I'm sure this has been covered, but I couldn't find the answer anywhere. Have a WE 551A ksu. I have 3 phone lines, currently 1 phone hooked up. Looking to have all 3 lines when called directly to ring or external buzzer. I understand I'd need the frequency generator to have all lines ring at the handsets. But can I get all lines to go to an external buzzer? I learned the 551 did not come with the 118a FG. This originally had just one line in use, where the yellow/slate pair was on the tip/ring. My question, I have a Bell System yard buzzer from our larger wall system that I'd like to have buzz for all incoming lines. Is this possible with this ksu? I've read several pages on this and so far my wiring combinations have been unsuccessful. I'm transferring from a larger 8 card wall unit to the 551 due to the larger unit acting up in hot weather, and dampness. Any help is MUCH appreciated!