I have an application needing a cable with the following rough requirements:
-4 twisted pairs, individually shielded (braided). Ideally standed 28AWG, but we could do down to 26 or even 24AWG. Solid conductors could also be acceptable. A foil shield could do as well.
-outer shield, ideally braided, but foil could be ok.
I think your expectations are unreasonable. Cost, put-ups (length of the reel), and the need for a cable for which there is very little demand, all come together to limit your choices and demand you make some of the compromises you seemed unwilling to make. So you will have to take what you can get, for what the market is willing to sell it for. Sorry. Try
I made up a set of such cables for a movie company once and just such a wire is available commercially. If you call Carol Cable They will tell you if it is in stock or if you drop me a line I will check on the remainder of the roll and tell you who sold it and the stock number. . . I DO NOT FOLLOW MANY OF THESE NEWS GROUPS To answere me address mail to snipped-for-privacy@aol.com
I do not think the need unreasonable. I have made up such cables for Movie companies who used balanced line mikes. . . I DO NOT FOLLOW MANY OF THESE NEWS GROUPS To answere me address mail to snipped-for-privacy@aol.com
One of the best deals around is stock SCSI-II cables and connectors. You can get a 25-pair cable for about $10-ish, and the connectors are very nice and are cheap. Pairs are not individually shielded, but you can just use 4 selected pairs and ground the rest, and get pretty good isolation that way.
Because, he asked for "individually shielded". The pairs in CatX are not individually shielded, even if the cable is overall shielded.
Personally I'm with Lizard, I've never seen anything that small... but if it exists, it's probably made by Mogami. Unfortunately, their web site is rather weak, and they're Japanese, so it's hard to actually tell what they sell or where to get it. Some creative Googling can help.
Mike, can you tell us more about your application? Maybe there's some creative alternative possible.
Shielded twisted-pair (STP) exists - we use it all the time for industrial applications. How do you think I was able to state the OD? Guess?? :-(
True, the pairs on this size are not individually shielded - this is precisely why I stated "If you are in a hurry". Small O.D. individually-shielded cables (even something like a Belden 9903 10Base5 LAN cable) will likely only be available on back order.
I have never seen anything individually-shielded less than 5mm O.D. Less than 7mm, yes, but not less than 5..
Look for LVDS interconnect cables. Amp also do coaxial ribbonised multiway cables with each coax 0.64mm diameter with their Mictor connectors. Not twisted pair, but shielded and controlled impedance. (You may not like the price ;-(
Generally, yes. I just had a look at the Van Damme catalogue, and their 'studio grade' microphone cables are available with four individually shielded pairs, and a single foil braid outside, but the diameter is 7.5mm. Belden do their 'high flex' multi-pair snake cables, with again four individually shielded pairs, and an overall braid, but this is 8.43mm OD, for four pairs. The thinnest I found, was double screened 'telecom' cable. This has single cores, rather than flex (reduced it's suitability for a flexible application), and has a foil screen round each pair, with a copper link wire and a copper braid externally. The 'four pair' version of this, just scrapes over the '5mm' specification (5.5mm nominal OD). Micro diameter cables smaller than this do exist, but a lot are 'special order' (not off the shelf items). The smallest diameter 'multi-pair' cable, with individually shielded pairs like this I have seen, was only about 4mm OD, and was made by 'Nexans', but was about £500 a roll (it was used in the interconnections in an ECG)!... I think an email to Nexans, is probably the place to start. The 'part' you want to talk to, is the area dealing with 'microcables', and they do do a version that is the sort of diameter required, but whether it is an 'off the shelf' item, I do not know.
Give HP a call. I think the stuff I used came from them. . . I DO NOT FOLLOW MANY OF THESE NEWS GROUPS To answere me address mail to snipped-for-privacy@aol.com
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