The Siren Board

Thunderbolt 612 wrote:In addition, I wonder what a 1003 with the 4/5 rotor would sound like in high-low mode.

If you've seen Greg's video of him testing his Hurricane in hi-lo, you'd roughly know.

Robert Gift wrote:If I could ever acquire a Thunderbolt, I would run the rotor at very low speed to feel the pulses. Wonder if they'd break windows?
Maybe THAT is why they shut off the blower early.

I wouldn't think that a Thunderbolt would break windows so much as it would just rattle them. Some people like to have a shorter wind-down when the signal is done, which is probably the reason for the changed settings on the blower.

The blower on mine cuts off a few seconds before the chopper stops. It can be set to go longer, but that screws up the restart when you use the AR timer. It won't allow the chopper to restart until after the blower has stopped. I might tinker with it and see if I can override that problem. When sounding in attack mode, it sounds weird to have the chopper nearly stop by the time it starts the next cycle. So by having it set where mine is, it's in sync better with the AR timer to give a more even ON-OFF wail.

Charles

Robert Gift wrote:

ver tum wrote:...The siren you linked me to has the same problem as all of our sirens do. The blower doesn't stay on for much of the winddown. Our sirens used to sound right, but now, the blowers all turn off almost as soon as the choppers start to wind down. I tried to tell Emergency Management, but they acted like I didn't have a clue what I was talking about.

That bothers me, too. They couldn't allow some extra seconds for the rotor to coast down?
Those last few seconds at low speed are the most fascinating sound of all.
Bet the pulses would feel great if anyone were near.

If I could ever acquire a Thunderbolt, I would run the rotor at very low speed to feel the pulses. Wonder if they'd break windows?
Maybe THAT is why they shut off the blower early.

Do you think that could mes up the blower motor if the siren is in Attack? I would be afraid that it could overheat from starting and stopping so many times, especially if it's a capasitor start motor, like other compressors have.

ver tum wrote:

Robert Gift wrote:That bothers me, too. They couldn't allow some extra seconds for the rotor to coast down?
Those last few seconds at low speed are the most fascinating sound of all.
Bet the pulses would feel great if anyone were near.
If I could ever acquire a Thunderbolt, I would run the rotor at very low speed to feel the pulses. Wonder if they'd break windows?
Maybe THAT is why they shut off the blower early.

Do you think that could mes up the blower motor if the siren is in Attack? I would be afraid that it could overheat from starting and stopping so many times, especially if it's a capasitor start motor, like other compressors have.

I'd keep the compressor running constantly - starting just before chopper start-up and ending 10(?) seconds after final chopper power-off so you get chopper wind-down.

I was wondering about that to. In common Thunderbolts, does the blower run nonstop during its attack cycle? Or turn on and off with the chopper?

ThunderboltFreak wrote:I was wondering about that to. In common Thunderbolts, does the blower run nonstop during its attack cycle? Or turn on and off with the chopper?

The blower should remain on during the attack cycle, otherwise the wind-down wouldn't be audible over a great distance.

Yes, I have wondered about this as well... there was a video that Ben Hinrichs posted from Wisconsin somewhere (Richardson sticks out for some reason). It showed a 1003 doing all three signals, it did THE MOST perfect attacks signal I have ever heard and I think it was due to the way the blower was set up. Alot of Thunderbolts doing attack have a quicker windown so they wind down much further before it picks back up so it sounds like a siren cycle and not like one cohesive tone (I just used the word cohesive.... I think I have been reading to many of Robert Gift's posts!! LOL)...this one has a slower wind down which is possibly because the blower continues to run while the siren is winding down. I can't recall the address to the video on youtube but I know it is up there somwhere.

Dave

That one was in RICHLAND CENTER, Wisconsin. Close, but, not quite!
Were the 4/5 Rotors ever placed in a ThunderBolt siren officially? (By Federal themselves).

That recording won one of the Siren Contests. The horn on the Thunderbolt has a frequency cutoff of 128Hz so you don.t hear anything below that pitch. Apparently Federal did install the choppers direct at the factory. I'm not sure of any practical reason for this.