Cutting back cable modem cable 1

[handlebars]

I have a cable modem (from blueyonder) going into an airport wireless router, and am try to cut back or at least tie back all wiring which seems to be taking up far too much room.

Easy to cut back this type of cable like coax and then reattach?

Short of making an cut how can i find out what is involved in such as operation?

Thanks in advance

Andrew

 

[Servamatic]

it should be a typical coax termination, just use high quality F-Connectors and you should be fine.
Do you know how to strip and trminate coax?
I wouldn't use anything less than a Digicon or Snap n Seal connector on it.

Richard S. Anderson, RCDD

http://www.smartbuilthomes.com

 

[AvayaNovice]

Cable modems are highly susceptable to bad fittings. Here are the important things to remember when crimping RG-6 or RG-59 (or their quadshield counterparts).

A) Ensure that the dielectric (foam) is even with the back of the fitting.
B) Make sure that absolutely none of the braided shield has come into contact with the center conductor.
C) When you put your fitting on, deflower the braided sheild back so that it looks like a peeled bannana.
D) Don't allow the center conductor to exceed more than 3/16 of an inch past the end of the fitting. A center conductor that is too long can cause major major problems.

Bad fittings can lead to decent forward signals, but terrible return path. One of the most typical trouble calls I receieve in the field involve bad fittings made by technicians before broadband level services became part of the equation.

You can actually crimp a T&B SnS connector with two pairs of channel lock pliers. Just adjust the pliers so they're a little bit wider than all the way closed, grip the fitting after the cable has been placed far enough in there to meet the above requirements, and then crimp both sides of the fitting simultaneously using those channel locks.

Also, make sure that the dielectric doesn't leave behind any residue on the center conductor. Clean it off if you see a small white tint on the conductor.

Just remember that making a modem come up and making a TV function are two different ball games. You really need quality fittings to make the return path function 100%. If you happen to have a return meter, make sure that your return levels are between 35 and 60, 45 is about ideal. Recall that return is affected in the opposite direction, IE if I have a return level of 35 and place a 6DB attenuator inline, my return level will be 41. It's a weird deal.

Anyhow. Back to the original point. You can use any type of fitting (ie. screw on, crimp on, etc.) but they have a much larger margin of error.

Just remember to keep that center conductor nearly even with the end of the fitting, dielectric is even with the back of the threaded portion of the fitting, and no gunk on the center conductor.

 

[ANFPS26]

"going into an airport wireless router, and am try to cut back or at least tie back ALL wiring"

If you are talking about your Cat5 patch cords, then you don't want to attempt shortning and re-connecting them. Buy shorter cables for that. These are factory made shielded cables and you shouldn't attempt to mess with them.

Jim

 

[buitenhek]

2 cents only: there was an 18"min coax length for RG58 (10base2). Is there a min for RG6&59?

 

[daronwilson]

No minimum for the RF length of coax in a CATV type installation that I am aware of.

Of course you can get interesting results at particular frequencies if you have even or odd half wave lengths (electrcially) of coax, but that really should not cause a problem in the typical CATV installation.


It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[AvayaNovice]

CATV distribution does have a minimum length, but that is only relative to signal strength. That being said, if you had an extremely high amount of signal... (ie. at a tap or an amplifier) you'd need to either have a sufficient length of cable to knock that signal level down to something usable, or attenuate it. Which is the entire theory to CATV... balance.

As far as the 18" minimum, that was a little different because it applied to interference I think (cross talk almost, between nodes).

But for instance... a lot of times when I put in an amplifier off of a hardline drop, with 1/2" hardline... and my taps are right next to them, I won't even use hardline -- I'll use an 8" piece of RG-6 as the signal loss isn't a big deal, makes my life easier rather than putting a bunch of L's and what not in. But coming out of an amp, you'll want a decent amount of cable -- or attenuators.

Some DC over coax power supplies also require a wee bit of length as well. 3' minimum, but that isn't relative to RF.

 

[handlebars]

Sorry to not respond sooner, I am finding it difficult/impossible get the end bit off the cable "cable". SHould it just twist off or pull off.

Also to attach a new termination, can i reuse the existing bit or do i need a new one? Where can i get hold of one?

Thanks for any responses.

Andrew

 

[AvayaNovice]

You'll need new ones. If you're stripping the coax and you can't manage to get the dielectric off the center conductor, twist it until it becomes free and it should slide off. A good stripper shouldn't leave it on there though, FYI.