Question about Cat 7 cable

I'm about to wire up my house, and have decided to run Ethernet cable pretty much everywhere, using it for both data and audio.

Was originally going to use cat 5, but have instead settled on Cat 7 (which in the UK only appears to be available from Canford). It will cost quite a lot more, but it's not often I have all my floorboards up, and I'd like to future-proof as much as I can!

My plan was to run the cat 7 to deep single- and double-gang metal boxes, to which I'd attach Canford connector plates with holes that will take either XLR, BNC, phono or BNC sockets. This way I have flexibility over what to feed to different locations.

One concern is that Cat 7 uses solid core rather than stranded conductors - will this create problems in connecting to the various sockets? I've seen reference to needing to connect using a punchdown block, and I'm not sure how this would work in the setup I'm envisaging.

This is a bit of a leap into the dark for me, representing quite a big investment plus a real headache if I put it all in, replaster my walls and lay the floors, only to find it doesn't work, so I'd be very keen for any thoughts.

Many thanks,

Chris

Reply to
reellifetv
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Cat 7 WTF is Cat 7... ah 4 individually screened pairs with overall screen, not cast in stone as standard yet either.

Installation cable uses solid conductors, only patch cables that need the flexabilty to with stand being flexed use stranded cores.

Unless you are going to be silly like one link I found on the web using Cat 7 with 100base network and line level audio down the same cable I'd have thought Cat 5e ample for the home. Though I guess using Cat 6 might be worth it, if you are going to start with a gigabit LAN. Audio, telephone, ISDN, base band video, are happy on much lessor cables...

Cat 7 seems definate overkill and as it appears not to be ratified you could, concievably, end up installing cable that doesn't meet the final spec.

Reply to
Dave Liquorice

Cat 5 uses solid cores too for installation cable. The patch cable variant is stranded. You shouldn't have a problem there.

Cat5e is the same cable construction as Cat5, tested and passed to a higher standard. At my work, most of the older Cat5 installation was retested and passed to Cat5e standards after the fact. And we do run gigabit over it quite happily.

I don't have personal experience of cat6 or 7 - but this might prove useful:

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cat5-7)

I did notice that they are specifying different connectors for termination (not RJ45) but the cores are the same (ie should punch down OK).

The only other things to note is that (in the sample we looked at) Cat6 was rather much stiffer than Cat5e and more difficult to route.

Cat7 is going to have multiple layers of shielding so it may also be more difficult - I think that stuff is fussier about minimum bend radii (too tight untwists the cores).

If it were me, I would be happy with Cat5e - you'll be good for gigabit and to be honest, with standard PC type kit, it's pretty hard to saturate a gig link, let alone anything higher.

What *I* would do is use [oval] conduit so re-pulling the cables later would be possible. But if you really wanted to go Cat7, stick it in, leave some slack and terminate RJ45. You can always change the ends if necessary in the future.

HTH

Timbo

Reply to
Tim S

IMHO, running Cat7 now is unnecessarily future-oriented.

Business premises have a *huge* investment in Cat5/5e, and have been laying fibre for faster links rather'n copper. There'll be supplies of Cat5e-compatible patchcords and kit for another 10 years at least, I'd guess; while Cat7 is barely out of its standards-committee nappies, and might sweep the world to exactly the same degree as HP's 100VG proposal. (No personal bitterness here, you understand - it was merely good mates of mine who lost years of their lives on that quixotic battle, not me ;-)

All Cat5/5e in-the-building-fabric uses solid core conductors - stranded is used only for patchcords, trading off impedance for the physical flexibility needed. As for punchdown blocks - your call, but for a domestic/small-biz-premises install I decided they were over the top. Instead, I just run all my Cat5e runs from RJ45 sockets in rooms direct to 24-way patch-panels, and have used homebrew custom cables to bring in the couple of Telco lines I needed.

You mention you want to use your structured wiring for audio too, and you mention the Big Blue Book Of AV Drool :-) So you'll have noticed that the 'official' way of routing balanced audio signals over Cat5 twisted-pair isn't exactly cheap in baluns. The economics of the 'puter industry being what they are, it's getting to be as cheap to use Ethernet streaming at both ends of a link, rather than sending analogue audio around! Of course, if you're a Real Audiophile, a basic tenet of faith is that digitising audio is bad-bad-bad... but it's something to think about. I haven't noticed any 'prosumer' products doing 'simple' Firewire (which Yamaha are leading the charge for in pro-audio distribution, calling it mLan) to Ethernet conversion, but I haven't looked; and there is more and more audioEthernet consumer and 'prosumer' kit appearing - Google for 'exstreamer' for one example.

HTH - Stefek

Reply to
Stefek Zaba

There's not much use for Cat7 yet (I'm not sure it;s even an official standard yet), so the price is high. When/if it becomes more common the price will come down a lot, of course everyone might start using fibre in a couple of years instead. Why not put the money into ducting, and fill it with Cat5 instead?

I think you missed out the RJ45 :-)

All fixed ethernet wiring is solid core with punchdown connections - stranded is for patch cables. Cat7 cable is screened both at the twisted pair level and overall, which makes it quite chunky and hard to route, more connections to make and the possibility of ground-loop complications.

Test it before you make good - I mean with a proper tester, not just DC continuity or plugging some miscellaneous ethernet equipment into it.

Reply to
Rob Morley

Cat7 was ratified two or three months ago, but Ethernet over Cat7 was not yet ratified at that time. The expectation was that it would support 10Gb over 100m, but it was still being worked on. (10Gb fibre ethernet has been out for some time now -- I think we just added support to Solaris for the 4th 10Gb NIC card.)

Cat7 uses different connectors. I don't know if they are RJ45 backwards plug compatible though.

Reply to
Andrew Gabriel

One would assume that it has at least 5 more connections than a bog standard UTP RJ45. One for each of those additional screens, seems a bit daft to got to all that trouble and either common or leave them open at the cable terminations... I wouldn't be surprised to find each screened pair treated as a minature twinax either, to maintain impedance and screening through a mated connector.

Reply to
Dave Liquorice

re cat5 vs cat7...

both standards will disappear into history, the one that will be usable the longest is the one that is most installed today - and that is cat5. Choosing 7 is the very oposite of future proofing.

NT

Reply to
bigcat

Thank you all for your thoughts.

After much consideration, I've decided to go with Cat 6 - the technical challenges of cat 7 (especially in its termination - RJ55 anyone?) at too much for a keen amateur like myself.

So, Cat 6 for data, phones and (probably balanced) audio, CT125 for RF, and SDV75 for video.

Many thanks to you all

Chris

Reply to
reellifetv

I have seen it on an RJ45-like connector with a second row of contacts, probably for the screens. I don't have one to look at now though, and didn't look carefully enough to check if it was plug compatible with an RJ45 connector if you didn't need the screens (and it might not be electrically compatible even if it is plug compatible). Also, I saw this before Cat 7 was finally ratified, so I don't know if that's the final connector.

Reply to
Andrew Gabriel

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's a shielded cat 6 plug. Unfortunately I don't have one to hand to see what the back looks like, but one assumes there is a way of connecting the cable screen to the plug or all that metal would be pointless??...

I'm pretty sure shielded RJ45 is plug-compatible with non shielded RJ45 as cat 6 itself is fully downwards compatible.

Timbo

Reply to
Tim

Why 125 size? Unless you've got some very long runs its disadvantages will outweigh the advantage of slightly lower loss. You'll find '125' very difficult to use in confined spaces such as back boxes for outlets, and in any case all the decent screened outlet plates on the market will only accept '100' size.

The difference in attenuation between 100 and 125 sizes is only about

2.5 dB per 100m at the top of the UHF TV band.

Also consider using a modern foam dielectric cable such as CTF100 or WF100 rather then the cellular air-spaced types like CT100. The foam types are more robust, with higher resistance to crushing and are generally easier to handle than the air-spaced types.

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for a list of 'benchmarked' TV distribution cables.

What's that - a type of coax? I found no relevant hits on Google.

Reply to
Andy Wade

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