Great find! I have a version of that manual without the acoustic testing photos that I scanned in late last year, along with some other stuff I need to get around to posting:
https://drive.google.com/file/d/16sj_Dd ... sp=sharing
Speaking of those testing photos, in case you can't tell by the labels and acoustic testing section below the manuals, that was all done by ATI. Here's a little background on ATI's early days:
In 1981 ATI started as a consultant dealing with sound and acoustic testing, both with individual sirens in anechoic chambers/outdoor testing as well as system design and field testing. They were especially involved with nuclear power plants, a few that come to mind off the top of my head are Zimmer here in Clermont County, Catawba in South Carolina, and Palo Verde in Arizona. In 1988 they began producing sirens, and I'm honestly not entirely sure if they continued the consulting side of things beyond that. It would not surprise me if they did.
I got most of this information from Dr. Bassiouni, whose name you will see featured prominently in most of these acoustical studies. He is currently president and CEO at ATI.
Christian Bricking, living in the Cincinnati Metropolitan Area.
Owner of a WPS-2804, Model L, and B9.
Certified Skywarn spotter since April 5, 2016.
