500

500
[[File: A 500-DHTT in Yonkers, NY. |200px]]
Company	Federal Signal Corporation
Produced	1953-1982?
Type	Electromechanical
Sound output	123-130?
Voltage	120, 220, 240, or 480 V
Succeeded by	RSH-10

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.

Earlier Models

The earlier 500, Mostly seen around Los Angeles. Were offered in 9/12 port, 12 port, and more rarer 8 port. Some models had intake supports to prevent the intake rivets from breaking which is an uncommon problem with these, especially in high humidity corrosive climates.

500-DHTT

The 500-DHTT is a dual horn variant of the 500SHTT, they have 2 rotors and stators each side, one 8 port, the other 12 port. They were offered with a 15 or 20 horsepower motor. Roughly 100 were ever made, and 7 units are known to exist as of 2018.

Media

• 10/12 500-SHTT in Dundee, Michigan
• 9/12 500AT in Bristol, Tennessee
• 12 port 500-SH in Stewartsville, Missouri
• 500-DHTT in Calhan, Colorado