We still have one of those touchtone versions.. Northern Telecom built to survive ANYTHING.. has even been dropped down the stairs [Linked Image]

I've seen plenty of 500-type phones here with Green, Red and Yellow wires too. The terminate on spades.

The yellow would generally be connected to a non-connected spareterminal screw in the junction box just to keep it out of the way. Only the green and red are connected.

The later versions had that heavy high quality RJ11 cabling that you could only get in the 1970s ..

We had
standard 500 dial phones
wall phone version
touchtone version which was initially used in areas where Ericsson ARF crossbars used internal MF signalling (c. 1963 onwards) and could cope with DTMF dialling.

The dial version was a lot more common.



[This message has been edited by djk (edited 01-16-2004).]