500 Series

500 Series
Company	Federal Signal Corporation
Type	electromechanical

The 500 Series was a line of electromechanical sirens produced by Federal Sign & Signal. It went through a lot of prototyping, ranging from a coded unit that allows it to make a "pulsed" signal, along with variants of single and dual tone models, even different phase motors were tested. They finally settled on one design that was compact, yet effective. This model unfortunately was advertised as a "mid-range" siren by Federal, which in turn caused their Thunderbolt siren to outsell it by a long shot. The most powerful unit they made was the 10/12 port, 3-phase 500SHTT, meaning single head two tone. This model packed a punch and performed well past their advertised 120dBc rating, pushing 128 or more. The most common inactive model of this sires was the 500T or the 500's used in L.A. the other models were the 500A 500B 500C ( 500 coded ) the 550 models 500-A-SH and 500-SH-TT. The 550's are quite rare with only around 50 of these models being made and only a few being left as of 2017-2018. the only 3 known locations of ones still standing are in Callahan CO, lockwood NV ontop of a fire station on canyon way, and somewhere in Yonkers NY (most likely inactive.)