The Siren Board

I don't really know if this has been answered/asked before, but this is really nagging me. I've seen a test video (Can't remember which one) Of either a Vortex or a 4004 blaring out DTMF codes at the beginning of it's test. I'm real curious as to why.

Its because the live PA function is on. When the live PA function is on, it essentially opens a live broadcast of the radio channel the siren controller receives its signals from. So not only does the live voice--which is broadcast over that frequency--get broadcast, any radio traffic also gets broadcast until the live PA function is canceled. Hence why you'd hear DTMF tones.

Interesting. Thanks for helping with that, its' been bugging me for ages.

Whelens activated by DTMF almost always play the DTMF out loud, it has nothing to do with the PA function. I'm not sure anyone but Whelen knows why.

Sirens from other manufactures do it too sometimes. There is a video online of a Modulator going into live PA and putting out FSK tones when they send the tones to make it run in wail.

Ziginox wrote:Whelens activated by DTMF almost always play the DTMF out loud, it has nothing to do with the PA function. I'm not sure anyone but Whelen knows why.

They shouldn't unless it's part of a recording on the controller. The Whelen systems around me are all activated by DTMF, and I've never heard them blare out the tones, except for one that malfunctioned on the base.