What exactly are you trying to determine about the tones? They appear to be “Alert”
tones sent by the dispatch operator ahead of the voice message. I don’t think they
actually serve as a signaling function as would commonly be found in analog paging
systems.
I believe that someone has already stated that there are only a handful of specific tones
or tone combinations that are provided for in the P25 vocoder. Any other tones or tone
combinations transmitted into the speech input of the vocoder quote likely will not
reproduce and exact replica as the source tone(s) primarily because the vocoder is
designed to encode and compress speech.
Bill, WA8WG
From: op25-dev(a)yahoogroups.com [mailto:op25-dev@yahoogroups.com]
Sent: Saturday, June 16, 2018 2:58 PM
To: op25-dev(a)yahoogroups.com
Subject: RE: [op25-dev] Re: Why can't I hear fire tones?
Here are the fire tones I hear on a Uniden Scanner. I am not sure if it actually goes to a
separate frequency just for the tones, but to me it doesn't sound like it.
https://soundcloud.com/nokoa-official/sets/fire-tones