Do you have a link to the video? Nevermind posted it for you... http://www.youtube.com/watch?v=BtJO3AIRf2M All of his Edmonton recordings are fake How do you know? It would stink royally if it was true, but if it is, I wonder where he got the CLM recording from? I'm fairly certain it's Ron W's 500A...

It sounds like it's using a single phase induction motor and the start capacitors are switching out too early.

DeWitt had a couple of Penetrators, either P-10 or P-15. Here's one of them on Google maps: http://tinyurl.com/cgwae7m That one is now gone. The other one was grey I think, and I don't remember exactly where it was or know if it's still there. I was in the area during a testing day a few months ago ...

It's possible that a large inductor and capacitor tuned for 60Hz would continue to resonate after the power is removed, thus supplying AC for a short time afterwards. Probably not long enough to make a major difference, and being connected to a load might stop the oscillation immediately. I've never...

Not with FM, because of the capture effect. Only one signal will be detected. Analog television uses AM for the video signal, but FM for the audio signal. The bandwidth for the audio signal is around 500KHz, I think, where as NOAA stations are spaced only 25KHz apart, very narrow in comparison.

I have a radio/cassette deck that have TV-L and TV-H bands on it. That explains it. TV audio is wider in bandwidth than some other broadcasts. So you could actually be tuned to a range of signals at the same time. I have an old black and white television that picks up NOAA broadcasts by tuning belo...

It sounds more like a 2001. Starting around 0:35 you can kind of hear that raspy undertone that 12 port sirens tend to have.

A few years ago I caught the tail end of a test with a T-128 sounding at that pitch. Quite a different sound.
http://www.youtube.com/watch?v=Toxx-25ac54

You could use a 555 timer, binary counter, and multiplexer to run sequentially through the mux inputs. Then a transistor and relay to drive the fire alarm. I'm not familiar with all the fire signals, but by changing the 555 frequency, how far the counter counts up, and the inputs of the multiplexer,...

A 555 would also be pretty useful for automating the entire activation, keeping it on for a few minutes, or turning it on and off for an attack signal.

If the capacitor is connected directly to the relay coil I think you can only increase the time by increasing either the capacitance or the voltage. Adding a resistor in series will discharge the capacitor slower, but also increase the voltage drop at the coil. To get longer times without needing hu...