In article , Nick philremovethisbit
writes

Phone is an old bakelite gadget with 3 wires that would have been hardwired
into a junction box.
Can this be connected to a more modern plug in BT socket and if so ~ how?

Yes. I'm assuming it's not so old that it doesn't have the BT standard
terminal layout - two rows of screw terminals, 1 to 9 on the top row and
10 to 19 on the bottom row.

Get yourself a BT plug-to-spade-connector lead (aka "a line cord").
Ebay item 170186909828 for example.

Open the phone and remove existing cord.

Remove strap between terminals 4 and 5 and insert a 2.2kohm 1/4W
resistor. This is to reduce the current drawn by the bell - the bells
in old phones are low impedance. You may see "500" on the bell coils -
this is their impedance (500+500). Ensure there is a strap between
terminals 5 and 6 and connect the BLUE wire from the cord to terminal 6.

Ensure there is a strap between terminals 8 and 9 and connect the RED
wire from the cord to terminal 8.

Ensure terminals 16, 17, 18 and 19 are all linked with straps and
connect the WHITE wire from the cord to terminal 18.

Connect the GREEN wire of the cord (it's unused) to terminal 14.

Test.

Be warned that old phones like this may degrade data calls using a modem
or affect a broadband connection.

Be aware that the DC voltage on a phone line is 48V, and that the
ringing current is ~90V AC. Don't work on a phone that's plugged in, as
the ringing voltage can be hair-raising.

--
(\__/) Bunny says NO to Windows Vista!
(='.'=) http://www.cs.auckland.ac.nz/~pgut00...ista_cost.html
(")_(")