sundance-communications.com/forum Forums TDM Business Telephone Systems Panasonic Telephones & Systems KX-TEA308 and BT Response 75 Answerphone

Hi,
We've just installed a KX-TEA308 system with 2 x CO and 5 x KX- T7730 phones. Everything works fine. Now been asked to add an existing BT 75 digital answerphone to the system. Cut off the 4-pin BT plug, fitted a 4-pin RJ11 plug (flat 4-core cable)and connected to port 6. Answerphone won't pick up any calls.
Two questions:-
1. What is the correct wiring to make this work? Should I only be using the inner pair (R and T)?
2. When it's working, will picking up any of the phones automatically disconnect the answerphone even if it has already taken the call?
Any help with this would be much appreciated...

Being on the wrong side of the 'pond', I can only guess, but if it wasn't made by Panasonic, and it's digital, IT WILL NEVER WORK on a Panasonic digital port. Proprietary interface is the appropriate description, I believe.

obt will tell you if the center pins are t and r over there most answering machines have an out jack on them you would have to have a barge in button on a spare co key wired to the out jack on the answerphone

Also ring voltage is important some answering machines require more ring voltage to detect an incoming call. Had this issue on the old TD systems it just didn't put out enough ring voltage on analog ports to trip the answering machine. If I remember right the TD put out 95 Volts for ring.

The problem is you cut off the plug. You should use a bt converter with a ring capacitor. The uk phones/ answering machines don't have the ring capacitor built-in

The phone system does use the inner pins but the uk phone uses the outer pins of bt plug

Best thing to do is open the machine and fit a capacitor inside
There will be 3 wires connected. 2 for the line and 1 would be for the ring cap. You need to find the 2 for the line and jump the cap from one side to the third wire. You will have to play around with it until it works.