Media for Splitting cable for internet access

Splitting cable for internet access

Hi, i am new here and rather new to cable modems as well.

I live in Venezuela, and we get this old modem. It says "Webstar" and has a "Scientific Atlanta" logo.

The cable from the street goes up to the building floor, and has a good splitter with it. From that point just outside the apartment, the cable goes to the room.

I went to some hardware store, and they sold me a cheap splitter. Searching other boards i saw that i needed a 2-way splitter that reached 1Ghz. This one says "Nippon America, 5-995Mhz". Is the 5Mhz really critical? When i use the splitter the internet connection doesn't even work and the tv quality degrades a lot.

What kind of specs should a splitter have? Is there a way i can measure my signal quality? (Maybe some software that is compatible with my phillips 7130 tv card?)

Thanks in advance.