Old 1A2 Key System

[vdvnewyork]

Does anyone remember how to do common ringing on all CO lines on a old 1A2 Key System ? Would you believe people still want to use this system ? Thank you for your help in advance.

 

[TouchToneTommy]

Loop the B1 and R1 of each line circuit together, then jumper to the Yel/Slt pair of the set for ringing.

 

[jlshelton]

To do it properly, you need a diode matrix, which will allow any phone to ring on any desired lines. If you don't mind ALL phones ringing on ALL lines, TTT's suggestion works fine. If you need more about diode matrixes, let me know.

 

[johnpoole]

what is the ksu type and i can still tell you what color the wires are.. those systems are unique. in the ksu you have

t (from the co)
r (from the co)
t
r
a
a1
lg
l
b
r


you loop b and r for all the numbers you want to ring on one phone.. if all lines ring in one place and more then one line needs to ring on another phone, a diode matrix would be needed.. if the system is square, ie, all lines on all phones, then a simple loop from the b r leads (all of them) to usually yellow slate pair in the phone.. some techs used the yellow orange pr for ca (common aud) and used the yellow slate for icm buzzers.. that was more common because all the phones had a ringer on the y/s. and usually only one or two phones rang for common aud..

john poole
bellsouth business
columbia,sc