RTT 56B rotary dial wiring - UK Vintage Radio Repair and Restoration Discussion Forum

Palacepounder · 4th Nov 2010, 2:14 pm

Hi,

Have just aquired an RTT 56B telephone.

On examination the 4 wires (brown, red, orange and grey) have been disconnected from the rotary dial.

Does anybody have any idea on which terminals they connect.

I have tried various combinations but to no avail.

There are 4 screw connectors on the dial.

Any help appreciated.

Thanks

Pete

julie_m · 5th Nov 2010, 12:46 pm

It should be possible to identify the "pulse" and "dial off normal" contacts using an analogue multimeter -- or a 9V battery, LED and 470Ω resistor.

You will then need a wiring diagram for the phone -- if you're lucky, this may be stuck inside it.

Palacepounder · 6th Nov 2010, 10:43 am

Thanks for that, the circuit diagram under the base plate has perished but have found copy from a previous post.

May need help with diagram after I,ve metered contacts.

Cheers

PeteN

4th Nov 2010, 2:14 pm	#1
Palacepounder Retired Dormant Member Join Date: Nov 2010 Location: Hereford Posts: 2	RTT 56B rotary dial wiring Hi, Have just aquired an RTT 56B telephone. On examination the 4 wires (brown, red, orange and grey) have been disconnected from the rotary dial. Does anybody have any idea on which terminals they connect. I have tried various combinations but to no avail. There are 4 screw connectors on the dial. Any help appreciated. Thanks Pete

5th Nov 2010, 12:46 pm	#2
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: RTT 56B rotary dial wiring It should be possible to identify the "pulse" and "dial off normal" contacts using an analogue multimeter -- or a 9V battery, LED and 470Ω resistor. You will then need a wiring diagram for the phone -- if you're lucky, this may be stuck inside it. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

6th Nov 2010, 10:43 am	#3
Palacepounder Retired Dormant Member Join Date: Nov 2010 Location: Hereford Posts: 2	Re: RTT 56B rotary dial wiring Thanks for that, the circuit diagram under the base plate has perished but have found copy from a previous post. May need help with diagram after I,ve metered contacts. Cheers PeteN