Semi is correct that sometimes if you bitch enough to your local cable company they will bring a tech and install a cable filter or even a drop amp. They did that with mine because the old place had poor old wiring (really old loft). The static on my cable TV disappeared and the picture was very clean and clear.
This is something what they installed.
http://electroline.com/en/products/drop_amplifiers/era/index.html
click on products...drop amplifiers...ERA 4100
I have the old 2400 model.
They also carry straight filters without a boost that the drop amps have. These products should be free from the cable companies. If not I believe they are less than $100 CDN depending on what model.
If you need pictures of my cable picture before drop amp and after I can supplies those too. No more static and fuzzy screen. But cable picture isnt the greatest to begin with.
