Noise with filters in test socket

I am having trouble with DSL. So I want to start from the test socket. I plug my analogue phone into the test socket and have a clear signal i.e. no noise. I then plug a filter into the test socket and can hear noise. So try two brand new filters (model Z-350UK) and still hear noise. I also screw the NTE5 plate back on and can hear noise. Very occasionally I hear no noise using the filters.

When the noise is worse I lose internet.

Where do I start?

at what point in the process was the ADSL router plugged in ?

Router plugged into DSL socket on the filters in all cases; not of course when the phone was plugged into the test socket.

try two filters in series on the phone.

It's probably a line fault - bad connection or near failing corrosion point. But might be your phone / filter combo.

Tried two filters but still internet drops.

Phone is very old. Will buy an up to date corded phone and see what difference that makes.

two filters should eliminate the phone from enquiries. Does it drop if you ring it without having a phone plugged in ?

I already had the phone removed from the filter, over an hour, so I could use the internet.

Tests of ringing my home phone, from my mobile, with phone remove from filter did not drop the internet.

I did notice that I could hear some noise on the line over the mobile on the first test but not on the second test but minor noise i.e. less than first test, on third test.

Also ran a Thinkbroadband speed test; download slightly down (3.4 from 3.7) but upload low (.2) normally (.4).

I share my telephone pole with an Openreach engineer who advises me that we have poor wiring between us and the exchange; many joints because we have two 50 bundle cables spliced and take a circuitous route. Other end of our road rewired some years ago and a more direct route. Considering Virgin cable for broadband; already have TV package.

any noise you hear on ringing is not from your line, as at that point there's no audio circuit in play just signalling. The ringing you hear when calling doesn't match the ringing of the phone.

Cable would make sense.

"..any noise you hear on ringing is not from your line,.."

Where does the noise come from then?

Where does the noise come from then?

Somewhere in the mobile network, or the exchange, not sure. Nothing at your end to generate a ring.

Also ring tone on calling handset out of phase with receiving phones.

I wonder if I am misunderstanding you.

"..
Somewhere in the mobile network, or the exchange,.."

I can see that the ringing is coming from somewhere else, say the exchange, other than my phone as that is disconnected but is the noise, over the ringing sound, coming from before my line from the exchange?

If my phone is disconnected does the exchange know (say a circuit not completed by the phone) and therefore does not send any signal down my line?

is the noise, over the ringing sound, coming from before my line from the exchange?

probably the mobile network or white noise from the exchange equipment, there's no audio data to send to you from the line without a phone off the hook.

the exchange sends a ringing voltage to ring, but your line is otherwise approximately open circuit.

With VoIP you can be listening to ringing tone for several seconds before the phone starts to ring, so it's generated at the caller's system end.

The noise on the mobile is probably from teh AGC circuit on the handset. There is no audio path until the call is established so with no audio the handset amplifier ramps up and any low level internal circuit noise is amplified until audible.

Thank you for your advice.

Turned out to be my Speedtouch router.

Replaced it with a Thomson TG784 and the noise and drop outs went.

However when the Speedtouch was used I was getting 3.7 down and .37 uploads.

Now, after 11 days without any drop outs I am getting 2.5 down and .37 uploads

this is the data from the Thomson:-

Uptime: 11 days, 4:15:53
DSL Type: G.992.1 annex A
Bandwidth (Up/Down) [kbps/kbps]: 448 / 4,512
Data Transferred (Sent/Received) [MB/GB]: 321.66 / 4.04
Output Power (Up/Down) [dBm]: 12.0 / 19.0
Line Attenuation (Up/Down) [dB]: 26.0 / 43.0
SN Margin (Up/Down) [dB]: 22.0 / 15.0
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 11 / 0
Loss of Signal (Local/Remote): 1 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 1 / 0
FEC Errors (Up/Down): 154 / 106,626
CRC Errors (Up/Down): 154 / 360
HEC Errors (Up/Down): 89 / 312

should I be getting better downloads?

Because your noise margin is so high. Do a BT speedtest to determine your profile.

BT profile:-

Download speedachieved during the test was - 3369 Kbps
For your connection, the acceptable range of speedsis 1200-4000 Kbps.
IP Profile for your line is - 3500 Kbps
The throughput of Best Efforts (BE) classes achieved during the test is - 11.05:23.04:65.91 (SBE:NBE:PBE)
These figures represent the ratio while sententiously passing Sub BE, Normal BE and Priority BE marked traffic.

The results of this test will vary depending on the way your ISP has decided to use these traffic classes.


Re-run of Thinkbroadband test now gives 3.2 down and .4 up.

Still down from 3.7 using Speedtouch router.

Note using BT line checker max is 6.

Edited by athegn (Fri 18-Feb-11 19:51:00)

Keep an eye on that noise margin. This :

SN Margin (Up/Down) [dB]: 22.0 / 15.0

is too high.

no surprise snr is high if you have been having dropouts, you can try ringing technical support and ask them to reset your line to 6db snr - tell them you changed a faulty router, this will increase your speed, if there is still a fault the snr will climb back to 12. Or you can leave alone and wait for the exchange to change you when it sees fit but this may take a little while.