Whelen Controller Questions

[WPS4004Man]

Brief Whelen Controller history...

The Whelen "Electronic Siren Controller", or ESC, started production with the introduction of their first Outdoor Warning Sirens in the '70s, the WS-1000 series. The controller shipped with these was analog, which means they featured older, adjustable controls, such as a pitch potentiometer. Think of these as the Whelen equivalent of the SiraTone. This was known as the "ESC-3000" controller, although I'm sure a different name exists. These are the ones with the graceful wail signal, such as Puyallup, Washington's WS-3000 and Fort Wayne, Indiana's Cell Tower WS-2000-115. Mount Pleasant, Michigan has two remaining "ESC-3000" controllers, both abandoned. I'll have to check and see if photos exist of the insides.

Sometime in the Mid-to Late '80s, Whelen switched some of the internal components and marketed their second, and last, Analog controller, the ESC-864-D. This is the controller more commonly seen on Analog Whelens, such as old-style 4004 heads and WS-2000-115s. These are distinguishable by their quick, sudden Wind-Up, whereas the "3000" has a slower windup. Analog controllers weren't as susceptible to hardware failures and pitch shifts as the SiraTone, but these kinds of failures still can occur over time as these controllers age. This is part of the reason why they're becoming less and less common.

Whelen's ESC-864-A was manufactured until around 1996 or 1997, when their first Digital Controller entered the market - the ESC-864-D. It featured digital circuitry and computer-based controls. It peaked at 465Hz from the factory, but this could be changed upon special request or programming. The ESC-864-D was introduced with the Newer-Style 4004 head and the Vortex series. It was manufactured until around 2003, when Whelen's next Digital controller was introduced - the ESC-2020.

This was the problematic controller. Originally set to peak at 450Hz, a silent test (polling) would cause the boards inside to "glitch" and drift down to 435Hz, which is the frequency most ESC-2020s run at. Later attempts to rectify this issue by setting the tone to 560Hz from the factory would cause drifts down to 530Hz, sometimes permanently. Famous examples exist in Columbus, Ohio and somewhere in Georgia I'm forgetting at the moment.

The framework for later ESC-2020 controllers would pave the way for the current, and possibly best, Whelen Digital Controller - the ESC-2030, introduced around 2008. It had received upgrades inside the controller that would no longer cause pitch drifts, was 560Hz, and was easily programmable to run other pitches. This is the controller most newer Whelen installs utilize, and is still in production today.

All Digital Whelen Controllers are programmable to run other signals, such as European signals. Famous examples of this include McKinney, Texas running Best Possible Protection, another town in Texas doing the same thing, and Deerfield Township, Michigan's 4004.

Other variants of all Digital controllers exist. Type I, Type II, Voice-Capable, Non Voice-Capable, the OA/VortexO/WPS-28X controllers, controllers with extra amplifiers or battery compartments, and a few more revisions. It's difficult to tell them apart just by looking at the outsides, but hearing them or seeing the internals can help identify.

So what are the 560hz ESC-2020s? We have a bunch in central Ohio, were they later models or just ones that didn’t glitch for some reason? (Sorry if I’m derailing the topic here)

[nvanw27]

So what are the 560hz ESC-2020s? We have a bunch in central Ohio, were they later models or just ones that didn’t glitch for some reason? (Sorry if I’m derailing the topic here)

Those are the later models that also had the glitch in some cases. The 530 4004 is a 2020 that did experience the glitch. The hardware used in the 2020 was faulty, even in the later models, which is why the 2030 exists in some cases. Some 560s in Franklin County are 2020s, while others are 2030s.

[uncommonsense]

Not all 2020s drifted to 530. As I understood it at the time the tone was raised to 560hz as it is the tone the drivers operated most efficiently at with the release of the 2900.

You can always tell the difference when listening to audio. The 560hz 2020 has a stepped wind down while the 2030 is smooth all the way down.