Hum on phone line

I'm getting Broadband connected on the 30th but there's a bit of what
I'm guessing is electrical hum on the line.

The worst of it is coming from the router and is obviously being
picked up by the phone handset (it get's louder when I move towards
it) and when I switch that off it makes a big difference but there's
still some hum there.

I've tried switching off every circuit on my switchboard but that
doesn't make any difference, nor did plugging the phone into the test
socket.

I guess it's possible it's the phone itself which is generating the
noise. Is it normal to hear a small amount of hum?

Will the noise from the router being picked up by the phone affect my
broadband, or will the ADSL filter stop that?

Doughboy

Doughboy wrote:

> I'm getting Broadband connected on the 30th but there's a bit of what
> I'm guessing is electrical hum on the line.

On what line. On the master socjet ?


> The worst of it is coming from the router

How do you know. By what method did you establish that ? You already have
an ADSL router then ?

Or do you mean the router's power supply (usually plugs into a 13A
socket).

And when you say 'coming from' do you mean if you put the nadset close to
it ?

You are being terribly vague.


> and is obviously being
> picked up by the phone handset (it get's louder when I move towards
> it)

It meaning .....?


> and when I switch that off it makes a big difference but there's
> still some hum there.
>
> I've tried switching off every circuit on my switchboard

Where did a switchboard suddenlt come into the equation. Why not mention
exactly what's connected to what first ?

> but that doesn't make any difference, nor did plugging the phone into
> the test
> socket.

You mean the phone hums when plugged into the test socket even with the
router turned off (and power supply turned off)?

Then you have a line fault.


> I guess it's possible it's the phone itself which is generating the
> noise.

No it isn't unless it's a mains powered phone in which case it is
possible.


> Is it normal to hear a small amount of hum?

NO.


> Will the noise from the router being picked up by the phone affect my
> broadband, or will the ADSL filter stop that?

Not a clue since you're not really explaining yourself very well, but in
practice I'll bet it doesn't unless it's symptomatic of some other
fundamental fault.

Graham

On Sun, 28 Sep 2008 14:43:16 GMT, "Ato_Zee" <(E-Mail Removed)>
wrote:

>
>> I guess it's possible it's the phone itself which is generating the
>> noise. Is it normal to hear a small amount of hum?
>>
>> Will the noise from the router being picked up by the phone affect my
>> broadband, or will the ADSL filter stop that?
>
>Ther are different sorts of mains hum. The low pitched 50Hz sine
>wave that you get on low level, such as microphne leads, and audio
>connections, or the higher pitched harmonic hums from mostly
>switch mode PSU's, or things like faulty fluorescent fittings.
>
>Is your phone mains connected with a plug in PSU?
>Such as answer phones, DECT phones, etc?
>A simple one lead table phone with BT plug is
>the criterion, it won't produce noise, and dial
>a single digit should give you a silent background,
>does it? If not the noise may be coming from
>outside your premises.
>Low pitched induced 50Hz hum shouldn't affect ADSL as
>the frequencies are above audio.
>If, as I have met, you have a drop wire, and it is
>resting on top of a high pressure street lighting
>dischrage lamp, having slid to rest against the
>ambient light sensor on top, then a situation like
>this could cause ADSL problems. The street
>lamp had just been replaced with a higher one
>which was supporting the drop wire.

Listening again, it does remind me of the sort of hum you get with
audio leads (when they're not properly grounded if I recall
correctly).

I've just got a wired phone with a single (curly) lead.

Good point about low pitched noise shouldn't affect ADSL. I've just
been reading about how the bandwidth is split between voice and ADSL.

I'll check outside to see whether I've got a drop wire or not.

Doughboy

On Sun, 28 Sep 2008 15:18:40 +0100, "Peter Crosland"
<(E-Mail Removed)> wrote:

>> I'm getting Broadband connected on the 30th but there's a bit of what
>> I'm guessing is electrical hum on the line.
>>
>> The worst of it is coming from the router and is obviously being
>> picked up by the phone handset (it get's louder when I move towards
>> it) and when I switch that off it makes a big difference but there's
>> still some hum there.
>>
>> I've tried switching off every circuit on my switchboard but that
>> doesn't make any difference, nor did plugging the phone into the test
>> socket.
>>
>> I guess it's possible it's the phone itself which is generating the
>> noise. Is it normal to hear a small amount of hum?
>>
>> Will the noise from the router being picked up by the phone affect my
>> broadband, or will the ADSL filter stop that?
>
>
>It is probably the router PSU so you might try changing that.
>
>Peter Crosland

Yes, the PSU does seem to be the main culprit, although the router is
radiating/amplifying the noise when the PSU is plugged into it.

Even so, the residual hum on the line when my entire flat is powered
down does seem to suggest a line fault. I only had the line installed
a month ago, but as the wiring was already in place from years ago,
all the engineer had to do in my flat was check the box and move it
slightly for me.

Doughboy

On Sun, 28 Sep 2008 17:05:14 +0100, Doughboy <(E-Mail Removed)> wrote:

>On Sun, 28 Sep 2008 14:43:16 GMT, "Ato_Zee" <(E-Mail Removed)>
>wrote:
>
>>
>>> I guess it's possible it's the phone itself which is generating the
>>> noise. Is it normal to hear a small amount of hum?
>>>
>>> Will the noise from the router being picked up by the phone affect my
>>> broadband, or will the ADSL filter stop that?
>>
>>Ther are different sorts of mains hum. The low pitched 50Hz sine
>>wave that you get on low level, such as microphne leads, and audio
>>connections, or the higher pitched harmonic hums from mostly
>>switch mode PSU's, or things like faulty fluorescent fittings.
>>
>>Is your phone mains connected with a plug in PSU?
>>Such as answer phones, DECT phones, etc?
>>A simple one lead table phone with BT plug is
>>the criterion, it won't produce noise, and dial
>>a single digit should give you a silent background,
>>does it? If not the noise may be coming from
>>outside your premises.
>>Low pitched induced 50Hz hum shouldn't affect ADSL as
>>the frequencies are above audio.
>>If, as I have met, you have a drop wire, and it is
>>resting on top of a high pressure street lighting
>>dischrage lamp, having slid to rest against the
>>ambient light sensor on top, then a situation like
>>this could cause ADSL problems. The street
>>lamp had just been replaced with a higher one
>>which was supporting the drop wire.
>
>Listening again, it does remind me of the sort of hum you get with
>audio leads (when they're not properly grounded if I recall
>correctly).
>
>I've just got a wired phone with a single (curly) lead.
>
>Good point about low pitched noise shouldn't affect ADSL. I've just
>been reading about how the bandwidth is split between voice and ADSL.
>
>I'll check outside to see whether I've got a drop wire or not.
>
>Doughboy

Actually, I've just remembered that the lines come in from the garage
below my block of flats, as I was down there years ago with a BT
engineer and I recall the tatty looking junction boxes screwed onto
the beams.

I suppose there might still be a drop wire going to the garage though.

Doughboy

On Sun, 28 Sep 2008 17:34:32 +0100, "Peter Crosland"
<(E-Mail Removed)> wrote:

>>>> I'm getting Broadband connected on the 30th but there's a bit of what
>>>> I'm guessing is electrical hum on the line.
>>>>
>>>> The worst of it is coming from the router and is obviously being
>>>> picked up by the phone handset (it get's louder when I move towards
>>>> it) and when I switch that off it makes a big difference but there's
>>>> still some hum there.
>>>>
>>>> I've tried switching off every circuit on my switchboard but that
>>>> doesn't make any difference, nor did plugging the phone into the test
>>>> socket.
>>>>
>>>> I guess it's possible it's the phone itself which is generating the
>>>> noise. Is it normal to hear a small amount of hum?
>>>>
>>>> Will the noise from the router being picked up by the phone affect my
>>>> broadband, or will the ADSL filter stop that?
>>>
>>>
>>>It is probably the router PSU so you might try changing that.
>>>
>>>Peter Crosland
>>
>> Yes, the PSU does seem to be the main culprit, although the router is
>> radiating/amplifying the noise when the PSU is plugged into it.
>>
>> Even so, the residual hum on the line when my entire flat is powered
>> down does seem to suggest a line fault. I only had the line installed
>> a month ago, but as the wiring was already in place from years ago,
>> all the engineer had to do in my flat was check the box and move it
>> slightly for me.
>
>
>It could well be. This would be a good place to improve your knowledge.
>
>http://www.dslzoneuk.net/socket.php
>
>Peter Crosland

Thanks, but I haven't got any extensions.

Doughboy

On Sun, 28 Sep 2008 17:31:54 +0100, Doughboy wrote:

>Even so, the residual hum on the line when my entire flat is powered
>down does seem to suggest a line fault. I only had the line installed
>a month ago, but as the wiring was already in place from years ago,
>all the engineer had to do in my flat was check the box and move it
>slightly for me.

Is your phone connected through a filter?

I had my modem on before ADSL was live and there was noise on the phone
line even with a filter in. Once the ADSL went live and the modem
synced it went silent. I'd wait and see what happens when you are on.

--
Regards - Rodney Pont
The from address exists but is mostly dumped,
please send any emails to the address below
e-mail ngpsm4 (at) infohitsystems (dot) ltd (dot) uk

On Sun, 28 Sep 2008 18:02:14 +0100, "Peter Crosland"
<(E-Mail Removed)> wrote:

>>>>>> I'm getting Broadband connected on the 30th but there's a bit of what
>>>>>> I'm guessing is electrical hum on the line.
>>>>>>
>>>>>> The worst of it is coming from the router and is obviously being
>>>>>> picked up by the phone handset (it get's louder when I move towards
>>>>>> it) and when I switch that off it makes a big difference but there's
>>>>>> still some hum there.
>>>>>>
>>>>>> I've tried switching off every circuit on my switchboard but that
>>>>>> doesn't make any difference, nor did plugging the phone into the test
>>>>>> socket.
>>>>>>
>>>>>> I guess it's possible it's the phone itself which is generating the
>>>>>> noise. Is it normal to hear a small amount of hum?
>>>>>>
>>>>>> Will the noise from the router being picked up by the phone affect my
>>>>>> broadband, or will the ADSL filter stop that?
>>>>>
>>>>>
>>>>>It is probably the router PSU so you might try changing that.
>>>>>
>>>>>Peter Crosland
>>>>
>>>> Yes, the PSU does seem to be the main culprit, although the router is
>>>> radiating/amplifying the noise when the PSU is plugged into it.
>>>>
>>>> Even so, the residual hum on the line when my entire flat is powered
>>>> down does seem to suggest a line fault. I only had the line installed
>>>> a month ago, but as the wiring was already in place from years ago,
>>>> all the engineer had to do in my flat was check the box and move it
>>>> slightly for me.
>>>
>>>
>>>It could well be. This would be a good place to improve your knowledge.
>>>
>>>http://www.dslzoneuk.net/socket.php
>>>
>>>Peter Crosland
>>
>> Thanks, but I haven't got any extensions.
>
>It is still well worth looking at the rest of the site as there is much
>useful information on it.
>
>Peter Crosland

Sorry, I thought you were just pointing me to that specific part of
the site. It certainly does look like a useful resource, so thanks
again.

Doughboy

On Sun, 28 Sep 2008 19:07:04 +0100 (BST), "Rodney Pont"
<(E-Mail Removed)> wrote:

>On Sun, 28 Sep 2008 17:31:54 +0100, Doughboy wrote:
>
>>Even so, the residual hum on the line when my entire flat is powered
>>down does seem to suggest a line fault. I only had the line installed
>>a month ago, but as the wiring was already in place from years ago,
>>all the engineer had to do in my flat was check the box and move it
>>slightly for me.
>
>Is your phone connected through a filter?
>
>I had my modem on before ADSL was live and there was noise on the phone
>line even with a filter in. Once the ADSL went live and the modem
>synced it went silent. I'd wait and see what happens when you are on.

Yep, I'm using a filter. There is actually some additional
high-pitched noise present if I plug the router into the filter, which
roughly follows a pattern of 3 secs on 3 secs off but I assumed I was
only hearing that because my ADSL hasn't been activated yet, so wasn't
too worried about that.

As you say, I'll just have to wait and see what happens. If I get the
sort of performance that I'm expecting, I might be able to ignore the
hum on the phone.

Doughboy

Doughboy wrote:

> Eeyore wrote:
>
> >You mean the phone hums when plugged into the test socket even with the
> >router turned off (and power supply turned off)?
>
> That's what I said.
>
> >Then you have a line fault.
>
> OK.
>
> >> I guess it's possible it's the phone itself which is generating the
> >> noise.
> >
> >No it isn't unless it's a mains powered phone in which case it is
> >possible.
>
> No, it's not a mains powered phone.

Problem solved them. It's a line problem. Furthermore it's audible as a voice
band problem, not related to ADSL per se but as another poster mentioned could
affect it depending on cause, so ensure it's reproducible then call out BT to
fix it PDQ. Their responsibility btw ends at the master socket. Ensure there's
no 'wild' wiring somehow attached by the way or they'll charge you ~ £100. I
assume btw you have an NTE5 master socket and know what that is and how to
properly use the test socket.

Sorry to have to ask so many questions but that honed it down.

You may want to show the engineer they send out some of this correspondence.
They do like a clear explanation of faults.

Graham