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Suggestions For a Coax-To-Ethernet Solution?

timothy posted more than 4 years ago | from the point-to-point dept.

Networking 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."

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Use the Coax as a wirepull for the cat5 (5, Insightful)

mtippett (110279) | more than 4 years ago | (#31187324)

If you have lots of coax running through pipes and if it is free, then use the coax as a wirepull to rewire the house.

Cat5 provides many more options than cat5.

Re:Use the Coax as a wirepull for the cat5 (2, Interesting)

ItsPaPPy (1182035) | more than 4 years ago | (#31187346)

Damn you beat me to it. As i was going to say the same thing. Attach your CAT5/6 to the end and pull like hell.

Re:Use the Coax as a wirepull for the cat5 (1)

negRo_slim (636783) | more than 4 years ago | (#31187430)

Since when did we stop using Coax for networking? Granted Cat5/6 is the way to go but back in the day it was not uncommon.

Seems like it's still kicking in one for or another... [newegg.com]

Re:Use the Coax as a wirepull for the cat5 (1)

mattventura (1408229) | more than 4 years ago | (#31187694)

You do realize ethernet originally ran over coax, right? Google '10BASE2'

Re:Use the Coax as a wirepull for the cat5 (2, Insightful)

frooddude (148993) | more than 4 years ago | (#31187724)

Looks like paying a pro to run Cat5 would be cheaper than these things all over the house.

Re:Use the Coax as a wirepull for the cat5 (1)

SatanicPuppy (611928) | more than 4 years ago | (#31187732)

Yea, but jesus it sucks. You'd get better performance and throughput by just putting in a couple of WAPs.

Re:Use the Coax as a wirepull for the cat5 (1)

Icegryphon (715550) | more than 4 years ago | (#31187728)

HIVEMIND, Me too

Re:Use the Coax as a wirepull for the cat5 (5, Funny)

0racle (667029) | more than 4 years ago | (#31187362)

Actually, I have found that Cat5 provides just as many options as cat5.

I admit though, my testing may not have been exhaustive.

Re:Use the Coax as a wirepull for the cat5 (1)

Hatta (162192) | more than 4 years ago | (#31187380)

I was going to say the exact same thing. I needed to bridge my upstairs and downstairs networks. I was able to use the existing runs of coax to guide my cat-5 up the wall. Just bought a new face plate with an RF-45 and F-connector and widened the existing hole a little bit.

Re:Use the Coax as a wirepull for the cat5 (5, Informative)

UID30 (176734) | more than 4 years ago | (#31187414)

If the coax was installed when the house was built, then the coax is probably stapled to the wall studs. If the coax was installed "after-market", then this trick might work.

</2cents>

Re:Use the Coax as a wirepull for the cat5 (1, Informative)

driftingwalrus (203255) | more than 4 years ago | (#31187666)

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 (2, Informative)

eam (192101) | more than 4 years ago | (#31187744)

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:Use the Coax as a wirepull for the cat5 (2)

mtippett (110279) | more than 4 years ago | (#31187466)

Aargh. Cat5 provides many more options than coax.. My bad.

Re:Use the Coax as a wirepull for the cat5 (1)

Anonymusing (1450747) | more than 4 years ago | (#31187534)

If the wire is nailed down (therefore not free to be pulled), perhaps he could use an Ethernet-over-coax adaptor [amazon.com] .

Re:Use the Coax as a wirepull for the cat5 (2, Interesting)

Anonymusing (1450747) | more than 4 years ago | (#31187578)

Or this one from Netgear [amazon.com] .

Anyone have experience with these?

Re:Use the Coax as a wirepull for the cat5 (2, Informative)

Lumpy (12016) | more than 4 years ago | (#31187668)

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 (2, Informative)

tepples (727027) | more than 4 years ago | (#31187678)

watanabe wrote:

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.

Re:Use the Coax as a wirepull for the cat5 (0)

Anonymous Coward | more than 4 years ago | (#31187600)

But what if I want cat5 and coax? I tried it once before, but I ran into an infinite loop situation.

Cat6 (0)

Anonymous Coward | more than 4 years ago | (#31187620)

Run Cat6.

HomeDepot got spools of the shit for OK prices and then there's these guys [mycablemart.com] that the electricians like and they're much cheaper than the big box stores.

As bandwidth improves and since you're using it for home entertainment, get the Cat6.

Re:Use the Coax as a wirepull for the cat5 (1)

Lumpy (12016) | more than 4 years ago | (#31187624)

Exactly!

  because I bet that it is all crappy RG59 cable and not RG6 or RG6Quad that would really be needed.

If the house was wired more than 7 years ago the coax in it is pretty much garbage.

It's also not hard to run new wires in existing homes, I dont know why people are so scared of it.

Re:Use the Coax as a wirepull for the cat5 (4, Informative)

Afell001 (961697) | more than 4 years ago | (#31187626)

Do this and run new Coax alongside, as well as a slip line for any future wire pulls you may have in mind. Just be aware to use duct tape liberally and if you don't mind the mess, some line-pull lube would go a long way for tight fits. You can then put a punch-down in the attic and run patch cables from the punchdown into a switch in the closet in the floor below the attic. I recommend that if you get a 12-block punchdown (should be relatively cheap), then run all twelve patch cables down to the closet, even if you are only using half of them. It will save you some work later on.

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 (1)

SatanicPuppy (611928) | more than 4 years ago | (#31187644)

I'll second the "use it for a wirepull" sentiment, though not the cat5 > cat5 sentiment.

No point in haggling with crappy old coax, and, happily, coax is really durable, so it's well suited to being a pull line.

Re:Use the Coax as a wirepull for the cat5 (2, Funny)

vivin (671928) | more than 4 years ago | (#31187648)

Cat5 provides many more options than cat5.

That's so zen.

Re:Use the Coax as a wirepull for the cat5 (1)

jeffmeden (135043) | more than 4 years ago | (#31187708)

Have any of you really tried this in a big house? Unless the house isn't that big (the OP says it is in fact big) and the coax was retrofitted and not installed permanently (which is quite possibly the case) trying to use the coax as a pull for cat5/6 is a bad idea.

There is a chance that the coax will reveal an ideal conduit (such as a hollow wall running from the basement to the attic) if you follow it carefully, from the living room down and then up. Using it as a pull from one end to the other is likely only going to achieve some strained hands.

Pitch the coax (1)

cusco (717999) | more than 4 years ago | (#31187758)

Toss the coax, it's junk. If it's standard TV coax then it's not even appropriate for security cameras (wrong impedence, wrong shielding, wrong insulation). Hopefully your walls aren't insulated yet, so you can run new CAT-5 down them. Don't bother with CAT-6, since it's a lot more expensive and the ends are a real pain in the ass to crimp successfully. Figure out where you want your network switch to go (almost certainly not in the attic) and where your Internet connection is going to come in and pull all of your new wiring to there. It's going to be a long weekend for you, but still a lot less time and frustration (and probably cost) than trying to get the existing junk to work.

How hard is it to pull the old wiring (1)

wiredog (43288) | more than 4 years ago | (#31187332)

and run new wiring? Does the old coax run in channels or conduits?

Use the coax to pull new Cat6 (0, Redundant)

scsirob (246572) | more than 4 years ago | (#31187350)

Don't even bother re-using the coax.
Use it to attach the end of a cat6 cable and pull the coax and cat6 through.
Just rewire.

Re:Use the coax to pull new Cat6 (0)

Anonymous Coward | more than 4 years ago | (#31187516)

Yes, use the coax as cable pull for Cat6. I don't think Cat6 is much more expensive than Cat5e.

Ethernet can actually use coax. In the old days (before RF-45 became such a dominating standard that people don't even know that ethernet started on coax) many cards came with both connections on them. My old Next pizza box has both coax and RF-45 connections on it.

Cat5/6 (-1, Redundant)

LBt1st (709520) | more than 4 years ago | (#31187352)

I'd tape Cat6 cables to the ends of the coax cables then pull them through. Presto new cables where the old ones were.

Re:Cat5/6 (1)

LBt1st (709520) | more than 4 years ago | (#31187398)

hahaha, the second I posted, I hit refresh and there's 20 other people saying the same thing :)

Maybe I'm missing something (-1, Redundant)

Ray (88211) | more than 4 years ago | (#31187354)

Why not just use the existing coax to pull cat5 into place?

Re:Maybe I'm missing something (2, Funny)

pcolaman (1208838) | more than 4 years ago | (#31187706)

Or, perhaps, as another thought, why not just use the existing coax to pull Cat5 into place?

That's not how coax works (3, Insightful)

Glendale2x (210533) | more than 4 years ago | (#31187358)

Coax gives you one braided shield and one center conductor to carry RF. It's not even remotely like UTP.

Re:That's not how coax works (0, Redundant)

marcansoft (727665) | more than 4 years ago | (#31187566)

Yup, dirty tricks like pretending cables are, well, hunks of copper stop working once you go beyond 1Mhz or so. Ethernet requires twisted pair wiring. Strictly speaking you might be able to use baluns of some kind to go from twisted pair to coax and back, and it might work, but it's so not worth it (plus you'd better know your RF theory) and you'd still need two coax wires per Ethernet jack (TX and RX). Just use the coax as a guide to pull brand new Cat5e or Cat6 wiring.

Re:That's not how coax works (0)

Anonymous Coward | more than 4 years ago | (#31187606)

So four coax cables are basically like two untwisted pairs of individually shielded wires. Since the purpose of the twisted pairs in Cat5 is to even out interference, a set of shielded cables should be able to do the trick just as well, if the shield is properly grounded. There's still the issue of impedance, which needs to be adjusted to the transceivers, but other than that I don't see why it wouldn't be possible.

That said, I concur with just about everyone else here: Install Cat5e. More is a waste, less is a hack.

Re:That's not how coax works (0)

Anonymous Coward | more than 4 years ago | (#31187642)

Even if you used multiple coax cables, you would probably be well outside of specifications in terms of skew.

10Base-2? (2, Interesting)

Chris Lawrence (1733598) | more than 4 years ago | (#31187360)

Well, 10Base-2 [wikipedia.org] uses coax. I think I have an old hub that still has a coax connector. :)

Re:10Base-2? (3, Informative)

marcansoft (727665) | more than 4 years ago | (#31187478)

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:10Base-2? (1)

marcansoft (727665) | more than 4 years ago | (#31187502)

... but apparently Slashdot never quite became friends with Unicode, and instead decides to do weird stuff when you try.

Re:10Base-2? (4, Informative)

Lumpy (12016) | more than 4 years ago | (#31187726)

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:10Base-2? (1)

Jim Hall (2985) | more than 4 years ago | (#31187568)

Well, 10Base-2 uses coax. I think I have an old hub that still has a coax connector. :)

I was going to write my own "10base2" comment, but instead I'll just reply to this one. Yes, your coax cables are essentially 10base2 cables - but may have a different connector. Sounds like you're willing to do a little work - so, get a cable conversion tool and add some correct connectors.

Once you have that, you'll need to have some 10base2-to-10baseT converters. You can probably get them cheaper elsewhere, but here's one at Amazon [amazon.com] .

My first workplace was wired entirely with 10base2, even in our server room. Some of our servers didn't support 10base2, so they had the media converters to go with them.

use the coax to pull ethernet cables (0)

Anonymous Coward | more than 4 years ago | (#31187364)

Tie one end of the coax to an ethernet cable and use the coax to pull the ethernet cable through the walls to the attic.

ATT Uverse runs over coax (4, Interesting)

your_mother_sews_soc (528221) | more than 4 years ago | (#31187370)

I have AT&T's Uverse for phone/TV/internet and its set-top boxes communicate over coax. They are using IP over coax, since the router shows the boxes' IP addresses as though they were on a an Ethernet network. The boxes run Windows Media Edition, for what it's worth.

Re:ATT Uverse runs over coax (5, Insightful)

your_mother_sews_soc (528221) | more than 4 years ago | (#31187406)

sorry, I realize my post contributed nothing.

Re:ATT Uverse runs over coax (5, Funny)

Anonymusing (1450747) | more than 4 years ago | (#31187444)

sorry, I realize my post contributed nothing.

This may be the most profound comment I've ever read on Slashdot.

Re:ATT Uverse runs over coax (0)

Anonymous Coward | more than 4 years ago | (#31187530)

And it applied to your post too, you just didn't note it. It applies to mine, and I'm noting it. Wait.

Re:ATT Uverse runs over coax (1)

pcolaman (1208838) | more than 4 years ago | (#31187736)

And it applied to your post too, you just didn't note it. It applies to mine, and I'm noting it. Wait.

What he said

Re:ATT Uverse runs over coax (0)

Anonymous Coward | more than 4 years ago | (#31187704)

The hilarious thing is that the original post is currently (Score 3, Informative) while the apology is currently (Score 4, Informative)!

Re:ATT Uverse runs over coax (1)

blippo (158203) | more than 4 years ago | (#31187560)

Not very likely. Instead, they use one of the "cable modem" protocols, perhaps DOCSIS.

Sorry. You might be able to use coax cable with some baluns to run 2 or 10 mbit, but thats probably not what you want.

Connecting each pair of a cat5 tp cable to a coax cable each will not work for any reasonable cable lenght. (if at all)

Repla

Re:ATT Uverse runs over coax (2, Informative)

brian1078 (230523) | more than 4 years ago | (#31187750)

Not very likely. Instead, they use one of the "cable modem" protocols, perhaps DOCSIS.

U-Verse uses HPNA for the coax networking.

Re:ATT Uverse runs over coax (1)

jeffmeden (135043) | more than 4 years ago | (#31187588)

Despite your humility, you may have in fact contributed something. If the OP doesn't want to invest money or significant time (if the house is indeed large the odds of using the coax as a pull string are very very low)... Then he can always just subscribe to a service that accomplishes exactly what he wants. While not the cheapest thing around, ATT will give you all the gear you need to make use of your coax.

Pull in fresh cat5e? (0)

Anonymous Coward | more than 4 years ago | (#31187388)

Why can't you tie a box of cat5e on a coax cable in your living room, then go to your attic and pull the coax (and cat5) up together? Or just go to the attic and fish down cat5 wherever you actually want it?

Re:Pull in fresh cat5e? (1)

Grishnakh (216268) | more than 4 years ago | (#31187630)

He did say that the house was big. In this case, it might be a 2-story house, and there might not be straight runs from the 1st floor up to the attic. Worse, the coax might be stapled to the studs if it was installed when the house was built.

pull lines (0, Redundant)

sl0ppy (454532) | more than 4 years ago | (#31187392)

why not just use the existing coax cable as pull lines and replace them with cat5e?

should end up being cheaper than building out some weird hybrid solution.

Re:pull lines (1)

Archangel Michael (180766) | more than 4 years ago | (#31187488)

Dang, that is exactly what I was gonna suggest. Pull Cable all the way! I always pull two or four cat6 cables for each drop. Two if I think I only want one, four if I think I'll need two or three. If I need Four or more drops, I'll drop a GB switch in at that location (and two drops) back to the closet.

It is all about planning ahead.

Or Just Run Cat5 (0, Redundant)

Princeofcups (150855) | more than 4 years ago | (#31187394)

Get a strand of cat5. Tie it to one end of the coax. Go to the other room. Pull the coax until you see the cat5. Crimp ends. Repeat.

Twisted pair, man (5, Insightful)

Spy Handler (822350) | more than 4 years ago | (#31187408)

100mb ethernet is four wires, yes? And I have four wires for every two coax cables.

The four wires in your coax are not twisted. It's not gonna work.

Pay $100 for those coax-ethernet transceiver things, or string some Cat5e. Seriously, if you can afford to buy a big ass house then what's another couple hundred??

Re:Twisted pair, man (1)

driftingwalrus (203255) | more than 4 years ago | (#31187710)

My mind has been boggling at how bad an idea his plan is. The conductor and shield in coax have capacitance between them, it's an unbalanced transmission line. There'd be noise and cross talk and impedance mismatches causing reflections.... It's like running the poor signal through a meat grinder.

Re:Twisted pair, man (1)

Grishnakh (216268) | more than 4 years ago | (#31187716)

They don't have to be twisted; they're shielded, which is generally even better. Of course, there's really only one wire in each coax cable (plus a shield).

d-link and netgear (0)

Anonymous Coward | more than 4 years ago | (#31187412)

both D-link and netgear make MoCA boxes that can be placed at each end of coax to convert ethernet.

www.netgear.com%2FProducts%2FPowerlineNetworking%2FCoax%2FMCAB1001.aspx&ei=wYN9S4-cOovUnAf_g-jXBw&usg=AFQjCNGap3DaokxxUbp8WxstG9dTTJTKUg&sig2=3YsnMh9tv1myz4zsV6qHlw

Re:d-link and netgear (0)

Anonymous Coward | more than 4 years ago | (#31187476)

MCAB1001 [netgear.com] is a link that actually works.

Use the Coax to pull CAT 5e cable (4, Insightful)

Cassini2 (956052) | more than 4 years ago | (#31187416)

If the coax is sitting loose in the walls, you can use it as a pull cable to thread in replacement UTP cable.

Old Ethernet worked over Coax. I just doubt you have the correct kind of Coax. Also, my experience with residential cable installs is that they tend to have damaged Coax cable, so it is pointless even trying to use it for high-bandwidth applications.

Finally, while it is theoretically possible to substitute 4 "pairs" of twisted pair with 4 Coax cables, my suspicion would be that you would have severe impedance mismatch problems. It might be good at 10 Mb, where the old Coaxial ethernet worked. I doubt it would handle modern 1 Gb Ethernet signals. Also, modern Ethernet expects all 4 pairs to be of approximately the same length, and it is unlikely someone would have 4 matched-length pairs of coaxial cable sitting in their wall.

Just bite the bullet pull Cat6 (3, Insightful)

name_already_taken (540581) | more than 4 years ago | (#31187424)

If you have access to the attic, it may be a full day's work to wire the whole house, but you'll be far better off pulling the correct wiring into place. Buy a 500ft box of cable and the appropriate wall jacks and plates and make a day of it. It's not hard with a fish tape or fish sticks (those bendy fiberglass poles for running wires).

I have been using an 802.11N bridge to connect my upstairs printer/scanner/thing and I have another computer up there with a wireless bridge and it's a pain compared to the situation downstairs where I ran Cat6 to a patch panel in the basement.

Buying all the cable, jacks and plates has cost less than the single 802.11N bridge, and I have gigabit Ethernet for my devices. The wiring is simple and once it's in place it's done.

Re:Just bite the bullet pull Cat6 (0)

Anonymous Coward | more than 4 years ago | (#31187628)

mmmm... fish sticks

No problem, just mind the impedance! (0)

Anonymous Coward | more than 4 years ago | (#31187432)

You need to transform 100 Ohm impedance of the CAT5 to the 50 Ohm (or 75 Ohm) impedance of the Coax cables.

50 Ohm case:

100 Ohm CAT 5 -> 2x 25 Ohm resistors in series -> 50 Ohm Coax -> 100 Ohm resistor in parallel -> 100 Ohm CAT 5
... and the other way round for for the other pair.

Re:No problem, just mind the impedance! (1)

marcansoft (727665) | more than 4 years ago | (#31187638)

RF doesn't work that way, that's not even going to remotely work - you can't magically transform the impedance of a cable just by sticking resistors on the ends. At best, if he has any chance of getting it to work, he needs baluns (transformers) to transform the 100ohm balanced pair into 75ohm unbalanced coax, but I highly doubt it's worth trying, and I wouldn't count on getting it to work at 100mbps (and forget about GigE, that needs four pairs).

Man up and pull some new wire (1)

enjar (249223) | more than 4 years ago | (#31187442)

You can use the existing wiring to pull the new stuff (If you don't have another use for it, of course), but really running some new Ethernet isn't so bad, get a long drill bit, some fishing tape and a helper. Also keep in mind that it's pretty easy to go through the wall and run the wire on the outside of the building in a lot of cases -- it's pretty easy to hide CAT5/6. Also you can get patch panels that give you a nice, clean, finished look and not a hack job.

Bite the bullet! (2, Informative)

CyberBill (526285) | more than 4 years ago | (#31187446)

Cat5 cable is what they call "UTP" - Unshielded Twisted Pair. Essentially, the losses and electrical noise of each pair of wires is canceled out because instead of comparing individual voltages, they compare differences of voltages between each wire in the pair. If you try to hook up an ethernet cable pair using a coax wire, you're going to end up with one wire (the shield) picking up the electrical noise and the inside wire won't pick up the noise. This is going to just make not work well. It'll work for short distances (just like if you crimp an ethernet cable but mess up the coloring so the pairs aren't matched) but over long distances of 20+ feet, it is just going to crap out.

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!

Use the coax to pull cat5 (1, Redundant)

seanmcgrath (112551) | more than 4 years ago | (#31187448)

Simple known process,
desired end result, low cost.

DOCSIS devices (0)

Anonymous Coward | more than 4 years ago | (#31187452)

Well, if you have lots of money to waste on very expensive Cisco DOCSIS (cable modem) backend gear, and you are a mental masochist for wanting to configure such gear, then you might be able to use the coax to carry the DOCSIS RF signals around your house.

Think of DOCSIS as kind of like 802.11b/g/n WiFi networking, but instead of transmitting the RF thru the air over antennas, it just encodes networking into RF and transmits/receives the RF over coax cables instead, and it runs at very different frequencies than 2.4GHz.

Adapting Coax to Twisted Pairs (1)

veektor (545483) | more than 4 years ago | (#31187456)

You have more problems than just selecting 4 wires. Each pair of wires from the 100 megabit Ethernet is a balanced pair, and coax is unbalanced. Also, the coax impedance is probably 75 ohms (if I remember correctly) and the twisted pair is around 120 ohms. So you would need a transformer for each pair to match the impedances and handle the balanced to unbalanced conversion. Finally, these transformers would need to be small and broadband to avoid unintentional impedance mismatches. Like the others have suggested, just use the coax as a pull wire for Cat 5e.

Coax won't support 100mbps (1)

imgod2u (812837) | more than 4 years ago | (#31187458)

As others have said, it's better just to use the coax cable to rewire the house. Ethernet at high data rates requires a differential and high frequency cable twisted pair. Coax does not give you any of this. There's also the problem that the impedance of a coax cable is orders of magnitude greater than cat5, so you'll either have to have a high-powered driver and matching terminator at both ends or a modem.

All in all, it's not worth the effort unless someone out there has already designed something like that.

MoCa (5, Informative)

MikeDataLink (536925) | more than 4 years ago | (#31187470)

I'm surprised no one has already mentioned MoCa,. Several companies make MoCa adapters that runs 100Mb/s ethernet over Coax cables: http://www.google.com/products/catalog?q=MOCA+adapter&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&cid=2590185696454305965&ei=PoR9S5uIC4mWtge8z5GfBQ&sa=X&oi=product_catalog_result&ct=image&resnum=1&ved=0CBQQ8gIwAA# [google.com] And read all about it on Wikipedia: http://en.wikipedia.org/wiki/Multimedia_over_Coax_Alliance [wikipedia.org]

Re:MoCa (1, Interesting)

Anonymous Coward | more than 4 years ago | (#31187636)

+1

i had the same dilemma for a mythtv hd frontend and a pair of netgear moca bridge devices worked like a charm. It was a bit pricey at $200 but i hear you can get refurbed actiontec devices from ebay from old verizon fios installs for about $60 each

Do category 6 (1)

wherrera (235520) | more than 4 years ago | (#31187480)

Category 6 is better for high speed multimedia, and the small extra cost is worth it.

Re:Do category 6 (0)

Anonymous Coward | more than 4 years ago | (#31187674)

Category 6 is better for high speed multimedia, and the small extra cost is worth it.

Cat5e will do gigabit. Cat6 will do gigabit. Gigabit is gigabit. Save the money and get some Cat5e.

Re:Do category 6 (0)

Anonymous Coward | more than 4 years ago | (#31187720)

It also can be broken by staring at it. Cat6 is incredibly fragile; and putting it into a house strikes me as a recipe for fail later on.

Can't re-use coax that way (1)

ThreeGigs (239452) | more than 4 years ago | (#31187482)

"And I have four wires for every two coax cables."

One of which is the shielding, and is subject to EMF interference, and one is the core, which is shielded, which would give you a potentially unbalanced system which would give you a lot of errors. Plus there's the issue of capacitance.

If speed isn't an issue, you could always put a BNC end on the coax, and pick up some 10 mbit hubs from eBay with both RG45 and a BNC coax connection. You'd be stuck at 10 mbit, but it's probably the cheapest/easiest solution.

Or as the above poster mentioned... simply regard them as your pulling wires. Attach new Cat5 and pull away.

Re:Can't re-use coax that way (1)

TomXP411 (860000) | more than 4 years ago | (#31187604)

yeah... that won't work.

He's using this for media extenders. That pretty much requires more bandwidth than 10Mb... it'd be fine for things like on-line video, but it's not enough bandwidth to stream DVD or Hi-Def video from his media server.

Besides, the TV cable in his house is 75-ohm cable, which is incompatible with 10-base2 Ethernet (which is what you're describing.) 10-base2 requires 50 ohm cable.

homepna 3.1 supports coax (1)

leuk_he (194174) | more than 4 years ago | (#31187492)

If you resists against pulling wires, homepna3.1 equipment exists just for the thing you want:

however devices are hard to find [cnet.com]

Just run new wires. (1)

phormalitize (1748504) | more than 4 years ago | (#31187500)

Seriously, it's not worth coming up with a hack to use the existing coax. Whether you can do what others here have suggested and use the coax to pull the new wire, or even if you have to run entirely new wires - it's worth it.

It will improve the resale value of your home, too, in my opinion - I bought a house recently and one of the things I considered was whether acceptable wiring was in place, and if not, how easy it would be to run it myself. That's only going to become more important to buyers in the future.

Different Philosophies of noise cancelation (0)

Anonymous Coward | more than 4 years ago | (#31187508)

Ethernet uses twisted pairs to keep the signal clean and strong. Coax uses a signal wire shielded inside a grounded return shell to keep the signal strong.

If the Coax is actually grounded anywhere it might really fnuck up what your trying to do. I'd also be-aware of signal boosters inline up at the attic. This setup was obviously made for cable/antenna and not made for data transmission.

You can try it. Get the pin-outs for ethernet get a crimper for cat 5 and coax and make your own adapters but beware of the grounding issue.

1000bt (very good for macs and time machine plus bigger DVR stuff) uses all 8 wires in ethernet and probably isn't going to tolerate a jury rigged adapter even if you have ridiculous numbers of coax runs.

Cat5e vs Cat6? (1)

the_macman (874383) | more than 4 years ago | (#31187540)

Many of the posts suggest to pullout the coax and rewire with cat5e. My question to the community is why not Cat6? When I bulit a small network in my house I concluded that ca6 is slightly better than cat5e, especially for gigabit speeds. If you're going to wire your house why not use cat6?

Related Questions (3, Interesting)

godrik (1287354) | more than 4 years ago | (#31187546)

If you were building a house today, which kind of connectivity would you set up ?

Since the expensive part is probably paying someone to put the cable, it could make sense to set up both gigabit ethernet and optical fiber in all rooms. Do any slashdotters have some opinion on that ?

Re:Related Questions (4, Insightful)

Corf (145778) | more than 4 years ago | (#31187740)

A conduit containing both CAT6 and some fishing line to pull through whatever's in vogue once CAT6 will no longer cut it.

Cat5 isn't "just" four wires (1)

diamondsw (685967) | more than 4 years ago | (#31187548)

The key here is "twisted pair". I'm not an expert by any means, but my understanding is that the twisting design limits electrical interference and noise. Without that, you're likely to get an extremely error-prone connection.

Wiring a house isn't actually that hard or expensive, presuming you either have an attic to drop wire from or a crawl space to move up from. It takes some time, but do it yourself and you can do it right with Cat6, some higher quality coax for video distribution, and more. Look up "Structured Wiring" and go nuts.
http://www.structuredhomewiring.com/ [structuredhomewiring.com]

And although I really should get around to installing proper AC outlets one of these days, you get the idea:
http://www.joshuaochs.com/Home/The_House/Pages/Home_Wiring.html#5 [joshuaochs.com]

It's not the same thing - "4 wires" (0)

Anonymous Coward | more than 4 years ago | (#31187550)

I very much doubt it would be possible to directly send a "modern" ethernet signal over coax. In cat5 cabling, the wire pairs are twisted together, and around each other in specific ways. This is required for shielding. A coax cable does not have the same layout - it is a single lead surrounded by a shield. While, at DC levels, the two cables might behave the same way, they will be very different when you try to send high-frequency signals. And, I don't even want to know what kind of reflection/impedance mismatch issues you will have when trying to mix cables like that.

If you are really feeling retro, you could try to run thinnet over the coax, but you'd have to look into impedance issues to make sure you have a suitable type of coax.
Hope this helps.

Use the coax.... To pull CAT6 (0)

Anonymous Coward | more than 4 years ago | (#31187554)

Cut the coax and use it to pull the CAT6!

Not another "pull Cat5 via Coax" Post (1)

Lookin4Trouble (1112649) | more than 4 years ago | (#31187572)

Would not recommend using the coax as a solder hack-job to RJ45 connectors. Running all new cabling is easy provided you have the proper tools (flashlight, fish tape/rod, box of cable, cordless drill, long drill bit 3/8-1/2" head, box of draw-string, and a helper)

Do yourself a big favor, and when you pull in your shiny new ethernet, tie in some drawstrings so you never have to repeat the process.

Cat5 != 4 separate wires (1)

dsojourner (695863) | more than 4 years ago | (#31187582)

Cat5 expects two pairs, each of which carries a differntial signal. If the wire lengths are too far off (and off the top of my head I would imagine is about 6 cm) it will not work.

(I got 6cm by using (a) speed in coax ~ 1/2 C, lamda = speed/2*pi*freq, matching needs 1/4 lamba or better)

Impedance differeneces (1)

Skuld-Chan (302449) | more than 4 years ago | (#31187592)

You really can't adapt this - the impedance for this coax is likely 70 ohm (for cable tv) and cat 5 is 100 ohms. You could build a balun, but you'd probably have some weird distance/speed related issues you've never had before. Anyhow if anyone had the parts it would be these guys:

http://www.blackbox.com/Store/Detail.aspx/CATV-Balun/IC448A-R2 [blackbox.com]

I know that's the wrong way, but it gives you an idea of how much you'd have to pay.

Rewiring is your best option. (2, Funny)

getclear (1338437) | more than 4 years ago | (#31187594)

First, any ethernet media converters you with coaxial as the medium, are going to be 10BASE-T 10Mbit connections. You will no longer be able to utilize 100Mbit across ethernet. Second, attempting to solder the wires from a twisted pair cable, and pinning it out over 4 shielded coaxial cables, is going to result in an extreme signal degredation and is completely out of the picture as a viable option. The posters above me stated that using one of the original coaxial cable as a base for pulling a snagless Cat5e/6 cable, and that is the direction that you need to take. If that is not an option, perhaps do some research and invest in a wireless setup that will suit your living area.

In summary, please, don't solder an RJ-45 connecter and the 2 relevant pairs to 4 coaxial cables. Please?

If you do, please, send pictures.

Also highly recommend pulling UTP but if you must- (0)

Anonymous Coward | more than 4 years ago | (#31187598)

Coax would require a different signalling protocol to allow 100Mbps service over untwisted wires. Several companies have developed products to try to fulfill this niche market such as DLink with the DXN-221 which allows around 220Mbps over coax. The cost alone would likely make you reconsider pulling your own UTP cables. There are many creative ways to rewire a house and trust me, its worth it in the end.

Pull Cable (0)

Anonymous Coward | more than 4 years ago | (#31187618)

Just pull new cables.

A spool of cat5e is pretty affordable. Buy a cable tester, some jacks and plugs, a good crimper and punch set, and replace your old cables with new. Tie on to the existing coax and use it to pull new cable thru the walls, crimp on new jacks/plugs connect to a switch in your attic and you are done. Its not a trivial project, but the results are more than worth the weekends effort.

Coax to Ethernet Bridge (1)

cmholm (69081) | more than 4 years ago | (#31187640)

The easiest way is to get some Ethernet to coax bridges: eBay [ebay.com] , Google [google.com] .

If you elect to replace the coax with Cat5 or Cat6, DO NOT try to pull it yourself. If you fuck it up, you'll end up paying someone else a lot more than if you just had an electrician do it in the first place.

MoCa to the rescue (1)

gad_zuki! (70830) | more than 4 years ago | (#31187646)

Sure, youre dropping around 100 bucks per drop [newegg.com] (less if you go with actiontec), but it saves you time and energy doing a cat5 conversion. The bitrates are pretty good too, although that depends on the quality and length of your wiring.

Powerline AV isnt bad, you can get a steady 40-50mbps with it, but that's pretty much wireless-N speeds, which is a lot cheaper.

Why not wireless? (1, Redundant)

H0p313ss (811249) | more than 4 years ago | (#31187662)

This sounds like a question from the 90s.

Why not just make the jump to wireless? Do you really need more that 56Mbps on a home LAN?

I did that six years ago when I started having to deal with my kids having their own computers on their desks to do homework for high school. (Mostly because after five minutes investigation I decided I never wanted to go into the insulated attic of my new house ever again if at all possible. Blown insulation is cheap an effective but it kind of makes the attic unusable without significant effort.)

Clarification (2, Informative)

alop (67204) | more than 4 years ago | (#31187682)

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.

Try it (1)

tie_guy_matt (176397) | more than 4 years ago | (#31187684)

A good coax can handle higher frequencies than the twisted pair used in cat 6 (Not sure if YOUR coax cable is good enough to handle higher frequencies than twisted pair but you can get a type of coax that can.) Of course the coax in your house might not be properly impedance matched and all that but for small distances it might not matter. I say take apart the twisted pair in a cat5 or cat 6 cable and solder it to the coax. Just make sure that you solder the stripped color wire to the same coax as the solid color wire. And yes ethernet only uses two of the twisted pair wires (meaning you only have to use two coax wires.) What is the worst that could happen? You waste a little cat 5 cable and a couple of connectors in a test that doesn't end up working? If it works then post the results of what happened and maybe you can get your sight slashdotted!

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