RE: phone tones and Keith Doxey's help?

["Keith Doxey" <ukha@xxxxxxxxxxx>]

I concur that it is NU tone.

Exchanges now give the called subscriber Number Unobtainable Tone (NU Tone)
if the incoming caller clears and the handset is not replaced. This
disappears after a period of time to be replaced by the "howler"
which is a
two tone noise that increases in volume to alert someone to the handset not
being replaced properly.

Description of tones can be found here
http://www-users.cs.york.ac.uk/~fisher/telecom/tones/

As it is actually 10 years since I worked on phone lines I cant be sure of
the exact conditions that are now present on phone lines but imeadiately on
termination of a call there was a momentary break in the line known as the
"K break". (Name derived from the relays used in early strowger
exchanges.
Each line had dedicated LR & K relays but shared the other exchange
equipment with many other lines)

Answering machines detect this condition and stop recording. I had an
answering machine that worked perfectly on an exchange line but when used
on
an extension on my Pentara it used to record continuously as it didnt see
the line break.

Out of interest... is this a BT line or some other provider ?

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