Bootleg - your system doesn't sound too good to me. Adding amplifiers in series like that, and especially if they are cheap amplifiers, could cause more noise on your system. In theory, you should provide the amplification that you need at the source. You should be able to distribute cable all over your house and not have enough loss to cause much of a problem. Anyway, RG11 is larger diameter yes, and less lossy. You should be able to easily push 150-200 feet on RG6 unless you are using some real high frequency signals which would be more lossy. Keep in mind, each 2 way splitter cuts the signal in half. A 3db drop is a loss of 1/2 of the signal strength. For the most part, you can draw this all out and add/subtract gain/loss in DB and see how you are doing. For example, if we just ASSUME that you have 0 dB coming in, you split it (-3db) you throw a 20 dB amplifier in (+17), you run 100 feet of coax at (-10dB@250Mhz) (+7), you should have more signal here than what you started with. But, throw in more splitters and such and you can easily drop things down below what you need for quality signals.
SO, be sure to use RG6 as a minimum everywhere, RG11 perhaps if you have very long runs, try not to cascade splitters if you can help it, make sure splitters are good to at least 1000 Mhz, use quality connectors (generally no twist on or hex crimp fittings) and get a quality amplifier (non-radioshack). I usually use holland or channelplus personally.
I don't know of any maximum distance from the DMARK to your equipment. For cable, the determining factor is signal strength, plain and simple. You need to know what your cable modems requirement for signal and give it that. Here in Charter country, at first they thought the modems had to be hit pretty hot, so we were splitting the drop when it first came into the house and sending one leg directly to the modem and the other leg to feed the house. After a few months they determined the modem did not like that much signal and they were back dropping 10dB pads in each modem circuit to get them to function better. Keep in mind that your cable modem is bi-directional, so anything in the circuit (amplifiers) will need to be bi-directional as well to get your signal pushed back to the cable company. Check with your provider.
For your Cat5e, the ethernet standard limits you to 100 meters (328 feet) for any circuit. In practical applications, I try to stay under 300 feet and not push it.
VSATECH - I'm sure not going to tell you there no such thing as noise on a ground conductor, but if you are picking up noise on your grounding conductor you likely have some other building wiring problems. Running cables next to a ground conductor should put you at the same potential as running cables in the dirt (ground). However if you are in doubt, it is should be simple enough to separate the coax from the Cat5e until you get to the outlet and everyone can be happy. Of course making sure the coax is grounding with a grounding block as it enters the building is a good idea too.
Good Luck! 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
