After the tornadoes last week there was a discussion on a local forum about Tinker Air Force Base using the voice capability of their Modulator system for the first time during an emergency. This led to a discussion of Oklahoma City?s Whelen system and how it is utilized.
The safetycom.com website
http://www.safetycom.com/spotlights/Oklahoma_city.html#
which belongs to the company that installed the system says that the directional sirens are tone only Vortex sirens. My observation of every unit that I have seen is that the directional sirens in Oklahoma City always return to a consistent predetermined point on the compass, which causes me some confusion as to whether they are Vortex models or actually of the WPS 4000 series. The Vortex sirens in Midwest City stop oscillating when the siren is deactivated and thus can wind up pointing in any direction. They also have a fin on the back of the driver housing much like a wind vane while the Oklahoma City units lack this feature. Since Oklahoma City has, so far, not used the voice capability, I am unable to determine if the rotating sirens are voice capable or not. It seems like a waste to put the sophisticated rotator and rotator electronics on a tone only siren, especially when there are around one hundred or so in the system.
I would be curious what some of you who are familiar with Whelen think which model they actually are.