[R_Willis]

I'm currently having high-speed cable internet installed (well, soon..) and the installer wants to come in on the side of the house with electric/phone/etc because of grounding purposes. I wanted him to come in on the opposite side of the house because of the short cable run and easier access to the equipment closet in basement. Figured it wouldn't be hard to install some type of ground on that side of the house.


If we end up going the long route, all the way from front of house, around back and to the other side we are looking at a serious amount of cable to make it there.


He said we would have to use RG7 or RG11. Anyone know the maxium efficiency length of these two types of cable? Cable would be installed underground, up to house, then into basement.



Hate to go through all this install to end up with some crappy high speed download speeds and cancel because there is no contract at all.


Thanks guys.

 

[tvtech1]

RG7 doesn't exist, so I guess it's RG11


RG11 is about 1/2" in diameter, low loss, but expensive.

RG6 should be fine.

 

[greywolf]

 http://www.cinergy.com/surge/ttip08.htm may help you decide how to best run things.

 

[Scooper]

It's not just sinking a ground rod at the other end of the house - it also has to be bonded with the first one as well.


Don't you have a crawlspace / basement that the wire could go in ?

 

[R_Willis]

tvtech1: heh, I didn't think either existed, well never had heard of them.

But, a little searching, seems to show both DO exist. RG7 link here @ http://www.nfwire.com.tw/NFC/e05a-3.htm


greywolf: thanks for the link


Scooper: can't I just use a ground roud at other side of house, and connect to the cold water pipe (copper) in the basement that is grounded to main one at electrical service panel. The main ground rod wire that comes in on the side with all the other services comes in and goes directly to the service panel, then branches back out and is tied into the water pipe with clamp.


and yes I have a basement, that is where the cable modem, router, and all CAT5e drops are. However, the equipment rack is on the opposite side of basement from the electrical service panel. Thus, the reason I would like to come in from the other side of the house which is VERY close to the equipment rack.


Thanks again guys. Invaluable as ever.

 

[greywolf]

The 2002 NEC specifies that a water pipe used for ground must have all ground connections within 5ft of where the pipe enters the building. Even the older codes specify a 6ga copper bonding wire be used to connect any auxiliary ground rod the the main building ground. Sometime in the future, somebody might replace a section of pipe with plastic without even considering electrical ramifications. Check with your local building department about how you can meet your local code requirements. You don't want your homeowners insurance to have a reason to not reimburse you if something happens because you did something to violate the building code.

 

[Scooper]

R-Willis - no, you can't , for the very good reasons we stated above. Even grounding to the cold water pipe would require bonding to the other ground rod. The whole purpose of this grounding is to provide a common reference point for all electrical, and using different points defeats this.


Heck, my house built in 1983 has ALL plastic plumbing. Unfortunately, it was that Polybutulyne stuff that had a nasty habit of springing leaks at the joints. All new work going in is now PEX, and by the end of the year, I'd like to have it all replaced (I can do this myself, just buying materials and renting the PEX crimp tools).

 

[R_Willis]

Ok, thanks for the information. Looks like the FAR side of the house will probably end up being the option then. Definately don't want to take any risks since this house is brand new and I still have lots of mortgage to pay.


BACK to the original question for sure then, what distances can RG7/RG11 be used without signifigant loss in quality. Looks like we'll have to go some 300-400 odd feet with this run from the box at the street. Installer commented the other day, RG6 would not probably be a good choice for this long of run.


The whole idea of having cable internet is SPEED, and if I'm going to lose it all, it won't be good.

 

[audiblesolutions]

I doubt you will lose speed with a long length of wire but you will have significant signal loss over such a long run. The common rule of thumb is that for every 100 feet of RG6 you lose 3db of signal. For 300-400 feet that would be between 9 and 12 db. In fact, RF is negatively sloped and depending on the frequencies of the foreword and return paths your signal loss could be much higher in the field. RG-11 provides much lower signal loss/100 ft. Your cable modem would very likely not work connected to such a long run of coaxial cable as it would not have sufficient signal to establish a connection. They are very finicky and do not tolerate great swings in signal level.


I had no idea RG7 existed. This is why one plays up here.


Alan

 

[Scooper]

I wouldn't think that RG6 will have any problem (it will be up to the cable tech to ensure an adequate signal reaches your cable modem), and if RG6 doesn't quite hack it - RG11 certainly will. At worst case, a bi-directional amp should take care of it - but again, let the cable tech worry about this.

 

[greywolf]

It sounds like you have a knowledgable installer Robert. Consider yourself lucky.