What are these tones called?

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FirstDue5

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My department uses these tones, it is the only department I know of or have heard that uses these tones, this tone is for a specific station, every station has a different tone. Can anyone help me out and explain these tones? I have attached a file with the tone in it.
 

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12dbsinad

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Those are DTMF tones. They can be used to open up a muted receiver, activate a siren, activate lights, etc.

It is a pretty common type of signaling.
 

majoco

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So now "Firstdue5" knows they are DTMF but that doesn't help him muh....

The sounds used for touch tone dialing are refered to as DTMF (Dual Tone Multiple Frequencies) tones. Each number (as well as the "#" and "*") is represented by a pair of tones. For instance, the number "1" is represented by the frequencies 1209 Hz and 697 Hz.
 

radioman2001

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There are actually multiple types in the Fire Service of what might be called DTMF, which Bell Labs created back in the 50's. There is the original DTMF used in telephone service then in the Fire service you have the DTMF format created by Mot in the 70's called 2+2 (the tones you hear on the TV show Emergency) there is the Knox Box DTMF from Federal Signal from the 80's and also Whelen who uses DTMF for their siren activation. Each uses a different set of base tones together to give a little more security for accessing whatever it is you want to activate. The original concept I believe was to ensure that random noise on a radio channel couldn't cause an unwanted activation. There were many FD's that had a single tone for activation which at times could be falsed by mixing and noise.

I tried to create an encoder years back to test my KNOX Box installs but was never successful. I ended up just recording the tones on my computer and testing them that way.

Quote"Does anyone know of any other department that uses these tones?

Rockland County New York, and another agency that I am not sure of in and around the Buffalo area. I think most of FD's using DTMF were originally Mot installs from the 60's and 70's.
 

andyk62990

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Quote"Does anyone know of any other department that uses these tones?

Rockland County New York, and another agency that I am not sure of in and around the Buffalo area. I think most of FD's using DTMF were originally Mot installs from the 60's and 70's.[/QUOTE]

Amherst Fire Control uses them for Knox Box contols, and they are used for the Niagara County Ambulance to Hospital calling on their med channel.....or atleast were a few years ago, but idk with the Niagara County TRS
 

FirstDue5

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What if I bought a Chinese TYT DMR VHF radio with a built in DTMF decoder/encoder. Would I be able to program the radio in a "nightmode" that monitors my departments frequency and then goes off with the tones that I attached in the first post?
 

mikegilbert

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I know most Kenwood radios can use DTMF for paging. I used to have a TK280 setup for that. It would only open up when a battalion chief was paged.
 

FirstDue5

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DTMF Signalling

So I ended up getting a TYT md-380 vhf model. I just received it today, got it all programmed up to listen to repeaters and public safety in my area. I got it because it has DTMF Signalling on it. Is there anyone that can give me hints or point me in the right direction to creating a "night mode" channel where the radio would only go off if certain tones are dropped? The tones are the ones that I attached in the first post of this thread. I am still new to radios and there are no youtube videos on this function for the radio. Thanks in advance if anyone can help!
 

toastycookies

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So I ended up getting a TYT md-380 vhf model. I just received it today, got it all programmed up to listen to repeaters and public safety in my area. I got it because it has DTMF Signalling on it. Is there anyone that can give me hints or point me in the right direction to creating a "night mode" channel where the radio would only go off if certain tones are dropped? The tones are the ones that I attached in the first post of this thread. I am still new to radios and there are no youtube videos on this function for the radio. Thanks in advance if anyone can help!
Your radio does not have a function to open squelch with DTMF signalling.
 

FirstDue5

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Do you know any radios that I would be able to program a function like that on? And also on this radio, it kills fire dept 2 tones as soon as they come over the radio, any way to fix?
 
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