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Whelen, a campus alert system

Posted: Sun Jul 19, 2009 2:14 am
by kb4mdz
Occaisionally get a chance to be at UNC- Charlotte NC, and have to go up on the roof of the library for something else.

Closeup of their Whelen siren stack:

Image

(Yup, that's a seriously problematic antenna there to the right of the stack)

& Controller box:

Image

Posted: Sun Jul 19, 2009 3:37 am
by ACAP10
Wow! That close up is one cool picture...it's big, but the Modulator is probably 3 times bigger...Mods are just HUGE!

Posted: Sun Jul 19, 2009 5:53 am
by Ninja Squirrel
According to the manual, a Mod 6048 stands at just a bit over 12' high with each cell measuring at a little over 4' in diameter.

A Whelen 2910 stands at just under 11' high with each speaker measuring at 32.5" in diameter. So, Mods are larger in size.

The only thing is that a 6048 is rated at 125 dB while a 2910 is rated at 129 dB. Which one is more accurate, though?

Posted: Mon Jul 20, 2009 1:06 am
by SirenMadness
The person-to-size comparison on Whelen's website is sooo deceiving. :lol:

Still, the WPS 2900s have one 400-Watt driver in each cell (don't forget EZ-Pull letting you access the driver from the top), while the Modulators have four 100-Watt drivers per cell with side access, but I think that the different pitches might have something to do with it instead, though with the Modulator having the higher pitch, it should have a smaller diameter.

Posted: Mon Jul 20, 2009 3:43 am
by Ninja Squirrel
In Fairview Heights, IL, there's a 5-cell omni-Whelen (unsure of the series) that I pass up a lot. What I end up doing is looking at it and comparing the size to parked cars beside the siren. The Whelen is about the same height as one of the pick-up trucks I've seen, so you know it's huge.

As for a Modulator, on the way to Indianapolis for a vacation, we drove by a 5 or 6-cell Modulator that was about 40 feet away. Upon looking up at it, my immediate thought was, "Holy crap, that thing is massive!"

Posted: Mon Jul 20, 2009 4:59 am
by ACAP10
Don't get me wrong, Whelen omni's are big. But when I saw my first Modulator at Midway Airport, I was like wait, that's a SIREN? The cells just completely blow the Whelen's out of the water. Can't wait to see the Mods they put up on campus in a month!

Posted: Mon Jul 20, 2009 7:15 am
by CJ
I saw a video once of a guy climbing onto a Modulator to hook it up and bolt it to the pole - he was tiny in comparison, it was a 7-cell (6 active of course) one.

Posted: Mon Jul 20, 2009 4:48 pm
by bwillcox
Nice pic. Shares two of my interests-- two way radio and sirens.

You should let their radio shop or whoever runs that site know about that busted DB224. Whatever transmitter is attached to that stick probably hates its life (if it hasn't killed itself due to infinite SWR).

It can probably be fixed though, just strap the hanging loop back up and sweep it to make sure the harness is OK. Worst case they can call Andrew up and get parts for them.

The DB420 on the other side looks great, though. Gives a good scale to just how big a WPS2910 is.

-b-

Posted: Mon Jul 20, 2009 6:19 pm
by Ninja Squirrel
I counted nine cells on it, so wouldn't it be a WPS 2909?

Posted: Tue Jul 21, 2009 1:26 am
by kb4mdz
I was there for something else, and wandered, er, took a break out on the roof, away from fan noise to make phone calls. Tried to trace the cable for the VHF back thru the wall, and I think it just dead ends. Good thing!

Seem to be a lot of rust mounts up there, tho.. Bleehhhhhh!!

Been trying to get a googlemaps streetview of it, but it's too far off the road to see properly.


[quote="bwillcox"]Nice pic. Shares two of my interests-- two way radio and sirens.

You should let their radio shop or whoever runs that site know about that busted DB224. Whatever transmitter is attached to that stick probably hates its life (if it hasn't killed itself due to infinite SWR).

It can probably be fixed though, just strap the hanging loop back up and sweep it to make sure the harness is OK. Worst case they can call Andrew up and get parts for them.

The DB420 on the other side looks great, though. Gives a good scale to just how big a WPS2910 is.

-b-[/quote]