25-11-2016, 07:09 PM
(This post was last modified: 25-11-2016, 07:12 PM by Mike Watterson.)
UK phones use a capacitor in the wall socket and more than two wires.
Other countries phones don't.
UK market phones and Faxes don't work outside UK unless you use an adaptor with capacitor. Some BT socket to RJ11 plug adaptors don't have this, so phone never rings and fax never answers. Argos now gives free BT socket to RJ11 jack adaptors with the capacitor in it as they insist in selling UK market phones in Ireland, which will never ring if the cable/plug is simply replaced/adapted. The Traditional RJ11 master socket has no ringing capacitor, the UK BT does. It's always best in UK to have an ADSL master socket that has a decent ADSL filter internally and then on phone side the BT type master with the capacitor.
Two additional "gotchas"
1) Israel uses (or did) the BT jack, but instead of two outer pins being Tip & Ring (the live pair), it's the same layout as RJ11, so a crimped straight cable RJ11 (on phone) to two inner wires BT plug <-> Wall Socket. Thus imported UK phones don't work AT all.
2) Some Faxes or POTS sockets on a Cable Modem, while having RJ11 sockets, are wired both the two inner and outer (Presumably so a UK BT plug crimped STRAIGHT to RJ11 works, otherwise you have swap outer & inner wires at one end, awkward). Often connecting a Fax or phone to PABX or POTs that has RJ11, you have to cut the two outer wires of the flat RJ11 <-> RJ11 patch cable. Otherwise it doesn't work at all.
Other countries phones don't.
UK market phones and Faxes don't work outside UK unless you use an adaptor with capacitor. Some BT socket to RJ11 plug adaptors don't have this, so phone never rings and fax never answers. Argos now gives free BT socket to RJ11 jack adaptors with the capacitor in it as they insist in selling UK market phones in Ireland, which will never ring if the cable/plug is simply replaced/adapted. The Traditional RJ11 master socket has no ringing capacitor, the UK BT does. It's always best in UK to have an ADSL master socket that has a decent ADSL filter internally and then on phone side the BT type master with the capacitor.
Two additional "gotchas"
1) Israel uses (or did) the BT jack, but instead of two outer pins being Tip & Ring (the live pair), it's the same layout as RJ11, so a crimped straight cable RJ11 (on phone) to two inner wires BT plug <-> Wall Socket. Thus imported UK phones don't work AT all.
2) Some Faxes or POTS sockets on a Cable Modem, while having RJ11 sockets, are wired both the two inner and outer (Presumably so a UK BT plug crimped STRAIGHT to RJ11 works, otherwise you have swap outer & inner wires at one end, awkward). Often connecting a Fax or phone to PABX or POTs that has RJ11, you have to cut the two outer wires of the flat RJ11 <-> RJ11 patch cable. Otherwise it doesn't work at all.
