OT - Pendant Light Cable

"JDS" wrote in news: snipped-for-privacy@corp.supernews.com:

It seems to be normal RG-58/59 coax with the outer insulation stripped off.

Radio Shack sells it cheap but you'd need to strip off the outer insulation.

You know, at 12 volts, that's five amps. The voltage drop at 75 feet is going to be pretty brutal because this is very low voltage. You'd have to use 6 gauge wire to keep the drop under the recommended 2%. In reality, I'd think 12 ga would be okay, but your lights won't be quite as bright.

Just food for thought, when you go looking at that cable. Due to the distance and low voltage, it needs to be pretty thick...

Appearances can be deceiving. I'm pretty sure this is not rg-58 type coax. There are *lots* of different kinds of cable.

Steve

You know, at 12 volts, that's five amps. The voltage drop at 75 feet is going to be pretty brutal because this is very low voltage to move 60 watts. You'd have to use 14 gauge wire to keep the drop under the recommended 3%. In reality, I'd think 16 ga would be okay, but your lights won't be quite as bright.

Just food for thought, when you go looking at that cable. Due to the distance and low voltage, it needs to be pretty thick...

On Sat, 9 Dec 2006 22:36:38 -0800, with neither quill nor qualm, "JDS" quickly quoth:

Grab some R-59 and a heat gun. String out the cable and heat the jacket, stripping it off the far side as it melts. Piece o' cake. ;)

If you have one, a good jacket stripping gun -might- do the trick without cutting the shield.

Thank you for the great suggestions, everyone. The actual length of the 4 finished cables will be around 14 ft. Hmmm, a heat gun is one thing I don't have in my arsenal of tools - I must get one! Jim

On Sun, 10 Dec 2006 07:21:03 -0800, with neither quill nor qualm, "JDS" quickly quoth:

I've had my $15 ($10 on sale) HF heat gun for a couple decades now. They're well worth the meager price. I stripped paint off an entire kitchen worth of cabinet doors (and learned to replace the doors next time.) and it never blinked. It survived a move, too.

What you have here is NOT coaxial cable. It is shielded wire. The practical difference from your standpoint is the size of the center conductor. Coax (RG-59, for example) has a very small center conductor (high loss, if you put much current through it) and a very precisely made insulator (dielectric) between it and the outer braid. It is true that you can get higher current coax, but it will be very large in diameter.

Shielded wire, on the other hand, is simply a piece of insulated wire of whatever guage you want (I've seen it from #30 all the way up to #8) with a shielding braid around it. You can get it both with and without an outer jacket. You can also get a spool of shielding braid in assorted sizes (I once got some to jacket a cable 1 1/2 in. in diameter...). You simply push it together like a Chinese Finger Trap, slip your wire(s) through it and stretch it back out again. It's easy to do unless your wires are longer than 30 ft. or so...

Try an electronic surplus store...

Jerry

The conductor on RG59 is about 20 to 22 gauge. You will loose almost a volt over 14' at 5 amps. Consider RG8U which is 13 gauge. Less than .2 volt loss and the thicker profile will probably look better too.

Just be sure you get coax with a tinned full braided shield. You find a lot with only a sparse braid and aluminum foil shield which would not look good at all.

With 10.0 amps DC flowing thru it the drop in 1 foot is 61.7 millivolts, so 14 feet carrying 5 amps would drop about 0.43 volts in the braid. It's equivalent to about 17 gage wire.

I think I have some-probably a lot--you should be able to read the mil-spec # and the gage if you slide the shield back---I'LL LOOK TOMORROW MORN--Jerry

Thanks to all of you! This is on the wire: AWM FEP 1332 18AWG

According to RAM³ :

Nor is there *likely* to be much of a response. That is not electrical engineering, just wiring. (This is assuming that any electrical engineers even *read* the alt newsgroup. Looking at the active file article counts, I think that it is a pretty inactive newsgroup.

No -- I don't think so. It looks more like single-conductor PVC insulated with a braided shield. The center conductor is heavier than RG-58 or RG-59 (for higher current), and the insulation is not as thick. At a guess (without seeing the center conductor bare), that is something like 16 Ga stranded wire.

Go to some electronics supplier like Digikey, or Mouser or Allied or Newark. If you've got a local industrial supplier, that may do, but you may have to by an entire spool from there.

Or -- you could buy plain PVC insulated single conductor, and a separate spool of braid. Push the braid to shorten it, and expand the size, then slip the wire through, and pull on the ends of the braid to shrink it to fit your wire. (You'll need to get the right size to be a good snug fit, of course.)

That's not really what you are looking for, I think. It is likely to be solid center conductor, not stranded, and thus won't take the flexing of a pendant over time -- even assuming that the center conductor can handle the current.

Good Luck, DoN.