Dealing with long cables 5

[Nelviticus]

I have a whole heap of electrical spaghetti coming out the back of my PC and I was just wondering whether there are any rules for which cables you can and can't coil or fold up.

I have network cables, A/V cables, power cables and USB cables. I know that network cables should always be coiled and never folded but I'm not so sure about the other kinds. I suspect that it doesn't matter too much for USB cables but I'm a bit worried about what will happen if I coil up the long A/V and power cables - I don't want the latter creating some sort of nasty electromagnetic effect! I know I CAN just coil them all up and nothing catastrophic will happen but signal quality is pretty important for the A/V cables so I wondered if anyone knew what "best practice" is.

Regards

Nelviticus

 

[kmcferrin]

I've never had a problem with coiling any cable. You might run into an issue with video cables if they are not well shielded, but if you use decent cables you should be fine. Anything that transfers data (i.e., network, USB, etc) should already be well shielded enough, and the communications protocol should (in most cases) have error detection and correction built in.

Audio cables are probably where you'll most likely have an issue. Not that they can't be coiled, but that they tend to not be heavily shielded, and EM interference is much more noticeable with audio than other cables.

 

[firewolfrl]

go to the dollar store and pick up their cheap cable ties. they are reuseable. I have stereo's and computer's using them

 

[Nelviticus]

Aha, but before you use cable ties you need to have already folded or coiled your cables.

The thing that worries me is that I have a lot of power cables - PC, monitor, printer, scanner, speakers, router, modem, NAS box - all close to each other, and if I coiled them all up in such a confined space would that a) create a potential heat problem and b) create a strong enough electrical field to interfere with the A/V cables?

My A/V cables are better than the basic budget ones but aren't heavily-shielded professional grade.

Regards

Nelviticus

 

[kmcferrin]

I think that you'll be fine. You definitely shouldn't have any heat issues, and I'd be very suprised if you had any EM-related issues.

 

[Johnthephoneguy]

I use velcro straps instead of cable ties. The velcro isn't expensive and you can unwrap and rewrap with ease, plus you don't have any sharp edges like you do when you snip the cable ties. Even cutting them flush you have this huge knob sitting there that is eliminated with the velcro.

JohnThePhoneGuy

"If I can't fix it, it's not broke!

 

[Gavona]

If you double up the cables before coiling then the EM fields will tend to cancel themselves out - or of course you can simply double and re-double.


Gavin

 

[G0AOZ]

It's unlikely to be a problem unless you have some cables with poor or no screening, but I would try and keep mains leads separated from other leads rather than have 'em all bunched tightly together.

The only thing about coiling up cables is if your coil hits the resonant frequency of the ham radio operator next door who's pumping out a kilowatt or two of RF!

ROGER - G0AOZ.

 

[Nelviticus]

Thank you everyone, I will coil them up and try to keep the power cables away from the others.

Regards

Nelviticus

 

[firewolfrl]

Smak! my head I meant to say the velcro straps at the dollar store.....lol

 

[wahnula]

I worked in the pro sound reinforcement field for a few years...the rule was when audio cable crosses power cables, that should happen at right angles. We used the "BBC" method of cord wrapping, Where you coil once one way and fold the next loop under, no twisting and the cords will always lay flat. But that was big cables and big wattages and big ohmages, but I still use the BBC style for all my card wrapping for storage. I believe in cable discipline!

The cords I use regularly (test mouse, KVM etc) all have a twist tie knotted around the cable at one end for easy storage. For my PC cables I gang similar cables together (USB, PS/2, audio, phone, CAT5) with black twist-ties I have saved from numerous purchases over the years. I try and use different color cables for different devices whenever possible. Then I gang them into one enormous trunk (excluding the power cable, that's always alone) with more extra-long twist-ties. If you have excess wire fold or coil it back upon itself close to the device once the trunk starts reducing in size. For real neat freaks there is the tubing with a slit in it that the trunk goes into and the individual cables come out where needed. I use this in my office and it looks really professional.

NEVER use the permanent zip-ties on external PC wiring, as the second you zip them you will realize you need to add or remove cables.

In case you cannot tell I am a wiring freak, our cell phone charging area has tidy folded wire held by zip-ties leading to their chargers and the excess wire on the answering machine is neatly folded and zipped into place, with of course the excess ziptie cut off.

It's also handy to mount your power strips/UPS on the wall or the side your desk, and gather the A/C cords separately from the others.

Hope I did not scare anyone...but without proper discipline cables will take over!!!

Tony

 

[Gavona]

The "BBC method" is equivalent to the doubling up I referred to. The emf produced by the current flow in one part of the cord is balanced by the emf produced by the current flowing in the other direction in the other bit.

Well documented principles for "structured wiring" include things like not running mains and data alongside each other and minimum distances betewwen parralel runs. Have a look at

http://www.swhowto.com/Reference.htm

for example.

If you want test things make up some unshielded cable to connect your mike to the PC and try running alongside a mains cable carrying a hefty current. See what the impact is of coiling, BBC coiling or doubling up. Then work on the principle that the less work the shielding on cables has to do the better will be the data transmission rate and or quality of signal. I've never done this as a controlled test but did discover it by accident years ago.


Gavin

 

[Nelviticus]

More excellent info, thanks! I don't quite understand the BBC method though - "coil once one way and fold the next loop under" - does that mean you make two loops and then kind of twist one around?

Nelviticus

 

[gbaughma]

Yeah... I'd be interested in seeing how that works. I work part-time in a professional lighting company.

We never "arm wrap" cords, we do an arm-length, then twist, so they coil up nice. But they never un-coil nice. I keep teasing the boss about buying self-tangling cables.



Just my 2¢
"Life gets mighty precious when there's less of it to waste." -Bonnie Raitt "Nick of Time"
--Greg

http://parallel.tzo.com

 

[Sympology]

Also use shorter cables!

Sounds daft, put how many people have standard 2m power cables?

I have my power strip attached to the back of the unit and the cables are cut to correct lentgh (with a little slack).
I use cat5's anywhere from 10cm up.

You could also make a swing arm, similar to servers.

all you need is a couple of pieces of wood, hinged at both ends and the middle. You attach one end to desk, other to pc. The cables are strapped to these using velco ties and hey presto, you can pull out you pcs, but all the cables stay neat and tidy when you put it back.

Stu..

Only the truly stupid believe they know everything.
Stu.. 2004

 

[LawnBoy]

I've never heard it called the BBC method but yeah that works beautifully. Every other "twist" is in the reverse direction. Keeps 'em nice and flat when you uncoil.

I had to have a guy show me before I 'got it', not sure if I can explain it well...

 

[gbaughma]

Lawnboy:

Can you find a link or something to a demonstration/illustration?



Just my 2¢
-There once was a man from Peru
Who wanted to write a Haiku
but...

--Greg

http://parallel.tzo.com

 

[Gavona]

I guess the "BBC" technique is as described at the foot of this article.

http://www.lavacable.com/cable_101.htm

Easier said than done I reckon!

Also found a link explaining why sheilded twisted pairs are best.

http://www.wici.com/technical_info/articles/wiring/wiring.htm

for the full article


Gavin

 

[wahnula]

The best way I can describe it is you twist once normally, hold the loop in your left hand. Then, the next loop, slide your right hand a good ways down the cable, then you spin (twist) the cable clockwise between the right thumb and forefinger and let the loop fall to the back side of your wrist. Then grab the cable from your right thumb with your left hand and repeat. When you are done, you should be able to grasp the end, and throw the cable out in a straight line. But keep your cable ends identified...if you grasp the wrong end and throw you will end up with a knot every 1 foot or so! This is one method of determining if your wrap is correct.

As for the "BBC-style" label, I got that from the lead sound engineer, he had been taught the method in college (!) and that's where he got the name, I got the name, and now everyone one this board gets the name. Is it correct? Don't know, but that's how U. of Miami sound engineers refer to it. I have also heard it called "firehouse style" or "fireman style" as it also is a great way to coil hoses so they can be pulled quickly without kinking.

We wrapped everything this way...from a 100' 48-channel audio snake (coiled on the ground) to 6' guitar cords. I have stage cords that are over 20 years old and still look new.

Tony

 

[LawnBoy]

I learned it playing roadie in my younger days. I also learned the Stagehand's Axiom:

Never lift what you can drag,
Never drag what you can roll,
never roll what you can leave.