UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 746 wiring diagram needs some explaining please

johnmarshmanagain · 4th Dec 2020, 8:54 pm

Hi All,

Referring diagram as below, I can see R,G and W wires coming in...

I think the R and G do the microphone/earpiece dc-powered loop, so if W receives ac and operates the ringing on coil 23, then which is the return wire for the ac : R perhaps ?

I can see 'MIC' at upper left - presumably microphone, but is 'TL' the earpiece ?

Also, what's that semicircle marked '1k S' between terminals T4 and T16 ? and which switch contact is associated with the spinning of the dial ?

If there's a website that explains all this for UK phones, then please by all means advise.

Suitable topic for a sticky perhaps ?

Obliged, Regards JM

http://www.samhallas.co.uk/repositor.../0000/N846.pdf

4th Dec 2020, 8:54 pm	#1
johnmarshmanagain Pentode Join Date: Aug 2005 Location: Northwich, Cheshire, UK. Posts: 206	746 wiring diagram needs some explaining please Hi All, Referring diagram as below, I can see R,G and W wires coming in... I think the R and G do the microphone/earpiece dc-powered loop, so if W receives ac and operates the ringing on coil 23, then which is the return wire for the ac : R perhaps ? I can see 'MIC' at upper left - presumably microphone, but is 'TL' the earpiece ? Also, what's that semicircle marked '1k S' between terminals T4 and T16 ? and which switch contact is associated with the spinning of the dial ? If there's a website that explains all this for UK phones, then please by all means advise. Suitable topic for a sticky perhaps ? Obliged, Regards JM http://www.samhallas.co.uk/repositor.../0000/N846.pdf