DSL Interference

[Peter Stahl]

My phone had been getting a lot of static in it so I thought it was just a problem with the line and would have to call Verizon. Before I did this I turned off the DSL Moden and Voila, clear as could be now. I have all the filters in place and didn't notice it being that bad until about a month ago, I always blamed it on the incoming callers phone. Is this typical with DSL? Is the Modem going bad? If I run a separate line for it out to where they connect outside would this help? Had cable modem but the DSL is cheaper and more dependable. Thanks for any help.

[glenn bradley]

Never had the problem but this is not normal. I would call Verizon.

[Rafael Carias]

Is your DSL modem the cheepo that comes free with the service? I had the same problem with when I first got DSL here.

[Peter Stahl]

Never had the problem but this is not normal. I would call Verizon.

Glenn,

Thought I'd ask around first to see if it would be something I could fix.

thanks, Pete

[Peter Stahl]

Is your DSL modem the cheepo that comes free with the service? I had the same problem with when I first got DSL here.

Rafael,

It's the wireless modem they gave me with the service. What did you do to fix the problem?

[skip coyne]

have you tried replacing the filters ?

[Peter Stahl]

have you tried replacing the filters ?

Skip,

Those filters aren't cheap. That would be the last thing I would do. All the phone had static until I turned the Modem off.

[Mike Henderson]

Let me discuss a bit about how ADSL works on your line and then I'll discuss one way that noise gets into your phone.

For voice, your phone uses the first 4KHz for the speech. The DSL signal is placed above this in the frequency spectrum - starting at about 25KHz and going to a bit above 1MHz.

So, if everything was perfect, you'd never hear the sound of the DSL signal in your telephone. But there's a small "gotcha". There's a DC voltage on your telephone line. I won't go into detail about why it's there, but most modern phones take that voltage and use it for certain things. To make sure they get the right polarity, your modern phone has four diodes in a bridge circuit. So no matter what the input polarity, after passing through the diode bridge the polarity is what the phone wants.

The problem is that a diode is a non-linear device. So when the DSL signal hits those diodes, it is converted to frequencies in the audible range. It usually sounds like white noise, but often fluctuates somewhat.

The phone company gave you some small bandpass filters to put on your phones. Those filters block the DSL signal from getting to the phone and therefore prevent the noise I discussed above. In the very early days of ADSL, one filter was put at the entry point of the house and a new, separate line was run to your ADSL modem. But that required a truck roll to the house which made installation expensive and slow. The new way, called "splitterless DSL" does not use that filter, but requires a filter on each phone or other phone device in the house.

If you have any phone devices, like an answering machine or a fax machine or a phone in an unused room, in addition to your normal telephones, you need a filter on all of them. An unfiltered instrument can cause that noise, even if the phone you're using does have a filter on it.

I can't say for sure that's why you're getting that noise, but it's perhaps the major reason for that report. Check all your instruments and if they all have filters on them, call the phone company and get them to send someone out.

Good luck!

Mike

[Joe Pelonio]

If it's wireless you can get interference from a neighbor's cordless phone, baby monitor, or security system, anything else that is also wireless and within range.

[Rafael Carias]

Rafael,

It's the wireless modem they gave me with the service. What did you do to fix the problem?


My router was not wireless but It was a cheepo. the problem went away when I replaced my phone with a better one.

[Lee Schierer]

Skip,

Those filters aren't cheap. That would be the last thing I would do. All the phone had static until I turned the Modem off.
We have Verizon DSL and the phone lines are absoultely quiet when the modem is working. We do occassionally have to turn off the modem and restart it to get connectivity.

If you turn off the computer and have the modem on do you still get the static? Verizon will charge you for a house call if they find your equipment is creating the problem. I would recommend disconnecting all but one phone and the computer leaving just one phone and the modem running and see if the problem is still there before you call Verizon.

[Peter Stahl]

Here's what I have. All phones do have filters on them. No filter on the Modem. We had a lot of static which went away when I turned the Modem off yesterday. I turned it back on today and everything is still fine. Don't know what caused it or what really fixed it. If it restarts again then I'll try a DSL splitter using one of the extra pairs of wires or running a separate cat5 line. Thanks everyone for your help. My wife called Verizon today, couldn't get a human to talk to and the message said it was $90/half hour for service.

[James Jaragosky]

If it is not too far you could just trade in your current modem at a branch office for a replacement. My local branch does not charge for this. If the problem still persists, then you can be fairly sure its not the router (not 100% sure but sure).

[skip coyne]

Skip,

Those filters aren't cheap. That would be the last thing I would do. All the phone had static until I turned the Modem off.


pack of 3 for $10.00

http://www.sureneeds.com/f5d59013.html

(Ive got a bunch of these if you want some PM your address and I'll send you a few )


I'll try a DSL splitter using one of the extra pairs of wires or running a separate cat5 line. Tno advantage to using cat 5 here , if you have it it will work but you wont gain anything over using Cat 3

[Dick Adair]

Pete, the phone company put a single filter outside at the box which solved a lot of my intermittent problems. Also when I had a static problem it was always in a line connection outside that occured usually after heavy rain. (squirrels love the phone lines). Some ideas to look at.

[Peter Stahl]

Pete, the phone company put a single filter outside at the box which solved a lot of my intermittent problems. Also when I had a static problem it was always in a line connection outside that occured usually after heavy rain. (squirrels love the phone lines). Some ideas to look at.

Yea, I hate intermittent problems. Especially when something stops doing when turn a piece of equipment off then it won't do it again when you turn it back on. Don't have to worry about squirrels unless they are ground squirrels.