RJ11 to RJ45 cables?

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PANiCnz

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#138428 3-Jan-2014 16:50

I want to use my Linksys PAP2T with my existing structure cabling, and am thus looking for some RJ11 to RJ45 cables, any suggestions on where to find these? (aka plug existing analogue cordless phone into RJ45 socket in the lounge and keep the PAP2T in the cupboard with the router and switch etc)

Will the RJ12 to RJ45 cables from Cables Direct be suitable?

http://www.cablesdirect.co.nz/catalog/entry?entry=384

Thanks

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#960837 3-Jan-2014 16:53

Yep RJ12 will be fine. Just has the extra two pins the RJ11 is missing.

InstallerUFB

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#960877 3-Jan-2014 17:37

Just to help with visualising the pinouts on the RJ Plugs (wired with ribbon cable for voice use)
here is a little pic

The Handset cord plug is also reffered to as RJ10

The discription after the name reffers to the number of Pins and then the number of Pins Connected

Zeon

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#960881 3-Jan-2014 17:39

You can actually put an RJ-11 plug in an RJ 45 socket but i don't think it's recommended.

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InstallerUFB

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#960883 3-Jan-2014 17:42

Zeon: You can actually put an RJ-11 plug in an RJ 45 socket but i don't think it's recommended.

Correct as the edges of the plug push up the sprung pins in the socket, and bend them up, so when you try to then use the socket for a data outlet later you have miss connections

RunningMan

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#960884 3-Jan-2014 17:43

Zeon: You can actually put an RJ-11 plug in an RJ 45 socket but i don't think it's recommended.

It will work quite happily. The problem can occur when you need to use an RJ45 back in the socket, and the outer pins are damaged.

ajobbins

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#960889 3-Jan-2014 18:02

RunningMan:
Zeon: You can actually put an RJ-11 plug in an RJ 45 socket but i don't think it's recommended.

It will work quite happily. The problem can occur when you need to use an RJ45 back in the socket, and the outer pins are damaged.

Does using RJ12 instead of RJ11 solve this? I've always wondered. Will a RJ12 cable fit into a device (like a phone) that is expecting a RJ11?

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chevrolux

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#960891 3-Jan-2014 18:18

ajobbins:
RunningMan:
Zeon: You can actually put an RJ-11 plug in an RJ 45 socket but i don't think it's recommended.

It will work quite happily. The problem can occur when you need to use an RJ45 back in the socket, and the outer pins are damaged.

Does using RJ12 instead of RJ11 solve this? I've always wondered. Will a RJ12 cable fit into a device (like a phone) that is expecting a RJ11?

Yes because the positions are still there on an RJ11 just not the pins.

InstallerUFB

833 posts

Ultimate Geek

#960893 3-Jan-2014 18:22

ajobbins: Does using RJ12 instead of RJ11 solve this? I've always wondered. Will a RJ12 cable fit into a device (like a phone) that is expecting a RJ11?

Yes as an RJ11 has the same basic profile as a RJ12 but the 2 outer pins are either blank (not installed) or the plug is molded without the slots - but the same dosent apply the other way around as a RJ12 socket can have the two outer spring pins damaged when a all molded RJ11 or RJ10 is inserted. Just like an RJ45 socket can be damaged with an RJ10, 11 or 12 plug inserted in them (even though it will fit)

webwat

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#961567 5-Jan-2014 16:31

They would be suitable. Alternatively I could make some and courier them to you. PM me the length you need for each cable and your physical delivery address for a courier.

Qualified in business, certified in fibre, stuck in copper, have to keep going ^_^

JWR

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#961678 6-Jan-2014 02:44

If you are making a RJ45 --> RJ11 cable, then what is the best cable to use?

Would you use Cat 5/6 and cut off the spare pairs at the RJ11 end? Or... use a 4 core cable?

webwat

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#974538 26-Jan-2014 10:57

You would use a stranded flat cable. Find an old BT cable that you don't need anymore and chop the BT plug off. Need to use a "flat" RJ45 plug to hold the cable in.

Qualified in business, certified in fibre, stuck in copper, have to keep going ^_^

jonb

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#1456517 24-Dec-2015 14:24

Having a bit of trouble trying to do the same thing.

Cat6 from patch panel to wall jackpoint, cable tested successfully with testing tool either end.

Have then snipped off the RJ11 connector to attach RJ45 connector instead, but the phone line is dead when I connect it to same jackpoint. Using the cable testing tool, only the 3rd wire lights up.

The phone cable comes out of the ONT POTS1 port. I snipped where this was originally scotchlocked to the blue pair of a cat6 cable strung under the house to connect to the copper ETP.

Crimped on an RJ45 connector:

Crimped the same RJ45 to the phone RJ11 cable.

RJ11 cable from ONT, RJ45 to patch panel (T568A), RJ45 from wall jack to RJ11 phone input.

Originally I wired them both the other way round, red then green, on both cables but no signal so tried green then red..

A bit stuck..

sbiddle

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#1456525 24-Dec-2015 14:44

What sort of cable tester are you using? If it's one of the cheap $5 ones they actually pieces of junk and can deliver false results for some kinds of wiring faults.

Can you test the cable with another jack?

Assuming you have RJ11/12 and RJ45 on the middle pins it should work. Colour & polarity isn't important for a phone.

sbiddle

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#1456527 24-Dec-2015 14:46

Just one other thought are the connectors and cable compatible? ie are you using stranded connectors for stranded cable? Mixing connectors and cable type (depending on the type of connector) can cause issues.

jonb

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#1456533 24-Dec-2015 14:56

A cheap $5 dollar junk one..

The RJ11 cable is a flat one, is that stranded? The RJ45 sockets are flat cable, stranded conductors

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