Can this coax cable be used for internet?

[rborth]

I'll take tips from whomever I can get them.

I learned of coax noise immunity in school when I got my BSEE. The 'dig safe' guy was commenting on where cables might be buried... not their noise immunity. Like I implied above, I'd avoid routing data with power.

OE

Guys, IMO is tough to give quick answers to complicated topics. To discuss induced noise one can only qualify a transmission system which includes the driving source and topology, the cable and the receiving source and topology and the common mode noise between send & receive. But generally, cables with twisted pairs or quads signal conductors have better immunity to magnetic fields than single signal conductors and overall shield(s) add immunity to E fields when paired with the proper electronics at each end. As in ElectroMagneticInterference.

IMO Running signal / control cables together with AC power supply cables is not a good idea for multiple reasons. Last I checked the US NEC code dis-allows this generally.

I repeat, not a simple topic, my go to reference; Grounding and Shielding: Circuits and Interference by Ralph Morrison, a mere 224 pages.

https://www.wiley.com/en-us/Groundi...and+Interference,+6th+Edition-p-9781119183747

 

[OzarkEdge]

Guys, IMO is tough to give quick answers to complicated topics. To discuss induced noise one can only qualify a transmission system which includes the driving source and topology, the cable and the receiving source and topology and the common mode noise between send & receive. But generally, cables with twisted pairs or quads signal conductors have better immunity to magnetic fields than single signal conductors and overall shield(s) add immunity to E fields when paired with the proper electronics at each end. As in ElectroMagneticInterference.

IMO Running signal / control cables together with AC power supply cables is not a good idea for multiple reasons. Last I checked the US NEC code dis-allows this generally.

I repeat, not a simple topic, my go to reference; Grounding and Shielding: Circuits and Interference by Ralph Morrison, a mere 224 pages.

https://www.wiley.com/en-us/Groundi...and+Interference,+6th+Edition-p-9781119183747

Hey thanks! I agree.

Radio is hard. Noise is harder! I generalized in this thread and got called out for it, rightfully so. I'll be more careful.

OE

 

[rborth]

Heck even fiber can be affected by really strong fields.

Fiber being light based wouldn't that have to be a strong light of the wavelength that that the transceivers have significant response to at a level after fiber cable attenuation? Then again mechanical vibrational interference could interfere with termination losses. Those I haven't heard of before but I guess it's possible? I have no where near the experience with fiber as I do with conductor based communications.

 

[drinkingbird]

Fiber being light based wouldn't that have to be a strong light of the wavelength that that the transceivers have significant response to at a level after fiber cable attenuation? Then again mechanical vibrational interference could interfere with termination losses. Those I haven't heard of before but I guess it's possible? I have no where near the experience with fiber as I do with conductor based communications.

Nope, strong magnetic field (including EMI) can bend, distort, attenuate, even modify the wavelength, but not directly, in reality it is impacting the cable armor or impurities in the glass. I suppose a strong enough field could directly impact the light, most likely slowing it down or attenuating it, or even accelerating it to potentially overcome the speed limitations of fiber (which is less than the speed of light). So far, the acceleration one has not been figured out yet, or maybe in a secret government lab. Granted this is extremely rare, just making the point that nothing is immune. I suppose mechanical/vibration could have an impact, but haven't heard of that. Probably if it happens to hit the natural oscillating frequency of something in the system. Powerful light in theory could do it but rarely is fiber exposed without a protective jacket and the design of fiber is that it would be very difficult to find the right angle of incidence to have it "pierce" the outer clad anyway.

In fact similar phenomena is used in passive fiber amplifiers (EDFAs). Injecting EM energy into the fiber passing through restores the "brightness" of the light (the light actually absorbs the energy) and it is good for another 50km or so. Can do this many many times before it starts to degrade and you have to use an active amp to regenerate a fresh signal. EDFAs eliminate the latency and reliability concerns of an OE-EO amp. In fact they'll often put one right after the output diode, boosting an already blinding (literally) ultra long haul laser even brighter, without having to put in some sort of liquid nitrogen cooled laser that would likely still burn out.

Coolest thing about them is you can amplify multiple wavelengths on the same fiber so it works with WDM and DWDM (though those are a bit more sensitive, so the number of times you can do it is reduced if you have a really dense DWDM with tight spacing).

Those long subsea fibers can have over 100 EDFAs in the path. A cross section of the cable shows that a large part of it is pretty massive power conductors due to the distance.

Guess I'm a bit of a fiber geek. Don't get me started on how impressive the FIOS/FTTP passive network is. I mean, it sucks that it is TDM but the design is still ingenious. And the timing is so fast now that the additional latency of TDM is miniscule. That ONT at your house is actually an exceptionally accurate clocking device (which is also kept constantly in synch from an even more accurate GPS or atomic clocking source).

 

[drinkingbird]

Guys, IMO is tough to give quick answers to complicated topics. To discuss induced noise one can only qualify a transmission system which includes the driving source and topology, the cable and the receiving source and topology and the common mode noise between send & receive. But generally, cables with twisted pairs or quads signal conductors have better immunity to magnetic fields than single signal conductors and overall shield(s) add immunity to E fields when paired with the proper electronics at each end. As in ElectroMagneticInterference.

IMO Running signal / control cables together with AC power supply cables is not a good idea for multiple reasons. Last I checked the US NEC code dis-allows this generally.

I repeat, not a simple topic, my go to reference; Grounding and Shielding: Circuits and Interference by Ralph Morrison, a mere 224 pages.

https://www.wiley.com/en-us/Groundi...and+Interference,+6th+Edition-p-9781119183747

NEC is pretty lenient on data cables. They're really only starting to get involved now that POE++ can easily melt an undersized cable and start a fire. As far as running data and electrical together, they could care less (as long as you don't bundle a bunch of power cables together or exceed the cable fill rules for a conduit, etc). I suppose with POE becoming more common they're probably going to start writing up rules for minimum wire gauge, bundled wires, conduit capacity, etc. So far haven't seen any major revisions yet.

When I rewired my house I took great care to maintain minimum 2 foot separation when running parallel or 6" separation when crossing at 90 degrees. In reality a 90 degree cross is likely going to be fine even if they're touching but why risk it. The electrical inspector was like "why bother just run them all together". Ok buddy, go back to your office.

I have heard that when there is no other option, you can wrap the data cable around the power cable (one twist every 6-12" or so) in an attempt to keep them from being parallel. The theory sounds good, but I also see some potential pitfalls with that idea. And it isn't realistic to do in most cases anyway. In reality, just size up the cable, and make sure it is properly shielded and grounded.

 

[drinkingbird]

I bought this thinking it might be better than the one from Xfinity/Comcast. Should I just return this and use the Xfinity one?

Since this got off topic - long story short, look at your comcast supplied cable. It is most likely PPC (Belden) perfect flex 6 (tri shield with excellent shield density), with PPC EX6 Plus ends on it. Pretty hard to beat that combo. Surprisingly, they give out excellent coax. Yes, it is copper clad steel (CCS) center conductor but perfectly fine, if you insert and remove it 500 times the copper might start to wear off, then just grab another freebie. The mediabridge is also CCS, hard to find coax that isn't. It will have no problem doing 1Ghz, 1.8Ghz, and probably even >3Ghz when that comes around.

I still have a lot of the older PPC quad shield they used, but the perfect flex tri shield is very very close to it in effective shield coverage, to the point that it isn't going to make much difference.

So no reason to buy an $8 mediabridge cable when the one you got free is probably much better. I do like mediabridge, but this is one where they're not necessary.

Heck even the generic black HDMI cables CC gives you work fine. I've honestly never had an issue with one. Probably made by the same place Monoprice gets their basic ones from, and cost under $1 to make but hey, they work. But admittedly for my own use, I use Mediabridge or Bluerigger. Even have a couple monster and audioquest ones I got for free, I would never pay the massive markup on those though.

 

[rborth]

Yep, nothing, even Fiber is completely absolute immune to noise. But can we say less of a probably than inflation, taxes and death which are more of a certainty? Not a partisan political statement, but more of an attempt of humor. ;>)

 

[drinkingbird]

Yep, nothing, even Fiber is completely absolute immune to noise. But can we say less of a probably than inflation, taxes and death which are more of a certainty? Not a partisan political statement, but more of an attempt of humor. ;>)

Make coax great again.

 

[rborth]

Since this got off topic - long story short, look at your comcast supplied cable. It is most likely PPC (Belden) perfect flex 6 (tri shield with excellent shield density), with PPC EX6 Plus ends on it. Pretty hard to beat that combo. Surprisingly, they give out excellent coax. Yes, it is copper clad steel (CCS) center conductor but perfectly fine, if you insert and remove it 500 times the copper might start to wear off, then just grab another freebie. It will have no problem doing 1Ghz, 1.8Ghz, and probably even >3Ghz when that comes around.

I still have a lot of the older PPC quad shield they used, but the perfect flex tri shield is very very close to it in effective shield coverage, to the point that it isn't going to make much difference.

NEC is pretty lenient on data cables. They're really only starting to get involved now that POE++ can easily melt an undersized cable and start a fire. As far as running data and electrical together, they could care less (as long as you don't bundle a bunch of power cables together or exceed the cable fill rules for a conduit, etc). I suppose with POE becoming more common they're probably going to start writing up rules for minimum wire gauge, bundled wires, conduit capacity, etc. So far haven't seen any major revisions yet.

When I rewired my house I took great care to maintain minimum 2 foot separation when running parallel or 6" separation when crossing at 90 degrees. In reality a 90 degree cross is likely going to be fine even if they're touching but why risk it. The electrical inspector was like "why bother just run them all together". Ok buddy, go back to your office.

I have heard that when there is no other option, you can wrap the data cable around the power cable (one twist every 6-12" or so) in an attempt to keep them from being parallel. The theory sounds good, but I also see some potential pitfalls with that idea. And it isn't realistic to do in most cases anyway. In reality, just size up the cable, and make sure it is properly shielded and grounded.

The NEC being insurance company sponsored could care less about actual practical working conditions like noise. Their goal is to reduce failures which could result in insurance claims. For example any co-mingled wires in the same path, conduit or box could be subject to a short or miss-connect that could result in a conductor not being protected by the power conductors supply protection. It had been dis-allowed to run any low voltage power limited cables with supply cables . Any chance a small AWG gauge conductor becoming connected to a much larger AWG power conductor? I'm not going on record saying it's AOK.

 

[Thomas01]

long story short, look at your comcast supplied cable.

Thanks for the advice! I assumed that the Xfinity one is crap and so I had decided to buy one from Amazon so I could get the max possible speed out of my internet plan from Xfinity as well as my new networking hardware. Also I am a complete beginner in networking and after I had already ordering the coax cable from Amazon I noticed most of the reviews did not mention it being used for an internet connection.

 

[drinkingbird]

Thanks for the advice! I assumed that the Xfinity one is crap and so I had decided to buy one from Amazon so I could get the max possible speed out of my internet plan from Xfinity as well as my new networking hardware. Also I am a complete beginner in networking and after I had already ordering the coax cable from Amazon I noticed most of the reviews did not mention it being used for an internet connection.

Coax is coax, that mediabridge one as well as the one comcast gives you both can do video or data (it is all data these days in reality, TV and phone are digital too). The comcast one is perfectly good for 1gbit and higher speeds, as is the mediabridge one. Now if you're running 1 gig or higher you want to make sure you have the right kind of ethernet cables between modem and router (if you have separate modem/router) and between the router and any hardwired devices (if you have hardwired stuff). Cat 5e can do up to 2.5 gigs no problem but at above 1G cat 6 or cat 6A is a bit better (at short lengths it won't really matter, unless you're bundling it in with a bunch of power cables etc).