500 Series
| 500 Series | |
| Company | Federal Signal Corporation |
|---|---|
| Produced | 1953-1982? |
| Type | Electromechanical |
| Sound output | 123-130? dBc at 100 feet |
| Horsepower | 10-20 |
| Voltage | 120, 220, 240, or 480V |
| 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, have a shorter projector unlike the later ones, they were offered in 9/12 port, 12 port, and more rarer 8 port. Some models had support bars inside the projector to mitigate warping. Some models used the STH-10 chopper and stator, and had a larger horn.
500-DHTT
The 500-DHTT is a dual horn variant of the 500, they were offered with a 15 or 20 horsepower motor. In 1957 they increased the length of the rotator shaft, giving the siren head more clearance of the rotator body. They were produced as late as 1965-67. Roughly 100 were ever made, and 7 units are known to exist as of 2021.
Details
The projectors are a two piece construction held together by rivets, it is attached to a sheet metal ring located on the stator by rivets and bolts. This ring also has a corrugated section for the motor cover to be held on by machine screws. The motor cover is fastened to the pedestal by 4 bolts, two on each side.
