This has been something that I have been wanting to figure out for a while now. How much does the chopper of a siren weigh? I assume that the model 5, STH-10 and model 7 choppers are pretty close in weight, and that an ASC chopper is much lighter than a Federal Signal chopper. But I'd like to know e...

Would some force from behind the chopper help bring it off?

This is something that has been bugging me for a while now. I understand the overall concept of a Fedelcode siren, regarding the use of a damper plate to cut off airflow to the chopper, but I am still unsure of how the whole setup actually works, especially with the model 2. I have scoured the inter...

Sorry to bring up an old discussion, but I noticed that the chopper motor is a model 2 one, and if I'm not mistaken, the British series thunderbolt had an enclosed c-face motor.