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Coaxial cable

tortuga

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
hbiss said:
Interesting to note that it's one of the reasons that the Code limits the length of OSP cables in buildings. The flooding compound is flammable and underground cable is required to go directly to a terminal in the building that has a steel compartment with a cover for the pairs to be punched down.
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Interesting I did not know that.
 
hbiss

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Incidentally, while IT weanies and BICSI insist on using nothing other than Velcro straps to bundle cables because they are soft and gentle, I have no problem with Ty-Raps as long as you keep them loose enough to not deform the cables.

-Hal
 
2

25yrApprentice

Member
Location
Denver, Colorado
Occupation
Specialty Electrical Contractor
hbiss said:
Haven't seen any, except for some things you said.
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Wow Hal, getting spicy with the new guy huh?! I'll have you know I was pulling cable since you were in diapers. The adult kind :ROFLMAO:
hbiss said:
Staples? That's not true, they are fine. But yes, anything that deforms the cable will cause problems. Preferably use insulated staples (because the plastic won't damage the cable) and don't sock them down. Stay away from staple guns, but sometimes you can't when you are doing exposed work. At least use the proper size staple and don't sock them down either. You should be able to slide the cable through the staple to show that it hasn't been compressed.
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Should we ask Ron Tellas over at Belden what he thinks about that statement? I thought this forum was for professionals, not home owners and hacks! ;)

The truth is, the only time it is acceptable to use electrical staples on coax or category cable is when you only have one box of cable on your truck and you're in a crawl space and you need to run a few drops to the same place so you lightly tack up a few staples to help route the wires. I'm ok with it as long as you go back and remove the staples as you screw clip those wires tight and neatly in place. But seriously, if you think it's ok to tell an apprentice to take a hammer and hang up this data cable in my client's home or business, I don't want you on my job.

I'm also ok with staples (with plastic inserts) on speaker wires, sprinkler cable, security wire and thermostat wire. In other words, "staples are for dummies" lol. Get it? Wires that don't communicate? Dummies? Yeah, stupid joke, sorry.

hbiss said:
Rule is that copper clad steel is economical for anything that isn't carrying power. For SAT dishes, etc. where the cable carries power also, always use a cable with a solid copper center conductor.
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I'm pretty sure that's what I said. Let me look... Yup, that's what I said.

hbiss said:
The jacket on direct burial cable is polyethylene (like sprinkler pipe) as opposed to PVC. Direct burial cable is filled with a flooding compound, variations look like grease, goo, etc. The flooding compound keeps any water that might enter through a nick or cut in the jacket from entering the cable or, if it does, from migrating along under the jacket. No, it does not coagulate.
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If you're going to correct me Hal, at least be right. You are getting confused between "underground" cable and "direct burial" cable. To be clear, I said "Direct Burial".

"Underground" cable jacketing is made from either PE for it's temperature resistance, or CPE (chlorinated polyethylene), for better water intrusion characteristics, but you are correct that it does need to be in conduit because it is also not "waterproof enough" or crush resistant. It does have a polymer gel flooding compound that resembles "goo" and you are correct that it is flammable and not to be run through a firewall outside of metal conduit and metal termination boxes.

"Direct Burial" cable jacketing is made from a thicker and chemically crosslinked CPE that is designed to be DIRECTLY BURIED in the ground with no conduit necessary, because the jacket must meet the same standards of crush rating, temperature resistance and water intrusion as a conduit would. It is filled with a *what? OMG* formulated powder tape that... wait for it... COAGULATES! when exposed to water to stop water intrusion from spreading. And you're going to love this last part Hal. It also carries a PLTC rating for flame resistance, so it can be run directly from outside to inside locations at any length up to 330' or 100m as per the usual, because of this specially formulated coagulating powder coated tape vs the flammable "goo".

Source: Used to work for Belden's largest distributor CSC and got to go to their manufacturing plant for a week long training on cable manufacturing. Super cool company.

-your new favorite IT weenie

PS Seriously, I hope we can be friends. My New Jersey self righteous attitude loves that New York I'm better than you arrogance.
 
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Z

zbang

Senior Member
Location
Roughly 5346 miles from Earls Court
You don't need to defend your honor, you need to defend your answers.

25yrApprentice said:
1. RG59 has higher loss over long runs, ...
2. RG59 with copper braid is used for analog surveillance cameras.
3. Quad shield has mid level loss compared to standard dual shield RG6...
4. Only cheap chinese RG6 and RG59 copper braid has no foil. ...
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All the blather about which RG is better is pretty much useless expect for overall size and impedance, give us a proper description or a mfg number. Baseband video? Belden 8281 was the bees knees (and IIRC "RG11") but was surpassed by 1694a (and 8241 worked fairly well, too). Want to run a DS3 signal? AT&T 743a is the usual ticket and could count as RG6. How about HD-SDI video? 8281 will do but 1505 (RG59 type) or 1694 (RG6 type) are common. Pick your acceptable loss/jacket material/size and run with it.

25yrApprentice said:
5. Don't use metal staples on coax (or cat5/6 for that matter). It causes frequency trapping. Use coax screw clips. Pinching the dielectric foam changes the frequency response.
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Citation please, the shielding should prevent external metal from affecting the signal. That said, don't hammer down the staple and crush the dielectric; that's a separate thing from the material. (It's interesting to see the signature of a crimp/crush on a TDR trace, spent a lot of time looking for those in the 90s.)

25yrApprentice said:
8. Never use hex crimped F connectors.
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Why not? unless you're using the wrong crimper with the the wrong connector which is destined to fail (connector and crimper should always match, especially when there are minute differences in jacket diameter).
 
Z

zbang

Senior Member
Location
Roughly 5346 miles from Earls Court
Yep, when I was doing PA/FA/burglar in the mid-atlantic, it was always West Penn unless the bid docs said otherwise. When I started going video work, the A & V were usually Belden, Canare, or occasionally CommScope, but control lines were still often WP.
 
W

waxerk5

Member
Location
California
Occupation
Contractor C7 & C10
nizak said:
Is there any performance difference between RG6 and RG6 Quad Shield?

Does the box store cable perform as well as what would be provided by say Charter for example.

It all appears to be 18 gauge.

Thanks
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What is the usage for? By performance difference, are you referring to the loss?
 
hbiss

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Is there any performance difference between RG6 and RG6 Quad Shield?
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Depends on the environment as talked about above.

Does the box store cable perform as well as what would be provided by say Charter for example.
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Dunno. What is the Big Box cable and how do the specs compare to whatever Charter uses? Loss vs frequency, shielding, etc. Then of course, like anything else today, is the Big Box stuff cheap Chinese junk or made by a reputable company.

It all appears to be 18 gauge.
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Nothing to do with anything except the 75 ohm cable impedance of an RG6 type cable.

-Hal
 
G

gene6

Senior Member
Location
NY
Occupation
Electrician
25yrApprentice said:
4. Only cheap chinese RG6 and RG59 copper braid has no foil. UL listed RG6 used in cable plant transmission and satellite tv etc is dual shield, has a layer of foil on the outside of the dielectric, followed by a certain percentage of aluminum braid (good stuff is typically 70%, but only american brands like belden actually meet their own spec).


Any questions?
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Is coax required to be UL listed in the NEC?
I am not even sure what the stuff we pull in new homes is, but I have never seen a listing mark on the boxes.
Sometimes the stuff we rope in is a coax with a cat-something all in one cable, or like two of each (4 cables).
 
hbiss

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
gene6 said:
Is coax required to be UL listed in the NEC?
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Yes. Just like any other CL2 or CM cable it comes in general, riser and plenum. Within a building, you must use a cable that has the proper listing printed on the jacket to be code compliant. For some reason not all cable will have the listing printed on it even though it is on the label on the reel or box. Naturally, the cheap Chinese stuff will never have it. I always had to make an issue of it with the supplier that I had to have cable with the listings printed on it.

-Hal
 
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