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[jhiker]

Hi - newbie here - looks like a very informative forum...

What do you make of this - I have an ongoing problem and am at my wit's end. It's a bit long and I apologise, but I'd be grateful for any suggestions.

I have a Netgear DG834 wireless ADSL modem router and it's causing high noise levels on my phone line to such an extent that it's hard to hold a telephone conversation. I have a BT phone line and my ISP is freedom2surf. I'm on Max ADSL and about 1km from the exchange as the crow flies.

My setup is this....
Phone line comes into house in hallway to a BT NTE5 master socket. I have fitted an ADSLnation filtered faceplate in place of the BT front cover. There are no satellite phone extensions running off this box.

Into the voice side of the faceplate this I have a 2-way phone splitter - one line runs to a 'normal' phone also in the hallway - one line runs to a mains powered DECT cordless phone in the kitchen.
My ADSL router is in an upstairs bedroom and is connected to the faceplate with a CAT5 twisted pair cable also from ADSLnation.

When the router is plugged in there's a hell of a lot of noise on the phone line which is evident on both phones - when I unplug the router the noise goes away - plug it back in and the noise returns immediately. It seems as if the router is feeing back noise into the phone line but I didn't know this was even possible. I don't think it's the phones - I can disconnect either of them and the noise remains on the other one - it has to be the router surely?

In an attempt to diagnose the problem I've tried the following;

Removed the faceplate and plugged an in-line filter into the hidden master socket to bypass the faceplate - plug phones in, no noise - plug router in also and noise appears immediately.
(Is this conclusive proof the problem is 'in the house' and not BT's cabling or are other factors at play here)

Bring router downstairs and plug into filtered faceplate using a fresh short modem cable to bypass the other, longer one that runs up to the bedroom - noise remains.

Replace Netgear PSU with a different make of same rating - noise remains though I kind of convinced myself it was less obtrusive - may be my imagination.

I'm not in a position to try another router though I'm coming round to the idea that I may have to buy a replacement if only to eliminate the present one from the equation.

Here are my line stats - I'm losing sync frequently and my connection speed is dropping off rapidly necessitating frequent router reboots - I've suffered 6 'loss of syncs' in the last 20 minutes.
Stats are variable but this is typical...
Upstream     Line attn:4.5dB Noise margin:17dB
Downstream Line attn:16dB  Noise margin:13dB

What's my next move - what should I try next in order to pin it down.
Thanks in advance.

[kitz]

Hi and welcome to the forums.

With an adsl NTE5 faceplate, the telephone side of faceplate should completely filter out any adsl frequencies (which is higher than voice data), therefore it shouldnt be possible for the adsl signal to interfere with the voice side of things.

Since you have tried an inline filter with the same effect then that would appear to rule out the possibility of faulty wiring in the faceplate.

What speed is your router syncing (connecting) to the exchange at?
Also its not 100% clear- so I just want to make sure - is the CAT5 connected to the downstairs (master) socket, and not a socket already in the background

Out of curiousity can you try the following.

Remove the faceplate and plug an inline filter in the test socket.
Dont plug the phones in yet... or the BT doubler.
Plug the cable in for the router.

Then go to your router and look at your line stats.
Make a note of what speed the router is syncing at.
Record the Noise Margins and the Attenuation.

Then plug in the normal phone - check the line stats and see if the noise margin or attenuation has changed.
Remove normal phone and plug in cordless phone - check stats again.

Remove Dect phone - insert BT doubler and both phones - record the line stats.

Now pick up the phone to open the circuit, and record line stats.

----
Also do you have a length of phone cable to check on the slim chance that theres nothing wrong with the CAT5 cable?

When doing the above tests you are looking for changes in sync, Noise Margin or attenuation.

Its far more likely that this is something local so calling out BT is likely to result in a hefty fee, and Im afraid any diagnostics is going to be down to you first. :/

[jhiker]

Hi Kitz, and thanks for the welcome.

Phew! - done all that and here are the results.
Just to clarify, the Cat5 is plugged directly into the faceplate splitter. I have no extensions coming off the main BT box. Also, I have tried a different (RJ11 - I think - came with the modem) cable to connect the router to the faceplate, bypassing the Cat5 - no improvement.
Anyway, here goes with the stats...

Router syncs initially at 8096kbps drops over short time to around 2000kbps then can drop further to around 160kbps!

Test results:
'Remove the faceplate and plug an inline filter in the test socket.
Dont plug the phones in yet... or the BT doubler.
Plug the cable in for the router'.

Sync 8096 d/strm 448 u/strm
Down       UP
LA  15dB   3.5dB
NM 15dB   27dB

'Plug in normal phone'
Sync 8096 d/strm 448 u/strm
Down       UP
LA  15dB   3.5dB
NM 14dB   27dB

'Remove normal phone - plug in DECT phone'
Sync 8096 d/strm 448 u/strm
Down       UP
LA  15dB   3.5dB
NM 13dB   27dB

'Insert BT doubler and both phones'
Sync 8096 d/strm 448 u/strm
Down       UP
LA  15dB   3.5dB
NM 15dB   27dB

* Sync drops off on next test *
'Pick up the (normal) phone to open the circuit'
Sync 3552 d/strm 448 u/strm
Down       UP
LA  15dB   3.5dB
NM 14dB   19dB

after a minute or two this drops off to...
Sync 160d/strm 288u/strm
Down       UP
LA  13dB   3.5dB
NM 11dB   6dB

...put phone back on hook...
Sync 160d/strm 288u/strm
Down       UP
LA  13dB   3.5dB
NM 27dB   6dB

open phone line with DECT phone...
Sync 160d/strm 288u/strm
Down       UP
LA  13dB   3.5dB
NM 28dB   6dB

put everything back together - refit faceplate & plug in Cat5 - plug in doubler & two phones
Sync 8128d/strm 448u/strm
Down       UP
LA  15dB   3.5dB
NM 13dB   28dB

..and it's been like that for about ten minutes...

Does this help - I'd really like to get to the bottom of this.

[havelock]

Hi jhiker

It sounds like there a fault there somewhere, but its gonna be a pain for you to get it sorted imho.

Basically it sounds like there are 2 (possibly related) issues - first your SNR margin is dropping, i suspect if you had a USB modem you'd be getting booted offline but your netgear is holding sync. Your main cause for concern is the noise bleed (crosstalk) from the adsl band to the voice band, which COULD be before the signal is filtered at your master socket (but it is fairly rare).

What I would suggest is the following.

1. Reduce your setup to BT-Test Socket (hidden behing your faceplate) >> A regular microfilter >> a USB modem if possible and a non-Dect phone.
2. If you still get interference on you line, call you ISP and tell them that on plugging in the equipment they supplied there is interference on your phones. If you explain you have swapped filters, phones and ADSL equipment, then this leaves only a possible line fault. It is likely your ISP will run a one-shot test on the line and then want to raise a fault to BT.
3. At this stage give BT retail a ring (151) and tell them that you have a "PSTN affecting broadband fault" and ask them to check the line for you. If they find a fault, ace, if not ask them to make sure the test results are logged.
4. Back to your ISP, allow them to raise the fault but make SURE they include on the notes that its a PSTN affecting broadband fault.

Unless your ISP books a CSE visit for an engineer to come to your premesis, then you will NOT be charged. If you check that none of your equipment (swapping router, cables, filters etc) is faulty and that your internal wiring or phones (swapping phones and unplugging the NTE faceplate disconnects all your wiring) is not at fault, again, you wont be charged.

Also remember charges are at the CSE's discretion - make him or her a cuppa and be nice (but firm) even if they aren't giving you answers you want to hear.

Rgds
Havelock

[kitz]

Thanks for doing all those tests.

The obvious to me is that you have a decent sync with all the equipment connected - until you open up the circuit by picking up the phone... and then you loose sync.

When you open up the phone line a small electric current is generated.  Problems at this stage can be the result of a high open fault, possibly caused by oxydisation of a joint on the line.

See Connection problems
~ adsl drops out when phone call is made or received.
and
~ adsl disconnects when the phone rings.

Try doing the quiet line test, to see if you can hear any noise on the line.
If you can - then this would be good, because you can report it on 150 which is quicker at getting resolved than going through the adsl route.

I'd save those results you just did, because they are very useful in showing that all is well until you open up the circuit, which in this case helps point the finger at an actual line fault.

[jhiker]

Thanks for that.
I assume I'm supposed to do the 'quiet line test' with only a single phone plugged in to the (hidden) master socket, i.e. the most basic configuration and no filters, splitters or ADSL plugged in - that right?

[mr_chris]

depends... it can be useful to try both... it may help determine where (if any) thesource of noise comes from. Try it first with your normal phone config... try it with a phone plugged in where your ADSL modem is... then if you do hear something, try it in the test master socket.

That way it will eliminate or point the finger at your internal wiring/equipment and avoid a hefty BT bill if they find it's the fault of your equipment.

Hope that helps

[broadbandbill2002]

Hi.
This is a very interesting fault.  I have dealt with hundreds of ADSL faults on a professional basis.  I have just returned from exactly what you have.  To prove it I put my own socket on at the incoming BT cable, used 2 non wireless routers, a filter 2000.  Tripled 3 ordinary micro filters and the ADSL noise was still present when in synch.
The answer is to try a filter LJU 10/14A this is a radio interference filter which will reduce or nullify the fault.
The actual fault comes from a conflict on your exchange card.  IF you can get this change (some hope!!) This will rid you of your problem.

[jhiker]

Well, it may just be coincidence but I don't think so..
My DECT phone stopped working two weeks ago (unbelievably, it was the day after the twelve month guarantee expired - are these things chipped  )
I took out the phone line and unplugged it from the mains. The noise on the remaining phone line has stopped and my modem hasn't dropped a connection since that date. Although I had isolated it from the phone circuit for testing I hadn't unplugged from the mains - seems the wireless must have been interfering with the modem in some way. I'm kicking myself for not having tried it before!

[roseway]

Hopefully you've got a result I've no personal experience of DECT phones transmitting interference into ADSL lines, but I do believe that it can happen, so you may well have fixed it.

Eric

[kitz]

>> I've no personal experience of DECT phones transmitting interference into ADSL lines

Me neither but I have seen a new DECT phone cause problems when the previous one didn't.  Turned out that it was actually something to do with the filter though.  Old phone worked fine with old filter. New phone worked fine with a new filter, so I just assumed that the old filter wasnt performing as well as it should have. :/

Thanks for getting back to us jhiker - glad that you problem seems to have sorted