Suggestions For a Coax-To-Ethernet Solution? 608
watanabe writes "I just moved from a house with Cat5e wiring to a house with ... a whole bunch of coax cables. Like, my living room has five coax cables coming out of a hole in the wall. All of them go back up to my attic.
The house is big, (and I like it, thank you), but I have realized that our digital usage pattern (media server + squeezeboxes + remote time machine backups to a linux box) will not work without wiring. I am currently bridging some old Linksys WRT54Gs to the right places, but of course, that slows everything down.
This got me thinking: 100mb ethernet is four wires, yes? And I have four wires for every two coax cables. What about a two coax-head -> ethernet jack setup? Has anyone done this before? Searching online only gives me $100+ coaxethernet transceiver type boxes. At that price, a HomePNY system would make more sense.
I'm willing to solder if I have to, but I first wanted to get advice and holes shot in my plan, if there are any."
Re:Use the Coax as a wirepull for the cat5 (Score:5, Informative)
</2cents>
Bite the bullet! (Score:3, Informative)
PLUS... Dude, you're going to want gigabit eventually - and it uses 8 wires and is even more sensitive.
Bite the bullet - use the coax as a guide and hook up an ethernet jack in every room that needs one. Use CAT-5E cable or CAT-6 cable so gigabit connections will work. And then buy yourself a gigabit switch, and piggy back it onto your WRT54G to handle the internet routing (or buy a gigabit router). Good luck!
MoCa (Score:5, Informative)
Re:10Base-2? (Score:4, Informative)
Except 10Base-2 is 50ohm coax, while TV coax (which is probably what he has) is 75ohm. Nope, not going to work.
Damn, I wanted to use a cute unicode omega, but apparently
Re:Use the Coax as a wirepull for the cat5 (Score:4, Informative)
Also, check building code in your area, as you may have to buy plenum insulated Cat6e as opposed to the cheaper PVC. Some jurisdictions actually restrict the use of PVC, even when it is behind a wall.
I went through and did this for a friend quite a few years ago (replaced all his phone cabling with Cat6e) and had an electrician friend of mine give us advice before we started. The electrician said we were OK to run the cabling ourselves, but we had to use plenum since that was what code required. The cabling was twice as expensive as PVC, even when bought in bulk. We also ran slip lines, which has been a god-send for my friend since he had to then follow up a year or so later and run more lines through to his home theater.
Re:Use the Coax as a wirepull for the cat5 (Score:1, Informative)
It won't, no way, no how. The capacitance of the coax cable will screw the whole thing up. You'll get relfections and crosstalk *everywhere*. What you need is an old fashioned 10Base2 card designed for coax, you need terminators and you need to make sure the cable is of the right impedance.
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
Far cheaper to pay someone to run cat5e for you. Around here it costs $100.00 a run for cat 5 runs under 120 feet. that includes new wallplates and termination at each end.
OP doesn't want to pay $100 (Score:3, Informative)
Searching online only gives me $100+ coaxethernet transceiver type boxes.
Anonymusing wrote:
If the wire is nailed down (therefore not free to be pulled), perhaps he could use an Ethernet-over-coax adaptor [amazon.com] or this one from Netgear [amazon.com].
Amazon wrote:
Ethernet-over-coax Converter/extender: $148.99
Netgear MCAB1001 MoCA Coax-Ethernet Adapter Kit (Black): $180.91
I imagine the OP was looking for a cheaper way to do this.
Clarification (Score:2, Informative)
Just wanted to clarify that Ethernet refers to a standard, not a cable. You can have ethernet over UTP, coax, fiber, etc...
If the coax in your walls is RG6, that's probably better than Cat5.
Homes with Fios or UVerse have nifty little coax to rj45 boxes that allow for the home networking setup.
Re:10Base-2? (Score:5, Informative)
yes it does. you impedance match the ends with baluns.
I did that a LOT back in the day of 10base2 when the office owner would not pony up for running wires.... yet he paid 2X that for baluns and impedance matching...
Re:Use the Coax as a wirepull for the cat5 (Score:2, Informative)
Hmm... I think you're replying to someone who is saying that you can use the coax to pull UTP cable. While using the coax instead of UTP won't work, using it as a pull cord should be OK.
Re:ATT Uverse runs over coax (Score:2, Informative)
Not very likely. Instead, they use one of the "cable modem" protocols, perhaps DOCSIS.
U-Verse uses HPNA for the coax networking.
Nope (Score:3, Informative)
First, to the original question. D-Link makes a product that lets you do this. Not that I'm recommending you buy their product, but they claim that, due to bandwidth limitations, your performance would be lower than 802.11n. Now D-link is doing some signal processing, before the packets hit the wire, so I suspect that trying to run a raw signal over coax will produce less than reliable results.
To all those people recommending using the coax to pull cat5 - that probably won't work. Generally the coax will be stapled or otherwise tied to the studs.
Character encoding (5:erocS) (Score:3, Informative)
Re:Clarification (Score:2, Informative)
Furthermore, googling around for RG6 to RJ45 yielded some results.
Network Video Technologies makes adapters that go from coax to rj45
http://www.nvt.com/ [nvt.com]
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
Um, "complete failure to understand parent post"?
This thread is talking about using the existing coax runs to wirepull Cat5 through the walls, not trying to run signals through the coax.
In theory, one could use four 50 ohm coax cables to run 100BaseT - Two 50 ohm single-ended coax cables can be used to form a 100 ohm differential connection, same characteristic impedance as Cat5 but with a hell of a lot more shielding and isolation.
However, if they were 75 ohm TV connections, they're useless as anything other than a physical cable to attach another cable to for the purposes of pulling it through the wall.
Re:Use the Coax as a wirepull for the cat5 (Score:4, Informative)
Another alternative (Score:5, Informative)
Re:Use the Coax as a wirepull for the cat5 (Score:5, Informative)
You do realize ethernet originally ran over coax, right? Google '10BASE2'
Only problem with that is 10Base-2 ran over 50 ohm impedance coax while CATV coax is 75 ohm impedance. The mismatch would reduce the power delivered to the receiving end and set up a standing wave that would deform the wave shape, possibly causing errors.
Re:Use the Coax as a wirepull for the cat5 (Score:5, Informative)
As for the question posted by timothy, it is by another slightly electronics-illiterate poster. The statement, "This got me thinking: 100mb ethernet is four wires, yes? And I have four wires for every two coax cables. What about a two coax-head -> ethernet jack setup?" needs to be examined here. You can't just assume that since Ethernet "is four wires" you can use any four conductors as a layer 1 transport. That might bring house electrical wiring into the equation. No, we can't do this since we are talking about transmission lines, and everything has to be impedance matched, and the PHY has to be able to handle what the symbols look like on either end of the line. We aren't talking DC here--there is a lot more involved to high speed communication links than "wiring stuff up."
So, I would either go with a coaxial media adapter or use the coax to do new Ethernet cable pulls.
Re:Use the Coax as a wirepull for the cat5 (Score:5, Informative)
Attach a CAT5/6 AND a string, and pull like hell. You'll be glad you have a string in the wall when you want to pull CAT7.
Just remember, when you attach something to the string, always attach a new string too. It sucks when you finally finish pulling a run, only to have forgotten the replacement string.
Wow... what are the odds (Score:5, Informative)
I was just searching for this same thing today and a friend of mine suggested this product:
http://www.netsys-direct.com/proddetail.php?prod=NH-310CEKIT&cat=27 [netsys-direct.com]
It's a 200Mb ethernet-over-coax solution that makes use of existing coax installs and uses traditional cable. We'll be testing it soon for a 200 metre install.
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
Similar project for me (Score:4, Informative)
If you can't repull (Score:3, Informative)
Re:Use the Coax as a wirepull for the cat5 (Score:5, Informative)
The crimping pliers I use cost about ten bucks, and I've produced one bad cable out of twenty - and that was the first one I'd ever made. When that happens you cut off an inch and redo.
Plus, if you're installing it fixed to a wall you'll likely use box sockets. The terminals on those are usually screw fit.
Here are some other products that will work. (Score:2, Informative)
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
Re:Why not wireless? (Score:1, Informative)
Basically, yes. Even 150Mbps isn't all that great. I happen to be one of those people who uses 802.11n for the house network because I couldn't run cables, and frankly, I'm rather unhappy about it. Big files don't copy as fast as they could, sometimes (though not as often as I feared) video stutters, etc.
Wireless is cool tech, but it is totally inferior to wires in situations where you can run wires. And maybe some day there will be wireless gigabit, but imagine how fast wired ethernet will be then.
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
The ones I got were pre-labelled and didn't require any crimping (just stripping the outer shell off). It looked more or less like this - http://www-personal.umich.edu/~csev/hng/book/06wiring/female.jpg [umich.edu]
Those clipped into the faceplate and my walls look nice and professional -- even though I did it myself. Regular pre-made cables from the wall to my devices.
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
However, pull gently, and coax it the whole way (pun not intended). If the coaxial runs through pipes, you'll probably run much less risk of stripping or breaking the Cat5/6. Almost none if you find a gallon or so of wire lube at Home Depot or Lowes and grease the hell out of the new cable as it enters the pipe. Just be sure to trail a strong cord along with it so you have another pull if you want to pull another line in later. If you test it and it doesn't work because a wire stretched too much, you can just pull another (trailing in another pull string).
Also, test the wires directly by twisting them all together at one end and connecting a bell/battery gadget to pairs at the other. When you ring the bell, both wires are good. If it doesn't, one or both are bad.
And if it were me, I would absolutely work on getting an updated Cat5/6 line in the house. Barring that, go wireless. The coaxial solutions are more expensive and in my experience, rarely come close the current wireless options. Good luck!
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
Re:MoCa (Score:3, Informative)
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
That's what I was thinking.
100BaseT is on twisted pair 100 ohm impedance.
Simply wiring up to the shield and conductor of the coax won't work worth a damn (50 or 75 ohm will cause bit error rates like hell).
Get a balun transformer that matches 100 ohms to 75 or 50 ohms (depending on your cable) and two cables + 4 baluns = one 100 meg run.
That said, the baluns have to work at 125MHz, and you'll find they are quite pricey. You'll likely want to simply pull new cable.
-nB
Re:That's not how coax works (Score:5, Informative)
Really? You might try telling that to Netgear [netgear.com] or D-Link [dlink.com] or any of the other companies that make Coaxial Ethernet Bridges [google.com].
This whole story could have been avoided if the poster knew the right term to Google.
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
Because coax was so unreliable it would make network admins cry.
In the good ole lan party days, the network would be disrupted every time someone needed to connect or disconnect a pc. Sometimes you had T piece that was a bit faulty and that also nuked the network. And when you had 12 machines on the network, finding the source of the error was even harder.
Performance was only a secondary reason for it's demise.
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
You don't need impedance transformers in this case. 75 Ohm terminators (in place of standard Ethernet 50 Ohm) will do the trick. These are much cheaper and can be hacked together at home if not found in stores.
10BaseT cards have high impedance transmitters and receivers that can drive/receive wide range of cable impedances, as long as the cable is matched at the ends (to avoid reflections).
Punchdown is much esier than crimping patch cable (Score:2, Informative)
I am all fingers when crimping cables but I punched down around 20 cables in around 2 hours.
Re:Use the Coax as a wirepull for the cat5 (Score:2, Informative)
You have two choices for the (good) wall sockets. Either pay a high price each, or a low price but buy the tool. When I wired my home I paid the low price each + highly priced tool and got the tool back the next day for a full reimbursement ;)
Yeah, that's called theft in the retail world. You bought a product, used it for its intended purpose successfully, and then returned it to the store for a full refund. The retailer is kind enough to offer this return service under the assumption that returns are because it didn't work for you, was defective, or some other honest reason. But it did work for you, wasn't defective, and your return for a full refund was dishonest.
They have a now-devalued used return item that they can no longer sell at the full price. You deprived them directly of that value as if you'd stolen the money from their pocket.
You are a thief and an asshole.
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
Before FIOS used the full routers standard, they use a Coax transciever and you can pick them up for about $100, sometimes cheaper, for 100Mbit over existing Coax.
Re:Use the Coax as a wirepull for the cat5 (Score:2, Informative)
Re:Use the Coax as a wirepull for the cat5 (Score:1, Informative)
If you went to engineering school: you were not paying attention. If you got this from a book or website: you need a new source, or possibly learn this stuff again. This would be filed under: transmission line fundamentals.
A cable can be approximated by having some distributed capacitance between the conductors, and some inductance along the conductors. These of course can be expressed in C/l (say F/m) and L/l (H/m). The combination of the inductance and the capacitance per unit-length gives you a characteristic real impedance that is independent of length.
You terminate the line with the characteristic impedance so that all the energy going there is absorbed and dissipated.
A real transmission line has a spec in ohms/meter: the loss. The loss can be modeled as a series resistance and a parallel conductance, which forms a real impedance (resistance) in ohms/meter. However the loss is a dissipative factor and for the short runs typically encountered in Ethernet (including Coax) can usually be ignored.
Motorola NIM100 coax bridge (Score:3, Informative)
Re:Use the Coax as a wirepull for the cat5 (Score:3, Informative)
pfft, kids these days. you can make them quite simply yourself with very cheap components (one of which could even some cat-5 wire pulled apart), hams have been doing it for decades. tons of info on the web, try "balun"