That central part is just BEGGING to have a woofer shoved in it.

I have done a TOTAL rebuild of this siren over the last couple of days. http://555-timer.clarkson-uk.com/operation/frames4.html for the timer. It runs 3:05. http://startingelectronics.com/Fbeginners/Fstart-electronics-now/tut13-555-wailing-siren For the actual tone generator. Pics and short vidya to...

Nice find!

All you need is a dry, unconditioned pair, a -48V DC power supply, and 'telephone' relays... To simply close the control circuit at each location. The AR timer, when placed across a master relay, at the control location would be used to tell the rest of the relays what to do... The additional relay,...

FYI: 30mA is enough to end ya if you're well grounded and wet. Many GFCIs will trip at 5ma, which is enough to jolt you real good.

There are a number (3-5 at least) of P50s in Germantown, TN as well.

Many sirens installed nationwide, where radio-controlled, used to or still generally run in three areas on the RF spectrum: Lo-Band, in the tens of Mhz - VHF at the 2 meter range, 140-160 MHz, and then, 800MHz as part of a metro area's trunked radio system, riding along with a virtual channel.

Even better. Power AND penetration do matter to forward-thinking EM directors! There's no escaping that low tone... It's sound carries comparatively well, even in the American South, where the air is nice and humid, making it very dense and the obstructions abound.

...And the single phase 2t22B motor is around a grand, new. Used prices may vary if you're able to snag one.

PS.... Lookie there, 550 Posts from a guy that likes 550-AT sirens

On their 550AT, Calhan,CO runs a 3 minute alert for All Clear. Their Take Cover (warning) signal is three one minute activations, with 15 sec gaps.

* Gunnison, CO had a model 5, which was tested daily as a noon whistle until a couple years ago. * Cant remember the name, but one mountain town had a 2t22 that did the same. * Hugo, CO has two sentry 3V8-Hs and a SD10, that go off at noon and six pm daily. Sourced from Baca County OEM Website, have...