Re: Repairman's knot


"N Cook" <diverse8@xxxxxxxxx> wrote in message
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Geoffrey S. Mendelson <gsm@xxxxxxxxxxxxx> wrote in message
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Ron(UK) wrote:

Presuming you mean to get rid of excess length of cable when the gear
is
installed. Don,t coil the cable, zigzag it.

I think what he means is something I was taught in electric shop in
junior
high school (1967?) called an electrician's knot.

Here's a drawing of it:

http://www.mtechnologies.com/building/3-fig3.jpg

and a description:
http://www.mtechnologies.com/building/atoz3.htm

I've often cheated in places where the cable was already run and did not
want to cut it to tie the knot by taking a large nylon cable tie (aka
Tie-Wrap) and placing it around the wire inside the unit. Be sure
to leave some slack so that if the wire is pulled it stresses the
cable tie, not the wire.

Geoff.

You are right about coiling the wire, it will create a magnetic field.
The one exception to that rule is coax, it can be coiled.





--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@xxxxxxxxxxxxx N3OWJ/4X1GM
IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice:
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Visit my 'blog at http://geoffstechno.livejournal.com/

Not that one.
For storing or just shelving unused equipment , so the mains cable was not
trailling about and no need for ties of any sort. All the cable is taken
up
into the hank/knot leaving just the mains plug exposed and all tight up
against the back of the chassis.
The person who showed me years ago how to do it , went overboard.
It used to annoy me that the bunching was so close to the chassis and
bunched so tight you needed a screwdriver to open up the knot and there
was
always a tight spiral of cable for 6 or so turns when undone that stayed
like that. I've long since forgotten how to do it.
I invented my own that did not deform the cable so much and easily undone
by myself or customers, but you cannot form it right up close to the
chassis.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/


Here's the one I was taught. Assuming that you are right handed. Zig-zag the
cable in your left hand, starting up close to the equipment, and making the
zig-zags about 8 inches. Make about 5 or 6 of them, which should have used
up about 1/2 to 2/3 of a 'normal' cable length. Stop zig-zagging when the
cable end, with plugtop, is away from you. Now take the remaining cable in
your right hand, holding it close to where the zig-zagged piece is hanging
out from your left fist, and take a single tightly pulled turn around the
end, winding away from yourself. As you complete that first turn, angle the
cable in towards your left hand, so that it crosses over the point where
that first turn started from. This locks the turn in place, and now you can
just go ahead and keep winding the spare cable around, feeding the
zig-zagged piece out of your fist, as you go. If you've judged it right (
years of practice ! ) You should get about 11/2 inches from the equipment
end of the zigzags, when you have about 6 or 8 inches of cable left. This
last piece of cable is formed into a squashed loop, and fed through the end
loops of the zig-zags. It is then pulled back over the zig-zag loops, and
finally, you pull on the plugtop, which pulls the last loop in nice and
tight. This method is the neatest I've ever seen, and NEVER comes undone on
its own, unlike attempts that I've seen many engineers make, to reproduce
something similar. Where they usually go wrong, is wrapping in the same
direction as they made the zig-zags, This fails to lock that first turn in
place, so the whole wrap becomes loose and sloppy. It's a lot easier to do
than describe, but if this is the standard old repairman's wrap that you
were looking for, I'm sure it will come right back to you as soon as you try
to follow this.

Arfa


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