I don't see how anything in your replies is helpful.

- They are definitely tone frames. Tones run through the vocoder
are irrelevant and OP25 would handle them just fine anyway.

- Why should the user seek other solutions? The system is sending
IMBE tone frames and any decoder thrown at it should handle it.

- And how does simulcast have anything to do with this? It doesn't.

To the OP: You need to record the raw signal (I/Q data or FM
demodulated audio) so someone can analyze it. Then the decoder logic
can be updated to accommodate tone frames and you'll get your audible alerts.

At 04:19 PM 16-06-2018, 'William Becks' wllmbecks@gmail.com [op25-dev] wrote:
>
>
>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.Â
>
>
>
>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