Will RG11 be safe for my equipment?

[zinchmwah]

I live in an apartment that is quite some distance from the cable tap. I'm the last building down from it. The cable I am connected to comes from the wall but also travels threw every apartment building across more coaxial cabling and splitters from the early 90's before reaching me. I tested my theory on how all of this wiring and splitting is making my Comcast service reek by going to a friends apartment who lives in the building the very tap is built onto. We have the same service but his signal and internet doubles what I get. So I decided that I should buy an RG11 coaxial and do some underground wiring. I can connect a single cable of mine to the tap and run it in a basement and up a peak hole of the floor to my splitter which splits to the cable box and modem. I am concerned though. RG11 has a 14AWG copper clad steel conductor. Will this damage the inside of a splitter if I try to fit it in or even in a cable box or modem? The way I want to do this is 100+ft RG11 from cable tap to splitter then 2 6ft RG6 for my services to be hooked up. I might even just get 2 6ft RG11 so long as it's safe in place of those RG6's. Over kill but oh well. I want to make sure I can get the most secure amount of dBs with no loss as much as possible considering I'm 100+ feet from the tap and an extra 50 from a power pole.

 

[hairystuff]

It shouldn't be a problem to use the RG11 in place of the RG6, but I would replace smaller 6ft pieces of RG6 with RG11 as it could cause problems with resonance and interference (I had a problem with resonace and interference when I used mixed type coax patch leads in a amatuer radio station).