Nice. We have a full home fire alarm system that I put in, but there are only photoelectric detectors on it (System Sensor 2W-B’s and 4WTA-B’s for the bedrooms). There don’t seem to be any dual sensor smoke alarms available for use with these low voltage systems. We do have a standalone AC smoke alarm in the common hallway, but that one is photoelectric too. It’s a Nest by the way, and I installed it as well. I’m thinking about replacing it with an ion alarm now.
And yep… The 907A2 has the bat out of hell AC squealer horn sound. The low tone with an earsplitting rasp to it. That’s the first alarm I’ve ever heard with a 4/6 squealer horn pattern. Also, there is a really old Westclox probably from the early 70’s that did a super slow march time pattern with the DC squealer.
By the way, here’s how to embed the Youtube video in your post… Copy the video ID of the video you want. For example, here is the link to a video of the Westclox smoke alarm with a DC squealer horn that does a Very slow march time pattern.
The video ID is o2SteFG_lY8, which is the part after the “v=” in the link. So, click the Youtube button to insert Youtube brackets, then paste the video ID into those brackets. The video will appear, like so: