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Author Re: REQ: Circuit to join two phone lines for 3-way conversation
Linker3000

2007-08-28, 1:25 pm

Lemmo wrote:
> I am in the UK.
>
> I have a Virgin Media/NTL landline and am considering installing a BT
> landline too. (I need Caller ID but VM/NTL don't have it in my area).
>
> If I have answered a call on VM/NTL and also on BT then how can I join the
> two lines to have a 3-way conversation?
>
> Is there a circuit I can build which will join the two lines?
>
> (1) Perhaps picking up the signals by a transformer across each of the two
> line cords?
>
> (2) Perhaps across each curly lead which goes from handset to phone?
>
> (3) Would I get better results "audio-coupling" the handsets. Holding one
> earpiece close to the other mouthpiece and vice versa?


Sounds messy. If you have broadband (?) why not look at Voice Over IP
options - like a small PC running Trixbox. That way you can have as many
incoming lines as you want (with caller ID) without needing another BT
one and you can do 'n' way conferencing.
Ivor Jones

2007-08-28, 1:25 pm



"Linker3000" <linker3000@google-mailnohyphen.com> wrote in
message news:46d466f6$0$11443$db0fefd9@news.zen.co.uk
: : Lemmo wrote:
: : : I am in the UK.
: : :
: : : I have a Virgin Media/NTL landline and am considering
: : : installing a BT landline too. (I need Caller ID but
: : : VM/NTL don't have it in my area).
: : :
: : : If I have answered a call on VM/NTL and also on BT
: : : then how can I join the two lines to have a 3-way
: : : conversation?
: : :
: : : Is there a circuit I can build which will join the
: : : two lines?

[snip]

The BT Converse 2025 2-line phone can do this. I believe it's out of
production now, but a quick search on eBay found this:

http://search.ebay.co.uk/search/sea...e=Converse+2025


No doubt there are other phones which have replaced it.


Ivor

Jono

2007-08-28, 5:25 pm

Ivor Jones explained :
> No doubt there are other phones which have replaced it.


Like this?
<http://www.rocom.co.uk/catalogue/in...29&categoryID=0>


Don Bowey

2007-08-28, 8:25 pm

On 8/28/07 1:17 PM, in article mn.e4fd7d78fcf74c17.48968@blueyonder.invalid,
"Jono" <nothanks@blueyonder.invalid> wrote:

> Ivor Jones explained :
>
> Like this?
> <http://www.rocom.co.uk/catalogue/in...duct&productID=
> 18129&categoryID=0>
>
>


Hard to say - it depends on how they do it. When the telco provided all the
phone service a simple modification could be made to a multi-line key phone,
so that two buttons could be down at the same time. This physically tied
the tip and ring wires of one to the tip and ring wires other the other. It
worked ok, because the lines were essentially identical.

Where two lines are dissimilar, having different battery and ground
references, the interconnection could be very detrimental.

A good approach would be to use a line isolation transformer to interconnect
two lines.


Phillip Devoll

2007-08-29, 5:25 pm

most 2 line phone have line 1 line 2 hold and confrence buttons
so check out a 2 line phone....

"Linker3000" <linker3000@google-mailnohyphen.com> wrote in message
news:46d466f6$0$11443$db0fefd9@news.zen.co.uk...
> Lemmo wrote:
>
> Sounds messy. If you have broadband (?) why not look at Voice Over IP
> options - like a small PC running Trixbox. That way you can have as many
> incoming lines as you want (with caller ID) without needing another BT one
> and you can do 'n' way conferencing.


Alastair

2007-08-30, 1:25 pm


"Jono" <nothanks@blueyonder.invalid> wrote in message
news:mn.e4fd7d78fcf74c17.48968@blueyonder.invalid...
> Ivor Jones explained :
>
> Like this?
> <http://www.rocom.co.uk/catalogue/in...29&categoryID=0>
>
>

Blimey, same as the 2025 but a different colour.



LinkBot





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