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[Discuss] Wire tester (like a tone tester)

On Fri, Oct 3, 2014 at 10:28 AM, Chuck Anderson <cra at> wrote:
>> I do have a pocket-size jack-checker that indicates presence of data
>> and if 10G or 100G if inserted into a dubious RJ45 ethernet jack. With
>> a RJ45 double-jack adapter (sold as cable extender?) it would report
>> if cable is passing data beyond the wall.
> Not sure what you are saying here.  A "double-jack adapter" sounds
> like those splitters that plug into a jack which is connected to a 4
> pair UTP cable and split it to two jacks, each with 2 pair.  You would
> need two such adapters, one on each end of the single UTP cable run,
> and it would only work for 10BASE-T or 100BASE-TX (10 Mbps and 100
> Mbps Ethernet).  1000BASE-T (1 Gbps Ethernet) requires all 4 pairs.

I meant a cable-extender that lets two Cat-[456] cables become one
longer cable (aka an RJ-45 F-F gender-changer, aka "RJ45 Joiner")
would allow my pocket 10baseT/100BaseT signal checker to check if a
cable plugged into a known good jack was good.

(I don't think it supports newer 1000baseT ... but newer ones might.)

Links for information only, i do not endorse buying from Patent trolls -

Bill Ricker
bill.n1vux at

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