
Since this vid I've tweaked the timer so that it cuts back on quicker during the wail. The timer assembly is shown at the end
http://www.youtube.com/watch?v=Yto68JCk4g4
Turn your speakers up for this one and listen for the echo, it's very faint. That's what you get for filming with a cell phone.
http://www.youtube.com/watch?v=K4-PMwRx8k0
Hopefully I will get a decent recording device that really captures the sound of this siren.
Any questions just ask.