Looking for a lightweight and flexible USB 3.0 Cable

[duncan webster 1Participant @duncanwebster1]

<p style=”text-align: left;”>Slight digression, I managed to cut the wire from my freesat dish when cutting the hedge. I repaired it with a connector sold for the job, but it has stopped working, no or weak signal. I suspect water ingress and corrosion. I know I should replace the whole length, but SWMBO won’t let me go up ladders any more. Anyone know of a waterproof connector for coax.</p>

[duncan webster 1Participant @duncanwebster1]

I’ve no idea where all the spurious stuff in the above post came from

[Michael GilliganParticipant @michaelgilligan61133]

Infuriatingly; I cannot now edit last night’s posts

my second ebay link is the ‘item’ that I ordered

… it was intended to be an edit, but I tapped the quote button …Grrr!!

MichaelG.

[duncan webster 1]

On duncan webster 1 Said:

Slight digression, I managed to cut the wire from my freesat dish when cutting the hedge. I repaired it with a connector sold for the job, but it has stopped working, no or weak signal. I suspect water ingress and corrosion. I know I should replace the whole length, but SWMBO won’t let me go up ladders any more. Anyone know of a waterproof connector for coax.

I would simply cover the entire repair with self-amalgamating tape

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Regarding the monstrously large  clip-on Ferrite:

I have just found this

https://www.quora.com/Do-USB-cables-really-need-ferrite-chokes

… and am somewhat comforted

.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Here’s a fun video : Making a very cheap probe

MichaelG.

[Russell Eberhardt]

On Russell Eberhardt Said:

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

You don’t actually need an anechoic chamber for most of the consumer test levels but it does make it easier. You can get a new professional pre-compliance test set up for about £50,000 or a lot less  for something from the far east. My used Rhode & Schwarz kit cost less than £3,000 including the antennas.
As for unlikely complaints, it is a bit late if the complaint i that your system interfered with a navigation system and caused an aircraft to crash…

[Ches Green UKParticipant @chesgreenuk]

A small AM radio can quite effectively locate electrically noisy devices from 6″ – 36″… ‘Using an AM Radio to Detect EMI’ – https://www.youtube.com/watch?v=lXPJvSU8MwI    Use about 1600kHz.

Worst offenders tend to be the cheapo switched-mode wall-wart power supplies. They really do play havoc with your and neighbours’ electrical devices.

I’m (like Dave) a mostly non-practicing Radio Ham…IIRC, if the radio can be held about 3 feet away from a device without much noise then generally things should be OK.

Ches

[Michael Gilligan]

On Michael Gilligan Said:

On duncan webster 1 Said:

Slight digression, I managed to cut the wire from my freesat dish when cutting the hedge. I repaired it with a connector sold for the job, but it has stopped working, no or weak signal. I suspect water ingress and corrosion. I know I should replace the whole length, but SWMBO won’t let me go up ladders any more. Anyone know of a waterproof connector for coax.

I would simply cover the entire repair with self-amalgamating tape

MichaelG.

I did that when I repaired it

[peak4Participant @peak4]

Also consider that some downfeed cable is partially air cored, rather than having a solid dielectric/insulator.
Damage through the outer to below the braid, and the outer part of the dielectric core, just acts like a small bore water pipe.
I have video recorder full of rusty water damage to prove the point; the cable being surrounded by melting snow just fed water straight down the core, through the plug and into the recorder. I only realised when I found a pool of water under the TV

Bill

[Ches Green UK]

On Ches Green UK Said:

A small AM radio can quite effectively locate electrically noisy devices from 6″ – 36″… ‘Using an AM Radio to Detect EMI’ – https://www.youtube.com/watch?v=lXPJvSU8MwI    Use about 1600kHz.

Worst offenders tend to be the cheapo switched-mode wall-wart power supplies. They really do play havoc with your and neighbours’ electrical devices.

I’m (like Dave) a mostly non-practicing Radio Ham…IIRC, if the radio can be held about 3 feet away from a device without much noise then generally things should be OK.

Ches

Unless of course the interference is between 108MHz and 118MHz (aircraft VOR and ILS navigation) or 1.575 GHz (GPS). Neither of these will show up on a medium wave radio but can wreak havoc with aircraft navigation.

[peak4]

On peak4 Said:

Also consider that some downfeed cable is partially air cored, rather than having a solid dielectric/insulator.
Damage through the outer to below the braid, and the outer part of the dielectric core, just acts like a small bore water pipe.
I have video recorder full of rusty water damage to prove the point; the cable being surrounded by melting snow just fed water straight down the core, through the plug and into the recorder. I only realised when I found a pool of water under the TV

Bill

Not a problem these days but in the days of valve TVs with transformerless power supplies the chassis was “live” and the protection from voltage on the antenna socket was a couple of capacitors built into the socket. Water coming down semi-airspaced coax could fill the socket. This shorted out the capacitors and resulted in a live antenna socket…….

[duncan webster 1]

On duncan webster 1 Said:

On Michael Gilligan Said:

I would simply cover the entire repair with self-amalgamating tape

MichaelG.

I did that when I repaired it

Then either use more tape, stretch it a bit more as you apply it, or clean the surfaces better before you start.

There is nothing wrong with the theory

MichaelG.

.

Edited to remove spurious quote

[Michael Gilligan]

On Michael Gilligan Said:

On duncan webster 1 Said:

Slight digression, I managed to cut the wire from my freesat dish when cutting the hedge. I repaired it with a connector sold for the job, but it has stopped working, no or weak signal. I suspect water ingress and corrosion. I know I should replace the whole length, but SWMBO won’t let me go up ladders any more. Anyone know of a waterproof connector for coax.

I would simply cover the entire repair with self-amalgamating tape

MichaelG.

That was how I repaired my downfeed after the VCR filled with water.
The repair lasted until I sold the house, and may still be in operation now.
It’s also how I was taught to waterproof the feeder co-ax to mobile phone masts, though I never did that job in the end, and moved to commissioning them for the initial roll-out of 3G.
After the self amalg. it was topped with black UV resistant PVC tape.
This sort of stuff, though we used Andrew connectors

Bill

[Michael GilliganParticipant @michaelgilligan61133]

For general interest … I have just found a useful paper by Intel [published 2012] about USB 3 interference problems.

It’s in my gallery.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

So … a question for the ‘well informed’

[ I hesitate to use the term Expert in this context ]

.

Is it significant that the Intel white-paper makes no reference whatsoever to Ferrites ?

MichaelG.

[Robert Atkinson 2Participant @robertatkinson2]

The intel article probably does not refer to clip-on ferrites because they have little effect at the 2400 MHz (2.4 GHz) frequency they were having problems with. Typical clip-ons have diminishing returns above 1000 MHz and most manufacturer’s performance data does not extend beyond 1000 MHz.
The Intel article is very subjective. They do not provide any quantifiable interference levels or detail of the probes and analyser used. It does appear that the interference levels they measured is below the permitted emissions levels for IT equipment though.

Robert G8RPI.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks for that, Robert

Yes, the Intel ‘white-paper’ does seem a little lacking in substance doesn’t it !

… that was basically my reason for doubting that there is anyone we might reasonably call Expert in this particular field.

MichaelG.

.

P.S. __ if somebody does find a better-documented experiment, please share it here.

[Robert Atkinson 2Participant @robertatkinson2]

Well I sit on a committee that sets EMC and other environmental standards for aircraft equipment (RTCA SC-135). I have also been involved in design for EMC compliance and testing for both aviation and commercial / industrial products for over 30 years so think I claim some expertise in the subject.
I don’t have a similar camera to test but have a USB 3.0 external hard drive somewhere. I’ll see if I can find it and set it up for a emissions test over the holidays.

Robert.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, Robert … Much appreciated.

MichaelG.

[duncan webster 1]

On duncan webster 1 Said:

On Michael Gilligan Said:

On duncan webster 1 Said:

Slight digression, I managed to cut the wire from my freesat dish when cutting the hedge. I repaired it with a connector sold for the job, but it has stopped working, no or weak signal. I suspect water ingress and corrosion. I know I should replace the whole length, but SWMBO won’t let me go up ladders any more. Anyone know of a waterproof connector for coax.

I would simply cover the entire repair with self-amalgamating tape

MichaelG.

I did that when I repaired it

Self-amalgamating tape is good, but I think heat-shrink tubing is better. Both can fail.

The problem is water gets through tiny gaps and capillary action positively pulls it in. It’s hard to guarantee a cable joint is 100% watertight. When electric power cables were Lead sheathed and sealed with a solder wipe, they still sometimes got wet inside.  I believe modern HV cables are pressurised with Nitrogen or Transformer Oil to keep water out.

If the connector is exposed to the weather, I’d throw the book at it.  Wrap in tape, put the whole in a plastic box (could be a length of pipe), and fill the box with bathroom sealant.   Also, arrange the cable so that rainwater can’t run over the joint.

Some people worry that Acetic Acid emitted by bathroom sealant as it cures causes corrosion. Maybe, but so far as I can tell after using bathroom sealant on antenna for many years, it doesn’t.  Could be luck, but I’m not normally lucky.

Waterproof coax connectors are expensive and in my experience have to be fitted skilfully.    I don’t think satellite down cable justifies waterproof coax connectors.  Like as not paying a man to replace the whole run will be better value for money.  Especially after fitting a pricey connector, the cable is found to have wicked water along the braid and it all has to be replaced anyway.

As a temporary test, or even a bodged permanent answer, the cable could be reconnected with an electrical choc-bloc,.  A choc-bloc will cause loss of signal and allow interference in, but if the TV works at all it proves the cable isn’t full of water.   A soldered splice is better, and a well-made coax plug/socket better again.  Best of all is an unbroken cable.   All coax joints are lossy, and those that introduce an impedance mismatch as well are worse.  However, despite quite serious problems the TV will work provided it gets just enough signal, and external interference is low.  Whatever is used to rejoin the cable, it has to be waterproofed.

Dave

 

 

 

[peak4Participant @peak4]

Whilst I appreciate it’s cheaper, look up Raytech Gel as an alternative to bathroom sealant.
There are other makes and suppliers available; I used it for re-potting my car reversing camera when I made a workshop magnifying display.
It comes as either a two-pack or ready installed in boxes such as this one

Bill

[SillyOldDuffer]

On SillyOldDuffer Said:

On duncan webster 1 Said:

On Michael Gilligan Said:

On duncan webster 1 Said:

Slight digression, I managed to cut the wire from my freesat dish when cutting the hedge. I repaired it with a connector sold for the job, but it has stopped working, no or weak signal. I suspect water ingress and corrosion. I know I should replace the whole length, but SWMBO won’t let me go up ladders any more. Anyone know of a waterproof connector for coax.

I would simply cover the entire repair with self-amalgamating tape

MichaelG.

I did that when I repaired it

Self-amalgamating tape is good, but I think heat-shrink tubing is better. Both can fail.

The problem is water gets through tiny gaps and capillary action positively pulls it in. It’s hard to guarantee a cable joint is 100% watertight. When electric power cables were Lead sheathed and sealed with a solder wipe, they still sometimes got wet inside.  I believe modern HV cables are pressurised with Nitrogen or Transformer Oil to keep water out.

If the connector is exposed to the weather, I’d throw the book at it.  Wrap in tape, put the whole in a plastic box (could be a length of pipe), and fill the box with bathroom sealant.   Also, arrange the cable so that rainwater can’t run over the joint.

Some people worry that Acetic Acid emitted by bathroom sealant as it cures causes corrosion. Maybe, but so far as I can tell after using bathroom sealant on antenna for many years, it doesn’t.  Could be luck, but I’m not normally lucky.

Waterproof coax connectors are expensive and in my experience have to be fitted skilfully.    I don’t think satellite down cable justifies waterproof coax connectors.  Like as not paying a man to replace the whole run will be better value for money.  Especially after fitting a pricey connector, the cable is found to have wicked water along the braid and it all has to be replaced anyway.

As a temporary test, or even a bodged permanent answer, the cable could be reconnected with an electrical choc-bloc,.  A choc-bloc will cause loss of signal and allow interference in, but if the TV works at all it proves the cable isn’t full of water.   A soldered splice is better, and a well-made coax plug/socket better again.  Best of all is an unbroken cable.   All coax joints are lossy, and those that introduce an impedance mismatch as well are worse.  However, despite quite serious problems the TV will work provided it gets just enough signal, and external interference is low.  Whatever is used to rejoin the cable, it has to be waterproofed.

Dave

 

 

I have to disagree Dave. Self amalgamating tape is about the best there is for waterproofing coaxial connectors. It is certainly better than hetshrink, even the glue lined type.

If properly applied self amalgamating tape forms a homogeneous piece so ther is no  capilary action between layers and it cannot come unstuck. Clearly the is an interface between the cable outer insulation but again if properly applied it’s elastic nature means the contact is intimate and copes with expansion, contraction and flexing. Heat shrink is inflexible by comparison and does not recover if stretched.
The only problem with self amalgamating is it is not resistant to UV light long term. This is easily fixed by a layer of PVC tape over the top.

Robert.

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