# Wiring Diagram For A 1970's Phone



## DangerMouse (Jul 17, 2008)

those old dialers usually had a 'ring volume adjust' tab/slider on the bottom. this may be the problem....but what do i know? i'm just a cartoon mouse......

DM


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## bobo (May 17, 2005)

dm,

yes it does have a ringer adjustment. i have it on loud, and it is adjustnig the bells far apart like it should. im going to hard wire the bell to tip and ring on the customer interface and have someone call me and see if it rings....bob


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## rjniles (Feb 5, 2007)

bobo said:


> dm,
> 
> yes it does have a ringer adjustment. i have it on loud, and it is adjustnig the bells far apart like it should. im going to hard wire the bell to tip and ring on the customer interface and have someone call me and see if it rings....bob


 
Hard wiring the ringer across the line will not work. The ringer coil will short cicuit the line and it will be busy to the caller. The network in the phone has a capacitor that is in series with the ringer that allows the AC ringing current into the ringer coil but blocks DC.

Between the the 2 ringer gongs is a mechanical adjustment wire that has 2 notches. It adds tension to the clapper arm. Try moving it to the other notch.


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## rjniles (Feb 5, 2007)

If the phone in question is a Western Electric 500 series phone here is a link (other manufacturers used basically the same circuit)

http://www.porticus.org/bell/images/500dm.gif

Ringer coil 1 between BK and S-R

Ringer coil 2 between S and R

Capacitor (part of network) between A and K

BK and R ringer leads connected across L1 and L2 (Tip and Ring)


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## Wildie (Jul 23, 2008)

It could also be that the capacitor has dried out and changed value.
Ringing voltage is 20 cycles per second, so the capacitance and the inductance of the ringer coils must be such, to allow the ringing current to flow.


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