It appears you have the older screw clutch model. To remove the elastic stop nut, you will have to lock the armature by using bolts threaded into the base mounting holes. Thread the bolts into the motor until you contact the armature. Now tighten the bolts approx 1/8 turn, do not over do it. Try rem...

One day I was standing on the hill and they had just taken a short break. I heard a funny sound coming from the front of the ambulance and went to investigate. There was a brisk breeze coming from the south, and that old Sireno was rolling all by itself! We actually traded the old siren off sometim...

Kevin did my S8 and this one:

Not being any kind of expert but it seems they wanted more of a horizontal dispersion instead of a vertical dispersion of the sound waves.

The people at Hedberg sirens noticed that, leading them to build vehicle sirens where the brushes are solenoid controlled to contact the armature only during spin up. The brush lifting siren motor was patented by C.P. Meussdorffer (CAM sirens) back in the 1930's. http://www.freepatentsonline.com/20...

[quote="Mac"]I'm confused as to the difference in the motor-starter and the relay..


A motor starter relay usually has some type of overload protection ( heaters for example) incorporated to protect the motor from overload damage. A simple relay does not.

The stator openings do not look like a Federal model 66. It appears to be a re-branded model WL. To check measure the rotor diameter, a model 66 has a 6 1/2" rotor, a model WL has a 5 1/2" dia. rotor. Federal model 66L: http://img.photobucket.com/albums/v691/Henry455/Federal%20Catalog/Fede...

Usually the larger the speaker housing the better. Here are some that in my opinion would give the best performance. One caveat, no consideration is given to price, availability or mounting practicality. All the following speakers have a 100 watt driver with 11 ohms NOMINAL impedance ( speaker imped...

jkvernon wrote:American Signal uses the Atlas Sound AS100N driver in all their sirens. They speak highly of the drivers too.

You might be surprised where that AS100N driver is made, I am almost positive Taiwan R.O.C.