Phone Lines Being Muted by DSL Filter

[G8racingfool]

Second post for help in as many weeks so you know I'm getting into some good stuff here...

Here's the scenario: Had one of my remaining residentials call, they found out that stinky-dink CenturyLink was offering DSL in her area and made the switch (before you say anything she had terrible satellite internet before that). She received the DSL modem and all the fun stuff that comes with it and wanted me to come help set it up.

Now, as you all know, with DSL you have to use LPFs to filter out the high frequencies on all of the phones in the house. CenturyLink generously sent her the required filters so I busy-about installing them. Everything works fine except for two wall-mount jacks. The only two wall-mount jacks in the house. Here's what happens:

• If I use no filter at all I have a dial tone (and a ton of DSL static) at a normal/acceptable volume.
• If I plug a filter in and then the phone I have no static, and a dial tone that is about 2db away from silence. (you could whisper over the top of it and not hear it)

At first I thought it was the wall-mount filters that were supplied so I tried just a regular pigtail: no difference. Also tried a different handset: still no difference. Tried the wall-mount filters on other jacks: works fine. It's just those two jacks that are the problem.

Now I'm no expert on POTS systems but I know enough to say that they're not exactly complicated. As long as the wires are connected correctly you should be golden. And the wires should be connected correctly because everything works perfectly when there's no filter in place (and works static-free when the DSL modem is unplugged).

I've checked the pins on the jacks and they're not damaged, have tried 3 different filters (2 wall-mount and 1 pigtail) and they all do the same thing but only on those two jacks. I also toned the lines out to the block and they appear to be solid. I wouldn't think it would be anything beyond that because then all of the jacks would have this behavior, not just these two.

I've seen bad filters allow static through and I've also seen them not allow anything through at all but I've never seen one, let alone three, only cause the tone/signal to be heavily muted before (but then work on other phone jacks).

So, I'm throwing out a life preserver here, has anyone here seen this before and, if so, what should I be looking at as the culprit?

 

[GreyWolf]

Is the DSL box a Alcatel and what is the make of her cordless phone? Some cordless phone models, VTech are the worst culprit in this type of issues.

 

[G8racingfool]

The cordless phone system is a Panasonic (not sure exactly what model # it is) and they work flawlessly (the base is plugged into a non wall-mount jack. The two jack's I'm having trouble with belong to an older pair of wall-mounted phones. (y'know, the big old baker handsets with the punch buttons)

The modem is a Zyxel C3000Z. In my experience they're fairly solid as far as DSL modems go.

 

[GreyWolf]

In the Zyxel you should have a line status information also depending on the line there could be collisions of a signal not made for the line calling the isp for a dslam test may give you an idea on the interference levels. As for those 2 problematic jacks could be faulty cables, a short even besides that depending on the configuration having the line split and entry point one for the dsl jack and one for the other lines with the filter on at the source may bring better results.

 

[Markverhyden]

If it's a truly analog setup your toner isn't much help. The lines are all tied together so you'll get tone everywhere. To identify individual lines you have to remove the lines from the NID to individually test. Do the number of lines at the NID match the number of outlets. Make sure to check everywhere as people tend to forget where outlets might be hidden behind things. Did you try to re-terminate the two miscreants?

 

[nerd2u]

Take it back to the demarcation point and disconnect everything then connect lines one at a time until the problem appears and go from there.

Do you have a telephone butt set?

Could also be a bad pin pair from the street I have this happen with a customer a couple weeks ago the Telco moves their service at the street and connected the wrong pin pair resulting in horrible static. Once they got the Telco out to fix the line from the street all was good.

May also be worth seeing what they charge for a seperate dry loop for the DSL.

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[Markverhyden]

May also be worth seeing what they charge for a seperate dry loop for the DSL.

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The catch with the dry loop is it's usually considered the same as having two phone numbers since it's actually a second line.

 

[nerd2u]

Also how many phone lines do they have coming in?

If you check the demarc with a butt set are you getting any odd sounds or anything on any other pin pairs?

Also how many pairs are connected at the jacks showing issues? If they only have 1 phone line disconnect any unused lines. Usually red and green are line 1 and black and yellow line 2 if it's old USOC and blue white/blue line 1 and orange white/Orange line 2 if it's cat 3.

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[nerd2u]

The catch with the dry loop is it's usually considered the same as having two phone numbers since it's actually a second line.

I know but sometimes a dry loop is like 5$ a month and comes in on its own pin pair allowing the modem to be connected to a completely different line sometimes it's just easier than messing with filters and troubleshooting lines.

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[G8racingfool]

If it's a truly analog setup your toner isn't much help. The lines are all tied together so you'll get tone everywhere. To identify individual lines you have to remove the lines from the NID to individually test. Do the number of lines at the NID match the number of outlets. Make sure to check everywhere as people tend to forget where outlets might be hidden behind things. Did you try to re-terminate the two miscreants?

It's a common household POTS setup (at least, common for around here). Telco lines run to the NID on the outside of the house where a single line runs into the house to a small 66 block where the internal lines run to the jacks. As for toning out, there was enough slack in the inside lines that I was able to pop them out of the block and attach my toner to each one individually. I then trimmed and re-punched them into the block so I effectively re-terminated most of the lines (only ones I didn't were the remaining lines after I found the two I was after).

Also how many phone lines do they have coming in?

If you check the demarc with a butt set are you getting any odd sounds or anything on any other pin pairs?

Also how many pairs are connected at the jacks showing issues? If they only have 1 phone line disconnect any unused lines. Usually red and green are line 1 and black and yellow line 2 if it's old USOC and blue white/blue line 1 and orange white/Orange line 2 if it's cat 3.

Single line coming up to the NID and then from there a single line into the house to the block. There are zero issues with the phone system until I add in the filters to those two jacks (and again, the issue is only present on those two jacks, the rest of the jacks are 100% fine and working perfectly with all filters installed).

I didn't have my butt set with me at the time but the client did have a spare phone that I could plug into the NID socket. Didn't have any audible issues there and again, all jacks work (including the two in question) without the filters in place. The two jacks work fine with filters in place on the other jacks but as soon as I plug filters onto them they get really, really quiet.

Wiring is a single pair at the jacks as they're wall jacks which typically (in my experience anyway) only ever have a single pair of pins. I'm beginning to wonder if it isn't something to do with the wall jacks themselves as the lines appear to be fine by all accounts. The wall jacks *do* appear to be older so maybe there's something there that's just not jiving for some reason.

 

[nerd2u]

Odd most of our wall jacks here can accommodate upto 3 pairs although 1 is usually punched down and the other two wrapped back.

Can you confirm the polarity of the jacks giving issues match the other jacks.

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[timeshifter]

Sorry if I didn't follow everything you tried, but did you try:

Only apply a filter at the problem jack? Don't have any filters plugged in anywhere else in the house. Also try with nothing plugged in to any phone outlet anywhere.

 

[Sky-Knight]

Back when I did PSTN on a regular basis, I'd use line 2 to feed the DSL, then out of the modem and back into the line 1 side to feed the house. That way the DSL modem is the filter itself, and I didn't have to waste all that time moving around the house.

Modern PSTN gear tends to be cordless with a single base station... any chance of just plugging that thing directly into the DSL router and foregoing all the filters?

 

[G8racingfool]

Odd most of our wall jacks here can accommodate upto 3 pairs although 1 is usually punched down and the other two wrapped back.

Can you confirm the polarity of the jacks giving issues match the other jacks.

*shrugs* Maybe it's a midwest US thing but I've only ever seen the wall mount jacks have a single pin set. I've always assumed it's because they're old as the hills and the phones that go on them can usually only handle a single line. As for polarity, I'll admit I didn't think to check that but I'll mark that down on my list for when I go back up there.

Sorry if I didn't follow everything you tried, but did you try:

Only apply a filter at the problem jack? Don't have any filters plugged in anywhere else in the house. Also try with nothing plugged in to any phone outlet anywhere.

One of the two wall jacks was the first jack I tried so can confirm it happens with no other filters plugged in. Did not try with no phones anywhere plugged in however.

Modern PSTN gear tends to be cordless with a single base station... any chance of just plugging that thing directly into the DSL router and foregoing all the filters?

For this particular person not likely. She has a weird mishmosh of phones. She's got two different cordless systems, two wall-mounted corded phones and one other corded phone in a library room as well. It's all over the place (as usual in these farm places).

I'll be headed back up there sometime this week so I'll be sure to try some of the suggestions provided here. Thanks to everyone for the suggestions so far.

 

[nerd2u]

If you get a chance pull the jacks and see if it's old USOC cabling there should be a second pair there.

I'm thinking there has to be some sort of short or cross talk or reverse polarity

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[Sky-Knight]

More than likely the polarity is wrong in a splice point in the wall somewhere, or there's a weak connection somewhere.

In any event, the home most certainly has other pairs available. It should be capable of at least two lines. Which is why I use the 2nd for the DSL, and create a two port jack on the wall behind the DSL router. The main line is disconnected from the DMARC, and fed via the DSL router. No filters, wiring trouble is largely bypassed.

But those quiet jacks? Those are technically still problems, and will likely remain so until the cabling is redone, because not only is that junk old, but was probably installed incorrectly to begin with. Not to mention damaged over decades of shoddy upgrades. That's why I refuse to deal with residential cabling, too expensive to fix properly, I'm not patient enough to figure out how to rig every job, and I feel like a crook billing for shoddy work.

 

[nerd2u]

Can you get us some pics of the jacks and wiring at them.

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[Sky-Knight]

You know... not sure why this took me so long...

But the polarity being reversed can cause the audio issue... so before you go too nuts, try flipping the wires around on the problem outlets. It may clear up the two problem spots without any more effort.

 

[G8racingfool]

Welp, problem solved. Ya'll are gonna love this.

So I get ready to head out to customers and give her a heads-up call that I'm on my way. When she answers I notice some nasty-ass static that cut out after about 2 seconds. Was a bit surprised to hear that as I had all of the phones on filters and the two non-working jacks were left unplugged.

So I get up there and pull the panels off the wall jacks, everything looks good. This time I took my butt set with and plugged into the wall jack with the filter annnd...

...everything worked perfectly. Turns out, it was the phones that were wired in a goofy way and plugging them into the filter screwed up how they received signal. I talked with customer and rather than mess around with it any more she just said she'd look for two new wall phones (these two were really old, like 1960s era old).

But! What about that static? The static I mentioned at the beginning of this post? Well, just before I left I decided to call her number from my cell and had her pick up. Sure enough there was about 2 seconds of static before everything went back to being crystal clear. I tried it again just for kicks, same thing. This time however it hit me, there was something strange going on when the phones were ringing. Remember above where I said she had basically 4 different phone systems (2 different cordless, a corded desk phone and the two wall phones). Well, the two wall phones were unplugged but I was still getting 4 different rings. So I play sound-detective and trace the ring to an ancient-as-hell looking whole-home-phone-ringer. This bаstard was directly wired into the phone system and rings every time the phones do. When you pick up it senses signal on the line and kicks out, a process which takes about 2 seconds. Customer didn't even realize it was there and had no qualms about pulling it out. Disconnected the thing and magically the static is gone.

So, tl;dr: managed to figure out two problems, the main one that this thread was about wasn't actually the jacks but was the phones themselves, second problem was a doorbell-esque device wired into the phone system that I didn't notice the first time. All is good now though. Thanks for the suggestions everybody, I definitely wouldn't have found the phone issue without ya'll.

 

[Sky-Knight]

Wow... all that ancient ground start gear... it's a miracle it still worked. Modern PSTN doesn't work like that!

The only thing you didn't find was a pulse dialer!