You could also use one of the 10V or 18V buzzers. Wire RB, RG to the appropriate (10 or 18) voltage and hook up the buzzers to the Y/S.

I worked for GTE for a while and while they didn't have a 551 type KSU their practice 0n the West Coast (NOT on the East Coast!) was to have the incoming lines be signaled by buzzer, not by a ringer. I'm not sure why, but...

Sam


"Where are we going and why are we in this hand basket?"