Strange question about RG6 cable length

[WEC4104]

I am rearranging some of the satellite cabling (RG6) inside my home, and I have a kind of quirky question. The reasons behind the question are too lengthy to get into here. I am sure others will suggest alternative work-arounds that don't answer the question, but here goes:

BACKGROUND:

I believe everyone agrees that you get the best results when you run your RG6 cabling from Point A to Point B with the shortest cable and without splices. "Splices" may not be the proper term, but what I am talking about is joining two cables together using the standard crimp-on F connectors and a small female/female adapter between the two.

Now suppose you had 120 continuous feet of RG6 already installed. The ends of the cable (Point A and Point B) are fixed and essentially inaccessible. However, near the center of the cable there is an access point with a bunch of slack.

THE QUESTION:

How many feet of slack would you need to get rid of before you felt it was justified to cut the cable and install a "splice"? (Assume high quality quad insulated RG6) I welcome all answers (scientific calulations, personal opinions, smart aleck heckling, etc.)

 

[stevenl]

By design a "Barrel" or female/female connector has 0db of loss. (a number low enough not worthy of measureing) RG6 loses about 5DB per 100ft @ 699mhz, So you do the math at what Freq your signals run at and what the estiamte loss is, to see if taking out 20ft of cable is really going to make any difference. Id say if it was over 40ft of slack it might be good to do but really your still only talking a couple db..

 

[lumpkin666]

By design a "Barrel" or female/female connector has 0db of loss. (a number low enough not worthy of measureing) RG6 loses about 5DB per 100ft @ 699mhz, So you do the math at what Freq your signals run at and what the estiamte loss is, to see if taking out 20ft of cable is really going to make any difference. Id say if it was over 40ft of slack it might be good to do but really your still only talking a couple db..

Typically I've read that barrel connectors give you .2 - .3 db insertion loss. Plus you get another .2db loss per crimp connector. So you're looking at minimum .6db+ loss for the "bypass", with the potential for worse problems when the connectors fail (moisture from the basement? pulled lose at some point, etc?). Unless you're looking at some major DB savings by cutting the cable, I'd not mess with it. I'd look more at ways to get to one end or the other and pull the slack out and add a new compression fitted end.

 

[stevenl]

Half a db is not worthy of consideration in a home enviroment

 

[WEC4104]

Thanks for the responses guys. Your comments were pretty much in line with what I had been thinking. I was thinking that 50 feet would be worth while trimming, but less than that the benefits diminish, especially since I am introducing a potential failure point. I'll continue to monitor this thread in case anyone else weighs in with comments.

 

[Stargazer]

120 foot of cable run should work fine with any satellite system as long as you use good RG-6

 

[oldvoom]

One plus you have right now is a potential future splice point if you ever need to Tee off or reroute. Until you cut it, it will last the lifetime of the wire. Think of it as a built-in available upgrade for when (if) the time comes.

I agree with you, mechanical failure would be my issue and is far reduced not cutting. Leaving even 50 feet is not altogether bad. Probably on the excessive side for space, but if it fits nicely without crimping and scrunching then leave it.