Quad 3 - Tornado Siren Testing Tones

[BudTurpa]

This morning I had an old analog only scanner turned on, I was setting it up for marine channels. In an old scan list I had "Quad 3" programmed from the days that the Barrington FD was on analog dispatched out of CenCom in Round Lake. Since Barrington FD moved to NWCD I didn't think the "Quad 3" channel was used any longer.

At 10am I heard two sets of Plectron-like tones followed by 3-4 batches of really rapid DTMF tones, followed by a slower batch of DTMF tones. This whole cycle seemed to repeat three times in the span of 10:00am to 10:04am. All three cycles sounded the same, as if they were repeats, but my ears are not good enough to determine if all three sets were the same Plectron type tones and if all the DTMFs were the same. All while this was happening on the radio I heard several local tornados sirens go off for their 10am, first Tuesday of the month, testing.

Questions for the forum...

Has Quad 3 been repurposed for these tornado sirens since fire dispatching left the frequency? Or, prior to Barrington FD moving off the frequency, were the siren tones combined with fire dispatching voice traffic? If the latter is true, why would siren tones be combined with dispatch voice? Didn't firemen "step on" the siren tones easily, especially during times of bad weather when the FD was being dispatched and tornado sirens were being turned on?

Are these siren tones transmitted from CenCom in Round Lake or somewhere else? The signal strength seemed so much stronger listening to this morning's siren tones - as if they were being transmitted somewhere very close - verses the slight static/noise I used to hear on the dispatcher side when CenCom was handling Barrington FD.

If what I was hearing were radio transmitted instructions for tornado siren triggers, to me it seems that Plectron type and DTMF tones are a bit "old school". I guess I thought the sirens were networked via fiber or on private/secure wireless and not sent over more general open frequencies. How is the connectivity generally done outside my (Northwest Suburbs) area?

 

[K9DAK]

Hi Bud! Great observations... hope I can help (I've lived in the district for years and work with my Village's Emergency Management Agency).

• Nope, the siren activation sequence has been broadcast on Quad 3 as long as I've lived here.
• Quad 3 was formerly shared by Barrington FD and Wauconda FD; it was actually Wauconda that left first when we merged our dispatch with Lake Zurich's, on their frequency / SC21 TGs.
• During bad weather, the monthly test would be moved to another day, so no worries about the tones being stepped on.
• AFAIK, the tones are transmitted from a transmitter located at Wauconda Station 1, pretty much the geographic center of Quad 3. There's been pretty good tropospheric ducting going on with the warm weather under a high pressure area, so that probably enhanced the propagation so you could hear the sequence with a stronger than usual signal.
• Fire districts are strapped for money these days, so if the current system works, they're not going to spend the bux to upgrade.

Hope that helps!

This morning I had an old analog only scanner turned on, I was setting it up for marine channels. In an old scan list I had "Quad 3" programmed from the days that the Barrington FD was on analog dispatched out of CenCom in Round Lake. Since Barrington FD moved to NWCD I didn't think the "Quad 3" channel was used any longer.

At 10am I heard two sets of Plectron-like tones followed by 3-4 batches of really rapid DTMF tones, followed by a slower batch of DTMF tones. This whole cycle seemed to repeat three times in the span of 10:00am to 10:04am. All three cycles sounded the same, as if they were repeats, but my ears are not good enough to determine if all three sets were the same Plectron type tones and if all the DTMFs were the same. All while this was happening on the radio I heard several local tornados sirens go off for their 10am, first Tuesday of the month, testing.

Questions for the forum...

Has Quad 3 been repurposed for these tornado sirens since fire dispatching left the frequency? Or, prior to Barrington FD moving off the frequency, were the siren tones combined with fire dispatching voice traffic? If the latter is true, why would siren tones be combined with dispatch voice? Didn't firemen "step on" the siren tones easily, especially during times of bad weather when the FD was being dispatched and tornado sirens were being turned on?

Are these siren tones transmitted from CenCom in Round Lake or somewhere else? The signal strength seemed so much stronger listening to this morning's siren tones - as if they were being transmitted somewhere very close - verses the slight static/noise I used to hear on the dispatcher side when CenCom was handling Barrington FD.

If what I was hearing were radio transmitted instructions for tornado siren triggers, to me it seems that Plectron type and DTMF tones are a bit "old school". I guess I thought the sirens were networked via fiber or on private/secure wireless and not sent over more general open frequencies. How is the connectivity generally done outside my (Northwest Suburbs) area?

 

[a417]

? Didn't firemen "step on" the siren tones easily, especially during times of bad weather when the FD was being dispatched and tornado sirens were being turned on?

The tones are likely transmitted w/o PL/DPL, and the radios the fire department likely uses has it set. They would not hear them unless they were monitoring the frequency in carrier squelch mode (CSQ)