I can hear them on the BCD436HP scanner and the online feed. OP25 hears them but it just doesn't play them properly, I sometime hear like two noises that sound kind of like, kkkt kkkt very low. I think that they are long enough for it to decode.

Same here. I can hear our tones on the high band. I think it depends on how the core is sending them. From: op25-dev(a)yahoogroups.com <op25-dev(a)yahoogroups.com> Sent: Sunday, May 20, 2018 10:36 AM To: op25-dev(a)yahoogroups.com Subject: [op25-dev] Re: Why can't I hear fire tones? Do the tones not go like voice over radio. Is it like a code that the scanner then changes into a beep?

At 11:35 AM 20-05-2018, nokoa3116(a)gmail.com [op25-dev] wrote: Generally, no. Yes. Tone frames encode a frequency index and a volume level. A receiver has to synthesize the indicated tone/volume for 20 ms per frame. Page 20 has a list of AMBE tones: <http://qsl.net/kb9mwr/projects/dv/codec/TIA-102.BABA-1%20%20P25%20Half%20Rate%20Vocoder%20Addendum%20.pdf> A slightly different list is found on page 58 here: <http://dvsinc.com/manuals/AMBE-2020_manual.pdf> IMBE tone frames are likely similar. --

You would have to separately listen for the tones on the highband system. The way the sitecontroller works is when the dispatcher clicks the screen for toneout the site controller bypasses the 800/700 system and routes straight to the highband transmitter. You will never get it unless they push a data packet to 80/700 radios that have the feature. So far I haven’t seen it deployed to any sites that I work. From: op25-dev(a)yahoogroups.com &lt;op25-dev(a)yahoogroups.com&gt; Sent: Monday, May 21, 2018 11:37 AM To: op25-dev(a)yahoogroups.com Subject: [op25-dev] Re: Why can't I hear fire tones? Okay, thank you for the information, this helped me understand a little more. But how would I go about implementing this into op25 so the tones could be heard?

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

I don’t think there is an easy answer because op25 uses a software vocoder written to decode speech as opposed to commercial P25 radios that employ the DVSI chips that were revised and redesigned to pass tone signaling, DTMF, Knox and single tone. If it’s important to your application to pass the tones to the listener then you should consider using a commercial radio or scanner that doesn’t affiliate or cause unwanted transmission on the public safety communications system of interest. There are a number of surplus p25 radios that could be used to accomplish this task. The major fly in the ointment would be if your system is a Phase-II system that would require a must more costly alternative. Perhaps one of the active programmers that regularly contribute to op25 will jump in here to do a better job of explaining the software vocoder in P25 that I am capable of doing. Lastly, I gather that your Uniden scanner passes the alert tones, so is there a reason that you can’t use it or a similar receiver for your application? Good luck, Bill From: op25-dev(a)yahoogroups.com [mailto:op25-dev@yahoogroups.com] Sent: Saturday, June 16, 2018 3:31 PM To: op25-dev(a)yahoogroups.com Subject: [op25-dev] Re: Why can't I hear fire tones? I figured they may not have been used for paging, I didn't know what to call them. The problem is I cannot hear those alert tones on OP25 and can't understand how I may fix it on OP25. They are quite important for listeners, as they get the listener's attention when a new fire call comes in.

Do you know if your p25 system is a simulcast (LSM) or not? Sometimes you can improve the reception of simulcast systems when using a consumer grade receiver not specifically designed for simulcast by using a highly directional (Yagi) antenna aimed at one of the transmitter sites nearest your location. This doesn’t always work if there is very strong overlap between the various transmitters in the network but is worth a try as the antennas are not all that expensive. Bill From: op25-dev(a)yahoogroups.com [mailto:op25-dev@yahoogroups.com] Sent: Saturday, June 16, 2018 4:02 PM To: op25-dev(a)yahoogroups.com Subject: [op25-dev] Re: Why can't I hear fire tones? OP25 works great in my city while all p25 p2 scanners that I tried don't do well at all, and constantly miss transmissions. I tried BCD436HP 996 and now SDS100. I understand what you mean software wise. Just curious if I can modify the vocoder on OP25 to make it work.

OK. I see that it’s a Phase II system but is not simulcast. I am wondering why you’re missing some of the transmissions? Have you checked to make sure the firmware in the scanner(s) that you’ve tested or are using have the latest and greatest firmware? Being that the system is Phase-II leave out any possibilities of using something like an XTL5000 or and XTS5000 radio. You’d have to up the radio and that could get costly. Maybe someone know of a Kenwood, Yaesu, or Icom radio that does Phase-II that may make a good non-affiliating receive only receiver? A Motorola APX would be pricey. Good Luck, Bill From: op25-dev(a)yahoogroups.com [mailto:op25-dev@yahoogroups.com] Sent: Saturday, June 16, 2018 4:29 PM To: op25-dev(a)yahoogroups.com Subject: RE: [op25-dev] Re: Why can't I hear fire tones? The system I monitor is http://www.radioreference.com/apps/db/?sid=7804 each site transmits on a different frequency.

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(a)gmail.com [op25-dev] wrote: