My wife and I have two lines in our house. Line 1 is the "home" line, and Line 2 is her "office" line. Our DSL service also comes in with Line 2. Line 1 has 3 phones coming off two jacks. One jack is in the office, and is connected to a phone with wirless handset. The other jack is in the bedroom with a splitter. One line goes to a phone/answering machine in the bedroom, while the other goes through the wall to a regular wall phone in the kitchen. Line 2 is split off the same jack as Line 1 in the office. It is further split by a phone company (also our ISP) device into the DSL and Line 2. The DSL line goes to their modem, then to a router for a home network with 2 hard wired desktops, a wireless desktop, and a wireless laptop. Line 2 goes to a Panasonic combined phone/fax, and through that to a standalone answering machine.
Line 2 appears to have no problem. There is no noise on my wife's business phone, fax works without problem, the DSL operates normally with good speed and no dropped connection.
Line 1 has constant noise, resembling AM radio static, very crackly. It ebbs and flows, sometimes being low, sometimes being so loud as to drown out conversation. My nephew heard it on his end and was convinced it was DSL noise, suggesting I get filters. I bought two filters and put them on both Line 1 jacks, with no noticeable improvement.
I have unplugged all phones and checked each, one at a time. Noise always present. I have checked Line 1 and Line 2 jacks at the box outside the house. No noise on Line 1, so the problem is inside the house.
Note: The noise began when the phone company/ISP upgraded a couple months ago. The DSL used to have a dedicated jack inside, but they rerouted into the configuration above. Their techs were actually in the house. Unfortunately, I was not. But because the line has no noise at the box, they do not consider it to be their issue.
I would appreciate any help anyone can offer. Thanks.