Tones before the dispatch tone...

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n2deep
Posts: 33
Joined: Mon May 01, 2006 7:55 am

Tones before the dispatch tone...

Post by n2deep »

I was wondering if anyone knew what these tones are for, they are played before the dispatch tone. Thanks

http://home.san.rr.com/jms1974/SDFD%20Tone%201.wav

http://home.san.rr.com/jms1974/SDFD%20Tone%202.wav
Rescue Pooh
Posts: 218
Joined: Mon Oct 25, 2004 9:59 pm

Post by Rescue Pooh »

Could be wrong, but I believe it's for station alerting.
hodad200
Posts: 147
Joined: Wed May 10, 2006 11:59 am

Post by hodad200 »

i'm sure tim will answer :D
thefish
Posts: 30
Joined: Fri Oct 29, 2004 8:34 pm

Station alerting

Post by thefish »

They're DTMF, or Dual Tone Multi Frequency tones used to activate the backup station alerting system. Usually at some time before you hear the DTMF usage, you will have heard, "All stations monitor 7A and 7B..." In other words, the link to the primary station alerting is down.
N6766J
Posts: 49
Joined: Mon Feb 19, 2007 2:32 pm

Tones

Post by N6766J »

The Fish has it right, although I never hear the tones on my BC246T, Used to hear them on VHF back in the day, though.
w6pix
Posts: 338
Joined: Wed Dec 31, 1969 4:00 pm

Re: Tones

Post by w6pix »

N6766J wrote:The Fish has it right, although I never hear the tones on my BC246T, Used to hear them on VHF back in the day, though.
You can always hear them on my first generation trunk scanner, the BC-235. It was always a heads up for a first alarm dispatch... counting the number of tone outs... But in the later scanner generations, they were (properly according to the Motorola trunk protocol) muted...
thefish
Posts: 30
Joined: Fri Oct 29, 2004 8:34 pm

Re: Tones

Post by thefish »

w6pix wrote: It was always a heads up for a first alarm dispatch... counting the number of tone outs...
OK, this is dating myself, but I can recall hearing the old Motorola tones and knowing if it was a fire by the fact that the last tone is always a bit longer than the rest. If the last tone of the second set of tones was longer, two units.. medical aid. If the last tone of the second set was the same length, then more units were going...

For that matter, I can still pick out our tones from when I was a vollie back east some two decades ago...
N6766J
Posts: 49
Joined: Mon Feb 19, 2007 2:32 pm

Dating outselves

Post by N6766J »

When I got my first scanner (1987) I can remember learning the tones, even for a medical aid. E17/M317 and E33/M133 were the easiest for me to discern.
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