Strange Dial-up/Phone/Computer Tones from T-128

[AST128_RyanK]

I went to record the T-128 at Plymouth Park in Midland, MI. The siren head is roughly 2 years old, but the controls are older having the old blue and white logos. The original siren head was damaged, with the rotor and controls working, but the siren wouldn't "sounded". Essentially when activated the siren would just rotate.

At this test following the growl test before the audible test, dial-up/phone/computer tones were coming from the control boxes. The tones were considerably loud being heard clearly at my vantage point roughly 100 feet away. I'm assuming the tones were the communication between the siren and the EM/Central Dispatch. Although I'm unsure.

[Valra Bellkeys]

I've never heard of tones coming from a siren at that distance, but I was once close to a UV modulator, and I could faintly hear the tones coming from it. It was one of the mods in Purcell.

[EOWS1212man]

I went to record the T-128 at Plymouth Park in Midland, MI. The siren head is roughly 2 years old, but the controls are older having the old blue and white logos. The original siren head was damaged, with the rotor and controls working, but the siren wouldn't "sounded". Essentially when activated the siren would just rotate.

At this test following the growl test before the audible test, dial-up/phone/computer tones were coming from the control boxes. The tones were considerably loud being heard clearly at my vantage point roughly 100 feet away. I'm assuming the tones were the communication between the siren and the EM/Central Dispatch. Although I'm unsure.

What you were hearing were most likely ASC "CompuLert" FSK tones.

http://www.sigidwiki.com/wiki/CompuLert

[AST128_RyanK]

I went to record the T-128 at Plymouth Park in Midland, MI. The siren head is roughly 2 years old, but the controls are older having the old blue and white logos. The original siren head was damaged, with the rotor and controls working, but the siren wouldn't "sounded". Essentially when activated the siren would just rotate.

At this test following the growl test before the audible test, dial-up/phone/computer tones were coming from the control boxes. The tones were considerably loud being heard clearly at my vantage point roughly 100 feet away. I'm assuming the tones were the communication between the siren and the EM/Central Dispatch. Although I'm unsure.

What you were hearing were most likely ASC "CompuLert" FSK tones.

http://www.sigidwiki.com/wiki/CompuLert

That's it!