Hardware video noise filter?? can a digital cable box work as one??

Just today i noticed how much my cable sux.I thought it might be just me and my rca 27quot; but i was wrong. I went over to my mother's house since she has a very expensive COAXIAL cable that is only 3 inch's long in connecting her tv to the wall...and the same deal. Her's looked alittle better(but still alot of noise). It might be because i have a splitter in the living room splitting one cable to a tv and the other 54'(feet) to another splitter which splis to my cable modem and the other to my vcr. From the vcr i run composite video to pc. From the pc i run s-video to the tv.

|=splitter
......................../-[cable modem]
........../----------|........./-[tv_2]
[wall]-|.......54'...\-[vcr|
..........\-[tv_1]............\-COMPOSITE-[pc]-S-VIDEO-[tv_2]

As you can see after all the splits i have a loop envolving the tv_2, vcr, and pc. I finally pinpointed a rooling luminace i have on my tv display...it comes from the cable line. If i disconnect the cable line from the vcr i elimate the signal from enetering the pc...which then elimanates the rolling luminance from the display. So i figured out how to loose the luminace...well sort of. That is good to do when i watch my dvd's because i play them in my pc and view them with the tv display. Ok well i also do that with the cable because it increase the picture size. Ive noticed that i get about another 1quot; of area all the way around when doing this...and also i get the rolling luminance. I have yet to figure out how to loose it. So i need to find some way of elimanting the noise created by either the splitting or just crappy cable service and the rolling luminace. Im wodering if i throw a digital cable box(a co-worker is giving me one)in the mix it would help things out...it would be like this while capturing/viewing my cable tv...

[dcb]=digital cable box ;p

......................../-[cable modem]
........../----------|........./-[tv_2]
[wall]-|.......54'...\-[dcb|
..........\-[tv_1]............\-COMPOSITE-[pc]-S-VIDEO-[tv_2]

IS there a possibility of it increase the picture quality this way??? If so how would i get the digital cable box to work with the channel i want it...or even just one channel(Cartoon Network).

If that is either too much of a question to ask or just impossible to do is there a HARDWARE based video noise filter that could help me???and if so what would the price be and how much would it benefit. Im searching currently and so far i only found one...and its not exactly the correct type of filter ;p...link below.

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welp..i got the digital box this morning. I dont have the service so i guess the box is just acting as a modulator of sorts. Although using this instead of my vcr has actually removed 33% of the noixe...so its a step up. Now all i have to do is find a actual hardware filter.

yep another follow up. well im investin gin a ati tv tuner card pci versions soon. in the meantime i have signed up for digital cable...he installe dit yesterday and i was quite derpressed...but i went ahead and hooked up the box my co-worker gave me last week with it...amazingly it looks nearly like iwant it to directly after caputre...im not sure why this has happened but im still researching. So far all i have been able to dig up is that some box's like the Motorola ones i got have some kind of built in filters...2 in each i believe. Also the frequency is higher so it might help soemthing aswell. So if you got digital cable and a extra box..andhappen to caputre video...try hooking your second digital box up to reduce noise. The 2 box's i got are the same model.