The Siren Board

Since I'm going here in 12 hours, I decided to finish up my map of the current Franklin County, OH, system. For those not familiar, this system is made up of 3016s and 4004s. Dublin also has omni Whelens in the northwest corner of the county. All sirens in the county are tested every Wednesday at 12 PM, with voice being tested on the first Wednesday of the month.

https://www.google.com/maps/d/edit?mid= ... sp=sharing

Nice, those are a lot of sirens. Didn't the Whelens replace thunderbolts and an assortment of other sirens, at least in Columbus?