Here's a Quick Time Video of the B&M Super Chief. It's a short clip but gives you an idea of what it sounds like and how the brake works: http://www.siro-driftsirens.com/images/SC8B_63434b.MOV B&M posted wiring diagrams and prices for their sirens this weekend, too. I'm glad to see that they...

my friend is an EMT. hes showed me before. trust me thats what they are for. There are some systems that use RF activation for traffic signal pre-emption. However, they do not use Yagi beams; you'll find a simple 1/4 wave UHF antenna on a box, usually on the control panel. In some systems, the ante...

Just out of curiosity, how many digits are required to activate a siren via dtmf? As many as you want.... It all depends on the system. It depends on how the decoders are set up. They can be activated with as few as 1 digit or as many as necessary for the particular system. Obviously, the more digi...

I'd love to hear -- or should I say feel one of those Rumblers! Great idea! Way to go, Federal.

John

I guess my question would be, "why"? Though it would look cool, I am sure, the fact is that most agencies rarely use Hi-Lo on the sirens that still have that function. Hi-Lo just doesn't work on an electronic. (European horns are an entirely different story, because they are horns). Beside...

Daniel wrote:I'd like to hear what that horizontal, dual-tone B & M air raid siren sounds like.

Amen to that!

>>Lex orandi, lex credendi

Amen to that, too

they sound like air-raid sirens What you are hearing is a response out of an LAFD fire station. The engines are the old Hall-Scott gasoline engines used by Crown Firecoach back in the 1950's and into the 1970's. The sirens on the trucks are B&M S-8's. Though the last truck pulling out may be a ...

http://www.lafd.org/hs.wav

You'll hear three of them.

John

In NY, the Yagi antennas on traffic lights communicate with the next traffic light down the road. This is done to coordinate cycles to keep the traffic moving. It is probably true of the ones you're speaking about, too. Take a look at the next traffic light down the road from the one you see. Notice...

The Michigan State Police had some type of sign on the front hood of their cars and the also had a single beacon with those clear stripes mounted in the center of the roof. I have not been back since the late 90's 98/99 but they were using that setup then. I remember those signs. I believe they sai...