are packed close to our neighbours, most of them owning at least a few leaky USB cables, and a suitable radio receiver will show an unnaturally high noise floor or worse.

Duff cables cause hard to trace intermittent problems with phones, internet, wifi, and other comms services.  As poor electronic hygiene adds to the many irritations of modern life, we shouldn’t deliberately remove ferrites or other protective devices.

The choke should be at the hot end of the cable.  In this case it’s the camera sending photos to the computer.   A computer is the hot end when it sends data to a printer.   Sometimes both ends can be hot, as with a combined printer/scanner, in which case the choke is usually at busiest end – printing generally sends more data than scanning.

USB cables are not all equally well-made.   Very cheap cables are just a pair of plugs with a wires soldered haphazardly between them.  Not physically strong, no shielding, maybe just a pair for recharging, and the wire could be thin copper or copper-plated steel, yuk.  Next step up, thicker copper wire in twisted pairs with better fixing to the connectors.  Then, for a little more money, the bundle of twisted pairs will be protected with an outer mesh, perhaps only thin.  A thick mesh is more expensive.   Beyond that, each twisted pair is individually shielded inside the cable as well.  At the high-end, Apple’s posh cable contains active electronics in the connectors.  These drive multiple extra twisted pairs, all individually shielded, and the whole cable is double shielded.  No expense spared!  Necessary to achieve the very high data-rates in the latest USB standard, and not cheap!!!   As only a few of my devices support USB3.0 at full-speed, I’m not rushing to buy high-end cables.  I own mid-range and if the manufacturer of a device happens to supply one with a ferrite choke, I leave it on.

Buying cables of known specification as an ordinary consumer seems to be difficult.   Few vendors give a spec, so price is the main clue.  An unreliable clue though, what with fakes and indifferent products deliberately priced to catch folk who like to buy ‘reassuringly expensive’.

Michael may have a valid reason for removing a heavy ferrite choke, but I note the cable is looped for extra suppression, suggesting the camera is unusually noisy.   May not be a problem if used infrequently or Michael doesn’t have close neighbours with sensitive equipment.   A USB cable is unlikely to interfere with mobile phones if the cell-tower is line of sight, but it will if the mobile signal is weak,

I’m an inactive radio ham partly because the man-made electronic racket around my home is so bad only strong signals can be heard, and mobile phones barely work here at all.  That being so, I don’t worry much about running the unfiltered VFD on my lathe.  The machine is at least 15 metres from my closest neighbour, and my occasional turning sessions are unlikely to make a bad situation worse!   I’d fit a filter if it was electrically quiet here, or my neighbours were closer.

Dave

 

 

[JourneymanParticipant @journeyman]

I thought that USB cables were supposed to be shielded. The spec says for USB 2 at least – ‘ USB cable must be made minimally of 5 conductors: the two power supply wires, the differential pair for communication, and a fifth conductor for shielding made of a stranded copper braid, which must surround all the others on the whole length of the cable and be connected to the plug shells at both ends’

Can’t imagine a ferrite will add much to the protection.

John

[MacolmParticipant @macolm]

A ferrite ring only filters common mode interference, so may reduce the ability of the whole cable to act as an aerial. It will have no effect on data within the cable provided it operates as a transmission line, and likewise will not attenuate interference exported by the camera as a differential signal. However, the screened outer conductor will contain such signals and interference within the cable, and the USB interface (and connected circuitry) is not susceptible to low level interference anyway.

[Ian PParticipant @ianp]

If USB and similar data cables that had two screening layers (so near 100% screening) existed, would they eliminate the need for the ferrite devices?

I suppose from the manufacturers point of view the extra screened cable would be more expensive than the ferrite.

Ian P

 

 

[MacolmParticipant @macolm]

No, an external ferrite core affects all internal wires equally, and only serves to attenuate interference conducted by the whole cable. It interacts with all the internal wires equally, including any screen(s). The screen performs a different function, to provide an approximation to a Faraday cage that surrounds the data wires. An additional screen would of course increase this effect, but would be a bit of a waste of time considering that an unscreened USB cable is usually adequate (neglecting considerations of exported interference).

[Journeyman]

On Journeyman Said:

I thought that USB cables were supposed to be shielded. The spec says for USB 2 at least – ‘ USB cable must be made minimally of 5 conductors: the two power supply wires, the differential pair for communication, and a fifth conductor for shielding made of a stranded copper braid, which must surround all the others on the whole length of the cable and be connected to the plug shells at both ends’

Can’t imagine a ferrite will add much to the protection.

John

Often a big gap between theory and practice!  USB cables are supposed to be shielded, but that doesn’t mean they are, or that the shielding is as good as it might be.

This photo is of 3 examples of the shielding in coaxial cable.

The white cable is DIY store 75 ohm TV down lead. Cheap because the mesh is widely spaced and there’s not much copper in the shield.  Whilst the shield is only mildly effective there’s a good chance most of us would get away with it, but the coax is too cheap in an area of marginal reception.

Centre example is inexpensive Satellite cable. Better because the shield is beefed up by aluminium foil, but lossy because Aluminium is a poor conductor compared with Copper.   Inferior rather than awful, but fit for purpose in most domestic installations.

The Black cable on the right is RG58C, a reasonably good 50 ohm communications coax.  The shield is a tightly woven copper mesh, much denser than the other two cables, and it is much better at keeping transmit power inside the cable and keeping interference out.  Not the best money can buy by a long shot – I have some coax about finger diameter where the silver plated copper inner is shielded by a tight silver-plated mesh, wrapped in thick copper tape, and again by a second tight copper mesh.  It’s too expensive to use!

How well even the best shielding works depends on how the cable is terminated.  Ideally there’s an exact impedance match and differential cables are balanced exactly, but these conditions are unlikely to be met unless particular care is taken.   If either is off, common mode currents bypass the shield.   For example, wires in cheap USB connectors are often soldered direct to the pins, and the result is unlikely to be balanced.  Better connectors mate the pins and wires via a small printed circuit board, one we hope was designed to provide a good match. Mileage may vary.

A ferrite choke might not be necessary if everything else was tickety-boo, but this is an imperfect world.

Dave

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Robert Atkinson 2Participant @robertatkinson2]

While the supplied cable with ferrite clip on should be used to limit interference, as noted by others, a device that needs one to pass EMC testing is bad. This is because there is nothing to ensure a lead with a ferrite is used. The should have sorted the issue interally to the camera. The fact that there are two turns through the core indicates that the interference on the lead is pretty bad…

Robert.

[Robert Atkinson 2]

On Robert Atkinson 2 Said:

[…] The fact that there are two turns through the core indicates that the interference on the lead is pretty bad…

… or just that someone at Motic decided that was how it should be

I don’t have the equipment to test it … but I have tried the original cable with, and without the ferrite, and another cable which has no ferrite … and, to date, can’t see any differences.

That, of course is just a rough check in one particular environment, and doesn’t prove anything.

From my selfish point of view, the fact that the original lead is so big, heavy, and stiff makes the camera very difficult to use … hence the opening question.

MichaelG.

 

[Michael GilliganParticipant @michaelgilligan61133]

 

http://en.copartner.com.tw/front/bin/home.phtml

http://en.copartner.com.tw/front/bin/ptlist.phtml?Category=101839#

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Looks like pretty-good stuff, to my uneducated eye

 

[Michael GilliganParticipant @michaelgilligan61133]

Having mentioned Thunderbolt … I think some ‘participants’ might appreciate this:

https://youtu.be/AD5aAd8Oy84?feature=shared

MichaelG.

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Edit: __ and here’s the referenced article, with more writing than giggling.

https://www.lumafield.com/article/usb-c-cable-charger-head-to-head-comparison-apple-thunderbolt-amazon-basics

[Michael Gilligan]

On Michael Gilligan Said:

I don’t have the equipment to test it …

That doesn’t surprise me you would need a wide frequency range spectrum analyser, calibrated antennas, and an RF anechoic chamber costing hundreds of thousands of pounds!  As others have said it won’t affect your equipment performance but could cause interference to others.

However I would be happy to use a cable without a ferrite and change it in the unlikely event of any complaints.

Russell

[Michael Gilligan]

On Michael Gilligan Said:

I don’t have the equipment to test it … but I have tried the original cable with, and without the ferrite, and another cable which has no ferrite … and, to date, can’t see any differences.

 

MichaelG.

As I hopefully explained; YOU might not notice any difference in performance of the device……

However, your mobile phone reception might become slightly worse, your Wi-Fi signal might become slightly less reliable. You or your elderly neighbour might have some sort of safety health monitoring device which might become unreliable.  Etc, etc.

As far as waiting for complaints; where would a person start? Knock on all the neighbours doors and ask them to switch off their devices one by one ? Not going to happen. As I say, it’s like dropping litter.

The device will radiate from the cable. It might do this even if the cable is the best quality expensive double screened professional cable. This is because certain radiation modes affect ALL the conductors in a cable, including the screen, (via so-called Common Mode Currents, which travel along all the conductors and the screen). The conductors then act as an aerial and radiate the interference.

This is why the ferrite needs to be as close as possible to the device, so that the very minimum amount of cable before the ferrite is ‘exposed’ to act as an aerial.

As a compromise, move the ferrite along slightly, but keep it as close as possible to the connector at the device.

You should be able to find more flexible cable, but it will need to retain the ferrite.

It looks like a nice little camera though.

[Michael Gilligan]

On Michael Gilligan Said:

… That, of course is just a rough check in one particular environment, and doesn’t prove anything. …

Just for emphasis ^^^

I do understand the issue

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Well … They don’t really meet most of my ‘wish list’ or some of the forum’s advice; but these are the right price and and are branded DELL

https://www.ebay.co.uk/itm/225880482824

 

I will dissect one when they arrive.

 

ebay seems to be flooded with stock, at various prices …

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Well … They don’t really meet most of my ‘wish list’ or some of the forum’s advice; but these are the right price and and are branded DELL

https://www.ebay.co.uk/itm/233369829172

I will dissect one when they arrive.

 

ebay seems to be flooded with stock, at various prices …

MichaelG.

[Ian PParticipant @ianp]

eBay is also now flooded with AI generated descriptions.

Ian P

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