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THE AM BULLETIN BOARD => Technical Forum => Topic started by: K6JEK on July 10, 2008, 01:46:42 PM



Title: Two wires one punchdown?
Post by: K6JEK on July 10, 2008, 01:46:42 PM
Can I get away with putting two wires into one punch-down slot?

I installed nifty RJ-45-s, the kind with punch down, not screw connections.   Now I realize I need two jacks in one location.  It sure would be nifty if I could get away with punching a second twisted pair into the existing jack.   

It doesn't help that the wire to this socket was a little short so I don't have the luxury of lots of wire to fool around with.

Thanks,

Jon


Title: Re: Two wires one punchdown?
Post by: Mike/W8BAC on July 10, 2008, 02:02:56 PM
Jon,

Are you talking about using cat5 cable and using the jacks for a computer network? If so I think each jack would require a home run to the router. If it is for phone service than it's a different story.

Looking at the leviton stuff I buy at the depot it has room on the metal fork for more wire but the snap/punch down might be tight holding two wires per spade.

Mike


Title: Re: Two wires one punchdown?
Post by: K6JEK on July 10, 2008, 02:11:11 PM
Jon,

Are you talking about using cat5 cable and using the jacks for a computer network? If so I think each jack would require a home run to the router. If it is for phone service than it's a different story.

Looking at the leviton stuff I buy at the depot it has room on the metal fork for more wire but the snap/punch down might be tight holding two wires per spade.

Mike
It's a phone line and it's those exact jacks you're talking about, the Leviton stuff.


Title: Re: Two wires one punchdown?
Post by: Bill, KD0HG on July 10, 2008, 02:27:03 PM
Jon, doing that is considered bad practice. (Not to say that it's not done).

There's the obvious mechanical issues; the first wire punched is going to spread the gripper making the second connection dicey and prone to oxidation.

I'd consider punching down both wires and then soldering the connections.

There *are* devices to let you properly connect two wires to one punchdown spade, the product is call a 3M Scotchlock. It's a little lug that a wire attaches to, then it pushes down onto the outside of the spade without affecting the wire already punched down.


.



-Bill


Title: Re: Two wires one punchdown?
Post by: Mike/W8BAC on July 10, 2008, 02:47:57 PM
Bill is right Jon. The scotchlock is the accepted way of doing this and might help out the short wire situation as well. Be sure you buy the right scotchlock for your size wire.

The scotchlock uses the same punch dowh type spades and it has silicone grease inside to seal and protect the connection.

Mike


Title: Re: Two wires one punchdown?
Post by: K6JEK on July 10, 2008, 04:52:52 PM
Thanks guys.  I'll do the job right instead of doing something half baked.
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