The sound of that alarm although electromechanical didn’t bother me. But again I have heard that DC or battery ones are much more higher pitched and screechier than AC ones. I also have another question about AC electromechanical alarms from that time period. I do have a Nortron smoke detector that is AC powered. I purchased it at a local antique shop almost a year ago. It has a brass squealer as well and I would say the detector was made between 1977 and 1980. How would I be able to set this alarm off? If anyone on here might know I think it would be you Fire Alarm Fan. But anyone is welcome. 