Phone without microfilter

My ADSL router won't connect and I suspect no signal is even leaving
the box so I am looking for a way to test this. I have tried plugging in
a phone without a microfilter while the modem is trying to connect and I
can't hear anything unusual, even while making a call. Does this prove
my suspicion?

--
David Hartley

On Fri, 17 Oct 2003 21:29:24 +0100, David Hartley
<(E-Mail Removed)> wrote:

> Does this prove
>my suspicion?

no, this proves that your hearing is normal and that you don't have a
radio frequency receiver built into your head.

unplug all phones and put the router into the master BT socket to
eliminate some potential problems.

Have you loaded the BT specific ADSL settings into the router, and are
you trying to connect to the BT test domain or to the ISP ?

Phil

In article <(E-Mail Removed)>, Phil Thompson
<(E-Mail Removed)> writes
>On Fri, 17 Oct 2003 21:29:24 +0100, David Hartley
><(E-Mail Removed)> wrote:
>
>> Does this prove
>>my suspicion?
>
>no, this proves that your hearing is normal and that you don't have a
>radio frequency receiver built into your head.
>
Thank you. But why then do we need microfilters? I've seen it said that
it's more to protect the ADSL signal from the telephone than vice versa,
but also that the ADSL signal is unfiltered, which seems contradictory.

....Ah, I think I see it now. The microfilters keep out signals of the
wrong frequency from my phone, and there must be something similar at
the exchange which does the same for incoming phone signals.

>unplug all phones and put the router into the master BT socket to
>eliminate some potential problems.
>
>Have you loaded the BT specific ADSL settings into the router, and are
>you trying to connect to the BT test domain or to the ISP ?

I've already tried all that. Nothing worked so I knew the faults either
in the router or beyond the phone socket. My ISP got BT to run some
tests but seemed to find them inconclusive. Finally this morning I
managed to borrow another ADSL modem which connected successfully
straight away, so now I know it's definitely the router. It will soon be
back were it came from, (only had it a week).

Thanks for your help.
--
David Hartley

"Phil Thompson" <(E-Mail Removed)> wrote in message > > Does this prove
> >my suspicion?
>
> no, this proves that your hearing is normal and that you don't have a
> radio frequency receiver built into your head.

ADSL is nowwhere near "radio frequencies"

When ADSL is active you will hear high frequency AUDIO on a normal
phone without a filter. However the BT Exchange equipment will not activate until IT
receives a signal from your modem.

On Sat, 18 Oct 2003 13:56:06 +0100, David Hartley
<(E-Mail Removed)> wrote:

>.Ah, I think I see it now. The microfilters keep out signals of the
>wrong frequency from my phone, and there must be something similar at
>the exchange which does the same for incoming phone signals.

exactly, the high frequency ADSL signal is peeled off into the DSLAM
at the exchange and the low frequency voice continues on through to
the exchange line card.

Some routers have multiple settings for different countries,
protocols, access methods etc. I just "fixed" one by selecting VCmux
instead of LLC for example. These settings will render the thing
useless and in some cases are quite well hidden.

Phil

"Brian McIlwrath" <(E-Mail Removed)> wrote:

>
> "Phil Thompson" <(E-Mail Removed)> wrote in message > > Does
this prove
> > >my suspicion?
> >
> > no, this proves that your hearing is normal and that you don't have a
> > radio frequency receiver built into your head.
>
> ADSL is nowwhere near "radio frequencies"
>
> When ADSL is active you will hear high frequency AUDIO on a normal
> phone without a filter. However the BT Exchange equipment will not
activate until IT
> receives a signal from your modem.
>

Hi,
I'm afraid that simply is not true. ADSL works in the frequency range
between about 300 KHz and 2.2 MHz, which covers quite a large part of the
readio frequency. The noise you hear on the telephone is more likely to be
due to the circuits using components that are not capable of dealing with
such high frequencies resulting in distortion and background noise.

--

Martin

Brian McIlwrath wrote:

> ADSL is nowwhere near "radio frequencies"

<panto_mode> Oh Yes it is! </panto_mode>

> When ADSL is active you will hear high frequency AUDIO on a normal

Most phones will not pick up any interference when being used
un-filtered on an ADSL enabled line - however some will. This is usually
down to poor design in the phone.

The filters primary job is to prevent the phones from causing
interference with the Data - the reverse effect is a bonus if you like.

(Note that phones can cause high frequency interference outside of their
normal audio bands and well into those frequencies used for ADSL data -
most often lifting and replacing the handset)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Sat, 18 Oct 2003 19:19:48 +0100, in article
<bms084$vdp$(E-Mail Removed)> "Brian McIlwrath"
<(E-Mail Removed)> wrote:

> ADSL is nowwhere near "radio frequencies"

If it's above audio then it is by definition radio.

Rugby MSF is in 60kHz, the lowest amateur radio band is at 137kHz.

--

Brian Morrison

please observe reply-to address

On Sun, 19 Oct 2003 10:57:50 +0100, Brian Morrison wrote:

> On Sat, 18 Oct 2003 19:19:48 +0100, in article
> <bms084$vdp$(E-Mail Removed)> "Brian McIlwrath"
> <(E-Mail Removed)> wrote:
>
>> ADSL is nowwhere near "radio frequencies"
>
> If it's above audio then it is by definition radio.
>
> Rugby MSF is in 60kHz, the lowest amateur radio band is at 137kHz.

And submarines use very low freq's, mind you its mostly one way traffic.

Dave

On Sat, 18 Oct 2003 19:19:48 +0100, "Brian McIlwrath"
<(E-Mail Removed)> wrote:

>ADSL is nowwhere near "radio frequencies"

<panto>

oh yes it is.

</panto>

ADSL runs up to 1 MHz. Now look at an AM radio - medium wave is 500
kHz - 1600 kHz, long wave Radio 4 is 200 kHz and so on.

0/10

Phil