Go see the Old system pictures here.
Type of System: 7 Whelen Vortex and 2 Whelen WPS-2810
Number of sirens: 8 discovered
Test Date: First Wednesday of month at 1 PM
Locations: many. Strategically placed in residential areas and by public
schools
Activation method: Radio in VHF Highband range. Coding Method is Quick
Call DTMF.
Installed by American Communications
in Haltom City Texas.
Test Procedure:
Minute and a half of the Alert tone (constant tone)
5 second pause
Minute and a half of the Whoop tone (low ramping up and stopping)
Silent testing is done each morning between 4 and 6 AM.
Here are several sound clips of a Whelen. These sirens are pretty talented.
All Files are in MP3 format.
This is one of the new Whelen sirens Lewisville has placed into service.
This siren is placed right by
Fire Station #4
A good place to hear this siren is at the Wal Mart Neighborhood market
about a quarter of a mile away
The Whoop mode echoes quite nicely when it stops
Another Vortex not too far from State Highway 121.
Note the Federal Signal Thunderbolt 1000 on the shorter pole nearby. Sadly the Thunderbolt has been taken down.
One of my co-workers reports that the Whelen is quite audible from an activation recently.
This Vortex covers the southeast portion of Lewisville
and is in a pretty good place
as there are lots of homes and schools nearby that need coverage.
Here is a shot of the controls on the Vortex.
This one gets power from the utility company.
Not surprising since there is a huge water tower nearby.
Here we have a shot of the driver/horn assembly.
These are made of cast fiberglass and bleach out to a very bright white
in the sun
but they come as gray.
Note that the pole is spun concrete. It would take a large tornadic vortex
to knock down this Vortex
Finally, though at a very strange angle, we see the front
of the siren.
The weird bulge on the pole is the motor that oscillates the siren head
through a 180 degree circle
I don't think this pic needs an explanation 
This Vortex is out in the middle of nowhere by some manufacturing
plants on SH 121
You can really see the detail of how Whelen assembles these speaker arrays
Here's the controls.
Just a nice, compact, unassuming white box emblazoned with the single
word Whelen
The antenna is a decent size whip about halfway up the pole.
Right near this siren is the concrete pad for the blower of the old Thunderbolt
that was here.
I love this picture. Definitely look at this full size.
We all love to make fun of Whelens but this Vortex is menacing
from this angle.
This picture also taught me that the Vortex cable won't snag as the siren
oscillates.
Here's that intersection for fellow siren hunters.
Here's the Big Daddy of the Whelen omnidirectionals...
a WPS-2810
From a distance like this, it looks pretty good. Tall, black, and sleek.
Getting closer. Not as pretty is it?
Sorry 'bout the focus. Really need a monopod when I fire up the digital
zoom
Now we're close. This really isn't very pleasing to look
at, but man is it loud
Not only that, this thing can project the human voice for a mile in all
directions around it.
Located where it is (the middle of Lewisville's biggest park) this is
a good thing.
Damn Sidehill Gougers 
Here's a nice tight zoomed in shot of the driver cells that make up a
WPS-2800
This siren really is huge. I bet it's easily taller than I am if you sit
it down on the ground.
Here's what feeds Big Daddy and gives him his shouting
voice.
Interestingly enough, there is no power meter on this siren at all, just
the solar cells you see here
Also, the same antenna that's on all the other sirens here.
Scooting a bit to the left, we can examine the controls
a bit better
The two lower compartments (bearing the Whelen logo) are batteries
The larger upper compartment has the radio/decoder, and the amplifier
boards to power
the drivers further up the pole.
This is the southeastern-most siren in the Lewisville system
and is very important
It covers the Vista Ridge Mall area where there are likely to be people
outdoors to hear it.
Here are the controls, antenna and power meter
This is where I can get close enough to the siren to really feel how tough
the concrete poles are.
A good side picture of the Vortex.
This is the first Vortex I saw in the Lewisville system and I still remember
the day I saw it.
I think I impressed my friend with my knowledge of curse words when I
saw what was replacing my Thunderbolts
Whelen equips these with a screen so birds don't get in
There are actually channels for each driver cast into the horn which I
didn't know about
"I just don't know Linus.... I just don't know" (with apologies to the great late Schultz)
Remember those channels I was talking about?
You can see them in the shadows of the horn in this picture.
Maybe if I get closer.....
Here we go. Nothing like staring into the mouth of the
beast
Now I understand why Whelen's logo is the way it is
(it looks like the inside of the Vortex)
The oscillator motor is real visible in this close shot too.
Here is another shot of how the horns are "piggybacked"
onto the mounting bracket
and why the Vortex doesn't rotate all the way around like other sirens
The sirens all have a simple ground-plane whip antenna
on them
The favorite KISS principle at work
See what I mean about the Whelen logo (large on the ends and skinny in the middle)
This is one of two Vortexes that is solar-powered.
I still don't know what the smaller horizontal tubes do on the antenna
on this siren.
Again, spun concrete for the pole here too.
Man this was a great day to be taking pictures.. can't
ask for a better backdrop
A nice install on this Vortex.
The white S-10 (GMC Sonoma actually) is my conveyance.
This Vortex is solar-powered too, just like the one at
the other middle school
The install here is real similar to the one at Huffines but
the solar cell is inclined much further to clear the trees
Going up.
You can see the driver connection cable on this particular siren
The drivers are in the flat back of the siren and are capable of handling
400 watts each
They blast forward through the channels and out through the horn being
massively amplified
yet maintaining good tonal quality which is suitable for voice
(though the Vortex doesn't talk)
Here I get a real reflection off the protective grille
at the front of the horn casting
and one can also see the channels cast into the horn
Now, stepping left some more
A similar shot to Uecker above, showing the fiberglass
gelcoat composition of the driver assembly
I hate to say it but these things scream "cheap" when you are this
close to them.
Still, this siren is in a great spot and does its job in exemplary fashion
No other known locations at the moment
