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Audio tone used for Nashville dispatch.
Posted: Sat Jun 04, 2011 7:04 pm
by mgsully
Nashville uses one of three tones for it's police and fire dispatch. Though these audio tones are no longer used for signal which unit or hall is dispatched (MOSCAD does that), these tones are used as an audio alert to signal police of a high priority call and fire of any call being dispatched. Fire dispatch uses a two tone, alternating signal for supression calls a single tone, beeping signal, and a single tone, steady signal for medical calls. Police use a two tone, alternating signal (same as fire). My question, if these are standard Motorola tone, what kHz are they. I have a project I am working on and need to know. I have an XTS radio that I am trying to program to stay muted until a priority dispatch is made.
Re: Audio tone used for Nashville dispatch.
Posted: Sat Jun 04, 2011 8:14 pm
by mgsully
From what I have figured out thus far:
The long, single tone - unknown
The alternating, two-tone - 1500kHz +/- and 800 kHz +/-
The on/off/on/off single tone - 1100kHz +/-
Are the standard tones for motorola, if programed into a xts radio, is there a tolerence for variation?
Re: Audio tone used for Nashville dispatch.
Posted: Sun Jun 05, 2011 6:42 am
by Bill_G
I think you are talking about the console alert tones a dispatcher can select to get people's attention before they announce. I doubt you'll find an equivalent decoder tone or sequence to trigger your rcvr since these were not intended for paging.
Re: Audio tone used for Nashville dispatch.
Posted: Sun Jun 05, 2011 9:57 am
by RESCUE161
Are they similar to the ones in the zip file on this thread?
http://forums.radioreference.com/south- ... tones.html
I made those using Audacity. The tones were 800.0 and 1499.0 Hz.
Re: Audio tone used for Nashville dispatch.
Posted: Sun Jun 05, 2011 10:10 am
by RESCUE161
mgsully wrote:From what I have figured out thus far:
The long, single tone - unknown
The alternating, two-tone - 1500kHz +/- and 800 kHz +/-
The on/off/on/off single tone - 1100kHz +/-
Are the standard tones for motorola, if programed into a xts radio, is there a tolerence for variation?
I don't think you will hear anything using those frequencies...hehehe

Nothing there but the AM broadcast band.