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ADSL modem connection affects telephone audio.

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NCapper

Technical User
Apr 16, 2009
9
AU
Hard to know where to start on this one, so please bear with me and ask for details on anything you want.

I'm on a 1500 ADSL1 connection over a standard suburban copper wire service. Appararantly my home is at the edge of the useful distance from the telephone exchange.
My problem is, even after buying a Netgear modem/router DG834G I have intermittent communication problems.
1. My best connection is around 1200 kbps but more often 600..
2. When it's down I can immeadiatley get a much faster connection by lifting and replacing the handset of the telephone.
3. At times the handset audio, when making or taking a call, is very "crackley" but if the modem is removed from the phone line it becomes very clear.. but upon reconnection, a pause of about 5 -10 seconds and the interference picks up again.
4. About 3 years ago I had the telephone utility techs in to check out the house wiring and my equipment and they said it was all without fault. They did say the line quality was at the lower limits and after a few hours they reconnected my street line connection to a different circuit ( my words, not theirs) and the chronic line dropouts that were plagueing me at the time were largely remedied. At that time I was lifting the handpiece , more or less succesfully, to regain connection.
At that time I was on a 512 connection plan with a different ISP.

I have done all the suggested in-house isolation tests.. and used a variety of line filters and 3 different modems... I even disconnected everything throughout the house and connected the modem to the first socket which is on the opposite side of the house wall where the utility company's box is fixed to the outer wall. The exact same results..
I'm concluding, rightly or wrongly, I guess, that the problem lays outside my property and with the telephone supplier's system. I'm about to ask them to come and recheck everything but thought I might just ask if there is anything else I could do or say?
If any specific info is needed please ask and I'll do my best to provide it.
 
I'm picking this one up pretty late after your posting...

Tell us your line stats, i.e. DS Margin and Attn figures.
What about electrical noise around your property?
Are you in a rural area or close to local industry, etc?
Do you have the favoured NTE5 Master socket, or something older?
What does the BT Checker say your maximum stable speed is set at?

But perhaps you're already sorted now...

ROGER - G0AOZ.
 
Thanks Roger..better late..etc... but even though I've fixe db the problem it s still good to get your suggestions.
While our external line may be a bit flukey at times we live in a typical inner city suburban enviroment with no manufacturing within 2 kms..
We certainly DO have the older type wall connections.. just 2 wires terminating in a 6 wire plug.. pin 2 & 6. Older than this they probably just used the top 2 strands of the fences !
I eventually got right down to suspecting the wall socket in the den ( about 12 years old) and so ran a 10 metre ( yes..I know..) extension from an adjoining room and found almost immediate relief. I was unable to locate a new wall panel of that exact type, and not having access to any tools to make a proper connection I've opted to just making a vanilla flavoured stright splice thru the wall opening to a short cable to the modem.
Since then ( 2 weeks ago) my line speed checker pretty well stays right on the 1295kbps every time..
so right now I'm happy with the situation, more so that I dont have to get people in.. so I'll run with what I have and keep the fingers crossed..
Strange thing is, that wall panel connections were as basic as you could expect.. just brass strip connection the input (metal thread screws) to the line socket. Try as I might I couldnt see why it should be faulty.. But the fact was.. faulty.
Thanks for your interest and support.
 
Glad you're sorted.

If you have only two wires, the normal convention is to use terminals 2 and 5, not 2 and 6. However, it's not going to matter unless you bring in some specialized equipment!

The normal IDC connections inside the sockets do deteriorate over time. I only went out to a client the day before yesterday who had a Broadband connection that was regularly dropping out. Watching the Downstream SNR I could see it suddenly drop from 4dB to 0dB with resultant loss of connection. Since I'd recorded the SNR on this particular circuit as 26dB two years ago, I knew there was a major problem somewhere. Re-punched the IDC connectors in both the Master socket and the Secondary socket, and Hey Presto! SNR back up to 26dB.

The white BT telephone plugs (I call them LJU plugs) do seem to develop corrosion between their connectors and the corresponding slim gold 'fingers' inside the sockets. It is difficult to effectively clean these without damaging them.

I have also found the basic TEE adaptor that is used to allow two phone devices to plug into one socket, can deteriorate over time - as can the basic ADSL filter unit. This again is usually down to corrosion problems.

Be aware that you might see your Downstream SNR drop with the onset of Christmas! Some of the myriad of Christmas illuminations can cause huge amounts of electrical noise, particularly the cheap and nasty imported ones. I have known several instances where these devices on a next door neighbour's property have caused ADSL dropout.

ROGER - G0AOZ.
 
Thanks once again Roger..
What you say is very indicative to the problem.. It might also answer why we get spasmodic audio interference on our voice phones from time to time.. I haven't thought to check it since but when it was bad ( my wife would let me know ;-) )I found if I removed the line from the modem there was an immediate cessation of the crackly hum.. Put it back in and in about 5 seconds, it was back.. Over the past few days I've lifted the handpiece several times and the audio standby warble is very clear. I spoke on the phone a couple of times yesterday ( easy to see I dont use it much..) and it was clear.. I asked my son on the other end (who has helped me on this testing over the months) and he said it was also clear at his end. I mention this only that there seems to be a connection ( no pun intended) with this abberation and the poor line connection.
I'm thinking now to ask a friend who has the proper telephone crimping gear call by and change over the two wall socket that are of the older loose wire connection type.. The wall phone plate has small round transparent connectors which clearly (there I go again..) keep out the air and moisture and do away with the metal strips. Does this sound advisable..?
I appreciate your advice.. and I'll give you the line quality readings that I take note of during the day..
And yes,, the house next door DOES do a Griswold.. Still, I can put up with a bit of interference ( if it happens) in the spirit of the season !
 
Certainly changing the old sockets over for new ones is a good idea. I'm sure your friend will understand it, but make sure the wire is punched down into the IDC connectors in a different spot so it makes a nice firm connection. Whilst it is possible to buy (and fit) a Master phone socket, BT will not look on this favourably. If at any time they need to carry out maintenance work which involves access to that socket in the house, you might get charged if they have to replace it, etc.

I take it all your telephone wiring is two-wire. Sometimes a third (bell) wire is connected to the Master socket (terminal 3) and leads out to the Secondary extensions. This is not needed these days and can be disconnected, AT BOTH ENDS, otherwise it acts as an aerial picking up noise, etc.

Not all festive illuminations create electrical noise of course, but just thought I'd advise you of it in case you notice a seasonal drop in the SNR.

ROGER - G0AOZ.
 
I'll make sure he checks for that 3rd wire.. The cable behind the wall was 4 strand with only 2 connected, as you would expect..
All's fine now..Thanks for your advice

 
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