An 11 ohm IMPEDANCE siren speaker will read between 4 and 5 ohms when checking the driver RESISTANCE.

Some guys on the Elightbars.org forum have acquired this siren and are asking help in identifying. This is what they wrote: "Attached is a photo of our original Sterling Model 10 siren recently rescued from a field in a neighboring township! I have been looking for this siren for 30+ years, I k...

Check your email, just sent it.

Tim

Not sure if you need it but I have a Alpha 12Q 7 page manual I could send you.

Tim

Videogamer, I have a homemade mounting base you can have for free, just pay the postage. Let me know.

Tim

All of my Federal products have had the simple ball & ramp clutch. When acquired, some of the sirens were in pretty bad shape but the clutches were always in good shape. Always wondered why Federal when to the screw clutch. http://img.photobucket.com/albums/v691/Henry455/Federal%20C5A/C5AClutcha...

Skip, it appears they are using a small one way bearing, roller clutch. Not near as robust as the B&M clutch roller assembly. My understanding is the the least little bit of foreign debris will cause these to drag. You can see it in this parts drawing, part #9. http://www.fedsig.com/docs/PPL%200...

The rotor retaining nut on older Federal Q sirens had a left hand thread.

Completely off the subject of efficiency is the fact that Whelens are built top to bottom in the USA. When large sums of public money are being spent, its still nice to know some of this money is staying right here. Community Professional Loudspeakers builds Whelen's drivers. In fact, Bruce Howze, ...

Now that's more like it. Sounds like there is nothing wrong with the siren. What bearings do you feel need replacing, it all sounds good to me.