I had a call for assistance from a friend - her Siemens cordless phone and BT wireless router were misbehaving.

A visit with a spare phone identified that the Siemens phone was the culprit in that it was loading the line too heavily - confirmed when I got home as it did exactly the same here. If it was the only item on the line it was OK, but add the router or the second phone and it either gave a waa/waa noise, or it a message saying 'Try re-dialling', or a silence with a distant clicking.

Reading up about REN, or RLA as it seems in this country, would indicate that perhaps there's a capacitor that's gone leaky. Anyone met this before with a phone ?

Rob

"robgraham" wrote in message
...
I had a call for assistance from a friend - her Siemens cordless phone and
BT wireless router were misbehaving.

A visit with a spare phone identified that the Siemens phone was the
culprit in that it was loading the line too heavily - confirmed when I got
home as it did exactly the same here. If it was the only item on the line
it was OK, but add the router or the second phone and it either gave a
waa/waa noise, or it a message saying 'Try re-dialling', or a silence with
a distant clicking.

Reading up about REN, or RLA as it seems in this country, would indicate
that perhaps there's a capacitor that's gone leaky. Anyone met this
before with a phone ?

Rob


The Ringer Equivalence Number only has any real validity when the instrument
is presented with the AC ring signal, and with modern phones, often not even
then. Modern phones have a totally electronic line interface, and there is
no reason why this should not, to all intents and purposes, be a virtual
open circuit to the DC line voltage when the phone is 'on-hook'. When the
phone goes off-hook, a diode bridge is usually switched across the line, and
this is often carried out using a transistor or two. These can fail, as can
the bridge. There may also be capacitors across the front and back sides of
the bridge, and / or various types of voltage limiting / surge arresting
devices which may include zener diodes and VDRs.

Sometimes, there is a deliberate ring load incorporated, probably to satisfy
some archaic regulation requirement from the old days of electro-mechanical
exchanges. In this case, you will sometimes see a label on the bottom of the
phone stating the REN as being 0.5, or half that of a 'conventional'
electro-mechanical phone.

It's been a while since I had any involvement with domestic telephone
equipment, as once we got onto 3rd generation cordless phones, which had
processors in the base and every handset, all whispering secretly to one
another, repairs became almost impossible to carry out in any practical
manner that made you any money, but prior to that, front end failures
involving any of the components mentioned, singularly or in cascade, were
quite common, particularly after thunderstorm activity. The front ends of
3rd gen and beyond phones, haven't really changed, so I would assume that
similar failures still take place.

Arfa

On Fri, 21 Feb 2014 11:24:56 -0800 (PST), robgraham
wrote:

I had a call for assistance from a friend - her Siemens cordless phone and BT wireless router were misbehaving.

A visit with a spare phone identified that the Siemens phone was the culprit in that it was loading the line too heavily - confirmed when I got home as it did exactly the same here. If it was the only item on the line it was OK, but add the router or the second phone and it either gave a waa/waa noise, or it a message saying 'Try re-dialling', or a silence with a distant clicking.

Reading up about REN, or RLA as it seems in this country, would indicate that perhaps there's a capacitor that's gone leaky. Anyone met this before with a phone ?

Rob

Was the router you tried at your house hers or yours?
The only time I have known an ADSL router to contribute *any* DC load
on the line is after it has been zapped by lightening.

As for the phone base unit, yes a leaky capacitor is a possibility,
maybe caused by storm damage. Is the line-cord the original one?
One borrowed from another device might not be electrically the same,
but I wouldn't expect that to cause the symptoms you describe.

REN is not really an issue with locally powered devices, in fact it
hasn't been much of an issue since the demise of electromechanical
bells.

On Saturday, February 22, 2014 7:22:07 PM UTC, Graham. wrote:
On Fri, 21 Feb 2014 11:24:56 -0800 (PST), robgraham

wrote:



I had a call for assistance from a friend - her Siemens cordless phone and BT wireless router were misbehaving.



A visit with a spare phone identified that the Siemens phone was the culprit in that it was loading the line too heavily - confirmed when I got home as it did exactly the same here. If it was the only item on the line it was OK, but add the router or the second phone and it either gave a waa/waa noise, or it a message saying 'Try re-dialling', or a silence with a distant clicking.



Reading up about REN, or RLA as it seems in this country, would indicate that perhaps there's a capacitor that's gone leaky. Anyone met this before with a phone ?



Rob



Was the router you tried at your house hers or yours?

The only time I have known an ADSL router to contribute *any* DC load

on the line is after it has been zapped by lightening.



As for the phone base unit, yes a leaky capacitor is a possibility,

maybe caused by storm damage. Is the line-cord the original one?

One borrowed from another device might not be electrically the same,

but I wouldn't expect that to cause the symptoms you describe.



REN is not really an issue with locally powered devices, in fact it

hasn't been much of an issue since the demise of electromechanical

bells.

Many thanks guys - being able to *sound* knowledgeable (but not actually having the knowledge !) is more than half the battle in this sort of situation. The lady is happy as she has a phone and router that work, and a friend who spouts complex technical words as to the possible cause of the problem !!

Rob